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Robotic Spacecraft (Astronomy, Planetary, Earth, Solar/Heliophysics) => Space Science Coverage => Topic started by: Blackstar on 01/27/2012 05:30 PM

Title: Proposed Europa Missions
Post by: Blackstar on 01/27/2012 05:30 PM
Europa orbiter study.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/27/2012 05:31 PM
Europa flyby study.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/27/2012 05:38 PM
Lander study.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/27/2012 07:01 PM
This is the Jupiter Europa Orbiter Component of the Europa Jupiter System Mission, dated March 2010.

This was the Europa mission as of a couple of years ago. This was a big, expensive spacecraft. It was too big to afford. The decadal survey recommended that this mission be de-scoped (i.e. reduced), but the committee was unwilling to do that de-scoping itself because there was no obvious way to do it.

As a result of the decadal survey, NASA told JPL to go back to the drawing board and try to come up with a cheaper Europa mission. The three concept presentations that I posted earlier summarize JPL's current effort to de-scope the Europa mission. Those proposals are a smaller orbiter, a flyby mission (Jupiter orbit, but not Europa orbit) and a Europa lander.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/09/2012 02:20 PM
I missed this when it came out, but this is from the March OPAG meeting. It shows more work on the Europa lander study.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/09/2012 02:26 PM
Here are summaries of the Europa studies.

Yesterday I heard that the studies were delivered to NASA last week. NASA and OMB/OSTP will review the studies before they are officially released. My guess is that will happen in a month or two.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/09/2012 02:27 PM
Another summary.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/09/2012 02:27 PM
The rest of the summaries.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/11/2012 06:46 PM
Heard some interesting stuff about this last week. Cannot discuss it, but it'll probably be public soon. When it does become public, I'll have to eat some crow. (But that's okay, I've got a recipe for eating crow.)
Title: Re: Proposed Europa Missions
Post by: ugordan on 08/11/2012 06:57 PM
Can you at least drop some hints?
Title: Re: Proposed Europa Missions
Post by: spectre9 on 08/11/2012 07:41 PM
I'm still trying to pick myself up after the hint hit me on the head  :P

Thanks Blackstar. Really excited by that news  8)
Title: Re: Proposed Europa Missions
Post by: jnc on 08/11/2012 09:34 PM
I'm still trying to pick myself up after the hint hit me on the head

So what do you think the announcement will be?

Quote
Thanks Blackstar.

Yes, those are very cool. Thanks very much for posting them. I had missed them previously (not much chatter about them).

Still processing them (will probably need to re-read them, there's an enormous amount of into there), but one thing caught my eye:tThe 'Wrapup' lists the flyby costs at $1.9B (pg. 5), but the 'Flyby Element' presentation gives it as $1.5B (pg. 24). Admittedly, the 'Wrapup' presentation is from ~5 months later, and also I haven't looked to see if there were major changes to the science packages/mission capabilites to see if that could have (reasonably) driven the costs, but an increase of $.4B in estimated cost in that time period is somewhat curious.

Noel
Title: Re: Proposed Europa Missions
Post by: robertross on 08/12/2012 12:49 AM
Here are summaries of the Europa studies.

Yesterday I heard that the studies were delivered to NASA last week. NASA and OMB/OSTP will review the studies before they are officially released. My guess is that will happen in a month or two.

Thanks for these!
Title: Re: Proposed Europa Missions
Post by: spectre9 on 08/12/2012 01:26 AM
I like the fly by concepts.

You will get the up close science on Europa without staying too close to Jupiter and getting cooked by radiation.

Gives you better instruments like IPR and allows you to do fly bys of other targets.

Any idea if an Io fly by is at all possible?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/12/2012 05:08 PM
I have to be careful. I can say what it isn't: a Europa mission is not going to get funded anytime soon.

What it is: JPL has continued to iterate the "clipper" (flyby) mission and the results have been positive, and surprising (to me). The iteration should lower the costs even further.

So the cost of a Europa mission may now be even lower than the previous studies show.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/12/2012 05:17 PM
1-Yes, those are very cool. Thanks very much for posting them. I had missed them previously (not much chatter about them).

2-Still processing them (will probably need to re-read them, there's an enormous amount of into there), but one thing caught my eye:tThe 'Wrapup' lists the flyby costs at $1.9B (pg. 5), but the 'Flyby Element' presentation gives it as $1.5B (pg. 24). Admittedly, the 'Wrapup' presentation is from ~5 months later, and also I haven't looked to see if there were major changes to the science packages/mission capabilites to see if that could have (reasonably) driven the costs, but an increase of $.4B in estimated cost in that time period is somewhat curious.

1-Here's a tip: you should regularly go to the websites for VEXAG, OPAG, MEPAG, LEAG, and SBAG. They have now started webcasting some of their meetings. And they usually put their presentations online soon after their meetings.

There is a LOT of stuff that happens in the planetary program that never gets covered in the popular media or on websites. There's a lot of fascinating stuff that you can tap into if you know where to look. So the assessment groups are a good place to start.

2-I don't know about the differences in cost estimates. I could find out. However, it is possible that these were preliminary and/or internal estimates versus final/independent cost estimates.

[more in a second post]
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/12/2012 05:21 PM
[Sorry to split this up, but my software is acting up and would not let me post longer.]

When we worked on the decadal survey we used a cost estimating process that was different than what NASA and JPL commonly used. They normally did a straight up cost estimate, and those estimates are actually pretty accurate if you assume no external impacts on the program. The problem is that lots of things happen to programs in development that are outside of their control. For example, launch costs can increase during development, and no matter how good and dilligent the spacecraft designers are, they cannot control that increase. So the process we used included "threats" to development, like what happens if NASA/OMB cuts the budget for your project, forcing a stretchout? Or what if launch costs go up?

When you add in the threats, it increased the costs of the projects on average of (I think) about 40% (could have been 60%--it's in the decadal survey and you can look it up because I'm too lazy at the moment). That naturally made the advocates of various missions angry, because they argued that their projects were not that expensive, and we were saying they would be (but not their fault).

So maybe the increase that you found is due to JPL going to Aerospace Corp and getting their independent estimate, which included program threats.
Title: Re: Proposed Europa Missions
Post by: jnc on 08/12/2012 06:30 PM
JPL has continued to iterate the "clipper" (flyby) mission and the results have been positive, and surprising (to me).

Can't wait to hear the latest+greatest! I have to say that of the three, that mission was the one I would have picked in today's budget environment. Yes, the lander would be 'way cool', and does some interesting science neither other mission can do, but with i) the much larger price-tag for the lander (almost 2x), and bigger risk, and ii) getting basically as much science out of the fly-by, it's (to me) a no-brainer.

Sigh, maybe we'll be able to afford the lander some day!

Here's a tip: you should regularly go to the websites ... They have now started webcasting some of their meetings. ... There is a LOT of stuff that happens in the planetary program that never gets covered in the popular media or on websites. ... So the assessment groups are a good place to start.

In my copious free time! :) (Seriously; space is my #2 hobby, see here (http://www.yoshitoshi.net/) for example about #1, at which I'm semi-professional, so after my real life (http://tools.ietf.org/html/draft-chiappa-lisp-introduction-01), I'm kind of short on time!)

So if you don't mind I'll continue to rely on you to keep us posted on all this cool stuff happening quietly in the corners!

[Sorry to split this up, but my software is acting up and would not let me post longer.]

No problem!

Quote
When we worked on the decadal survey we used a cost estimating process that was different ... When you add in the threats, it increased the costs of the projects on average of (I think) about 40% ... So maybe the increase that you found is due to JPL going to Aerospace Corp and getting their independent estimate, which included program threats.

Hmm. That's about the right magnitude, but... I went back and looked, and the orbiter didn't show a similar increase. (Couldn't find a number for the lander in the November presentations.)

The increase may well be as a result of the Aerospace review, but my guess would be that's it's not too likely that JPL added the 'threat' factor to one, and not the other. So perhaps the Aerospace review found something else?

Probably an interesting question to ask them, though.. :)

Noel
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/12/2012 09:42 PM
Yes, the lander would be 'way cool', and does some interesting science neither other mission can do, but with i) the much larger price-tag for the lander (almost 2x), and bigger risk, and ii) getting basically as much science out of the fly-by, it's (to me) a no-brainer.

Risk totally rules out the lander for now. It was included simply for completeness, and (I think) because by defining a lander, you could also identify any precursor requirements that would need to be incorporated into an orbiter or flyby mission. The lander mission study made it clear that high resolution imaging of the surface is required before you can fly a lander.
Title: Re: Proposed Europa Missions
Post by: jnc on 08/12/2012 09:55 PM
high resolution imaging of the surface is required before you can fly a lander.

Would they get enough from a fly-by, or would it require an orbiter?

(Although now that I think about it, the lander mission defined in the presentations had an orbital phase where they did a lot of imaging for selecting a landing spot - would that have been enough on its own, or would they have needed a separate imaging mission as well?)

Noel
Title: Re: Proposed Europa Missions
Post by: spectre9 on 08/12/2012 11:27 PM
Fly by doesn't mean that the distance for observations is longer.

It just means the probe doesn't stay at the one moon.

It flies in takes the readings and flys away. Obviously doing it like this takes a lot longer to image the full surface but I do think it's worth it.

It's like Cassini how it does a fly by of Titan or Enceladus every now and then.

The orbiter/lander mission can come later.

Thanks for clarification about what the hints you were dropping were about Blackstar.

I'm guessing that a cut down fly by mission from the ones in the already posted presentations are what is being considered?

C'mon outer planets!!!  8)
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/13/2012 12:18 AM
I'm guessing that a cut down fly by mission from the ones in the already posted presentations are what is being considered?

I didn't say "cut down."

I said cheaper...

(and, surprisingly, better too--put another way, more capability at less money)
Title: Re: Proposed Europa Missions
Post by: spectre9 on 08/13/2012 12:24 AM
Ok thanks for the added clarification.

Now I'm excited again but I still realise that outer planets has a fight ahead of them to get anything approved in the current environment.
Title: Re: Proposed Europa Missions
Post by: jnc on 08/13/2012 02:34 AM
It just means the probe doesn't stay at the one moon.

Got that, thanks.

Quote
Obviously doing it like this takes a lot longer to image the full surface

They might get full surface imagery, but not at the level of detail the orbiter would give them. If you look at pg. 12 of the "Mission Studies" presentation, you'll see that the orbiter gives pretty good coverage at 100 m/pixel.

The multiple passes of the flyby won't give anything like as good coverage at high resolutions; check out the ground tracks (pg. 17 of the "Mission Studies") and the Topographic Imager coverage chart (next page).

Of course, 100 m/pixel is not enough resolution to really check out for landing spots, a point made on pp. 17-18 of the "Pappalardo Lander Forum" presentation. And while looking for the cite on that, I noticed that the "Lander Technical" presentation says, on pg. 10, that they need .5 m/pixel for a reasonably safe landing. (Which I guess kind of answers the question in my previous post...)

I see on pg. 11 that they're going to do hi-res imaging, and site selection from that imaging, as phases 1 and 2 of the landing process, but it's not clear from any of this material if they do that from the initial orbit (parameters not given), or the 200x5 km 'pre-landing' orbit; the timeline on pg. 9 makes it sound like it's from the inital orbit.

Noel
Title: Re: Proposed Europa Missions
Post by: spectre9 on 08/13/2012 03:05 AM
For a nominal mission length yes I would agree that the orbiter is going to get the better mapping but consider this.

Cassini was a 4 year mission.

It's been going for 8 and doesn't look like the probe will die any time soon.

The flyby can also get closer to the surface. Some of those tracks are <25km. If it's just the type of camera stopping the detail from being better possibly the instrumentation could be altered?

It seems to me like these 2 separate spacecraft are designed to be the one mission so if one is flown and the other is not that would be a different mission design.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/13/2012 04:10 AM
The multiple passes of the flyby won't give anything like as good coverage at high resolutions; check out the ground tracks (pg. 17 of the "Mission Studies") and the Topographic Imager coverage chart (next page).

Hmmm...

I'm not sure when the next OPAG meeting is, but you might check on that.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/24/2012 11:42 PM
Okay, I'll post the slides later, but here's the deal:

JPL has been studying the Europa Clipper mission since around May and now thinks that it is possible that they could do the mission with solar. That would reduce the cost of the mission, and possibly also decrease risk, since the ASRGs are considered risky. (So, while I previously posted that solar won't work for Europa missions, I may eventually have to eat my hat, with a heaping of crow.)

That's not a done deal, however. One of the big problems is that the Clipper would go into shadow for a long time (I think I heard them say around six hours) and that requires batteries and batteries are heavy. There are also other problems, such as the radiation damage to the solar panels and the issue of cold--a Clipper mission would get more radiation and more cold than Juno.

Another potential problem is jitter. The panels could introduce vibration. Now why is that important?

Well, it turns out that one of the other big things they have been looking at is adding a high-resolution camera to the Clipper to take photos of potential landing sites for a future mission. Apparently the lander mission that they studied got people sufficiently excited that they think that the lander is feasible, provided that you could get good landing site data.

I didn't hear the presentations that well, but the camera adds something like $200 million to the mission, pushing it over a cost cap (of, I think, $2 billion). Using solar instead of ASRGs then brings the cost down. Not sure if it brings it back into the cost cap, but it helps a lot.

Now let me be clear on this: THERE IS NO MONEY TO DO THIS MISSION. A senior planetary official made that clear at the end of the presentation--just because a study has reduced the cost doesn't mean that there is actual money to do a Europa flagship mission. But it does show that there is promise here.

I'll post the slides later.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/25/2012 12:26 AM
Thanks Blackstar!

They may not have the money, but perhaps it could generate enough interest outside the science community (and in the political arena) to find funding in a gov't/private partnership (doubt that would happen, but you never know).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/25/2012 01:50 AM
They may not have the money, but perhaps it could generate enough interest outside the science community (and in the political arena) to find funding in a gov't/private partnership (doubt that would happen, but you never know).

No. Impossible. Price tag is $2 billion. Nobody foots serious cash for stuff that they assume the government should fund. This is going to be the big problem for B612 and their asteroid search spacecraft.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/25/2012 04:28 AM
Here's some of it.
Title: Re: Proposed Europa Missions
Post by: simonbp on 09/25/2012 02:53 PM
That is interesting.

The solution to the jitter may be a separate scan platform (like Voyager), which could both cancel out the jitter and allow more imaging during the pass. This would add to the cost, but solar+scan platform could still be cheaper than with an ASRG.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/25/2012 03:21 PM
They may not have the money, but perhaps it could generate enough interest outside the science community (and in the political arena) to find funding in a gov't/private partnership (doubt that would happen, but you never know).

No. Impossible. Price tag is $2 billion. Nobody foots serious cash for stuff that they assume the government should fund. This is going to be the big problem for B612 and their asteroid search spacecraft.

aww shucks.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/25/2012 04:09 PM
Here is the first half of the presentation.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/25/2012 04:09 PM
Here is the rest of the presentation.
Title: Re: Proposed Europa Missions
Post by: Star One on 09/25/2012 09:34 PM
With that kind of price tag no one is going to fund this anytime soon are they?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/25/2012 11:20 PM
With that kind of price tag no one is going to fund this anytime soon are they?

The quick answer is "no." The more complex answer is that OMB has apparently decided to not approve any flagships for planetary science, so it doesn't matter which ones get proposed, in what order, there is simply no support for doing it.

That said, the real action now is in the Mars area. Complex story, but you can find the threads.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/25/2012 11:39 PM
Here is the rest of the presentation.

Hot off the presses! Thank you Sir.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/26/2012 12:06 AM
Very cool to see a 0.5m/pixel camera on the enhanced Clipper. That should be more than adequate. :)

Really like the margins.

I also like the Magnetometer boom addition.

Using SLS: 6 years to 2.8 years!! Wish it was affordable (but nowhere near holding my breathe...maybe pre-breathing) Really like the nanosat concept tied to it.

(smal spelling issue at bottom of Part 2, page 30)
Title: Re: Proposed Europa Missions
Post by: Solman on 09/26/2012 01:33 AM
 Just want to suggest that a solar concentrator might have many advantages for a Europa mission. L'Garde has demonstrated one that focuses 17KW thermal roughly per KW thermal. Around 170W/kg at Saturn even. My mind wandered toward Enceladus and sampling of volcanic emissions by an orbiter ...
 A concentrator can double as a high baud antenna for such an outer planet mission due to its size.
 The solar cells that use concentrated sunlight have the highest efficiency - over 40% - and best specific power.
 The concentrator can power a solar thermal engine for LEO to escape saving much time over solar electric and power a solar electric engine after that.
 The concentrator can double as a radio telescope for some very long baseline interferometry and SAR at Europa.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/26/2012 01:56 AM
Using SLS: 6 years to 2.8 years!! Wish it was affordable (but nowhere near holding my breathe...maybe pre-breathing) Really like the nanosat concept tied to it.

One of the people who worked on the study is really enthusiastic about SLS for this mission. My impression is that he's the only one.

It's simple: a really big rocket can give you really great margins for missions like this, and everybody would just love to have more mass and more delta-v to play with. And theoretically, you could possibly save money on your spacecraft design because you don't have to design anything to be extremely light weight, which always costs a lot.

The problem is programmatics--fitting a science spacecraft onto a non-existent rocket that actually belongs to another part of NASA, and which will be too expensive on a per-unit basis for the science part of NASA to afford. The science guys have said that they would only really consider this if the HEO part of NASA agreed to foot the bill for the launch, essentially providing the SLS launch for free for a science payload. Why would HEOMD agree to do that? They'd be giving away their money. And even if they agreed to it, there's no guarantee to the science guys that they would stick to that decision, and three years into the program the science program could find itself suddenly being stuck with the launch costs and having to cannibalize other parts of their portfolio.

So from a programmatic perspective, it is far safer for the science program to simply design for a rocket that already exists and that they already have some experience with. Now if you assume that SLS gets built, and flies successfully, and this Europa mission gets approved, then SLS might be an option. But it would be crazy to baseline it now.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/26/2012 02:28 PM
and that is a 100% perfect assessment of the situation, and totally agree.

I might only add that they (HEOMD) might consider doing this if they could do a dual launch (launch of opportunity) for something else, like an empty depot, another spacecraft, or goodness knows what. But not likely.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/26/2012 02:34 PM
and that is a 100% perfect assessment of the situation, and totally agree.

I might only add that they (HEOMD) might consider doing this if they could do a dual launch (launch of opportunity) for something else, like an empty depot, another spacecraft, or goodness knows what. But not likely.

I do think it would be an interesting--possibly worthwhile--exercise to evaluate the benefits of heavy lift for planetary missions. I know of no detailed studies that have done it. When we did our assessment of Constellation for science, we didn't have any planetary missions to look at, so all we could really do was discuss the C3 and payload benefits without having anything more.

Dual manifesting has some potential in niche cases, but would require study. There was a ridiculous study about five years ago called CEMMENT (Worst. Name. Ever.) that looked at the possibility of doing an engineering test of a human lander at Mars that would be loaded up with science experiments. The basic idea was reasonable, but they went crazy with it, thinking that because they would have a lot of payload and volume, they should fill it all up with sciency stuff. The end result was a science fiction fantasy, because there was no way that, even if they got the launch vehicle and lander for free, the science program could afford to build all the science spacecraft.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/26/2012 03:03 PM
and that is a 100% perfect assessment of the situation, and totally agree.

I might only add that they (HEOMD) might consider doing this if they could do a dual launch (launch of opportunity) for something else, like an empty depot, another spacecraft, or goodness knows what. But not likely.

I do think it would be an interesting--possibly worthwhile--exercise to evaluate the benefits of heavy lift for planetary missions. I know of no detailed studies that have done it. When we did our assessment of Constellation for science, we didn't have any planetary missions to look at, so all we could really do was discuss the C3 and payload benefits without having anything more.

Dual manifesting has some potential in niche cases, but would require study. There was a ridiculous study about five years ago called CEMMENT (Worst. Name. Ever.) that looked at the possibility of doing an engineering test of a human lander at Mars that would be loaded up with science experiments. The basic idea was reasonable, but they went crazy with it, thinking that because they would have a lot of payload and volume, they should fill it all up with sciency stuff. The end result was a science fiction fantasy, because there was no way that, even if they got the launch vehicle and lander for free, the science program could afford to build all the science spacecraft.

I don't know if a study was done per se, but using the Ares V (more like Ares VI...hehe) for science missions was definitely persued (more like flaunted) by NASA (obviously to gain support). Those docs are here on the public side or the L2 side.

Edit: here it is:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070038373_2007037046.pdf
Title: Re: Proposed Europa Missions
Post by: vjkane on 09/26/2012 04:42 PM
With that kind of price tag no one is going to fund this anytime soon are they?

The quick answer is "no." The more complex answer is that OMB has apparently decided to not approve any flagships for planetary science, so it doesn't matter which ones get proposed, in what order, there is simply no support for doing it.

I think that you have to look at a Europa mission as a long game.  With JWST overruns and manned spaceflight budget challenges, this is not the time to ask for new Flagship missions in any of the science disciplines.  However, this is the first Europa mission proposal that comes in at $2B and doesn't require significant new technology development.  I believe that if the space community keeps Europa as a focus, then getting a new start after JWST flies later this decade would be a reasonable goal to work towards.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/26/2012 06:21 PM
I don't know if a study was done per se, but using the Ares V (more like Ares VI...hehe) for science missions was definitely persued (more like flaunted) by NASA (obviously to gain support). Those docs are here on the public side or the L2 side.

Edit: here it is:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070038373_2007037046.pdf

You linked to a paper about using heavy lift for astronomy. That's an obvious option.

The NRC did a study around 2008 or so on using Constellation for science missions. When we did that study we had a lot of options for astronomy and other missions using heavy lift. We did not have any previous studies of using it for planetary missions. I was pointing out that there could be value at looking at this issue beyond simply additional mass and C3. It might allow you to do innovative orbits, or more complex mission architectures (not necessarily more complex spacecraft--for example, you could simply add fuel and do better things with your orbits). And the impact on spacecraft design could be significant, but so far all the discussions have been superficial.

What this really comes down to is a cost-benefit trade that nobody has really made. That could be summed up like this: "The HLV rocket costs you an extra $700 million for launch; can you save more than $700 million in spacecraft design using heavy lift?" Nobody has really looked at those trades.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 09/26/2012 11:33 PM
Thanks very much for the information provided Blackstar.

Interesting that the mission can be traded to solar.

Asking for the money or not this is a mission that needs to be done.

The decadal survey says so. No MSR = Europa. That's the flagship priority. The MSR guys just can't let go yet.

The next survey might not be so sympathetic to their cause. Could awesome discoveries made by Curiosity push the priority for MSR back? I mean that's the whole reason for having something like SAM isn't it? So you can test the rocks at Mars without bringing them back.

I like the idea of using big rockets for exploring, the ice giants are so far away something like SLS really helps.

At $2 billion this is a cheap flagship for the science that can be had. These big questions about Europa have had planetary scientists giddy for years now, it's time to get some answers.  8)
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/27/2012 01:35 AM
1-Interesting that the mission can be traded to solar.

2-The decadal survey says so. No MSR = Europa. That's the flagship priority. The MSR guys just can't let go yet.

3-I mean that's the whole reason for having something like SAM isn't it? So you can test the rocks at Mars without bringing them back.

1-It might be possible to do with solar. The studies are not done yet.

2-No, that's not really how it works. (Trust me, I was there.) The first choice in the decadal was MSR. The Office of Management and Budget decided to not do any flagships at all. It is not the case that because OMB said no to sample return that we now go on to Europa.

3-No. There are three, maybe four reasons to do sample return:

-the samples can be analyzed on Earth by hundreds of different research teams
-the samples can be analyzed for decades after they return (the best science done on Apollo samples is being done TODAY with modern instruments)
-you can use a far greater number of instruments to analyze samples on Earth than you can on a planetary body

One additional argument in favor of sample return is discovery--when you provide the samples to a broad group of people, rather than the narrow team that works on a single space mission, you can get discoveries that you never would have otherwise gotten.

The SAM instrument on Curiosity is an impressive piece of space hardware. It is very primitive and limited in capability compared to even a modest university chemistry lab on Earth. We have no way to squeeze all the incredibly sophisticated instruments that exist on Earth into a small package on a spacecraft. SAM is no substitute for bringing back the materials.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/27/2012 10:23 PM
I still think about the C3 benefits of a Heavy launcher (or a depot architecture). How do you trade the possibility of basing one mission on the results of previous one? If you have 6 to 8 years of travel, you can't get more than one mission per decade, if you are lucky, that need the previous one. On the other hand, at 2 to 3 years of transit, you can do twice the number. It get's interesting if you can use the previous missions assets. Say you want to send a lander to Europa. Communications with Earth is very difficult. May be, if it only has to wait for five years, there's a way to put it on hibernation and use the orbiters communication capabilities to support the lander. But if it took longer, the degradation would be too great, even in case of hibernation and protecting shrouds.
On hte other hand, a heavy launcher could send the communication orbiter AND the lander on the same mission. I'm just trying to get creative.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/28/2012 01:50 AM
I still think about the C3 benefits of a Heavy launcher (or a depot architecture). How do you trade the possibility of basing one mission on the results of previous one? If you have 6 to 8 years of travel, you can't get more than one mission per decade, if you are lucky, that need the previous one. On the other hand, at 2 to 3 years of transit, you can do twice the number. It get's interesting if you can use the previous missions assets. Say you want to send a lander to Europa. Communications with Earth is very difficult. May be, if it only has to wait for five years, there's a way to put it on hibernation and use the orbiters communication capabilities to support the lander. But if it took longer, the degradation would be too great, even in case of hibernation and protecting shrouds.
On hte other hand, a heavy launcher could send the communication orbiter AND the lander on the same mission. I'm just trying to get creative.

I think that is the kind of trade it would be interesting to perform. But the key trade to explore would be cost reduction in missions. For instance, if you decrease the transit time and increase the mass margins and fuel margins and things like that, could you bring the cost of the mission down significantly? I've only seen very thin speculation about this, but nobody has actually gone into it in any depth.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/28/2012 08:11 PM
[...]

I think that is the kind of trade it would be interesting to perform. But the key trade to explore would be cost reduction in missions. For instance, if you decrease the transit time and increase the mass margins and fuel margins and things like that, could you bring the cost of the mission down significantly? I've only seen very thin speculation about this, but nobody has actually gone into it in any depth.

My intuition, is that any sort of increase in structural or payload mass due to lowering the cost, will be offset by the increased fuel and thrust increase needed. After all, the rocket formula is exponential on the pmf. Besides, AFAIK, the bulk of cost it on certification and testing, not on the materials themselves.
The other issue, and I think this is the core issue, is: how do you keep the scientists and engineers from adding features and science payload that actually increases the cost since they have weight and volume to spare? In other words, if the budget was made reasonably, the biggest danger is the project management's own desire for a better mission.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/28/2012 09:03 PM
1-My intuition, is that any sort of increase in structural or payload mass due to lowering the cost, will be offset by the increased fuel and thrust increase needed. After all, the rocket formula is exponential on the pmf. Besides, AFAIK, the bulk of cost it on certification and testing, not on the materials themselves.

2-The other issue, and I think this is the core issue, is: how do you keep the scientists and engineers from adding features and science payload that actually increases the cost since they have weight and volume to spare? In other words, if the budget was made reasonably, the biggest danger is the project management's own desire for a better mission.

1-I don't think that's an issue here because the initial margins are so huge. We're talking about throwing a relatively small spacecraft to the outer planets. With a heavy lift vehicle you can easily throw twice the mass. So if you give the designers 50% more margin to play with, the other penalties don't really bite.

2-Yes, that is an issue. But you're going to be cost constrained from the start. The way to do the initial trade is to take a spacecraft designed for a smaller vehicle and then tell the designers "You cannot add instruments, but you can add mass, fuel, operations, and other margins." I imagine that in some missions that would cause the scientists to hyperventilate and faint because they'd love to have those things even without more instruments. For example, the key limitation is radiation. If you told the scientists that instead of a 180 day mission they could have enough shielding for a five-year mission, they would be more than happy.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/29/2012 03:46 PM
1-My intuition, is that any sort of increase in structural or payload mass due to lowering the cost, will be offset by the increased fuel and thrust increase needed. After all, the rocket formula is exponential on the pmf. Besides, AFAIK, the bulk of cost it on certification and testing, not on the materials themselves.

2-The other issue, and I think this is the core issue, is: how do you keep the scientists and engineers from adding features and science payload that actually increases the cost since they have weight and volume to spare? In other words, if the budget was made reasonably, the biggest danger is the project management's own desire for a better mission.

1-I don't think that's an issue here because the initial margins are so huge. We're talking about throwing a relatively small spacecraft to the outer planets. With a heavy lift vehicle you can easily throw twice the mass. So if you give the designers 50% more margin to play with, the other penalties don't really bite.
But more mass means higher thrust engines. Higher mass means higher momentum of inertia, thus, bigger reaction wheels and thrusters, plus thruster fuel, etc. Bigger fuel tanks in relation to the payload also means a more over sized control authority when the tanks are near empty, thus requiring higher precision firings and more sophisticated control. Then you have to certify and test everything. I seriously doubt you would save much. The only way I see this saving money is if they can use a legacy platform and parts that are already designed and certified for the expected environment. If said parts and/or platform was too heavy for the "small" LV, then yes, using a more powerful rocket might actually lower the cost. But you won't save much, if anything, by doing it custom.
You know very well that planetary missions have very particular requirements that nobody else needs. You have to tolerate the environment from Venus to the outer planets (if you do a VVEGA maneuver), the radiation degradation environment is unique to deep space probes, and the thermal environment is very particular. You might save a bit if you can use a bigger LV to save the Venus Gravity assist, and thus you don't have to design for that thermal environment. Of course, we are talking about a mission already planned with a conservative estimation and good margins. If you want to put a 2.5tonnes mission on a 1.9tonnes LV, of course it's going to be cheaper to put it on a bigger LV than making enough technological advances to reduce the weight enough. But going from an EELV to SLS the jump in performance is so huge, that's not the case.

Quote
2-Yes, that is an issue. But you're going to be cost constrained from the start. The way to do the initial trade is to take a spacecraft designed for a smaller vehicle and then tell the designers "You cannot add instruments, but you can add mass, fuel, operations, and other margins." I imagine that in some missions that would cause the scientists to hyperventilate and faint because they'd love to have those things even without more instruments. For example, the key limitation is radiation. If you told the scientists that instead of a 180 day mission they could have enough shielding for a five-year mission, they would be more than happy.
I quite get how it would be ideally. But you have to plan the system for the "misbehaving". And in any case, more mass usually means more cost. You can add some layers of composite Ti/Br to protect the electronics. But then you have to actually certify that for a five year radiation and thermal environment. That means weeks, if not months on environmental testing chambers and more time in from of the accelerator. And then, how do you protect your sensors? You added protection to your electronics but now you have to develop hardened sensors, which you can't protect unless you don't want to get any reading. Might be an option if you want to take extended time domain samples. But then you have to design, certify, integrate and test a sensor protection system. More money and complexity.
And again, I think you can do that if you jump from an Atlas V531 to a 551. But even from a Falcon Heavy to SLS there's so much differential, that I can't think of any use save delta-v that will be "cheaper".
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/30/2012 01:56 PM
1-My intuition, is that any sort of increase in structural or payload mass due to lowering the cost, will be offset by the increased fuel and thrust increase needed. After all, the rocket formula is exponential on the pmf. Besides, AFAIK, the bulk of cost it on certification and testing, not on the materials themselves.

2-The other issue, and I think this is the core issue, is: how do you keep the scientists and engineers from adding features and science payload that actually increases the cost since they have weight and volume to spare? In other words, if the budget was made reasonably, the biggest danger is the project management's own desire for a better mission.

1-I don't think that's an issue here because the initial margins are so huge. We're talking about throwing a relatively small spacecraft to the outer planets. With a heavy lift vehicle you can easily throw twice the mass. So if you give the designers 50% more margin to play with, the other penalties don't really bite.
But more mass means higher thrust engines. Higher mass means higher momentum of inertia, thus, bigger reaction wheels and thrusters, plus thruster fuel, etc. Bigger fuel tanks in relation to the payload also means a more over sized control authority when the tanks are near empty, thus requiring higher precision firings and more sophisticated control. Then you have to certify and test everything. I seriously doubt you would save much. The only way I see this saving money is if they can use a legacy platform and parts that are already designed and certified for the expected environment. If said parts and/or platform was too heavy for the "small" LV, then yes, using a more powerful rocket might actually lower the cost. But you won't save much, if anything, by doing it custom.
You know very well that planetary missions have very particular requirements that nobody else needs. You have to tolerate the environment from Venus to the outer planets (if you do a VVEGA maneuver), the radiation degradation environment is unique to deep space probes, and the thermal environment is very particular. You might save a bit if you can use a bigger LV to save the Venus Gravity assist, and thus you don't have to design for that thermal environment. Of course, we are talking about a mission already planned with a conservative estimation and good margins. If you want to put a 2.5tonnes mission on a 1.9tonnes LV, of course it's going to be cheaper to put it on a bigger LV than making enough technological advances to reduce the weight enough. But going from an EELV to SLS the jump in performance is so huge, that's not the case.

Quote
2-Yes, that is an issue. But you're going to be cost constrained from the start. The way to do the initial trade is to take a spacecraft designed for a smaller vehicle and then tell the designers "You cannot add instruments, but you can add mass, fuel, operations, and other margins." I imagine that in some missions that would cause the scientists to hyperventilate and faint because they'd love to have those things even without more instruments. For example, the key limitation is radiation. If you told the scientists that instead of a 180 day mission they could have enough shielding for a five-year mission, they would be more than happy.
I quite get how it would be ideally. But you have to plan the system for the "misbehaving". And in any case, more mass usually means more cost. You can add some layers of composite Ti/Br to protect the electronics. But then you have to actually certify that for a five year radiation and thermal environment. That means weeks, if not months on environmental testing chambers and more time in from of the accelerator. And then, how do you protect your sensors? You added protection to your electronics but now you have to develop hardened sensors, which you can't protect unless you don't want to get any reading. Might be an option if you want to take extended time domain samples. But then you have to design, certify, integrate and test a sensor protection system. More money and complexity.
And again, I think you can do that if you jump from an Atlas V531 to a 551. But even from a Falcon Heavy to SLS there's so much differential, that I can't think of any use save delta-v that will be "cheaper".

You seem to be under the mistaken assumption that I'm an advocate for this. I was pointing out that I think it might be worthwhile to do a trade study. If you're looking to argue about this with somebody, you'll have to find somebody else.

And the actual advocates of this have claimed that more mass does not automatically mean more cost if you allocate that additional mass to "dumb" parts of the spacecraft, such as structure, fuel, shielding, etc. I just think it might be worth looking into that.
Title: Re: Proposed Europa Missions
Post by: baldusi on 10/01/2012 03:17 PM
Quite on the contrary. I have you in very high regard and really enjoy exchanging ideas with you. What I'm trying to say, and I apology if my term come sort of too candid, it's due to subtleties of the English language that I miss. What I do say is that for a certain "small" range, in some parts, you can trade cost for weight. But also, SLS is so out there in payload capabilities, that I find it extremely unlikely that it would offer any opportunity of lowering costs by adding that much weight. I also believe such trade studies are extremely hard to do in a general sense, because it depend both on unknown factor and the margins of the rest of the assemblies.
I would love a study on general patterns of weight trades that work. And an investigation on non weight savings that can be achieved if you have a significantly bigger LV (say optimizing trajectories for cost rather than delta-v, trading comm costs on the spacecraft with DSN time, etc.).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/01/2012 03:31 PM
Don't get me wrong, I'm not offended. I'm just not advocating this as an idea, and I don't want words put in my mouth, because I need the room for inserting my foot in there.

I do think that it MIGHT be possible to lower the cost of an outer planets spacecraft by taking the mass issue out of the equation. But I also think that the SLS vehicle cost is going to wipe that out. You would have to save a LOT of money on a spacecraft to justify the launch vehicle cost. Suppose that an Atlas is going to cost you $300 million and an SLS is going to cost you $1 billion. You would have to save more than $700 million on the spacecraft simply to justify the change in launchers.

I also think that you went off on a tangent there that does not really lead to anything. All of these spacecraft are custom designed. They don't use standard equipment. So, for instance, just because the spacecraft is bigger (with SLS) and this requires bigger control moment gyros, does not mean that the cost will go up because of that. In fact, the argument is that the cost should go down overall because all of these components can be built with bigger margins--no need to try innovative and risky design features just to squeeze half a kilogram of mass out of the system.

That said, there are other things that this could do that I think it might be worthwhile to explore. For instance, if you could double the amount of propellant on your spacecraft, you might be able to do more things with that spacecraft that you would never consider doing. It doesn't just extend the lifetime, it could mean that you could visit more moons at Jupiter, for instance. It could really open up the trade space.

But I also think that doing a study like this might be really premature now. It might only make sense to do this after there is an SLS flying, when you have a good idea about the capabilities and the costs of the rocket.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/14/2012 02:11 PM
Another proposal the Europa Clipper has been outlined in an article on Space.com

Quote
But NASA is also thinking about ways to investigate the possible habitability of Europa, Jupiter's fourth-largest moon. One concept that may be gaining traction is a so-called "clipper" probe that would make multiple flybys of the moon, studying its icy shell and suspected subsurface ocean as it zooms past.

"We briefed [NASA] headquarters on Monday, and they responded very positively," mission proponent David Senske, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said here Dec. 7 at the annual fall meeting of the American Geophysical Union.

http://www.space.com/18901-nasa-mission-jupiter-moon-europa.html
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/20/2012 07:57 PM
The Europa de-scope final report studies have been finished. Unfortunately, the flyby and lander volumes are 23 megs apiece, which makes them too big to post here.

Here's the intro.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/20/2012 07:58 PM
Here's the orbiter study. Note that the orbiter is no longer the preferred option. You can get the best science-cost ratio out of the flyby mission.

None of the three studies mentions the SLS at all. It's not a preferred way to accomplish any of these missions.
Title: Re: Proposed Europa Missions
Post by: butters on 12/20/2012 08:05 PM
The chronic mechanical problems plaguing the scientists drilling that frozen lake in Antarctica don't bode well for the classical sci-fi notion of drilling the ice sheet on Europa. That kind of mission seems to be well beyond our near-term capabilities.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/20/2012 08:26 PM
The chronic mechanical problems plaguing the scientists drilling that frozen lake in Antarctica don't bode well for the classical sci-fi notion of drilling the ice sheet on Europa. That kind of mission seems to be well beyond our near-term capabilities.

This is from the lander study:

"Over time, the composition of the surface ice
is modified by fragmenting and sputtering
larger molecules, and by emplacement of ions
from space such as sulfur (Carlson et al. 2009).
Thus, samples acquired from the very surface
will not compositionally represent the ocean.
Depending on the type and geographic location,
this radiation damage is expected to reach
depths of several centimeters (Patterson et al.
2012), and obtaining samples from as deep as
10 cm becomes necessary. Additionally, obtaining
a near-surface sample (from 0.5–2 cm
depth) and a deeper sample (5–10 cm depth)
would provide an in situ assessment of the
effects of radiation on ice composition. Therefore,
the recommended strategy is to drill into
the surface up to a depth of 10 cm, obtaining
samples from at least two different depths."


So not a very deep drill.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2012 06:00 PM
I was able to split the files up. Here is part 1 for the flyby study. This is actually the best option of the three in terms of cost-benefit.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2012 06:01 PM
Flyby part 2.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2012 06:02 PM
Europa lander study, part 1.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2012 06:03 PM
Europa lander study, part 2.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2012 12:31 AM
Some images from the Europa Lander study report.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2012 02:15 AM
Europa Flyby spacecraft report images.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2012 02:15 AM
Europa Orbiter spacecraft report images.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/23/2012 12:08 PM
@Blackstar

That article I posted from Space.com about the Europa Clipper how does that fit in with the materials you have just posted?
Title: Re: Proposed Europa Missions
Post by: Alpha_Centauri on 12/23/2012 01:01 PM
Europa Clipper was an early name for the Europa Flyby option above.
Title: Re: Proposed Europa Missions
Post by: Alpha_Centauri on 12/23/2012 01:11 PM
A question from me,

I'm not up to date with the specifics of American politics.  I know there were attempts to get NASA's budget settlement reviewed, what is the current status on this?  Given that the new MSL 2020 rover has been planned based on the current projected budget envelope, if there were a change in the settlement to restore some of the planetary budget would there be sufficient funds to start work on the Europa mission, given that the Mars mission is already selected?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/23/2012 09:55 PM
A question from me,

I'm not up to date with the specifics of American politics.  I know there were attempts to get NASA's budget settlement reviewed, what is the current status on this?  Given that the new MSL 2020 rover has been planned based on the current projected budget envelope, if there were a change in the settlement to restore some of the planetary budget would there be sufficient funds to start work on the Europa mission, given that the Mars mission is already selected?

Normally, the President's proposed FY2014 budget would be released in early February. Right now it is on hold and probably will not be released until late February or even March. Until that is released, we will not know what the planetary budget looks like. For instance, did the administration choose to fund the Mars 2020 rover by putting back into the budget the money that it proposed removing last year? Or did it choose to fund the Mars 2020 rover by cutting money from elsewhere in the planetary budget, like New Frontiers and Discovery?

Assume that they restored the money that they cut and that planetary is at about the rate it was projected to be a couple of years ago. There will still not be enough money to fund both the Mars 2020 rover and a Europa mission. Too expensive. The proper thing to do would be to put the money back into the New Frontiers and Discovery program lines, because those were cut too, along with the Mars budget, in the President's proposed FY2013 budget.

Assuming a relatively flat planetary science budget, the earliest that a Europa mission could be funded is in the 2020s.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 12/23/2012 10:23 PM
I think it's a rort.

Sample return can't be done.

A caching rover is not sample return.

This mission is being cheated away.

I'm sure it's worded in such a way that lets it swoop in a steal the money at such a low fidelity (MSL repeat capability) but that doesn't mean it's the right thing to do and everybody is going to agree with it.  >:(
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/24/2012 01:27 AM
I think it's a rort.

Sample return can't be done.

A caching rover is not sample return.

This mission is being cheated away.

I'm sure it's worded in such a way that lets it swoop in a steal the money at such a low fidelity (MSL repeat capability) but that doesn't mean it's the right thing to do and everybody is going to agree with it.  >:(

Okay, first of all, I don't speak Australian, so I don't know what a "rort" is.

Second of all, I'm not sure if you're worth taking seriously or not. So instead of replying, I'll just observe and then make a decision.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 12/24/2012 01:57 AM
I found a word Americans don't use lol

Here's what wiki says
Quote
Rort is a term used in Australia and New Zealand to mean a scam or fraud.[1] It is commonly used in relation to politics or a financial impropriety, particularly relating to a government programme.

Build MSL copy, get samples. No it takes billions more dollars. The whole Europa mission can be done and out the way for the same price.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/24/2012 02:53 AM
I'll just continue observing.

But please read the executive summary of the decadal survey as well as these new Europa documents that I posted.
Title: Re: Proposed Europa Missions
Post by: baldusi on 12/26/2012 12:01 AM
I found a word Americans don't use lol

Here's what wiki says
Quote
Rort is a term used in Australia and New Zealand to mean a scam or fraud.[1] It is commonly used in relation to politics or a financial impropriety, particularly relating to a government programme.

Build MSL copy, get samples. No it takes billions more dollars. The whole Europa mission can be done and out the way for the same price.
Why don't you go and read the MSR discussion on the MSL forum? It has answers to what you think.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/27/2012 05:35 PM
A question from me,

I'm not up to date with the specifics of American politics.  I know there were attempts to get NASA's budget settlement reviewed, what is the current status on this?  Given that the new MSL 2020 rover has been planned based on the current projected budget envelope, if there were a change in the settlement to restore some of the planetary budget would there be sufficient funds to start work on the Europa mission, given that the Mars mission is already selected?

Normally, the President's proposed FY2014 budget would be released in early February. Right now it is on hold and probably will not be released until late February or even March. Until that is released, we will not know what the planetary budget looks like. For instance, did the administration choose to fund the Mars 2020 rover by putting back into the budget the money that it proposed removing last year? Or did it choose to fund the Mars 2020 rover by cutting money from elsewhere in the planetary budget, like New Frontiers and Discovery?

Assume that they restored the money that they cut and that planetary is at about the rate it was projected to be a couple of years ago. There will still not be enough money to fund both the Mars 2020 rover and a Europa mission. Too expensive. The proper thing to do would be to put the money back into the New Frontiers and Discovery program lines, because those were cut too, along with the Mars budget, in the President's proposed FY2013 budget.

Assuming a relatively flat planetary science budget, the earliest that a Europa mission could be funded is in the 2020s.

I would favour taking all the money from the Discovery & New Frontiers budgets for however long it takes and putting it into this instead. As the second highest ranked priority after Mars sample return I regard the financing of this project as far more important than any project that either of these two programmes might be financed for at this time.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/27/2012 07:22 PM
I would favour taking all the money from the Discovery & New Frontiers budgets for however long it takes and putting it into this instead. As the second highest ranked priority after Mars sample return I regard the financing of this project as far more important than any project that either of these two programmes might be financed for at this time.

It's fun to have opinions, isn' it?
Title: Re: Proposed Europa Missions
Post by: Star One on 12/28/2012 06:55 PM
I would favour taking all the money from the Discovery & New Frontiers budgets for however long it takes and putting it into this instead. As the second highest ranked priority after Mars sample return I regard the financing of this project as far more important than any project that either of these two programmes might be financed for at this time.

It's fun to have opinions, isn' it?

Is there any good reason not to go this route when money is tight?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/29/2012 12:53 AM
I would favour taking all the money from the Discovery & New Frontiers budgets for however long it takes and putting it into this instead. As the second highest ranked priority after Mars sample return I regard the financing of this project as far more important than any project that either of these two programmes might be financed for at this time.

It's fun to have opinions, isn' it?

Is there any good reason not to go this route when money is tight?

Yes.

Have you read the decadal survey? Do you know what it says? Are you familiar with the history of American planetary science programs over the past thirty years?

I'm guessing that the answers to all my questions are "no."

But what the heck, here goes:

-the priorities for the American planetary science program are established in the planetary science decadal survey. That decadal survey states the EXACT OPPOSITE of what you just asked. It states that when money gets tight, the first thing to do is to scale back or delay flagship class programs like the Europa mission. Only after that is done should cuts be made in other areas, like New Frontiers and Discovery. You can find the decision rules in the decadal survey. At no point does it say that smaller missions should be sacrificed for larger missions.

-Europa is ranked second to the Mars caching rover in the decadal survey. Unfortunately, what this means is that it will not get funded in this decade. Even assuming a flat budget, or even one with a slight increase, the decadal survey does not say do both flagship missions. Now there are a lot of reasons why that happened (the big one being that the Europa mission that was presented to the decadal survey was a bellybuster and not affordable, and it took a blow to the head for the Europa community to actually come up with an affordable mission, which they have now apparently done), but them's the breaks.

-if you want a good example of why what you proposed is a stupid idea, take a look at the astronomy and astrophysics program at NASA. They have sacrificed all their small and medium missions in favor of JWST, which is now eating their lunch. Focusing on a single large mission puts you in a situation where you will have one or two missions per decade vs. half a dozen or more.

-if you want a good example of what could happen, look at NASA's planetary science program during the 1970s into the 1980s. They got into a vicious cycle of fewer and fewer larger and more expensive missions. The result was what many people call "the lost decade" in planetary science. You can see various effects of this, such as 17 years between Mars missions culminating in the very expensive Mars Observer failing on its way to Mars. It's a bad idea to fall into that circle again.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/31/2012 05:08 PM
I would favour taking all the money from the Discovery & New Frontiers budgets for however long it takes and putting it into this instead. As the second highest ranked priority after Mars sample return I regard the financing of this project as far more important than any project that either of these two programmes might be financed for at this time.

It's fun to have opinions, isn' it?

Is there any good reason not to go this route when money is tight?

Yes.

Have you read the decadal survey? Do you know what it says? Are you familiar with the history of American planetary science programs over the past thirty years?

I'm guessing that the answers to all my questions are "no."

But what the heck, here goes:

-the priorities for the American planetary science program are established in the planetary science decadal survey. That decadal survey states the EXACT OPPOSITE of what you just asked. It states that when money gets tight, the first thing to do is to scale back or delay flagship class programs like the Europa mission. Only after that is done should cuts be made in other areas, like New Frontiers and Discovery. You can find the decision rules in the decadal survey. At no point does it say that smaller missions should be sacrificed for larger missions.

-Europa is ranked second to the Mars caching rover in the decadal survey. Unfortunately, what this means is that it will not get funded in this decade. Even assuming a flat budget, or even one with a slight increase, the decadal survey does not say do both flagship missions. Now there are a lot of reasons why that happened (the big one being that the Europa mission that was presented to the decadal survey was a bellybuster and not affordable, and it took a blow to the head for the Europa community to actually come up with an affordable mission, which they have now apparently done), but them's the breaks.

-if you want a good example of why what you proposed is a stupid idea, take a look at the astronomy and astrophysics program at NASA. They have sacrificed all their small and medium missions in favor of JWST, which is now eating their lunch. Focusing on a single large mission puts you in a situation where you will have one or two missions per decade vs. half a dozen or more.

-if you want a good example of what could happen, look at NASA's planetary science program during the 1970s into the 1980s. They got into a vicious cycle of fewer and fewer larger and more expensive missions. The result was what many people call "the lost decade" in planetary science. You can see various effects of this, such as 17 years between Mars missions culminating in the very expensive Mars Observer failing on its way to Mars. It's a bad idea to fall into that circle again.

1. I have made a start on the decadal survey but what with Christmas & the new year haven't got any further than that.

2. As to JWST one would hope that NASA would have learnt their lessons from the problems with the management of that project and would seek not to repeat them with any similar large-scale Mission. Also just because they have had issues with JWST I fail to see how that should mean that they will automatically have problems with the management of any future large scale projects.

3. If your logic is accepted then what the heck is NASA doing starting another major project like building a second flagship Martian rover. The re-use of spares aside your logic would dictate that the cost of its development is bound to lean in an upwards direction and impact on other smaller projects.

4. Some might argue that this current fixation on Mars represents a potential lost decade (or longer) of exploration of the rest of the Solar System.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/31/2012 06:05 PM
1. I have made a start on the decadal survey but what with Christmas & the new year haven't got any further than that.

2. As to JWST one would hope that NASA would have learnt their lessons from the problems with the management of that project and would seek not to repeat them with any similar large-scale Mission. Also just because they have had issues with JWST I fail to see how that should mean that they will automatically have problems with the management of any future large scale projects.

3. If your logic is accepted then what the heck is NASA doing starting another major project like building a second flagship Martian rover. The re-use of spares aside your logic would dictate that the cost of its development is bound to lean in an upwards direction and impact on other smaller projects.

1-Good for you. We need knowledgeable people.

2 and 3-Balance. Balance. Balance. Balance. Balance.

Maybe I should repeat that again: Balance.

The decadal survey says to pursue a "balanced" program of small, medium, and large missions. It says that if money gets tight, you do NOT cancel the small and medium missions only to pursue a single big mission. It says that if money gets tight, you delay or de-scope the flagship, and protect the smaller missions, existing missions, and research and analysis funding.

I agree that just because JWST went pear-shaped that this does not mean that other large spacecraft missions will also do so. But the danger is that a flagship class mission that goes over budget is so big that it squashes everything else. For instance, a 20% cost overrun on a $2 billion flagship mission is enough to wipe out an entire Discovery class mission. But I'd also note that this is irrelevant to what you were proposing--you were proposing wiping out all the smaller stuff to fund the big mission that you think is cool, and that's not the way that things work, or should work.
Title: Re: Proposed Europa Missions
Post by: simonbp on 01/01/2013 02:29 AM
The decadal survey says to pursue a "balanced" program of small, medium, and large missions. It says that if money gets tight, you do NOT cancel the small and medium missions only to pursue a single big mission. It says that if money gets tight, you delay or de-scope the flagship, and protect the smaller missions, existing missions, and research and analysis funding.

Advice which they appear to have completely ignored. The mood at DPS NASA night was positively sour when Jim Green confirmed that there would be no new Discovery selection until 2017. But apparently we've got money for another giant Mars rover!

Those of us in the Not Mars (and Not Geology for that matter) planetary community cannot help but feel rather abused.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/01/2013 03:06 AM
Advice which they appear to have completely ignored. The mood at DPS NASA night was positively sour when Jim Green confirmed that there would be no new Discovery selection until 2017. But apparently we've got money for another giant Mars rover!

Those of us in the Not Mars (and Not Geology for that matter) planetary community cannot help but feel rather abused.

The fact that OMB completely ignored the decadal survey was not lost on many people. The announcement of the Mars 2020 rover appears to be a reluctant acquiescence to do the decadal's top flagship recommendation--doing the right thing after exhausting the alternatives.

Title: Re: Proposed Europa Missions
Post by: Star One on 01/01/2013 04:10 PM
Advice which they appear to have completely ignored. The mood at DPS NASA night was positively sour when Jim Green confirmed that there would be no new Discovery selection until 2017. But apparently we've got money for another giant Mars rover!

Those of us in the Not Mars (and Not Geology for that matter) planetary community cannot help but feel rather abused.

The fact that OMB completely ignored the decadal survey was not lost on many people. The announcement of the Mars 2020 rover appears to be a reluctant acquiescence to do the decadal's top flagship recommendation--doing the right thing after exhausting the alternatives.



So much for your argument on balance when NASA themselves don't seem to be following that mantra?

In fact have they not just done to a degree what I was talking about which is to take money from other smaller projects to fund a larger project in the form of a second Martian rover?

As to reading the DS well the copy I have, unless, it's suddenly an extended version, is 410 pages long (as you no doubt already know) & having only recently got my hands on it I might be excused for not having read it all yet. :-\ 
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/01/2013 10:06 PM
1-So much for your argument on balance when NASA themselves don't seem to be following that mantra?

2-In fact have they not just done to a degree what I was talking about which is to take money from other smaller projects to fund a larger project in the form of a second Martian rover?

3-As to reading the DS well the copy I have, unless, it's suddenly an extended version, is 410 pages long (as you no doubt already know) & having only recently got my hands on it I might be excused for not having read it all yet. :-\ 

1-No. A bad idea is a bad idea no matter who comes up with it. But I'd note that your bad idea is different than what OMB has done. In the FY2013 proposed budget, the OMB essentially killed the Mars flagship and cut money across the board from everything else. That's not really what you were proposing, which was to kill all the small and medium stuff and pump it into the flagship mission that you think is cool.

2-No. The cuts to small and medium missions came before the most recent proposal to revive the Mars rover idea. See also #1 above.

3-You don't need to read the entire thing, although doing so would give you a leg up on everybody (assuming you understand it). The executive summary does a good job of explaining what and why. It also explains the decision rules.
Title: Re: Proposed Europa Missions
Post by: Star One on 02/17/2013 06:41 PM
New article on the proposed Europa Clipper.

Quote
"On Earth, everywhere where there's liquid water, we find life," said Robert Pappalardo, a senior research scientist at Nasa's jet propulsion laboratory in California, who led the design of the Europa Clipper.

"Mars exploration is part of the bigger picture of human exploration," said Pappalardo. "However, part of Nasa's mission is to go explore and that should include places that are an extremely high scientific priority. It really is one of the most profound questions we can ask: is there life elsewhere in the solar system?"

Whereas Mars might have been habitable billions of years ago, he said, Europa might be a habitable environment for life today. If it took 50 years before humans ended up sending probes and then landers to Europa, Pappalardo said, "we're going to look back and say we should have been doing this all along – and that would be tragic".

http://www.guardian.co.uk/science/2013/feb/15/nasa-europa-clipper-mission-jupiter-moon?INTCMP=SRCH
Title: Re: Proposed Europa Missions
Post by: Dalhousie on 02/17/2013 10:33 PM
The decadal survey says to pursue a "balanced" program of small, medium, and large missions. It says that if money gets tight, you do NOT cancel the small and medium missions only to pursue a single big mission. It says that if money gets tight, you delay or de-scope the flagship, and protect the smaller missions, existing missions, and research and analysis funding.

Advice which they appear to have completely ignored. The mood at DPS NASA night was positively sour when Jim Green confirmed that there would be no new Discovery selection until 2017. But apparently we've got money for another giant Mars rover!

Those of us in the Not Mars (and Not Geology for that matter) planetary community cannot help but feel rather abused.

Whatever "Not Mars" group you belong to, you are getting more than the Mars people were getting between 1976 and 1996.
Title: Re: Proposed Europa Missions
Post by: truth is life on 02/22/2013 02:18 AM
Whatever "Not Mars" group you belong to, you are getting more than the Mars people were getting between 1976 and 1996.

Ice giants? There has, quite literally, not been an ice giants mission since before I was born (if only by a matter of days).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/06/2013 09:37 PM
Had an interesting conversation with a NASA official today. Apparently the solar powered Europa mission is still considered rather dicey. Lifetime is low, and there is limited confidence in the solar option in terms of risk. As a result, NASA is going to keep open the option of using the MMRTG on a future Europa mission.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 03/06/2013 10:07 PM
Thanks for that update Blackstar.

Hopefully this happens not long after the Mars 2020 rover.... and I'm still alive when it makes JOI.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/22/2013 08:10 PM
Well, uh oh...

http://www.bbc.co.uk/news/science-environment-21341176

Ice blades threaten Europa landing
By Paul Rincon Science editor, BBC News website, The Woodlands, Texas

Jupiter's icy moon Europa is a prime target for future space missions as it harbours a buried ocean that could have the right conditions for life.

But attempts to land may face a major hazard: jagged "blades" of ice up to 10m long.

A major US conference has heard the moon may have ideal conditions for icy spikes called "penitentes" to form.

Scientists would like to send a lander down to sample surface regions where water wells up through the icy crust.

These areas could allow a robotic probe to sample a proxy for ocean water that lies several kilometres deep.

Details of the penitentes theory were announced as scientists outlined another proposal to explore the jovian moon with robotic spacecraft.

On Earth, these features (so named because of their resemblance to the pointed caps worn by "penitents" in Easter processions around the Spanish-speaking world) form in high altitude regions such as the Andes.

Here, the air is both cold and dry, allowing ice to sublimate (turn from a solid into vapour without passing through a liquid phase).

Penitentes begin to form when irregularities in the surface of the snow are enhanced by the Sun's energy. These furrows then act as a trap for solar radiation, and, as they deepen, the tall peaks are left behind.
Sun overhead

Dr Daniel Hobley, from the University of Colorado, who presented his research at the 44th Lunar and Planetary Science Conference in Texas on Tuesday, said the formation of penitentes also required the Sun to be overhead as much as possible.

"Light coming in at a high angle will illuminate the sides of the blades, causing them to retreat away," he explained.

On Earth, this restricts them to between 30 degrees latitude from the equator.

"Europa is very strongly tidally locked to Jupiter and Jupiter is very strongly tidally locked to the plane of the Sun. So the Sun is always coming down straight from above on Europa," said Dr Hobley, so the moon fulfils this requirement nicely.

He added: "You need a strong thermal gradient between the spike at the top of the penitente and the pit at the bottom. So any mechanism that acts to suppress that, i.e. warm cloudy days - or hot air - will also kill them."

With its negligible atmosphere, this wouldn't be a problem on Europa, suggesting the moon could have more or less ideal conditions for the formation of these icy blades.

"From our point of view, if the surface of Europa is subliming - if it is being sculpted by the sunlight - it will form these features," Dr Hobley told BBC News.
Title: Re: Proposed Europa Missions
Post by: baldusi on 03/22/2013 08:23 PM
Ouch! What sort of instrument would they need to fly there to get that sort of resolution? Were they planning on a retroburn just before the land? That would melt almost anything. Would leave a big hole to land, too.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/22/2013 08:50 PM
Ouch! What sort of instrument would they need to fly there to get that sort of resolution? Were they planning on a retroburn just before the land? That would melt almost anything. Would leave a big hole to land, too.

If you read the article all the way through, you see that not everybody accepts this explanation.

Anyway, the plan is to map Europa first before any mission to send a lander, so that would answer the question. However, even if Europa does not have these ice spikes, it could still be very dangerous terrain. That said, NASA funded some neat technology work called ALHAT that allows a lander to detect the terrain and avoid dangerous obstacles. No landers have really done that before. If they continue work on ALHAT, it would be very useful for a lander mission.

I always sigh when people start talking about submarines on Europa. That is probably a century or more away. Just landing on Europa will be difficult.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 03/22/2013 10:10 PM
Speculation is all we're left with.

Mars has been mapped in high resolution and is being bombarded by probes yet nobody has a clue what the surface of Europa really looks like.

I hope that all that is stopping a mapping mission being funded is the plutonium.
Title: Re: Proposed Europa Missions
Post by: baldusi on 03/22/2013 11:41 PM
Ouch! What sort of instrument would they need to fly there to get that sort of resolution? Were they planning on a retroburn just before the land? That would melt almost anything. Would leave a big hole to land, too.

If you read the article all the way through, you see that not everybody accepts this explanation.

Anyway, the plan is to map Europa first before any mission to send a lander, so that would answer the question. However, even if Europa does not have these ice spikes, it could still be very dangerous terrain. That said, NASA funded some neat technology work called ALHAT that allows a lander to detect the terrain and avoid dangerous obstacles. No landers have really done that before. If they continue work on ALHAT, it would be very useful for a lander mission.

I always sigh when people start talking about submarines on Europa. That is probably a century or more away. Just landing on Europa will be difficult.
I worked in the Andes and thus have seen the penitentes. I that does makes me assume they are there. But I've never talked about submarines. Rather that a lander would make a mess at retroburn, which probably would contaminate any samples.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/23/2013 01:02 AM
I hope that all that is stopping a mapping mission being funded is the plutonium.

No. It's money.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/23/2013 01:04 AM
I worked in the Andes and thus have seen the penitentes. I that does makes me assume they are there. But I've never talked about submarines. Rather that a lander would make a mess at retroburn, which probably would contaminate any samples.

I talked to a well-known Titan scientist who saw this guy's talk about the penitentes at LPSC. He called it "unconvincing."

You're right that there may be a problem with a lander contaminating the site. The solution would be some kind of sampling arm. Perhaps a small rover, although that would be really difficult. Any Europa lander mission would have to possess a lot of autonomous capability.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 03/23/2013 02:46 AM
I hope that all that is stopping a mapping mission being funded is the plutonium.

No. It's money.

A little politics but only for reference.

Quote
Provided, That $75,000,000  6
shall be for pre-formulation and/or formulation activities  7
for a mission that meets the science goals outlined for the  8
Jupiter Europa mission in the most recent planetary  9
science decadal survey

What about this? What's that for?

I thought Europa missions have already been studied over and over...  ???
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/23/2013 03:15 AM
A little politics but only for reference.

Quote
Provided, That $75,000,000  6
shall be for pre-formulation and/or formulation activities  7
for a mission that meets the science goals outlined for the  8
Jupiter Europa mission in the most recent planetary  9
science decadal survey

What about this? What's that for?

I thought Europa missions have already been studied over and over...  ???

I don't know, but if I had to guess, that's an earmark for JPL. That's to throw them some more technology development money. They have already gotten a lot of money over the years (over $400 million starting around 2002 for JIMO tech development). Yes, Europa has been studied over and over. My guess is that the money will go for radiation hardened electronics research, and JPL overhead. JPL always has overhead.
Title: Re: Proposed Europa Missions
Post by: Galactic Penguin SST on 03/23/2013 04:10 AM
A little politics but only for reference.

Quote
Provided, That $75,000,000  6
shall be for pre-formulation and/or formulation activities  7
for a mission that meets the science goals outlined for the  8
Jupiter Europa mission in the most recent planetary  9
science decadal survey

What about this? What's that for?

I thought Europa missions have already been studied over and over...  ???

I don't know, but if I had to guess, that's an earmark for JPL. That's to throw them some more technology development money. They have already gotten a lot of money over the years (over $400 million starting around 2002 for JIMO tech development). Yes, Europa has been studied over and over. My guess is that the money will go for radiation hardened electronics research, and JPL overhead. JPL always has overhead.

I wonder after all if flying to Ganymede would have been the better option - while not as "sexy" as Europa, it does have an ocean underneath after all. The radiation level is lower there - hence the ESA JUICE is now targeting there instead of Europa, and that the Russians are making noises for making a lander for this mission (which I took with a handful of salt  ::)). It would be the intermediate step towards an eventual Europa surface mission.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 03/23/2013 04:40 AM
Thanks for the reply Blackstar.

I guess it's just a risk reduction to get prepared for when the stars align and the mission is funded.

As for Ganymede JUICE will be orbiting it for years. NASA doesn't have to go there as they'll just be duplicating the science done by ESA.

NASA has access to RTGs and Europa is their 2nd highest priority planetary flagship. I would hope the mission launches sometime in before 2030 which is likely unless the next survey shafts it into 2nd place again after Mars 2020 is underway.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/23/2013 12:23 PM
I guess it's just a risk reduction to get prepared for when the stars align and the mission is funded.


I suspect nobody involved knows how they will spend that money now other than to keep paying salaries of people at JPL. Congress cannot really initiate a "new start" of a program; the president has to do that. One possible good way to spend that money would be to start buying another MMRTG for this mission. That's hardware that could probably be purchased now even if it is not incorporated into a spacecraft for another 20 years (RTGs are mostly structure).

I know that JPL management, and to a lesser extent the broader scientific community, is concerned about losing a valuable resource in the form of all the good people at JPL with unique skills. I suspect that this money is partly intended to keep them employed. But it's also a case that there is a member of Congress who has no political interest in JPL (he comes from another state) who has a lot of personal interest in a Europa mission. He thinks it is cool and wants it to happen. He may be partly responsible for this language in the bill.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/23/2013 12:31 PM
I wonder after all if flying to Ganymede would have been the better option - while not as "sexy" as Europa, it does have an ocean underneath after all. The radiation level is lower there - hence the ESA JUICE is now targeting there instead of Europa, and that the Russians are making noises for making a lander for this mission (which I took with a handful of salt  ::)). It would be the intermediate step towards an eventual Europa surface mission.

The U.S. scientific community has a different view. Without looking this up, I think that the issue is that Ganymede's ocean is not as thick and scientists do not believe that it touches the core. In other words, it is water sandwiched between two layers of ice, whereas Europa's ocean is believed to have rock on the bottom and ice on top. This is important because the possibility of life is believed to be greater if the water is enriched with minerals by touching the rock. (I would also guess that you'd get more circulation, but I don't know that.)

The American scientific community has more geologists and biologists, so they are more interested in the search for life. Plus rocks.

The European community has a different bias. They have more scientists interested in magnetosphere physics. Ganymede is therefore where they want to go.

At times, science can be somewhat like the drunk who looks for his car keys under the street lamp because that's where the light is. Scientists pick things to study because that is what interests them, not necessarily because they are what are most "important" in some objective sense. I haven't looked at the latest plans for JUICE, but in earlier iterations they were going to try to do at least a couple of flybys of Europa.
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 03/23/2013 10:23 PM
Well, uh oh...

http://www.bbc.co.uk/news/science-environment-21341176

Ice blades threaten Europa landing
;D
Well one simple solution is to clear a landing zone for the lander like they used to do in SE Asia for improvise jungle helo pads. Maybe with a cluster kinetic impacters that will take some close up images before impacting with a separate launch several weeks prior to the lander launch.

Of course this idea is wild & wacky. Probably not workable.
Title: Re: Proposed Europa Missions
Post by: Alpha_Centauri on 03/23/2013 11:26 PM
The American scientific community has more geologists and biologists, so they are more interested in the search for life. Plus rocks.

The European community has a different bias. They have more scientists interested in magnetosphere physics. Ganymede is therefore where they want to go.

It isn't that the European scientific community is any less interested in Europa (or for that matter geology or biology...) it's simply that the technical challenges would push a European Europa mission well over the L-class mission financial threshold and so could only ever be part of an international collaboration.  Remember JUICE is the phoenix from the ashes of ESA's contribution to EJSM, JGO.

Ganymede does however provide a useful test of the subsurface studies required on Europa and other icy moons, and on a budget more affordable in the economic times.
Title: Re: Proposed Europa Missions
Post by: plutogno on 03/24/2013 08:28 AM
Without looking this up, I think that the issue is that Ganymede's ocean is not as thick and scientists do not believe that it touches the core. In other words, it is water sandwiched between two layers of ice, whereas Europa's ocean is believed to have rock on the bottom and ice on top.

I think that another important difference is that Europa's ocean is much closer to the surface than that of Ganymede (a few kilometers instead of tens of kilometers)
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/02/2013 09:40 PM
It isn't that the European scientific community is any less interested in Europa (or for that matter geology or biology...) it's simply that the technical challenges would push a European Europa mission well over the L-class mission financial threshold and so could only ever be part of an international collaboration.  Remember JUICE is the phoenix from the ashes of ESA's contribution to EJSM, JGO.

Sorry for the late reply. I don't read all the threads on this site regularly.

I'm going to disagree on the first point, with the proviso that I don't have direct experience with this, but am basing it upon what I've heard from people who do have direct experience (in other words, maybe I have no idea what I'm talking about). And what I've heard is that the European community is more biased toward magnetospheric physics than the American planetary science community (where magnetosphere physics is often ignored). Now that's a relative thing, so your mileage may vary. But the United States did build up a substantial astrobiology community over the past two decades, and that helps tilt the scales as well.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/02/2013 09:43 PM
Well one simple solution is to clear a landing zone for the lander like they used to do in SE Asia for improvise jungle helo pads. Maybe with a cluster kinetic impacters that will take some close up images before impacting with a separate launch several weeks prior to the lander launch.

Of course this idea is wild & wacky. Probably not workable.


It's not workable. What you want is a predictable landing site. One problem with trying to blast it flat is that you have no way of knowing if that is actually going to work. What happens if you try this and the spacecraft looks down and all it sees is more lousy terrain? Indeed, one of the problems with trying to blast landing zones in the jungle during Vietnam was that it created a lot of debris that then got in the way.

What you want is a mission that finds a flat spot.
Title: Re: Proposed Europa Missions
Post by: copernicus on 05/09/2013 02:55 AM
   Here is a link to an update on the status of the Europa Clipper mission.  I wrote it as a guest on Van Kane's "Future Planetary Exploration" website. 

http://futureplanets.blogspot.com/2013/05/europa-clipper-update.html

I hope that it answers some questions about the mission. 



Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/09/2013 01:37 PM
I'm not so sure about the $75 million earmarked for Europa. Is it really intended to fund Europa Clipper, or to send money to JPL? I'm not sure that there's an efficient way to spend that money on Europa studies. It is too little money to start development, and too much to perform studies. Now if it goes into something like the RTGs, that would be useful. You could build a new MMRTG for Europa Clipper and put it on the shelf and use it fifteen years from now.

Good reference to Solar Probe, however. I had forgotten about that. There's a good story behind the creation of Solar Probe Plus. My limited understanding/memory is that Congress kept putting money in the budget for that but NASA kept ignoring them. NASA just did not think that they could afford Solar Probe. Finally, Alan Stern said to that community (this is almost a direct quote from a talk he gave) "Do you want 100% of nothing or 80% of something?" And he forced them to redesign Solar Probe into a mission that NASA could afford and got a new start on it.
Title: Re: Proposed Europa Missions
Post by: JohnFornaro on 05/13/2013 01:39 PM
Quote
"On Earth, everywhere where there's liquid water, we find life," said Robert Pappalardo, a senior research scientist at Nasa's jet propulsion laboratory in California, who led the design of the Europa Clipper.

"Mars exploration is part of the bigger picture of human exploration," said Pappalardo. "However, part of Nasa's mission is to go explore and that should include places that are an extremely high scientific priority. It really is one of the most profound questions we can ask: is there life elsewhere in the solar system?"

Whereas Mars might have been habitable billions of years ago, he said, Europa might be a habitable environment for life today. If it took 50 years before humans ended up sending probes and then landers to Europa, Pappalardo said, "we're going to look back and say we should have been doing this all along – and that would be tragic".

That would be tragic.
Title: Re: Proposed Europa Missions
Post by: Star One on 05/13/2013 05:29 PM
   Here is a link to an update on the status of the Europa Clipper mission.  I wrote it as a guest on Van Kane's "Future Planetary Exploration" website. 

http://futureplanets.blogspot.com/2013/05/europa-clipper-update.html

I hope that it answers some questions about the mission.

Thanks for that link. Pretty sad state of affairs that Congress have to 'kick' NASA into putting some money into this program.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/13/2013 08:05 PM
Thanks for that link. Pretty sad state of affairs that Congress have to 'kick' NASA into putting some money into this program.

Not really.

You cannot do everything. You have to establish priorities and fund the things you can reasonably do. They've established the priorities. Read the decadal survey.

What may be happening (and I say "may" because I don't really know) is that Congress may be earmarking this money not because of the program, but because of where it is being done (JPL). In other words, it's pork. It is hypocritical to decry pork in general but say that it is acceptable as long as the money is being spent on the particular flavor of pork that you enjoy.



There is, of course, a lot more that could be said about the whole subject, but I'd have to start writing a textbook.
Title: Re: Proposed Europa Missions
Post by: ChileVerde on 05/14/2013 05:48 PM

There is, of course, a lot more that could be said about the whole subject, but I'd have to start writing a textbook.

You might want to start doing that, or at least a book of some sort on the subject. The world will thank you for it.

Actually, it probably won't, but it should. Such is the way of the world.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/15/2013 01:21 PM

There is, of course, a lot more that could be said about the whole subject, but I'd have to start writing a textbook.

You might want to start doing that, or at least a book of some sort on the subject. The world will thank you for it.

Actually, it probably won't, but it should. Such is the way of the world.



Nobody cares.

As you may know, there's a whole process for developing priorities for space science missions in each of the disciplines. It is difficult for people who are not intimately involved in that process (and even difficult for some people who ARE involved in that process) to understand how it works. But it does work, and it actually works pretty darn well. We have been working on improving that process, and there is always room for making things better. But I think that the American taxpayers and the American scientific community are both served well by how it all works. It would take a lot of time and effort to explain all of that to outsiders.

Now how does that relate to Europa? Well, the process, as enshrined in the decadal survey, came up with a series of decision rules for how to plan the planetary science program over the next decade, and also a priority list for the flagship missions, with starting Mars sample return first, and Europa second. There was a lot of work and careful consideration that led to those recommendations, and as close to a consensus opinion as you could get out of the scientific community. Abandoning that approach, or shortcutting it, simply because you disagree with it, could cause a lot of damage to the overall health of the program.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/15/2013 03:10 PM
Dunno if this is accurate, but it does seem to be a case of what I mentioned in the previous post, where the decadal survey essentially said to protect Discovery and research budgets before giving money to flagships, but the administration is doing the opposite. Of course, this could also be interpreted as the administration saying to Congress: "Okay, if you want to earmark money for Europa, we'll cut it out of other things that you think are important too. You're welcome."


http://spaceref.com/news/viewsr.html?pid=44031

"After removing essentially all of funds added by Congress to Planetary Science, NASA and and others in the Administration have further chosen to reallocate significant funds from present planetary research and Discovery budgets to pay for new studies in support of a future Europa mission. The next Discovery call will certainly be delayed. The impact to research programs will be severe - further reduced selection rates can be anticipated. Might existing awards be retroactively reduced? Damage is made worse by the fact that these cuts are being implemented in the final months of the fiscal year."
Title: Re: Proposed Europa Missions
Post by: Star One on 05/15/2013 07:02 PM
Dunno if this is accurate, but it does seem to be a case of what I mentioned in the previous post, where the decadal survey essentially said to protect Discovery and research budgets before giving money to flagships, but the administration is doing the opposite. Of course, this could also be interpreted as the administration saying to Congress: "Okay, if you want to earmark money for Europa, we'll cut it out of other things that you think are important too. You're welcome."


http://spaceref.com/news/viewsr.html?pid=44031

"After removing essentially all of funds added by Congress to Planetary Science, NASA and and others in the Administration have further chosen to reallocate significant funds from present planetary research and Discovery budgets to pay for new studies in support of a future Europa mission. The next Discovery call will certainly be delayed. The impact to research programs will be severe - further reduced selection rates can be anticipated. Might existing awards be retroactively reduced? Damage is made worse by the fact that these cuts are being implemented in the final months of the fiscal year."

I imagine this will result in yet another tug of war between the various sides which will no doubt do no one any good in the end.

That said and I am aware of what the survey recommended but you have to admit we do seem to have a number of quite vocal scientific proponents in favour of the Europa mission so it is not like there isn't support for it out there.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/15/2013 07:35 PM
1-I imagine this will result in yet another tug of war between the various sides which will no doubt do no one any good in the end.

2-That said and I am aware of what the survey recommended but you have to admit we do seem to have a number of quite vocal scientific proponents in favour of the Europa mission so it is not like there isn't support for it out there.

1-Yes and no. Note that what is going on here is that JPL got itself an earmark. That's money that is specifically going to JPL because they have political clout. Now that's not a good thing. The planetary science community includes a lot of competition, which makes for better science and also better spending of money. Anything that shortcuts the competition is probably bad. So, just because this earmark happened, should everybody else who plays by the rules just roll over and give up? Should they let the process just fall apart?

2-So what? People who lost out complain. Yeah, that's happened. But should they tear everything apart because they didn't get what they wanted?

There's no good way to discuss this without sounding nastier than I want to be about it. There's a lot of nuance and complexity to the whole issue that I just could not write down, and I'm not anti-Europa. I am against bypassing procedures and processes that work pretty good at keeping politics out of the way we select planetary science missions.

But if you watched the whole thing play out over several years, you'd have a better understanding of what went on. In short: the Europa advocates walked into the decadal survey with a mission proposal that was fat and bloated and not able to be funded (it would have wiped out the entire planetary budget). It was cost estimated at $4.7 billion. There was no way to fund that mission. As a result, it was not placed at the top of the priority list and they were told to go back and redesign their mission so that it was affordable. Now they have done that. But that is no reason that this mission should then come back and stomp all over other priorities for planetary science, including ones that proposed realistic missions from the start. It's kinda like missing the medal in the Olympics because you're fat and out of shape, practicing a bit, and calling for another Olympics a year later so you can win a medal this time. It's unfair to the people who played by the rules.
Title: Re: Proposed Europa Missions
Post by: Star One on 05/15/2013 08:55 PM
Well if they have got themselves more into shape then maybe to be generous to them perhaps that's a basis for congress allocating money to the studies.

Also isn't Europa such a scientifically important mission that it automatically outranks virtually any other proposed mission, it certainly should be the top ranked mission at the next survey. You may not like their approach and from what you have said I can see why, but I do understand why they feel the need to make the noise they do about it.
Title: Re: Proposed Europa Missions
Post by: robertross on 05/16/2013 12:13 AM
Dunno if this is accurate, but it does seem to be a case of what I mentioned in the previous post, where the decadal survey essentially said to protect Discovery and research budgets before giving money to flagships, but the administration is doing the opposite. Of course, this could also be interpreted as the administration saying to Congress: "Okay, if you want to earmark money for Europa, we'll cut it out of other things that you think are important too. You're welcome."


http://spaceref.com/news/viewsr.html?pid=44031

"After removing essentially all of funds added by Congress to Planetary Science, NASA and and others in the Administration have further chosen to reallocate significant funds from present planetary research and Discovery budgets to pay for new studies in support of a future Europa mission. The next Discovery call will certainly be delayed. The impact to research programs will be severe - further reduced selection rates can be anticipated. Might existing awards be retroactively reduced? Damage is made worse by the fact that these cuts are being implemented in the final months of the fiscal year."

Appreciate your commentary on all this. I've been sitting here catching up on the posts.

Going back to your previous comments on all this, and the pace of SLS and such, I'm now getting into a position where I am accepting of a slow down on these massive & costly missions to protect the overall Planetary Science community. JWST should have taught us all a valuable lesson: we can't afford it all (even being a Canadian looking at these massive American budgetary requests).

It's not as if Europa is going anyware. It's not as if we could do anything about finding life there even if we found it (just as in the case of Mars, if it were to be made true). We anough enough priorities closer to home to be happy with the New Frontiers & Discovery class missions. Such Flagship missions can wait for when the economy has light at the end of that tunnel so that money (hopefully) isn't as scarce.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/16/2013 03:33 AM
It's not as if Europa is going anyware. It's not as if we could do anything about finding life there even if we found it (just as in the case of Mars, if it were to be made true). We anough enough priorities closer to home to be happy with the New Frontiers & Discovery class missions. Such Flagship missions can wait for when the economy has light at the end of that tunnel so that money (hopefully) isn't as scarce.

I'd point out that flagship missions are important. They, more than any other missions, fundamentally advance the science. A decade without New Frontiers and Discovery would be bad. But a decade without a flagship mission would be bad too. It's all about balance.

However, we are now at risk of having a decade with only a flagship and few or none of the smaller missions. That's not good.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 05/16/2013 03:34 AM
http://www.planetary.org/blogs/casey-dreier/2013/20130515-nasa-steals-back-money-from-planetary-science.html

NASA Robs Planetary Science
Leaked document shows NASA funding other programs with planetary money


Posted By Casey Dreier

2013/05/15 05:04 CDT

Topics: NASA Budget

Despite Congress rejecting cuts to NASA's Planetary Science Division in March, NASA plans to raid the restored funds for use in other projects for the remainder of this year. This is a stunning rebuke to Congress and a very rare move by NASA that continues to undercut this popular and productive program.

Just to recap: the final budget for 2013 wasn't passed until late March of this year. It provided $1.42 billion for Planetary Science, over $200 million more than the President's original request. This extra money would support initial work on the 2020 Mars Rover, formulation activities on a mission to Europa, and increase the pace of small missions. Of course, the sequester reduced this total to approximately $1.3 billion if applied evenly, still much better than the original proposal.

But NASA is not applying the sequester evenly. Mark Sykes of the Planetary Science Institute obtained a leaked draft of NASA's operating plan, which details the the actual implementation of the approved budget. Operating plans are prepared only after budgets pass Congress and must be submitted to the relevant appropriations committee within 45 days for review. Federal agencies have leeway in how they spend their allocated money internally, and up to 5% of any program's budget can be used to buttress other accounts. This is called "reprogramming."

However, the sequester requires that NASA find hundreds of millions of dollars of savings within its science programs. This requirement, combined with the ability to reprogram money as needed, drove NASA to essentially offset sequester cuts in other areas at the expense of the Planetary Science Division. Planetary's entire increase has been reprogrammed away for this.

This is an entirely separate issue from the proposed 2014 budget, which continues cuts to this program next year.

Key people in Congress will be very upset about this, especially Adam Schiff, Dianne Feinstein, and John Culberson, who wrote an open letter to the NASA Administrator just last month warning them to not defy congressional will on the importance of planetary science.

This is a leaked draft of the document, and may not reflect the final version sent to Congress on Friday. Once the operating plan is submitted Congress can voice their objections to it, and historically the agency works with them to address these issues. It's hard to say if that's the case this time since NASA was so clearly warned not to do this.

Planetary Science cannot get a break. NASA and the White House seem determined to underfund and sacrifice the future of planetary exploration despite the efforts of Congress and the public. Congress is our greatest ally in this struggle, and we've spoken to them about this. More details to come as we know them.

Note: Tomorrow I'll start posting more details about the Society's visits and discussion with Congress this week. There is lots to talk about.
Title: Re: Proposed Europa Missions
Post by: robertross on 05/16/2013 11:50 AM
http://www.planetary.org/blogs/casey-dreier/2013/20130515-nasa-steals-back-money-from-planetary-science.html

NASA Robs Planetary Science
Leaked document shows NASA funding other programs with planetary money

...

UNreal

Quote
Note: Tomorrow I'll start posting more details about the Society's visits and discussion with Congress this week. There is lots to talk about.

don't know how to take that (hopefully it isn't too bad), but looking forward to it!
Title: Re: Proposed Europa Missions
Post by: Star One on 05/16/2013 05:26 PM
That's pretty outrageous no doubt the fall out on it is going to be something to follow.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/05/2013 10:05 PM
July 15-16 is the meeting of the Outer Planets Assessment Group in Washington, DC. OPAG provides advice on outer planets missions to NASA. The Europa Clipper mission is going to be discussed. You should be able to listen in via the web:

http://www.lpi.usra.edu/opag/

http://www.lpi.usra.edu/opag/jul2013/agenda.pdf

OPAG Agenda
July 15-16
Monday theme: where are we today
9:00 am Intro, welcome and objectives (Candy Hansen)
9:15 NASA PSD report, incl. responses to OPAG findings
(Jim Green)
10:15 Outer planets report, incl. JUICE (Curt Niebur)
10:30 Break
10:45 PSS Report (Janet Luhmann)
11:00 Europa Clipper update–Instrument development funding (Curt Niebur)
–Other progress (Bob Pappalardo & Barry Goldstein)
12:15 Destination Europa (Brittney Schmidt)
Title: Re: Proposed Europa Missions
Post by: JohnFornaro on 07/06/2013 01:59 PM
Appreciate your commentary on all this. I've been sitting here catching up on the posts.

Going back to your previous comments on all this, and the pace of SLS and such, I'm now getting into a position where I am accepting of a slow down on these massive & costly missions to protect the overall Planetary Science community. JWST should have taught us all a valuable lesson: we can't afford it all (even being a Canadian looking at these massive American budgetary requests).

It's not as if Europa is going anywhere.

Ditto on the appreciation, JWST's not-lesson, and the stability of Europa's future orbit.

The prioritization of these proposed missions is flawed in that the question, "What's the rush?" is not satisfactorily addressed, at least by my take.

I keep beating the MSR drum as an example of the "hurried" approach:  What's the rush?  MSR has been seen as high priority for many years, but the knowledge learned in the meantime has fundamentally changed the thinking on where to look.

Here we are, still looking for life on Mars, with equipment that can still be perfected, and with several more locations yet to be searched.  Are there not lessons still to be learned on how to conduct the search for a second genesis of life?  How can it be that it is already known how to do this on Europa?

We should not have flagship missions if we are not prepared for them.
Title: Re: Proposed Europa Missions
Post by: ClaytonBirchenough on 07/06/2013 04:23 PM
Thanks Blackstar for the wealth of information! Makes for a good read...
Title: Re: Proposed Europa Missions
Post by: grondilu on 07/08/2013 07:11 PM
It seems that lake Vostok is indeed full of life.

http://io9.com/new-evidence-antarctica-s-ancient-ice-covered-lake-is-706010511

Hopefully this will encourage space agencies around the world to actually send a probe to Europa.
Title: Re: Proposed Europa Missions
Post by: baldusi on 07/08/2013 07:26 PM
It seems that lake Vostok is indeed full of life.

http://io9.com/new-evidence-antarctica-s-ancient-ice-covered-lake-is-706010511

Hopefully this will encourage space agencies around the world to actually send a probe to Europa.
It might. But please remember that Earth was completely covered by ice at least twice in history. Thus, terran life developed without ice but was selected to survive. The Europan case is completely different. But most important, to reach the actual Europan ocean is currently not feasible, much less affordable. Currently we'd be extremely happy with an orbiter, and periodic flybys would put a smile on every single related scientist.
Only then we can thing of landing, and only after landing a couple of times (successfully) can we think if it's even possible to drill deep enough. Regrettably, that's at least a century away.
Title: Re: Proposed Europa Missions
Post by: EE Scott on 07/08/2013 07:35 PM
July 15-16 is the meeting of the Outer Planets Assessment Group in Washington, DC. OPAG provides advice on outer planets missions to NASA. The Europa Clipper mission is going to be discussed. You should be able to listen in via the web:

http://www.lpi.usra.edu/opag/

http://www.lpi.usra.edu/opag/jul2013/agenda.pdf

OPAG Agenda
July 15-16
Monday theme: where are we today
9:00 am Intro, welcome and objectives (Candy Hansen)
9:15 NASA PSD report, incl. responses to OPAG findings
(Jim Green)
10:15 Outer planets report, incl. JUICE (Curt Niebur)
10:30 Break
10:45 PSS Report (Janet Luhmann)
11:00 Europa Clipper update–Instrument development funding (Curt Niebur)
–Other progress (Bob Pappalardo & Barry Goldstein)
12:15 Destination Europa (Brittney Schmidt)

Great stuff, I look forward to it. Thx for letting us know.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/08/2013 10:11 PM
July 15-16 is the meeting of the Outer Planets Assessment Group in Washington, DC. OPAG provides advice on outer planets missions to NASA. The Europa Clipper mission is going to be discussed. You should be able to listen in via the web:

http://www.lpi.usra.edu/opag/

http://www.lpi.usra.edu/opag/jul2013/agenda.pdf

OPAG Agenda
11:00 Europa Clipper update–Instrument development funding (Curt Niebur)

Great stuff, I look forward to it. Thx for letting us know.

All of this should be web broadcast, but I cannot find any evidence of that. They might not post the link until just before the meeting.

Funny note: if you watch the movie "Europa Report" you'll see that Curt Niebur was one of the consultants. However, they misspelled the poor guy's name!
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/08/2013 10:16 PM
But most important, to reach the actual Europan ocean is currently not feasible, much less affordable. Currently we'd be extremely happy with an orbiter, and periodic flybys would put a smile on every single related scientist.
Only then we can thing of landing, and only after landing a couple of times (successfully) can we think if it's even possible to drill deep enough. Regrettably, that's at least a century away.

Yeah. That's something that gets lost in just about every popular article about Europa spacecraft and particularly the submarines. They will discuss the oceans, the possibility of life, and then include an artist impression of the submarine. Members of the public see that and think "That would be REALLY COOL!" But nobody bothers to explain that the technology to do this is way way out there, not to mention the budget and policy concerns.

I imagine that somebody who works on this stuff has probably developed a crude roadmap for Europa exploration, listing the things that need to be done and a notional timeline. We know that a Europa flyby or orbiter mission will not happen for the next ten years, and even if it gets prioritized in the early 2020s it will not get built and launched until the late 2020s, meaning it won't reach Europa until the mid-2030s. You can work out things from there. We're 20 years away from at least getting a close-up look at Europa.

Well, except for JUICE.
Title: Re: Proposed Europa Missions
Post by: Star One on 07/09/2013 07:36 AM
I am hoping that the Russian's can get things resolved in time & I know it is a big if, to get their Ganymede lander onto the JUICE mission.

It feels like at least ESA is showing some drive in outer planetary exploration which is more than it seems NASA can manage these days who instead are more than willing to go along with a cut in their planetary budget.

Sorry for the rant but I get rather steamed up by this whole situation on the planetary budget at the moment. :)
Title: Re: Proposed Europa Missions
Post by: grondilu on 07/10/2013 06:21 PM
http://www.scientificamerican.com/article.cfm?id=new-space-engines-interplanetary

« The scientists and engineers are developing a new plasma propulsion system designed for ultrasmall CubeSats. If all goes well, they say, it may be possible to launch a life-detection mission to Jupiter's ocean-harboring moon Europa or other intriguing worlds for as little as $1 million in the not-too-distant future. »
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/10/2013 07:16 PM
http://www.scientificamerican.com/article.cfm?id=new-space-engines-interplanetary

« The scientists and engineers are developing a new plasma propulsion system designed for ultrasmall CubeSats. If all goes well, they say, it may be possible to launch a life-detection mission to Jupiter's ocean-harboring moon Europa or other intriguing worlds for as little as $1 million in the not-too-distant future. »

I read an earlier version of this and to put it mildly it all seemed like total B S to me. They haven't even flown anything, and yet they're talking about super cheap spacecraft operating in one of the most difficult environments that exist? What's the power source at Europa? How do they deal with radiation? How can they afford any instruments at all and do all this for $1 million?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 12:31 AM
The latest on Europa Clipper. Note the new spacecraft configuration on slide 12 (there is no slide 10).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 12:32 AM
Here's the new configuration as two separate slides.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 12:34 AM
Here's some information on using SLS for the Europa Clipper mission.
Title: Re: Proposed Europa Missions
Post by: robertross on 07/26/2013 02:12 AM
The latest on Europa Clipper. Note the new spacecraft configuration on slide 12 (there is no slide 10).

Thank you Sir!

15kg (at this stage of the game) isn't too bad a savings.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 07/26/2013 02:46 AM
Thanks Blackstar. You're a champion.

Cool new stacked design. Makes sense.

I'm excited about the close up shots with the recon camera.  :)

All this time being taken to refine the mission seems to be paying off. The science objectives, the mission con ops, the spacecraft design.

I like how the stacked design allows it to be built in segments and then plugged together. Hopefully this modular approach creates a better funding profile.

Which module first? The avionics module with the vault? I assume the lower propulsion module will be last as the ASRGs will not be available for a while.

Seems like the orbit has possible encounters for Callisto and Ganymede. Might be an option for an extended mission if there's extra power.
Title: Re: Proposed Europa Missions
Post by: EE Scott on 07/26/2013 03:28 AM
So exciting the possibility, so remote the chance.  Still I'll allow myself to believe it could happen.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 12:48 PM
I think that the likely power source would be an MMRTG. NASA is building another one for Mars 2020, which maintains the experience/production base.

NASA is building/has built (my guess is that they are majority complete) two ASRG units that will be placed in "bonded storage" (what the heck does "bonded" mean in this context?). The problem is that the ASRGs would not be flight proven before this mission would enter build phase--although who knows when that will be? So I think that NASA would take the most conservative option and go with the MMRTG for a multi-billion dollar mission.
Title: Re: Proposed Europa Missions
Post by: robertross on 07/26/2013 12:54 PM

NASA is building/has built (my guess is that they are majority complete) two ASRG units that will be placed in "bonded storage" (what the heck does "bonded" mean in this context?).


Just 'secure' I beleive, but perhaps even with armed security. We see a lot of that here in Halifax with all the container traffic.
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 07/26/2013 07:37 PM
NASA is building/has built (my guess is that they are majority complete) two ASRG units that will be placed in "bonded storage" (what the heck does "bonded" mean in this context?). The problem is that the ASRGs would not be flight proven before this mission would enter build phase--although who knows when that will be?


Maybe they can test fly the ASRG unit and recover it for refueling with a space capsule.
Title: Re: Proposed Europa Missions
Post by: EE Scott on 07/26/2013 07:44 PM
I think that the likely power source would be an MMRTG. NASA is building another one for Mars 2020, which maintains the experience/production base.

NASA is building/has built (my guess is that they are majority complete) two ASRG units that will be placed in "bonded storage" (what the heck does "bonded" mean in this context?). The problem is that the ASRGs would not be flight proven before this mission would enter build phase--although who knows when that will be? So I think that NASA would take the most conservative option and go with the MMRTG for a multi-billion dollar mission.


Any idea what (or when) the first ASRG-equipped mission might be? 

Someone's got to step up and just do it so we can get a better idea of its true performance potential.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 08:44 PM
Maybe they can test fly the ASRG unit and recover it for refueling with a space capsule.


No.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 08:47 PM
Any idea what (or when) the first ASRG-equipped mission might be? 

Someone's got to step up and just do it so we can get a better idea of its true performance potential.

The next real opportunity will be with the next Discovery or New Frontiers selection. I think that the next Discovery selection is not slated to happen before 2016 and the next New Frontiers before 2017 or so. But both are going to slip because of ongoing budget cuts. And even if such a mission was selected, it would take five or more years to build the spacecraft, so we won't see an ASRG mission fly in this decade.

The last Discovery selection included three potential missions. Two required ASRGs and the third was conventional. That one, InSight, was selected, probably because it was the least risky of the three missions.

There are people inside of NASA who were pushing for an ASRG mission, but they did not win out.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/26/2013 08:49 PM

NASA is building/has built (my guess is that they are majority complete) two ASRG units that will be placed in "bonded storage" (what the heck does "bonded" mean in this context?).


Just 'secure' I beleive, but perhaps even with armed security. We see a lot of that here in Halifax with all the container traffic.

I'm guessing that it means storage in clean-room/controlled conditions, as opposed to being stuck in a warehouse. NASA kept the DSCOVR spacecraft in a temp and humidity controlled container at Goddard for many years, I believe, before retrieving it for refurbishment.
Title: Re: Proposed Europa Missions
Post by: robertross on 07/27/2013 12:44 AM

NASA is building/has built (my guess is that they are majority complete) two ASRG units that will be placed in "bonded storage" (what the heck does "bonded" mean in this context?).


Just 'secure' I beleive, but perhaps even with armed security. We see a lot of that here in Halifax with all the container traffic.

I'm guessing that it means storage in clean-room/controlled conditions, as opposed to being stuck in a warehouse. NASA kept the DSCOVR spacecraft in a temp and humidity controlled container at Goddard for many years, I believe, before retrieving it for refurbishment.

not the typical definition of bonded storage; it would need to state that explicitely (or be clean room/controlled by default with the added feature of being in bonded storage).

Bonded is essentially lock & key with tamperproof features to ensure no tampering is possible without someone knowing about it.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/27/2013 02:36 AM
not the typical definition of bonded storage; it would need to state that explicitely (or be clean room/controlled by default with the added feature of being in bonded storage).

Bonded is essentially lock & key with tamperproof features to ensure no tampering is possible without someone knowing about it.

Well, I'm presuming that because it is nuclear-related materials that there are certain restrictions applied to it. So, yeah, locked up, but probably also environmentally controlled as well.

On a tangentially-related note, I heard a story several years ago from a now-former NASA official about the remaining supply of Neptunium that would be used to create Pu-238 fuel. Apparently this guy ordered a NASA official to go and slap NASA inventory numbers on the containers filled with this fuel. He didn't want some DoE person to come along and assume that it was just DoE material and discard it. I'm sure that he did something, but I found the story to be a little hard to compute, because I'm pretty sure that NASA does not own that material and in fact is probably not allowed under law to own it, so I don't know how NASA could label it. But it's in a secure DoE warehouse somewhere, probably next to the Ark of the Covenant and Jimmy Hoffa's frozen corpse.
Title: Re: Proposed Europa Missions
Post by: EE Scott on 07/27/2013 02:59 AM
Any idea what (or when) the first ASRG-equipped mission might be? 

Someone's got to step up and just do it so we can get a better idea of its true performance potential.

The next real opportunity will be with the next Discovery or New Frontiers selection. I think that the next Discovery selection is not slated to happen before 2016 and the next New Frontiers before 2017 or so. But both are going to slip because of ongoing budget cuts. And even if such a mission was selected, it would take five or more years to build the spacecraft, so we won't see an ASRG mission fly in this decade.

The last Discovery selection included three potential missions. Two required ASRGs and the third was conventional. That one, InSight, was selected, probably because it was the least risky of the three missions.

There are people inside of NASA who were pushing for an ASRG mission, but they did not win out.

Thanks for your thoughts on this.  The pace of progress is maddening to me.  There are so many promising ways to stretch resources, like ASRG, or aero capture/braking, etc.  But if we don't fly the first mission to try out these new technologies and techniques, we are stuck with the same capabilities.  I guess we don't even have the budget to choose a decent amount of conventional mission profiles, let alone something that pushes the boundaries.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/27/2013 02:01 PM
The pace of progress is maddening to me.  There are so many promising ways to stretch resources, like ASRG, or aero capture/braking, etc.  But if we don't fly the first mission to try out these new technologies and techniques, we are stuck with the same capabilities.  I guess we don't even have the budget to choose a decent amount of conventional mission profiles, let alone something that pushes the boundaries.



With the Discovery program NASA had three mission options:

-TiME (Titan lake lander), ASRG, probably the most expensive of the missions
-Comet Hopper, ASRG, probably medium expensive
-InSight, Mars lander, solar panels, proven hardware

When I say "expensive," you have to understand that Discovery is cost-capped. That means that technically, all three mission proposals cost the same (~$475 million, I think). But TiME and Comet Hopper were more likely to go over budget than InSight.

When we say that we want NASA to take more risk, we also need to understand that we (or Congress, people in general) are just as likely to criticize those decision-makers when things don't go perfectly. So when TiME went over budget, people would complain and call for the leadership to be punished/fired, etc.

In addition, NASA's planetary budget was going down. In that environment, the safest course of action is to pick the cheapest mission, or at least the one that is unlikely to bust its cost cap.
Title: Re: Proposed Europa Missions
Post by: EE Scott on 07/29/2013 01:49 AM
The pace of progress is maddening to me.  There are so many promising ways to stretch resources, like ASRG, or aero capture/braking, etc.  But if we don't fly the first mission to try out these new technologies and techniques, we are stuck with the same capabilities.  I guess we don't even have the budget to choose a decent amount of conventional mission profiles, let alone something that pushes the boundaries.



With the Discovery program NASA had three mission options:

-TiME (Titan lake lander), ASRG, probably the most expensive of the missions
-Comet Hopper, ASRG, probably medium expensive
-InSight, Mars lander, solar panels, proven hardware

When I say "expensive," you have to understand that Discovery is cost-capped. That means that technically, all three mission proposals cost the same (~$475 million, I think). But TiME and Comet Hopper were more likely to go over budget than InSight.

When we say that we want NASA to take more risk, we also need to understand that we (or Congress, people in general) are just as likely to criticize those decision-makers when things don't go perfectly. So when TiME went over budget, people would complain and call for the leadership to be punished/fired, etc.

In addition, NASA's planetary budget was going down. In that environment, the safest course of action is to pick the cheapest mission, or at least the one that is unlikely to bust its cost cap.

Yes.  In this budget environment, I should just be happy if we can get conservative missions funded. Even though I would love to see TiME chosen as a bonus mission (Senate proposal), or this Europa mission become reality. Because if there is some strange way the SLS fiasco could somehow be of use, because they are desperate  for missions/payloads using SLS, that would be a consolation.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/29/2013 07:07 PM
http://thespacereview.com/article/2338/1



Talk of an icy moon at Vegas for Nerds
by Dwayne Day
Monday, July 29, 2013

Every July a hundred and thirty thousand people descend upon San Diego for Comic-Con, an event best described as “Las Vegas for nerds.” There are thousands of events that take place both inside and outside the San Diego Convention Center over four days, some exclusive, some open to anybody who walks in. One of the more difficult to reach venues is the convention center’s Hall H, which can seat more than 6,000 people, and is the stage for most of the biggest-hyped and popular panels at Comic-Con, such as the ones where major Hollywood movies are rolled out and big name movie stars and directors unveil their new productions. Getting into Hall H often requires standing in line for many hours starting out in the early morning, or even sleeping on the lawn outside the Convention Center overnight—something you can do in your teens and twenties, but can strain the backs of people older than that. In all my years of going to Comic-Con I’ve never tried to get into Hall H, but last week Thursday I gave it a shot and easily got into the panel for the new movie Europa Report. The movie premieres in theaters August 2, but is already available via download or on demand (see “Life and death and ice”, The Space Review, July 1, 2013).
Title: Re: Proposed Europa Missions
Post by: simonbp on 07/29/2013 08:29 PM
With the Discovery program NASA had three mission options:

-TiME (Titan lake lander), ASRG, probably the most expensive of the missions
-Comet Hopper, ASRG, probably medium expensive
-InSight, Mars lander, solar panels, proven hardware

From the scuttlebutt around the time of the decision, it sounded like the breakdown was more:

- TiME: Low technical risk (essentially a reflight of Huygens hardware with an added ASRG), high science risk (not much data returned, risk of landing somewhere where the terrain impedes downlink).

- Comet Hopper: High technical risk (no one has ever landed on an comet), low science risk (no one has ever landed on an comet, anything is new)

- Insight: Low technical risk (Phoenix reflight), low science risk (it will return data, just not necessarily high-priority data)

Based on that, Insight had the lowest technical and science risk, and therefore was least likely to go overbudget. Plus, it's not a confidence that they announced Insight shortly after MSL landed...

For Europa, IMHO that means that the solar option may come to the fore. Assuming the solar arrays on Juno work well (and keeping in mind its periapse is much closer to Jupiter than Io), the JPL margin on them may come down enough that they are similar mass to the RTGs (and still lowest cost).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/29/2013 08:40 PM
- TiME: Low technical risk (essentially a reflight of Huygens hardware with an added ASRG)

I have a hard time believing that it was a reflight of Huygens hardware. For starters, this was a U.S. mission and Huygens was built by ESA. But I know somebody who was on TiME and Huygens and can ask him.
Title: Re: Proposed Europa Missions
Post by: arachnitect on 07/30/2013 01:22 AM

Based on that, Insight had the lowest technical and science risk, and therefore was least likely to go overbudget. Plus, it's not a confidence that they announced Insight shortly after MSL landed...


IIRC, they had already made the decision before MSL reached mars and were sitting on it so that the Discovery announcement wouldn't get lost in the MSL excitement.

When they explained the selection, I got the impression that the science return from all 3 proposals was considered very good and technical maturity/low risk alone sealed the deal for InSight.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2013 01:27 AM
I got the impression that the science return from all 3 proposals was considered very good and technical maturity/low risk alone sealed the deal for InSight.

There's a challenge with that. How do we rate the science return? According to NASA, the science return for all three missions was rated as "high," and therefore they were equal in terms of science. I know a highly respected space scientist who thought that all three were high value science missions.

But the value of that science also depends upon who is doing the valuing. I think that seismology is not rated highly by many scientists because they consider it to be narrow. So even though InSight would be the first seismic data from Mars, I don't think many scientists care. The flip side is that although we've never actually sampled a comet's surface, the group of scientists interested in primitive bodies like comets is isolated from the group that is interested in things like Mars habitability.

So it's not easy to make these comparisons.
Title: Re: Proposed Europa Missions
Post by: neveroddoreven on 07/30/2013 03:49 PM
So, currently the notional launch vehicle for this clipper would be the Atlas V 551. Using this vehicle the thing would have to use a VEEGA trajectory and end up taking six and a half years to get to Europa. Then they are talking about SLS as an alternative which would enable a direct route that would take less than 2 years, but we all know that them using SLS on this mission is unlikely. Well, looking at Falcon Heavy's new payload to GTO of 21,200 kg (relative to 551's 8,700kg) and payload to Mars of 13,500 kg (not sure what 551's is here, but I'm assuming significantly lower) I was wondering if it would be a feasible option as well. Would it be capable of a direct route like SLS or would it not have the power? If direct isn't possible could you use a trajectory different than VEEGA like VEGA or VGA to cut down on time or would the position of the planets not allow for such a trajectory?

On top of a possibly shorter trip Falcon Heavy would be significantly cheaper as well. They are listing it as costing $133 million whereas wiki says the 541 (couldn't find a price for the 551) is $223 million.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2013 04:24 PM
On top of a possibly shorter trip Falcon Heavy would be significantly cheaper as well. They are listing it as costing $133 million whereas wiki says the 541 (couldn't find a price for the 551) is $223 million.

I don't want to get into a tiresome discussion of launch vehicles and their costs, but I'd just caution that you cannot make these comparisons using that available data. There are several reasons:

--FH is not operational

--the publicly quoted SpaceX costs are not the actual costs to NASA because they leave stuff out*

--FH is not rated for carrying Pu-238**



These back of the envelope comparisons are not that precise.


*(Hey, look! A footnote!) There's an explanation for this that you might be able to find if you dig around on this site for hours. But it basically comes down to the fact that there are a lot of payload processing, vehicle-unique mods, and other things that are not included in the website costs of SpaceX's rockets. If you want a better idea of actual costs, you need to look at NASA's stated costs for their launch services contract, which puts everything on the same baseline. But the bottom line is that the numbers are closer than you've stated. Of course, assuming that FH works as advertised, you'd get a lot more payload capability probably at equal or lesser price to a big Atlas, so it might still be a deal.

**(Hey, look! Another footnote!) It costs a decent amount of money to do all the assessments to certify a vehicle to carry Pu-238. That cost is already sunk for Atlas. Falcon 9 or FH would have to undergo the same certification. There has been some talk of eventually doing that, but NASA's (eminently logical) position right now is that it's premature to think about this until the rocket has started flying and demonstrated some reliability and lots and lots of data.

Title: Re: Proposed Europa Missions
Post by: neveroddoreven on 07/30/2013 04:40 PM
Ah, okay. I wasn't aware that vehicles had to be rated to carry Pu 238.

Also, sorry if my comment was a bit too OT. I was just curious about the advantages that a different launch vehicle could bring to the mission.
Title: Re: Proposed Europa Missions
Post by: baldusi on 07/30/2013 08:08 PM
I think that the 2020 rover studies had pegged the Atlas 551 cost for nasa at 320M, if I recall correctly. I also think I heard that the marginal cost of an SLS launch would be around 400M or so. For this mission the marginal cost might be closer to 500M. But still not such a huge difference. I mean, that's 180M, but you save four years of operations, which might well be around 80M. 100M is a lot of dough for SMD, but if Congress would want to actually use the rocket, I think it's feasible, albeit rather improbable.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2013 10:10 PM
1-Ah, okay. I wasn't aware that vehicles had to be rated to carry Pu 238.

2-Also, sorry if my comment was a bit too OT. I was just curious about the advantages that a different launch vehicle could bring to the mission.

1-They have to be certified as a vehicle. Then each launch has to be individually certified (because of specific configurations, trajectories, the payloads, etc.). I heard what this would cost, but have forgotten. I think that the overall vehicle certification is a few tens of millions of dollars and the individual launch certification is (maybe?) less than $10 million. It is surprisingly expensive, but it's an exhaustive engineering analysis.

2-Not completely off topic. It's just that too many people on NSF tend to treat every issue as if it's a rocket issue and they don't care about payloads, which is not how people in the space business look at stuff (it's not how you get there, it's what you're going to do there).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2013 10:16 PM
I think that the 2020 rover studies had pegged the Atlas 551 cost for nasa at 320M, if I recall correctly. I also think I heard that the marginal cost of an SLS launch would be around 400M or so. For this mission the marginal cost might be closer to 500M. But still not such a huge difference. I mean, that's 180M, but you save four years of operations, which might well be around 80M. 100M is a lot of dough for SMD, but if Congress would want to actually use the rocket, I think it's feasible, albeit rather improbable.

It's not going to trade off that easily. For starters, NASA and the science community have experience with the Atlas. They're used to it. How many unique issues will they have to address if they go to an entirely different booster? For instance, Atlas is certified to carry Pu-238 missions, SLS would have to be certified. That's money.

I know that I'm going to sound strident on this topic, but when I'm not working directly in this subject area I'm at least hovering around the edges and talking to people who work directly in it, and there's almost zero interest in the planetary science community in hitching a ride on an SLS. Yeah, it could offer all kinds of advantages, but there are a lot of hidden pitfalls that people are wary of as well (like will the rocket still exist by the time you expect the mission to require it?). There is really only one person I know who is pushing the idea, and although he's really well-qualified and knowledgeable, I don't know of anybody else who agrees with him. So I cringe whenever I see an article that doesn't provide all kinds of qualifiers about how an SLS is unlikely to ever be used for such a mission.

That said, the idea is probably worth studying at a very low level, although there's still a risk that people will take it seriously and start shoving the program in that direction. That would be non-good.
Title: Re: Proposed Europa Missions
Post by: baldusi on 07/30/2013 10:47 PM
I didn't state that the actual scientists were interested. I just stated that the price difference might not be that huge as we used to think. I started thinking the launch would be an additional 1B or so. And who know, may be after doing trades the exploration program considers that certifying SLS for PU-238 is worth it, so they wouldn't charge it to SMD. May be they need an instrument to be left on an asteroid, or something. Those engineering works at MFSC are very politically viable.
And, regrettably, you have to actually get your money appropriated by Congress. And may be, just may be, they might the authorization for this flagship mission on the condition that it flies on SLS. A purely political decision, but it wouldn't be the first time that Congress forces NASA to use a "flagship" LV to launch a flagship mission even if it would actually cost more. And of course they will still try to lower the overall budget.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2013 11:26 PM
And who know, may be after doing trades the exploration program considers that certifying SLS for PU-238 is worth it, so they wouldn't charge it to SMD.

If NASA had a viable exploration program, they would certainly certify SLS for Pu-238 on their own at some point. Previous lunar exploration studies included RTGs for emergency backup power for the lunar outpost. I just cannot see them spending that money when they don't have a clear requirement.
Title: Re: Proposed Europa Missions
Post by: baldusi on 07/31/2013 02:41 AM
What would be the timeframe for an actual decision on this? I certainly wouldn't expect the Clipper mission to be given a go ahead before 2018. So many thing will happen in this four years wrt SLS, the political landscape, the LV fleet, the ISS, etc. That, even though I'm not saying it will happen, I do say that not impossible, merely that it would be extremely unlikely. As stated before, assuming that the SMD gets to do a flagship after JWST and the 2020 Mars Rover, it would be the cheapest possible payload for SLS. Not cheaper exactly, but if you look at it from an SLS supporter, say a Congressman, you're already doing the flagship, so if you put as little as 200M estra, you'd get an extra SLS launch, and you can say that its even used for flagship missions. It's, from that point of view, even cheaper than an Orion. And they might even put the very budget for the mission as a condition on using SLS. Again, assuming that by the time this is decided the SLS is a reality and theres a clear path in exploration to assure it's existence going forward. If Europa gets authorized in 2018, it would be expected to launch by 2024/5? that might work well with current exploration proposals. USA will have to recuperate its economy, eventually.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/31/2013 05:05 PM
What would be the timeframe for an actual decision on this?

An honest answer, based upon my analysis skills and not any real information (because there is no real information--nobody knows what is going to happen in 2014, 15, 16, 17 or 18) is that there will be no new-start on a Europa mission until after the next planetary science decadal survey, which will probably start in 2018 and produce a report by 20 or 21.

That's based upon reading tea leaves. Right now there is actually insufficient money in the NASA budget to do the Mars 2020 rover on time. And the administration is continuing to cut money out of the planetary sciences budget. Given that reality, there is no way that another flagship-class planetary mission is going to be approved before the current one (Mars 2020) is essentially paid for and ready to launch.

There's also a nasty little dynamic that happens in these things, which is that Washington lives by the saying "Why put off today what you can put off tomorrow?" As we get farther from the 2011 decadal survey, and nearer to the start of the next decadal survey, the decision makers will decide to defer any decisions in order to wait and hear what the decadal survey will say. In other words, even if the next president puts a lot more money into planetary science in 2017 or 2018, people will say "We should not start a new big mission until we hear what the scientists say in 2021..." And so the decision could easily get delayed from 2018 until 2022.

Something similar happened during the last round. NASA could have started working on the Europa mission. But they ended up deferring that work to wait for the decadal survey. (Note: that probably was not a bad idea, because the Europa mission being discussed in 2008 was too expensive and really needed to be de-scoped.)

Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/03/2013 03:55 PM
Some current papers on Europa Clipper and Europa Lander.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/03/2013 03:58 PM
http://www.jpl.nasa.gov/news/news.php?release=2013-243&cid=release_2013-243

If We Landed on Europa, What Would We Want to Know?
August 07, 2013

Most of what scientists know of Jupiter's moon Europa they have gleaned from a dozen or so close flybys from NASA's Voyager 2 spacecraft in 1979 and NASA's Galileo spacecraft in the mid-to-late 1990s. Even in these fleeting, paparazzi-like encounters, scientists have seen a fractured, ice-covered world with tantalizing signs of a liquid water ocean under its surface. Such an environment could potentially be a hospitable home for microbial life. But what if we got to land on Europa's surface and conduct something along the lines of a more in-depth interview? What would scientists ask? A new study in the journal Astrobiology authored by a NASA-appointed science definition team lays out their consensus on the most important questions to address.

"If one day humans send a robotic lander to the surface of Europa, we need to know what to look for and what tools it should carry," said Robert Pappalardo, the study's lead author, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "There is still a lot of preparation that is needed before we could land on Europa, but studies like these will help us focus on the technologies required to get us there, and on the data needed to help us scout out possible landing locations. Europa is the most likely place in our solar system beyond Earth to have life today, and a landed mission would be the best way to search for signs of life."

The paper was authored by scientists from a number of other NASA centers and universities, including the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.; University of Colorado, Boulder; University of Texas, Austin; and the NASA Goddard Space Flight Center, Greenbelt, Md. The team found the most important questions clustered around composition: what makes up the reddish "freckles" and reddish cracks that stain the icy surface? What kind of chemistry is occurring there? Are there organic molecules, which are among the building blocks of life?

Additional priorities involved improving our images of Europa - getting a look around at features on a human scale to provide context for the compositional measurements. Also among the top priorities were questions related to geological activity and the presence of liquid water: how active is the surface? How much rumbling is there from the periodic gravitational squeezes from its planetary host, the giant planet Jupiter? What do these detections tell us about the characteristics of liquid water below the icy surface?

"Landing on the surface of Europa would be a key step in the astrobiological investigation of that world," said Chris McKay, a senior editor of the journal Astrobiology, who is based at NASA Ames Research Center, Moffett Field, Calif. "This paper outlines the science that could be done on such a lander. The hope would be that surface materials, possibly near the linear crack features, include biomarkers carried up from the ocean."

This work was conducted with Europa study funds from NASA's Science Mission Directorate, Washington, D.C. JPL is a division of the California Institute of Technology, Pasadena.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2013 07:13 PM
Ta da.
Title: Re: Proposed Europa Missions
Post by: Star One on 09/04/2013 07:43 PM
In your opinion which would be the best power source for it to use & does this differ from the power source it is most probable to end up with?
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/04/2013 07:50 PM
Why was the ASRG taken out of the option space?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2013 09:27 PM
Why was the ASRG taken out of the option space?

Complexity. They needed to narrow down the options and could not keep studying three, so they went down to two and got rid of the most complex one.

Interesting trades with solar. It is heavier, but cheaper. Batteries drive the mass.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/04/2013 10:19 PM
Why was the ASRG taken out of the option space?

Complexity. They needed to narrow down the options and could not keep studying three, so they went down to two and got rid of the most complex one.

Interesting trades with solar. It is heavier, but cheaper. Batteries drive the mass.
Aren't solar cells more sensitivo to radiation? Is there a trade off in expected life? Or will they destructivelly end to avoid danger or contaminatin Europa?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/05/2013 01:36 AM
Aren't solar cells more sensitivo to radiation? Is there a trade off in expected life? Or will they destructivelly end to avoid danger or contaminatin Europa?

Yes. Yes. Yes.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/05/2013 06:05 PM
Some more.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/05/2013 06:14 PM
Now that they got me thinking. Couldn't this mission help a lot in the understanding of Earth's processes? Because you tend to do lineal models and/or taking first order processes, but when investigating other solar bodies you start to understand extremes and secondary and/or tertiary processes that can refine greatly your understanding of Earth.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/06/2013 05:25 PM
Some more.
Title: Re: Proposed Europa Missions
Post by: EE Scott on 09/06/2013 07:29 PM
Great stuff!  Europa is such an exciting target (as are the other Jovian moons); so much potential low hanging fruit here that could be just mind blowing.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/06/2013 08:40 PM
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/06/2013 08:44 PM
Just for the sake of inquiring. Couldn't a Gainymede or Callisto probe be an exact replica? Yes, it would be overbuilt for the radiation environment. And it would overstep with JUICE. But may be doing a second copy from the beginning, specially a solar powered one, would be particularly cheap. And may be it wouldn't need all the instruments.
Title: Re: Proposed Europa Missions
Post by: vjkane on 09/07/2013 05:29 AM
If we were to build a replica, I'd send it to Titan and Europa (with some different instruments).  Assuming sufficient plutonium, of course.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/07/2013 05:27 PM
If we were to build a replica, I'd send it to Titan and Europa (with some different instruments).  Assuming sufficient plutonium, of course.
Are you aware that Titan is in Saturn, right?
I was wondering basically because each time the experts like Blackstar tells me why not, I learn a lot.
Title: Re: Proposed Europa Missions
Post by: ugordan on 09/07/2013 05:30 PM
If we were to build a replica, I'd send it to Titan and Europa (with some different instruments).  Assuming sufficient plutonium, of course.
Are you aware that Titan is in Saturn, right?

I'm pretty sure (http://futureplanets.blogspot.com/) he is...
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/07/2013 08:56 PM
Just for the sake of inquiring. Couldn't a Gainymede or Callisto probe be an exact replica? Yes, it would be overbuilt for the radiation environment. And it would overstep with JUICE. But may be doing a second copy from the beginning, specially a solar powered one, would be particularly cheap. And may be it wouldn't need all the instruments.

I don't know. Europa Clipper is really tied to its orbit. It might be possible to fly a similar spacecraft to do different orbits at another body, but I'm not sure that the science return would be good. EC actually has to fly very low over Europa to do the radar science, and that's considered a risky move. There is the danger of hitting the moon. And they go into eclipse several times, unlike Juno, meaning that they need batteries during that time.

I think I have a JUICE presentation that I can post here. They are different missions.

Nobody cares much about Callisto. It doesn't rank high for science prioritization.

Title: Re: Proposed Europa Missions
Post by: hello2 on 09/08/2013 11:43 AM
Hi, sorry to intrude on the topic, but I'm a software engineer and I've always been fascinated with robot missions to other planets/moons, especially those towards Mars and Europa. It would be wonderful if I could contribute to the spacecraft/lander software in any way (as a volunteer). Do you know who can I contact? Is there any way to do this? Unfortunately that NASA only hires US citizens, but maybe they don't have such restrictions for volunteers.
Title: Re: Proposed Europa Missions
Post by: spectre9 on 09/08/2013 12:13 PM
I'm starting to come around to the idea of solar panels.

The "toe dip" into the heaviest radiation should give the spacecraft some breathing room.

The only reason I don't like it is the potential to build a great spacecraft bus that could cover all future missions to all the gas giants. Standardize the power, propulsion and tanks and then just change the instrumentation on top.

Then maybe launch on cheap SpaceX rockets.

Outer planets exploration on a budget? Perhaps I'm being too optimistic.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/08/2013 03:02 PM
Here's the rest.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/08/2013 08:44 PM
Now that I'm looking at this mission, it feels like Cassini. In the sense that there are quite a few instruments, that it could probably use some international coolaboration, and that they should apply the market based management system.
Ehat they did with Cassini was to assign three resources to each instrument: mass, power and bandwidth. And their assigned budget. They even put the assigned margins to each group to manage. And they developed a market where any group could trade against any other. So, if you had a mass problem but were under power budget, you could go and trade against somebody who had excess mass margin but needed some extra watts. And if you had none, you could apply your budget margin and go buy margin from some other group. And the master stroke: you could donate any of your margins to any other instrument that was above their budgets but you were interested in their data (probably because the data was complementary, like mass estimations and diameter estimation that allow for density estimation).
The way I'm looking at this if they don't apply it, it would be a shame.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/08/2013 09:41 PM
That could work. But it's really premature. You don't do something like that until you enter development. This project has not even been approved, and there might be better ways to manage it than what they did with Cassini.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/09/2013 01:15 AM
I'm an economist and Cassini used a market based solution, I can't avoid rooting for it  ;)
The other part that surprises me is the price difference with the SLS launch. Just 150M for a flagship and getting your data back much sooner to feed the next proposal is very interesting. And, as I speculated before, Congress might be more than happy to use an additional SLS for relative little money and with a certain advantage, it could be politically viable. In particular, those congressmen might still be in office by the time it arrives if launched in SLS. I know, that number might be pure wishful thinking, and the science team themselves might not care, but, Congress has forced worse things due to political influence.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/09/2013 02:30 AM
The other part that surprises me is the price difference with the SLS launch. Just 150M for a flagship and getting your data back much sooner to feed the next proposal is very interesting.

My impression is that most of the people involved in defining the Europa mission do not want anything to do with SLS. The reason is that Atlas (and Delta) is a known vehicle. It is something they are familiar with. There's a lot of data on how the rocket performs, what it costs, what it can do. If they were given a go-ahead to build Europa Clipper tomorrow (which is not going to happen) they can easily design to an Atlas V. They cannot do that for an SLS.

There are a lot of other issues too. For one thing, you can count on the Atlas V being around for at least another 10-20 years. So it is a guaranteed ride. That's not true for SLS, which could be canceled next year or in five years. Nobody in their right mind would want to bank on that.

And then there's the nasty issue of cost. Who is going to pay for the rocket? Right now, the planetary division has to pay for its own launch vehicles. So they want the least expensive one they can get that will do the job. If they have to pay an extra $150 million for a launch vehicle, they are going to ask what else they could do with that money. Could it go for better instruments? Or more science?

There's another tough thing to try and explain, but saving time getting to Jupiter doesn't necessarily benefit you in many ways, because there is no Jupiter program guaranteeing future missions, unlike Mars. For Mars, you fly a mission, get the data back, and then design a new mission. Mars is a campaign. It is budgeted that way and planned that way. But Jupiter is different, and flying Europa Clipper and getting the data back faster theoretically makes it possible to fly a follow-up mission faster, but there's no program that allows you to do that. And because Jupiter missions are all expensive (billion dollar plus), getting the data back faster and having more time to plan another mission does not mean that you can afford a follow-up mission sooner. So the benefit is really not all that great. Put another way, by using SLS and flying a mission to Europa faster, you may have only increased the waiting time between Europa Clipper and any follow-on mission.

That said, if Europa Clipper found something really interesting on Europa, such as a very active surface indicating thin ice and a lot of activity under the ice, then that could create an argument for flying another mission, such as a lander, as soon as possible. But those are some big what ifs, and that assumes that the science priorities would change. That may not happen at all.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/09/2013 01:56 PM
Here's a presentation on NASA participation in the JUICE mission.

There are some complicated and (I think) interesting aspects to NASA being involved. Part of the issue is that NASA has limited money to provide instruments. Then there's the standard issue that the U.S. may be good at some types of instrumentation, but the Europeans would rather do those things themselves (to build capabilities, help scientific teams, etc.). So there's a lot of back and forth negotiation.

My impression is that the American Europa science community would like to be much more involved in this than they are, but there just isn't the money to do it.
Title: Re: Proposed Europa Missions
Post by: baldusi on 09/09/2013 05:43 PM
I decided to compare the Europa Clipper and the JUICE instruments. Help me here because I'm just comparing the abstracts of each instrument. I've put them in order of how similar they are. Since they are examining the same bodies, I would expect them to have a lot of similar science. On the other hand, since JUICE will be visiting three moons (and barely overflying Europa two times) while EC will concentrate on just one, even if they were identical they'd get different data. And I would expect JUICE to have a couple more instruments, too.

Europa ClipperJUICE
Instrument NameScience TypeSciente TypeInstrument Name
Ice Penetrating Radar (IPR)RadarRadarRIME
Magnetometer (Mag)Magnetometer Magnetometer Magnetometer   Magnetometer   JMAG
Reconnaisance Camera (Recon)CameraCameraCamera   JANUS
Langmuir Probes (LP)PlasmaPlasma & FieldsRadio and Plasma Wave Investigation (RPWI)
Neutral Mass Spectometer (NMS)ParticlesParticlesParticle Environment Package (PEP)
Gravity Science Antenna (GS)GravityGravityRadio Science 3GM
Topographical Imager (TI)TopographyTopographyLaser altimeter   Ganymede Laser Altimeter (GALA)
Shortwave Infrared Spectometer (SWIRS)SW/FIR SpecHeterodyne receiverSubmillimeter Wave Instrument (SWI)
Thermal Imager (Thermal)IR ImageIR Imaging SpectometerMAJIS
UV SpectographUltraviolet Spectograph (UVS)
VLBIPRIDE
One thing that this makes me wonder, is that JUICE is an approved Large Mission. And they'll be there by 2030 (hopefully). I simply don't see Europa Clipper arriving earlier, save for some miracle in SLS use (which you have so clearly assigned an infinitesimal probability). I'm right that Europa clipper might well be a decision for the 2020 Decadal Survey? If so, and given that by that time JUICE is well on track, how do you feel the science community would react? Would they feel that having dual missions to Jupiter would give great synergies and could mean the next big (science) exploration frontier, or that given the data that ESA will bring, it would be better to get at least the info on the two flybys and decide if it's worth it or not?
Title: Re: Proposed Europa Missions
Post by: ugordan on 12/12/2013 04:24 PM
I might as well put this in here...

Via unmannedspaceflight.com comes (IMHO huge) news of the first observations of water plumes on Europa.

Articles:
http://www.nature.com/news/hubble-spots-water-spurting-from-europa-1.14357
http://www.newscientist.com/article/dn24743-first-water-plume-seen-firing-from-jupiter-moon-europa.html

Quote
Now images taken by the Hubble Space Telescope have revealed a large cloud of hydrogen and oxygen – most likely in the form of water vapour – extending from the moon's south pole. A model suggests that it is a plume 200 kilometres high that is spouting 3000 kilograms of water per second.

Paper: http://hubblesite.org/pubinfo/pdf/2013/55/pdf.pdf
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/12/2013 04:25 PM
http://io9.com/massive-plumes-of-water-are-erupting-from-europas-icy-1481376874
Title: Re: Proposed Europa Missions
Post by: Star One on 12/12/2013 07:47 PM
This article from the Washington Post seems to indicate that this discovery increases pressure on NASA to move forward on a Europa mission.

http://www.washingtonpost.com/national/health-science/hubble-space-telescope-sees-geysers-on-jupiters-moon-europa/2013/12/12/b6f780ac-62c8-11e3-a373-0f9f2d1c2b61_story.html?hpid=z5
Title: Re: Proposed Europa Missions
Post by: Danderman on 12/12/2013 08:06 PM
This article from the Washington Post seems to indicate that this discovery increases pressure on NASA to move forward on a Europa mission.

http://www.washingtonpost.com/national/health-science/hubble-space-telescope-sees-geysers-on-jupiters-moon-europa/2013/12/12/b6f780ac-62c8-11e3-a373-0f9f2d1c2b61_story.html?hpid=z5

The implication is that the requirement would be for a Europa Polar Orbiter.

Watch that turn into a 3 billion dollar project.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/12/2013 09:12 PM
This article from the Washington Post seems to indicate that this discovery increases pressure on NASA to move forward on a Europa mission.

http://www.washingtonpost.com/national/health-science/hubble-space-telescope-sees-geysers-on-jupiters-moon-europa/2013/12/12/b6f780ac-62c8-11e3-a373-0f9f2d1c2b61_story.html?hpid=z5

Except that it's not NASA's call. It's a White House decision, and OMB has been cutting the planetary budget. This will get some more attention, but unless OMB puts money back into the planetary budget, nothing is going to happen.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/12/2013 09:13 PM
The implication is that the requirement would be for a Europa Polar Orbiter.

Watch that turn into a 3 billion dollar project.

It refers to Europa Clipper, which is not a "Polar Orbiter."
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/13/2013 12:37 AM
Aaand Bill Nye is at it again
http://www.planetary.org/press-room/releases/2013/1212-the-planetary-society-calls-for-a-mission-to-explore-europa.html

The interesting sentences there say that .. Europa could be habitable now. But, if more money is not given, we wont be going to Europa. We are going to Mars in 2020 again - to really figure out if the environment on that planet, once in distant past, could in fact have supported life.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/13/2013 12:44 AM
The interesting sentences there say that .. Europa could be habitable now. But, if more money is not given, we wont be going to Europa. We are going to Mars in 2020 again - to really figure out if the environment on that planet, once in distant past, could in fact have supported life.

Yeah, so?

Space policy, and space science policy, cannot be and should not be run like a bunch of five year olds playing soccer, running after the ball no matter where it goes. Take that approach and you never go anywhere, you never make any progress, because each new project continues for a short time and then gets canceled in favor of another new project that continues a short time and gets canceled too.

NASA's space science program succeeds at achieving its goals because it is not at all run like the human spaceflight program.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/13/2013 03:58 AM
A couple of thoughts on this.  First, the discovery appears to be based on a single observation from the press accounts (I haven't had time to download and read the paper).  The plumes need to be observed several times before we can be confident that they are real and persistent.

If the plumes prove to be persistent, then I would be surprised if no one proposed a Discovery mission to follow up.  A spacecraft with an UV spectrometer and a near IR spectrometer (if a mapping spectrometer, then useful observations of the terrain could also be made) to characterize the plumes over time and a mass spectrometer for sampling during flyby(s) would be a nice focused mission.  The characterization could be done from outside Europa's orbit to lower radiation and one to a few flybys could sample the plume to determine its composition.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/13/2013 07:14 AM

The interesting sentences there say that .. Europa could be habitable now. But, if more money is not given, we wont be going to Europa. We are going to Mars in 2020 again - to really figure out if the environment on that planet, once in distant past, could in fact have supported life.

Yeah, so?

Space policy, and space science policy, cannot be and should not be run like a bunch of five year olds playing soccer, running after the ball no matter where it goes. Take that approach and you never go anywhere, you never make any progress, because each new project continues for a short time and then gets canceled in favor of another new project that continues a short time and gets canceled too.

NASA's space science program succeeds at achieving its goals because it is not at all run like the human spaceflight program.

The problem with relying on something that is only run every decade is it makes no allowances for discovers like this. How often has something in that survey been marked as important in the survey only to seem less important in the intervening period or for other items to come up that look more important but cannot be looked into because they are not in the survey or had less importance in it when it was drawn up.
Title: Re: Proposed Europa Missions
Post by: AJA on 12/13/2013 10:13 AM
I'm amused by mentions in various places that it's somehow 'easier' to get to the sub-surface ocean now.

Yeah, you can sample the sub-surface ocean by sampling the plume, but getting to the sub-surface hasn't become any easier. Trying to get in through the geysers (as opposed to melting/drilling your way through) is going to be like throwing a paper clip into a garden hose which is spewing water.

Nonetheless, if some probe demonstrates that such a thing, is in fact, feasible, I propose we call it "Salmon".

Btw, here's Emily's repost of Leigh Fletcher's comprehensive post: http://www.planetary.org/blogs/guest-blogs/2013/1212-fletcher-the-plumes-of-europa.html
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/13/2013 01:15 PM
The problem with relying on something that is only run every decade is it makes no allowances for discovers like this. How often has something in that survey been marked as important in the survey only to seem less important in the intervening period or for other items to come up that look more important but cannot be looked into because they are not in the survey or had less importance in it when it was drawn up.

That's what the Discovery Program is (or used to be) for.  Cost-constrained but responsive investigations.

I'd also note that if there are active plumes a couple decades from now, ESA's JUICE mission will image them in UV.

I dunno if NASA's Juno mission, due to arrive in 2016, can help prove out the plumes from its polar orbit, but it will be interesting to see if the team tries.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/13/2013 03:58 PM
The problem with relying on something that is only run every decade is it makes no allowances for discovers like this. How often has something in that survey been marked as important in the survey only to seem less important in the intervening period or for other items to come up that look more important but cannot be looked into because they are not in the survey or had less importance in it when it was drawn up.

The Discovery program makes allowances for discoveries. So does adjusting instrument selection on approved missions. So does observation times on telescopes. And just how quickly do you think missions actually happen?

You wouldn't really want to initiate a multi-billion dollar program based upon an announcement that was made one day ago, would you?
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/13/2013 04:20 PM
You wouldn't really want to initiate a multi-billion dollar program based upon an announcement that was made one day ago, would you?
That is exactly what planetary society releases call for.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/13/2013 04:33 PM
You wouldn't really want to initiate a multi-billion dollar program based upon an announcement that was made one day ago, would you?
That is exactly what planetary society releases call for.

Interest groups don't run the program.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/13/2013 06:54 PM

The problem with relying on something that is only run every decade is it makes no allowances for discovers like this. How often has something in that survey been marked as important in the survey only to seem less important in the intervening period or for other items to come up that look more important but cannot be looked into because they are not in the survey or had less importance in it when it was drawn up.

The Discovery program makes allowances for discoveries. So does adjusting instrument selection on approved missions. So does observation times on telescopes. And just how quickly do you think missions actually happen?

You wouldn't really want to initiate a multi-billion dollar program based upon an announcement that was made one day ago, would you?

But you couldn't expect a discovery class mission to investigate something like this I would have thought.

Hopefully there might be some adjustment within JUICE to allow it to look into this, I would imagine that mission is still early enough in its planning to incorporate developments such as this.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/13/2013 08:59 PM
1-But you couldn't expect a discovery class mission to investigate something like this I would have thought.

2-Hopefully there might be some adjustment within JUICE to allow it to look into this, I would imagine that mission is still early enough in its planning to incorporate developments such as this.

1-Probably not. It might be possible to do a single flyby on a Discovery budget, but I doubt it. However, there HAS been a proposal for an Earth-orbiting planetary observatory, particularly for looking at Jupiter.

2-And that's what you do: you use current and planned assets to look more closely at the phenomena. More Hubble observing time. Maybe point some big ground-based telescopes at it. Maybe get some observing from Juno if possible. JUICE as well.

What you don't do is completely shelve existing plans to go chasing after the Neat New Thing. This announcement was made at the American Geophysical Union meeting. AGU will happen again next year. Should we cancel whatever we do in 2014 to go after what new information gets revealed next December? Of course not.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/13/2013 09:32 PM

1-But you couldn't expect a discovery class mission to investigate something like this I would have thought.

2-Hopefully there might be some adjustment within JUICE to allow it to look into this, I would imagine that mission is still early enough in its planning to incorporate developments such as this.

1-Probably not. It might be possible to do a single flyby on a Discovery budget, but I doubt it. However, there HAS been a proposal for an Earth-orbiting planetary observatory, particularly for looking at Jupiter.

2-And that's what you do: you use current and planned assets to look more closely at the phenomena. More Hubble observing time. Maybe point some big ground-based telescopes at it. Maybe get some observing from Juno if possible. JUICE as well.

What you don't do is completely shelve existing plans to go chasing after the Neat New Thing. This announcement was made at the American Geophysical Union meeting. AGU will happen again next year. Should we cancel whatever we do in 2014 to go after what new information gets revealed next December? Of course not.

Fair points. Can only hope that next time around in the survey the focus moves away from Mars towards Europa.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/13/2013 09:57 PM
Can only hope that next time around in the survey the focus moves away from Mars towards Europa.

Why don't you start working on a white paper to submit for the next survey?

And this has been said over and over again, but the last survey did not neglect Europa. In fact, a Europa mission was rated equal in science with the MAX-C mission. It was essentially a tie in terms of science.

The problem was that the Europa mission proposal that was submitted to the decadal survey cost $4.7 billion. That was not affordable. In fact, it was so big that it completely wrecked the rest of the planetary budget (and this was a year before the administration started cutting the planetary budget). Simply put, the planetary science community looked at the mission options, decided that they didn't want to follow the path of their astronomer colleagues who advocated a mission that destroyed their program, and so they did not advocate the REALLY EXPENSIVE EUROPA MISSION.

Now if JPL had proposed something like Europa Clipper instead, with a much lower cost estimate, then that mission probably would have been ranked first, if only to maintain consistency with the last decadal survey.

So, you may ask, why didn't JPL propose something like Europa Clipper? Because they couldn't comprehend something like that. Because they were thinking in terms of a Christmas Tree mission, putting everything they could on it. It was only when they got smacked in the head by not getting selected that they finally started to come to their senses. And even then it took them awhile. I've heard a JPLer who was involved in the Europa Clipper effort say exactly that--that it took them a long time (over a year) to come up with Europa Clipper because lots of people didn't want to give up their sacred science instrument in order to design a mission that could be affordable. They had to be confronted with cold harsh reality before they would change their views. That only came after the decadal survey. So one of the results of the survey was to force JPL to produce an affordable mission. But that was after, not before.
Title: Re: Proposed Europa Missions
Post by: baldusi on 12/13/2013 11:21 PM
More realistic. In the best missions I always get vulcan unicorns. :p
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/14/2013 03:54 AM
So, you may ask, why didn't JPL propose something like Europa Clipper? Because they couldn't comprehend something like that. Because they were thinking in terms of a Christmas Tree mission, putting everything they could on it.
To be fair to JPL, they initially looked at reduced capacity missions.  NASA headquarters instructed them to focus on the sweetspot that included a very robust set of capabilities.  JPL thought the mission they came up with was ~$2B.  The Decadal Survey concluded that the cost would be twice that.

What has always puzzled me, and perhaps Blackstar has some insight, is how the JPL and Decadal Survey cost models could differ by a factor of 2.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/14/2013 04:27 AM
how the JPL and Decadal Survey cost models could differ by a factor of 2.

Advocate (JPL) versus independent (decadals use Aerospace Corp, IIRC) cost estimates.  Setting aside issues of potential bias, the former is grounds-up while the latter is a high-level parametric model that correlates the complexity of the spacecraft/mission to historical figures.  The decadals started using an independent cost estimator to: 1) ensure an apples-to-apples cost comparison when considering different proposals, and 2) produce conservative plans that will better stand the test of time.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/14/2013 03:02 PM
how the JPL and Decadal Survey cost models could differ by a factor of 2.

Advocate (JPL) versus independent (decadals use Aerospace Corp, IIRC) cost estimates.  Setting aside issues of potential bias, the former is grounds-up while the latter is a high-level parametric model that correlates the complexity of the spacecraft/mission to historical figures.  The decadals started using an independent cost estimator to: 1) ensure an apples-to-apples cost comparison when considering different proposals, and 2) produce conservative plans that will better stand the test of time.


I'd have to go check (and I'm too lazy to do that, so I'll let somebody who is less lazy than me), but I don't think that the difference was that big. I think that the JPL estimate was greater than $2 billion and the decadal was $4.7. (And I vaguely remember hearing that a late JPL cost estimate done just before the decadal did the CATE estimate was much higher, and closer to the CATE.)

However, the CATE process used by the decadal (Aerospace Corp did the CATE) is based upon the history of a broad range of programs. It includes factors that the program does not control, particularly funding shortages due to budgeting issues. So it essentially says to the program "If everything went perfectly for you, your estimate would probably be right. However, all kinds of things happen that you cannot control. For instance, you expect peak funding of $X, but it is more likely that you will get peak funding of $X-1, and that will end up costing you more money in the long run."

Once this is explained to the program (the advocates for a mission), they are generally less hostile, because they realize that the blame for many of the cost increases is put on external forces (like Congress and OMB) and not them.

Now JPL is convinced that they do great cost estimates, but there might be some people who dispute that...

I believe that Aerospace is constantly calibrating their CATE process and comparing its predictions to each new mission. And I believe that they have shown that many of the advocate estimates are NOT wrong, they just don't account for exterior factors. They often say to the program people "You did everything right, but you got screwed over by things outside of your control."

Steve Squyres tells a good story about MER. They were forced to do an independent cost estimate and it came in much higher than the MER program (at JPL) predicted. He said that they never believed it--until their costs started rising. He said that in the end the independent estimate was very close to the actual cost and it changed his opinion about independent estimates.

Title: Re: Proposed Europa Missions
Post by: Star One on 12/14/2013 03:15 PM
If that's going to be the price tag it seems like they may need to attract other agencies such as ESA in as partners to share the cost.
Title: Re: Proposed Europa Missions
Post by: AJA on 12/14/2013 06:45 PM
So it essentially says to the program "If everything went perfectly for you, your estimate would probably be right. However, all kinds of things happen that you cannot control. For instance, you expect peak funding of $X, but it is more likely that you will get peak funding of $X-1, and that will end up costing you more money in the long run."

1. How does that not become a self-fulfilling prophecy?

cf. The PI for OSIRIS-REx, Dante Lauretta - did an AMA on Reddit (http://www.reddit.com/r/IAmA/comments/1sif2f/i_am_the_principal_investigator_for_the_nasa/cdxvz9w)

2. Is it really heresy to talk about fixed-price contracts for robotic missions, a la new space launch services providers? Yes, I know that exploration missions de facto require development in knowledge, technology and maybe even capital infrastructures - on the part of the agency that wins the bid, and is tasked with discharging the mission. Yes, I concede that the frontier nature of these things would make a 'realistic' cost estimation hard, and if fixed-price contracts are artificially mandated, then these costs would inflate to become conservative, and make the whole exercise pointless. (Also, development costs for new space haven't entirely been borne by the fledgling companies. They've had substantial programmatic support.)

However, what if you de-linked technology development from missions? I'm not talking about technology development like "cheaper" this or "cheaper" that... but mission-enabling technologies that are still in low TRL, but whose qualification and availability in a proposed mission time-frame is assumed, and the costs of getting from TRL..say 3-9 is factored into mission costs. I confess I've never read a proposal yet, and I don't know if the proposal guidelines specify a certain minimum readiness for all proposed sub-systems - if the advocates want a program seriously considered.

Anyway, my question is - if you did that, and just allocated this 'uncertainty' money to technology development, would it allow for a greater rate of missions? If nothing else, the certainty would make a major difference to human resources - people will work at the same thing for longer, and develop competencies, slashing the time spent learning on the mission budget's dime.

</Greenhorn_Rant>
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/14/2013 09:11 PM
... I don't know if the proposal guidelines specify a certain minimum readiness for all proposed sub-systems...

Yes, competed programs like Explorer, Discovery, New Frontiers, etc. require a high level of technology readiness.  They typically don't suffer schedule delays and cost growth from immature technologies.

It's the big, strategic missions (JWST, most of the Mars program, Solar Probe, etc.) assigned to field centers in the absence of competition that typically require a lot of technology development.  And they're the missions that most suffer delays and overruns from immature technologies.

My 2 cents is that this disparity between the competed and strategic missions in technology readiness should be rebalanced.  Any investor who understands portfolio theory or asset allocation would tell NASA/SMD that it's asinine to undertake nearly all of the agency's/directorate's technology risks on big expensive missions. 

The competed programs need to find a way to stop rejecting proposals with anything below a TRL9 or TRL7 out of hand and allow new technologies to finish development and get flight tested on their smaller missions.  There has to be a way to assess the likelihood of a successful technology development at lower mid- and high-TRLs, along with their mission criticality and alternatives.

And the strategic missions have to find a way to resist political pressure to go forward in the absence of adequate technology work just to maintain full employment.  The way ESA carries studies and technology development for two or three major candidate missions before downselecting to one may be the answer.

Of course, as pointed out upstream in the thread, technology development is not the only source of cost growth in either competed or strategic missions.

Quote
if you did that, and just allocated this 'uncertainty' money to technology development, would it allow for a greater rate of missions?

NASA has tried various schemes to separate technology development from mission development in the past with varying degrees of failure.  Herding inventors and technologists is harder than herding cats, and it gets worse when you erect a wall that separates technology work from the needs of mission management.   NASA's old New Millennium Program, for example, provided dedicated missions to flight test unproven technologies.  But it's record was mixed at best with about half the missions never getting to flight and not a lot of technology transfer from the demonstration missions into science missions.  NASA's old Aerospace Technology Enterprise was even less responsive to science mission needs when it had the technology portfolio.  NASA has gone back to that model with the current Space Technology Mission Directorate, but they're not even following their own priorities from the technology decadal, nevertheless science mission technology priorities.

The downside to putting technology development under mission management is that mission managers rarely take risks on anything new and the technology budget gets redirected to cover overruns on the missions.  The technology developed will be relevant to the missions, but there will be very little of it.

My 2 cents is that either scheme could work, and some of both (technology-push and mission-pull) are needed in the end.  But it takes honest brokers, intelligent risk-takers, and good relationships to make it work, commodities in short supply in almost any organization.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/14/2013 10:45 PM
So it essentially says to the program "If everything went perfectly for you, your estimate would probably be right. However, all kinds of things happen that you cannot control. For instance, you expect peak funding of $X, but it is more likely that you will get peak funding of $X-1, and that will end up costing you more money in the long run."

1. How does that not become a self-fulfilling prophecy?


Huh? It's based upon historical data. It is already the reality. It's not an excuse for them to spend more money.
Title: Re: Proposed Europa Missions
Post by: Andrew_W on 12/14/2013 11:36 PM
So it essentially says to the program "If everything went perfectly for you, your estimate would probably be right. However, all kinds of things happen that you cannot control. For instance, you expect peak funding of $X, but it is more likely that you will get peak funding of $X-1, and that will end up costing you more money in the long run."

1. How does that not become a self-fulfilling prophecy?


This bit here: "all kinds of things happen that you cannot control."

"Self-fulfilling" means doing things you can control to bring about your own (in this context usually negative) expectations.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2013 04:08 AM
NASA's old New Millennium Program, for example, provided dedicated missions to flight test unproven technologies.  But it's record was mixed at best with about half the missions never getting to flight and not a lot of technology transfer from the demonstration missions into science missions.  NASA's old Aerospace Technology Enterprise was even less responsive to science mission needs when it had the technology portfolio.  NASA has gone back to that model with the current Space Technology Mission Directorate, but they're not even following their own priorities from the technology decadal, nevertheless science mission technology priorities.

The downside to putting technology development under mission management is that mission managers rarely take risks on anything new and the technology budget gets redirected to cover overruns on the missions.  The technology developed will be relevant to the missions, but there will be very little of it.


Well, yeah, you can create a separate program line for technology development and develop it there. That's what they did with New Millennium. There are two problems. One is the one you cite, which is that it is difficult to focus such a program on developing the most needed and useful technologies and getting those into flight and then making them ready for operational missions.

The other problem is that separate technology development budgets are nice big fat targets for raiding, first by NASA itself, then OMB and also Congress. I am sure that there have been lots of NASA officials over the years who sat in rooms with higher level people and sputtered when somebody said "We see you need more money for program X, which is supposed to launch in three years. Well, we're going to take it out of your R&D budget, because you say that those technologies will not be mature for another 5-10 years." Or they get the latest OMB passback, or the congressional language, that simply moves the money out of R&D and into an operational program without ever explaining it at all. Poof! It's gone!

Now I used to think that the reason that these programs got raided for cash was because they were poorly managed, which meant that they had a lot of fat and they became targets for raiding. There seemed like there were lots of examples of that, such as NASA developing several different in-space propulsion technologies simultaneously instead of focusing on a very few.

But I've heard from at least a few people who have been in positions of authority over this stuff that they think it's just sort of the natural order, that separate R&D accounts are going to get raided no matter what, because it is a hard argument to make that we have to develop technology for a mission that doesn't exist yet.

Title: Re: Proposed Europa Missions
Post by: cosmicvoid on 12/16/2013 04:51 AM
... because it is a hard argument to make that we have to develop technology for a mission that doesn't exist yet.
Seems like a good way to ensure that those kinds of missions will never exist, I think. No budget for forward thinking.
Title: Re: Proposed Europa Missions
Post by: simonbp on 12/16/2013 04:58 AM
It's not so much the project that makes it self fulfilling, but the funding agency. If there are no consequences for missions that abuse the system (JWST, MSL), then the abuse will continue.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/16/2013 05:44 AM
If there are no consequences for missions that abuse the system (JWST, MSL), then the abuse will continue.
The consequences appear to be ones that everyone will suffer -- the end of Flagship missions for the foreseeable future.  I listened in as Bolden told the NAC Science Subcommittee that they needed to be thinking of smaller missions because Flagships just are affordable.  Grunsfeld seconded the message.  (Yeah, there was a politically correct clarification issued afterwards that basically said NASA fully supports Flagship missions when funding is available.  And, if it didn't rain so much in Seattle, we'd have a lot more sunshine.)

For Astronomy and Astrophysics, there are mission studies for ~$1B as alternatives to WFIRST.  Grunsfeld said he wanted to see how much science could be done with a New Frontiers plus mission for Europa and other Flagship destinations.

I think that the lesson that OMB and senior NASA management have taken away is that Flagships always go well over budget, so don't do Flagships.  The one exception appears to be the ~$1.5B 2020 rover, which is about as safe a Flagship mission as you can get.  Rebuild a rover and EDL system and fly less expensive instruments.

We may end up with a science program in which the most expensive missions allowed are $1.25B to $1.5B, which is similar in size to ESA's Large science missions.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2013 01:38 PM
... because it is a hard argument to make that we have to develop technology for a mission that doesn't exist yet.
Seems like a good way to ensure that those kinds of missions will never exist, I think. No budget for forward thinking.


Well, I said it was hard, not impossible. It has been done in some cases. Dawn is using technology developed in New Millennium. And the technology directorate is currently working on new entry descent and landing technology that could have a range of uses. One inherent problem with this approach is that you develop a technology that could then sit on the shelf for a decade or more before a mission comes along to use it, and that is difficult to justify even in the best of cases.

And if you go back a few posts in the thread, you see that the other way to do it is to perform the technology development in the mission budget itself. That's what they did with JWST and with Curiosity. In JWST that approach really bit them in the ass.

(Curiosity less so, because I think that the cost overrun problems were not so much due to the new technology development but to problems that were encountered in things that were not pushing the technology. But I would like to see a "lessons learned from Curiosity" report. I think there is one in existence. I'll have to look for it.)
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2013 01:54 PM
The consequences appear to be ones that everyone will suffer -- the end of Flagship missions for the foreseeable future.  I listened in as Bolden told the NAC Science Subcommittee that they needed to be thinking of smaller missions because Flagships just are affordable.  Grunsfeld seconded the message.  (Yeah, there was a politically correct clarification issued afterwards that basically said NASA fully supports Flagship missions when funding is available.  And, if it didn't rain so much in Seattle, we'd have a lot more sunshine.)

For Astronomy and Astrophysics, there are mission studies for ~$1B as alternatives to WFIRST.  Grunsfeld said he wanted to see how much science could be done with a New Frontiers plus mission for Europa and other Flagship destinations.

I think that the lesson that OMB and senior NASA management have taken away is that Flagships always go well over budget, so don't do Flagships.  The one exception appears to be the ~$1.5B 2020 rover, which is about as safe a Flagship mission as you can get.  Rebuild a rover and EDL system and fly less expensive instruments.

We may end up with a science program in which the most expensive missions allowed are $1.25B to $1.5B, which is similar in size to ESA's Large science missions.

I avoided commenting on all that in the other thread for a few reasons. For starters, I think that Bolden's comments were taken somewhat out of context. The science community is aware of those issues, so Bolden was not telling them something they didn't know.

Grunsfeld is interested in looking at the management of missions, so his comments might have been in that context. I don't know about $1 billion WFIRST missions, but WFIRST was intentionally designed to be much cheaper.

All that said, there's only so much you can do to squash these things down before they are not worth doing anymore. You end up with a spacecraft where you are spending a huge amount of money simply to get it somewhere, and then it does almost nothing while there. In some ways that is why there are different mission classes, to delineate levels of science as well as cost.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/16/2013 04:33 PM
It's the big, strategic missions (JWST, most of the Mars program, Solar Probe, etc.) assigned to field centers in the absence of competition that typically require a lot of technology development.  And they're the missions that most suffer delays and overruns from immature technologies.

My 2 cents is that this disparity between the competed and strategic missions in technology readiness should be rebalanced.  Any investor who understands portfolio theory or asset allocation would tell NASA/SMD that it's asinine to undertake nearly all of the agency's/directorate's technology risks on big expensive missions. 
From financial and also human resource management perspective you would want exactly the opposite of the current situation - take minimal risks with big budget items and take high risks with low budget items. A CubeSat mission can afford to test a claimed warp drive - when it predictably fails to work the absolute financial loss is going to be tiny and a bunch of young people that worked on it a lot more experienced and smarter.  No careers will be hurt and someone can get a "craziest space idea attempted" medal.

And thanks everyone for the very insightful comments in the latter part of this thread.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/16/2013 05:06 PM

The consequences appear to be ones that everyone will suffer -- the end of Flagship missions for the foreseeable future.  I listened in as Bolden told the NAC Science Subcommittee that they needed to be thinking of smaller missions because Flagships just are affordable.  Grunsfeld seconded the message.  (Yeah, there was a politically correct clarification issued afterwards that basically said NASA fully supports Flagship missions when funding is available.  And, if it didn't rain so much in Seattle, we'd have a lot more sunshine.)

For Astronomy and Astrophysics, there are mission studies for ~$1B as alternatives to WFIRST.  Grunsfeld said he wanted to see how much science could be done with a New Frontiers plus mission for Europa and other Flagship destinations.

I think that the lesson that OMB and senior NASA management have taken away is that Flagships always go well over budget, so don't do Flagships.  The one exception appears to be the ~$1.5B 2020 rover, which is about as safe a Flagship mission as you can get.  Rebuild a rover and EDL system and fly less expensive instruments.

We may end up with a science program in which the most expensive missions allowed are $1.25B to $1.5B, which is similar in size to ESA's Large science missions.

I avoided commenting on all that in the other thread for a few reasons. For starters, I think that Bolden's comments were taken somewhat out of context. The science community is aware of those issues, so Bolden was not telling them something they didn't know.

Grunsfeld is interested in looking at the management of missions, so his comments might have been in that context. I don't know about $1 billion WFIRST missions, but WFIRST was intentionally designed to be much cheaper.

All that said, there's only so much you can do to squash these things down before they are not worth doing anymore. You end up with a spacecraft where you are spending a huge amount of money simply to get it somewhere, and then it does almost nothing while there. In some ways that is why there are different mission classes, to delineate levels of science as well as cost.

Is WFIRST still planning to use the gifted NRO telescope?
Title: Re: Proposed Europa Missions
Post by: baldusi on 12/16/2013 05:18 PM
It's the big, strategic missions (JWST, most of the Mars program, Solar Probe, etc.) assigned to field centers in the absence of competition that typically require a lot of technology development.  And they're the missions that most suffer delays and overruns from immature technologies.

My 2 cents is that this disparity between the competed and strategic missions in technology readiness should be rebalanced.  Any investor who understands portfolio theory or asset allocation would tell NASA/SMD that it's asinine to undertake nearly all of the agency's/directorate's technology risks on big expensive missions. 
From financial and also human resource management perspective you would want exactly the opposite of the current situation - take minimal risks with big budget items and take high risks with low budget items. A CubeSat mission can afford to test a claimed warp drive - when it predictably fails to work the absolute financial loss is going to be tiny and a bunch of young people that worked on it a lot more experienced and smarter.  No careers will be hurt and someone can get a "craziest space idea attempted" medal.

And thanks everyone for the very insightful comments in the latter part of this thread.
Think of JWST. They had to develop active optics that worked at 4K. They had to design a frame that tolerated that. They had to design a sunshield. They had to design the folding mechanism. They had to design some serious cryocooler. Then think of the scale we're talking about. I don't think they could have retired much risk in small missions.
What they could have done, is take a bit longer to develop, ONLY do the critical demonstrations of TRL<7 or 6. And only then do an independent cost estimate. That would have lowered the cost estimate variance. And only then give it the full authorization to proceed. I don't believe that if they had come with an 8B price tag when they had spent 400M, they would have gone ahead with it.
BTW, MSL did try to do dry lubricated actuators and/or axes. I think to remember that that part failed and had to go with more traditional technology. Plus, they developed that flashy EDL system. And the cost of missing a launch window was 2 years of R&D overhead. That's the sort of risk that has to be embedded on a mission budget. Think of New Horizon, for example, where you simply couldn't miss the launch window. It was no only the Earth-Pluto window, but the fact that they wanted to arrive before it freezes over.
Title: Re: Proposed Europa Missions
Post by: baldusi on 12/16/2013 05:32 PM
Now that I think of it, losing the competitions helps with budgeting. I believe that if they accepted risky missions only if they first do TRL reduction investment, and only then take a final decision, it would be a very interesting approach. You know, instead of doing it in five, say seven, and only invest very little the first two to get a good idea on the cost of getting the technology to whatever they need. It would have two "problems":
1) Risky missions would take longer. The problem is that if you don't know your budget environment in five year, seven is worse.
2) Selected missions might not be final. Say you do a NF mission, but after two years you find it will cost 2X to make it happen. The mission is given the axe. But can you call a new NF again?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2013 05:40 PM
Is WFIRST still planning to use the gifted NRO telescope?

My quick answer is "I don't know." I'm much more familiar with the planetary stuff than astro.

I think the more wavering answer is that I don't think they have "planned" do do anything with that mirror yet. They are merely studying it. That could simply be a lousy way to do anything. They have to fully explore the alternatives first.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2013 05:44 PM
From financial and also human resource management perspective you would want exactly the opposite of the current situation - take minimal risks with big budget items and take high risks with low budget items. A CubeSat mission can afford to test a claimed warp drive - when it predictably fails to work the absolute financial loss is going to be tiny and a bunch of young people that worked on it a lot more experienced and smarter.  No careers will be hurt and someone can get a "craziest space idea attempted" medal.

1-Cubesats cannot do much of jack squat. They're too small. They lack power. You can do some tech development with them, but not much. They are not a good way to retire risk.

2-If you're talking about taking higher risk on cheaper missions, yeah, people talk about how the Discovery class missions should assume higher risk. But that idea runs smash dab into reality. If you are a principal investigator, you don't want to get risky. Why should you? Lose the mission and you are doomed. And you have a cost cap on your mission, so you cannot develop new technology.

There is a possible lower level of missions, Explorer class, where you could take higher risks and could possibly develop new technologies. But there's no funding for them.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/16/2013 06:46 PM
1-Cubesats cannot do much of jack squat. They're too small. They lack power. You can do some tech development with them, but not much. They are not a good way to retire risk.
I was trying illustrate my point, Cubesats being one extreme and multibillion dollars the other far extreme of the cost spectrum. There is a lot of middle ground.
Besides, planetary Cubesats are a serious topic now and potentially can actually enable completely new mission capabilities - and there is a lot of active tech development happening in the area for comparatively low budgets. But this belongs in another thread.

Quote
If you're talking about taking higher risk on cheaper missions, yeah, people talk about how the Discovery class missions should assume higher risk. But that idea runs smash dab into reality.
That reality should hit much sooner and more acutely with flagships.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/16/2013 09:24 PM
Recent article from the New Scientist on using cubesats for interplanetery missions. (This looks to be a cut down from the full magazine article I read.)

http://www.newscientist.com/article/dn24679-boxy-cubesats-get-a-propulsion-boost-in-new-space-race.html
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2013 09:24 PM
That reality should hit much sooner and more acutely with flagships.

Yeah, and everybody should floss more.

The fact remains that flagships are still where the most science and technology development are accomplished. They advance the field the most.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/17/2013 02:00 AM
1-Cubesats cannot do much of jack squat. They're too small. They lack power.

What an ignorant statement.

Landsat-class imagery with multiple revisits per day is not "jack squat".

http://www.planet-labs.com/

The cosmic x-ray background is not "jack squat".

http://www.kentuckyspace.com/?catid=45:kentuckyspaceblog&id=505:unbridled-spirit-cosmic-x-ray-background-nanosatellite&Itemid=194&option=com_content&view=article

Transit searches for super-Earths around nearby stars is not "jack squat".

http://space.skyrocket.de/doc_sdat/exoplanetsat.htm

Gene expression in microgravity is not "jack squat".

http://www.space.com/1495-genesat-1-small-satellite-tackles-big-biology-questions.html

Quote
2-If you're talking about taking higher risk on cheaper missions, yeah, people talk about how the Discovery class missions should assume higher risk. But that idea runs smash dab into reality. If you are a principal investigator, you don't want to get risky.

Because the existing proposal and review process for Discovery (and all the other competed mission programs) doesn't reward it.  Change the criteria and PIs will propose differently.
Title: Re: Proposed Europa Missions
Post by: Danderman on 12/17/2013 05:47 AM

1-Nope. Jack squat. They're still toys. They don't advance the field in any meaningful way. That's why nobody is using them for operational military, civilian, or NASA science missions.


The statement above is doomed to become obsolete, as systems become smaller and more efficient. There will be CubeSATs flying all sorts of significant missions, unless our technological base somehow freezes in the next few years.   CubeSATs may become useful for planetary missions as subsatellites, allow multiple sensors to be flown in differing orbits.

And in the present there is:

http://www.planet-labs.com/
Title: Re: Proposed Europa Missions
Post by: QuantumG on 12/17/2013 06:48 AM
And the other thing to remember is that "cubesats" are getting bigger. There's also other standards for "smallsats" that give you the greatest advantage of a cubesat: minimal integration costs.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/17/2013 09:01 AM
1-Nope. Jack squat. They're still toys. They don't advance the field in any meaningful way.

This statement is now ignorant in multiple fields.  "Toys" can't provide Landsat-class imagery, measure the cosmic x-ray background, observe exoplanet transits, or take data on gene expression in microgravity.

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That's why nobody is using them for operational military, civilian, or NASA science missions.

Wrong.  NSF employs cubesats in operational, civil science missions.

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2-Why? What's that going to buy you?

More science, better science, enabled science, lower cost for the science baseline, budget bonus for technology validation or ride-ons, backup/alternative subsystems, etc.  It depends on the mission and technologies in question and how the AO incentivizes the PI.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/17/2013 01:40 PM
I've met the NSF guy who started their cubesat program. That's not what they're doing. NSF doesn't do "operational civil science missions." It's not their mission, not in their charter.

This NSF presentation on their cubesat program states that the program's goal is to "advance research in many science areas" and that "space missions [are] within the scope of traditional NSF grants".  A table in the presentation lists five of 12 missions as "operational".  Science targets and instruments include:

Auroral turbulence
Bistatic UHF radar - ISR measured E-Field

Stormtime E-fields and Plasma Density
E-field, langmuir probe, magnetometer

Radiation Belt Structure & Dynamics
Geiger-Mueller Tube

Energetic Ion, e- & Neutral Drivers
Multi-particle telescope & magnetometer

Outer Belt & Solar Energetic e- & H+
Electron/proton telescope

Iono Structure, Comp/Fields/Winds
WINCS, GPS RO UV Photometery

Relativistic electron microbursts
Ion implanted solid-state detectors

Terrestrial gamma ray flashes
RF, gamma-ray, and optical detectors

Thermosphere Comp/Dynamics
Wind, temp & mass spectrometer (WINCS)

Exosphere Structure & Dynamics
WINCS tuned for light Ions and neutrals

http://mstl.atl.calpoly.edu/~bklofas/Presentations/DevelopersWorkshop2013/Jorgensen_NSF_CubeSat_keynote.pdf
Title: Re: Proposed Europa Missions
Post by: baldusi on 12/17/2013 02:05 PM
1-Nope. Jack squat. They're still toys. They don't advance the field in any meaningful way.

This statement is now ignorant in multiple fields.  "Toys" can't provide Landsat-class imagery, measure the cosmic x-ray background, observe exoplanet transits, or take data on gene expression in microgravity.
Now you're getting bad mannered.
The original point was cubesats to increase technology TRL. You can validate only small components, and only those that fit the energy/heat rejection/communication limitations of a cube sat. You can't do that for most technologies.
Cubesats are useful, but you can't compare Skybox, Satellogic and much less Planet-Lab with Landsat 8. You can do useful things with cubesats. You can even get very good science. But you can't really advance the technology that BEO missions need.
And please remember that instruments might be 70% or more of the mission cost. And you can't use a cube sat for all instruments. Specially for surface operations. Or many properties where is actually cheaper to test it on ground.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/17/2013 03:37 PM
The original point was cubesats to increase technology TRL. You can validate only small components

That's not the point of this discussion.  The other poster was claiming that cubesats can't do "jack squat".  I pointed out that cubesats are being used to do all kinds of remote sensing and space science, which surely counts as much more than "jack squat".

I wasn't arguing about how much technology validation can be done on cubesats.  I readily concede that cubesats will never replace certain satellites and technologies simply due to the laws of physics.  But there's a big gulf between that and "jack squat".

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Cubesats are useful, but you can't compare Skybox, Satellogic and much less Planet-Lab with Landsat 8.

PlanetLabs is already delivering Landsat-class imagery using 3U cubesats.  If they deploy their whole fleet, they'll provide Landsat-class imagery for the same location on Earth several times a day.

Skybox is promising imagery that's much better than Landsat-class resolution.  But they're not using cubesats.

I don't know Satellogic and can't speak to them.

Quote
you can't really advance the technology that BEO missions need...  And you can't use a cube sat for all instruments... Specially for surface operations.

Some technologies and instruments but not all.  For example, here's a blurb on one JPL study to sample Phobos using interplanetary cubesats.

http://www.gizmag.com/cubesats-phobos-nasa/22037/

Quote
Now you're getting bad mannered.

I'd argue that it's pretty "bad mannered" to use terms like "jack squat" in reference to the capabilities of an entire class of spacecraft.

The fact that they even had to state that should tell you how much they felt they had to justify it.

I'll take what's written in black-and-white in an NSF presentation over hearsay and innuendo.

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You're not going to find cubesats prioritized as scientific platforms in any decadal survey.

After completing the ongoing program, the top priority in the last solar and space physics decadal includes a doubling of NSF's cubesat program.

Quote
They're used for minor things,

Demonstrably wrong from the links I provided earlier, but clearly you don't want your bubble burst.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/18/2013 04:15 AM
Is WFIRST still planning to use the gifted NRO telescope?
According to the most recent updates from the Astronomy and Astrophysics program, the NRO telescope is one option.  I don't think that a firm cost has been assigned to that option, but I remember that it was ~$1.5B (any have a clearer recollection?).

In a parallel effort, the program is examining at least two and perhaps several ~$1B alternative missions that would not fulfill all the goals for WFRIST.  I believe they would be more focused on exoplanets (or at least some of them).
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/18/2013 04:28 AM
Without being an expert in this field, I did look at proposed planetary SmallSat and CubeSat missions based on what is being discussed by the engineering community.  My walkaway was that by the time you upgrade a CubeSat to be able to travel to an interplanetary target, communicate over long distances, and carry useful instruments, you are really in the SmallSat world.  I think that CubeSats will play a role, but as deployed auxiliary instruments carried to their destinations by larger craft.  (Note: I do think that someone will do a standalone Mars or asteroid CubeSat mission just to prove it can be done, but I think that will be the exception.)

Whether SmallSats in the end represent a good return for the investment scientifically is another question that is best left to a review panel. 

Anyway, you can read what I wrote at

SmallSats: http://futureplanets.blogspot.com/2013/08/small-could-be-beautiful-planetary.html (http://futureplanets.blogspot.com/2013/08/small-could-be-beautiful-planetary.html)

CubeSats: http://futureplanets.blogspot.com/2013/10/cubesats-to-planets-ive-seen-evolution.html (http://futureplanets.blogspot.com/2013/10/cubesats-to-planets-ive-seen-evolution.html)
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/18/2013 02:41 PM
I think that CubeSats will play a role, but as deployed auxiliary instruments carried to their destinations by larger craft.

Cubesats will play that role, but they'll also provide powerful capabilities on their own.  Planet Labs attracted over $50 million of investment just today.  Their initial constellation of 32 Earth observing satellites consists entirely of cubesats.

https://www.newspacewatch.com/articles/72542-planet-labs-raises-52m-in-series-b-financing.html

FWIW...

Title: Re: Proposed Europa Missions
Post by: Jim on 12/18/2013 02:49 PM
"Toys" can't provide Landsat-class imagery,


Proof please and not based on advertisements.
Title: Re: Proposed Europa Missions
Post by: Jim on 12/18/2013 02:58 PM

I'll take what's written in black-and-white in an NSF presentation over hearsay and innuendo.


what hearsay and innuendo?
Title: Re: Proposed Europa Missions
Post by: Jim on 12/18/2013 03:01 PM

This statement is now ignorant in multiple fields.


And yours are also in overstating the role of cubesats.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/18/2013 03:42 PM
Proof please and not based on advertisements.

From the Financial Times:

Quote
The quality of the images is similar to a person peering out of the window of a commercial airline flight and the resolution is 10 times higher than pictures produced by NASA’s Landsat programme, first launched in 1972 and now widely used for earth imaging.

http://www.ft.com/cms/s/0/a8b611c0-5661-11e3-ab12-00144feabdc0.html#axzz2nqMsqlBt

Planet Labs four cubesats in orbit have already produced images with 3-5m resolution, some of which you can see in compressed form by opening the "Photo Gallery" here:

http://www.planet-labs.com/

If you don't know, Landsat 7/8 images are 15-100m resolution.

Quote
what hearsay and innuendo

The other poster claimed that he had talked to someone at NSF and they said that space research was not part of NSF's mission.  I quoted from and linked to an NSF presentation that stated the exact opposite.  With some tortured logic, the other poster then claimed that the fact the presenter had to put that mission down on paper is proof that the mission does not belong to NSF.

Again, I'll take what is written in black-and-white in an NSF presentation over the other poster's hearsay (his claim that he talked to NSF) and innuendo (the ridiculous implication that space research is not part of NSF's mission because they wrote it down).

Quote
And yours are also in overstating the role of cubesats.

I take offense at that statement.  In response to the other poster's claim that cubesats can't do "jack squat", I've provided multiple, factual examples of cubesats obtaining remote sensing and space science data on par with larger, modern spacecraft.  These examples have been backed up with links.  I've further stated that I don't think cubesats can do everything that other satellites can do.  The laws of physics tell us this.  But there is a huge gulf between the limits of physics and "jack squat".  Unlike the other poster, I've stuck to the facts and backed them up with references.  That's not overstating anything.

If you feel the need to upbraid someone with your morning coffee, please take the other poster to task for the false, ignorant, and understated claim that cubesats can't do "jack squat".

Title: Re: Proposed Europa Missions
Post by: savuporo on 12/18/2013 03:46 PM
Without being an expert in this field, I did look at proposed planetary SmallSat and CubeSat missions based on what is being discussed by the engineering community.  My walkaway was that by the time you upgrade a CubeSat to be able to travel to an interplanetary target, communicate over long distances, and carry useful instruments, you are really in the SmallSat world. 

If a 6U cubesat is called a SmallSat then yes ( that is, a 6kg sat ) . Previously i thought something SMART-1 scale would be called a smallsat ( a 300kg vehicle )

http://www.planetary.org/blogs/guest-blogs/van-kane/20130823-smallsats-small-could-be-beautiful.html

Quote
An emerging class of spacecraft – I’ll call them SmallSats – would fit between LargeSats and CubeSats.  These spacecraft make use of the design techniques of CubeSats but scale the form factor up to a meter or so and the mass up to 50 to 100 kg or so.
Title: Re: Proposed Europa Missions
Post by: Jim on 12/18/2013 03:49 PM

If you don't know, Landsat 7/8 images are 15-100m resolution.


Landsat's forte is not visual resolution but multi spectral imaging.  Unless cubesats can do the same bands, then the comparison is nonsense.  The proper comparison is to the other commercial imaging spacecraft.
Title: Re: Proposed Europa Missions
Post by: Jim on 12/18/2013 03:50 PM

 I've provided multiple, factual examples of cubesats obtaining remote sensing and space science data on par with larger, modern spacecraft.


Another overstatement.  far from "on par.  They have a niche role.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/18/2013 05:30 PM
Landsat's forte is not visual resolution but multi spectral imaging.  Unless cubesats can do the same bands, then the comparison is nonsense.

Planet Labs' wavelength coverage is approximately the same as Landsats 1-5 and the first four bands of Landsdats 6-8.  AFAIK, Planet Labs does not do IR bands.

With Planet Labs, you trade Landsat's IR bands against a much higher revisit rate (multiple times daily) and resolution.  Images are free to small users under either provider.

Unless your application is all about IR imagery, Planet Labs provides more and better data than Landsat.

The proper comparison is to the other commercial imaging spacecraft.

It's not for Planet Labs.  Skybox is the new remote sensing company aiming for ~1m resolution in DigitalGlobe's ballpark.  Skybox uses smallsats, not the cubesat standard.

Another overstatement.  far from "on par.  They have a niche role.

Sure, have it your way.  Landsat-class imagery, the cosmic x-ray background, nearby exoplanets, gene expression, a dozen space physics missions, and the top initiative in a decadal survey are all "niches".
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/18/2013 06:12 PM
I think the Landsat versus Planet Lab comparisons are misleading.  Landsat produces highly geometrically precise and spectrally consistent images in a range of bands from the visual to mid-infrared (which is the equivalent of several instruments).  It really matters, for example, that the spectral measurement made this year can be compared to the one made a decade from now.  (There is drift, and it's carefully tracked, but minimized by design.)  Sensitivity of the instrument is essential and precisely calibrated.

Planet Lab plans to produce rapidly acquired images for visual interpretation.  There's no need for Landsat quality images or spectral range.

It's like comparing a phone camera to a top-of-the-line Nikon.  Both are very useful and both are used differently.  Neither is bad.


Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/18/2013 07:25 PM
I think the Landsat versus Planet Lab comparisons are misleading.  Landsat produces highly geometrically precise and spectrally consistent images

It would be misleading to imply that Planet Labs does not perform georectification, orthorectification, and color calibration.  They do.

Chill. You called me ignorant multiple times

I never called you "ignorant".  I wrote that two of your statements are "ignorant" and provided the facts that those statements were ignorant of. 

Quote
Don't give more people no reason to take you seriously.

Sage advice from someone who employs very serious terms like "jack squat".
Title: Re: Proposed Europa Missions
Post by: robertross on 12/18/2013 10:32 PM
Okay, enough.

This was a great thread.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/25/2013 09:53 PM
Wouldn't one of the biggest challenges be dealing with the high speed of the return capsule for such a mission, aren't we talking about speeds higher than that of the Stardust mission?
Title: Re: Proposed Europa Missions
Post by: ugordan on 12/25/2013 09:58 PM
Wouldn't one of the biggest challenges be dealing with the high speed of the return capsule for such a mission, aren't we talking about speeds higher than that of the Stardust mission?

Reentry via a Hohmann-type trajectory from the Jupiter system would likely pale in comparison to what the Galileo entry probe had to endure.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/25/2013 10:35 PM
I wonder if it would be possible to use two spacecraft approach for in-situ science. Park the bigger one with most science instruments on a Juno-like polar orbit with a similar "Radiation vault", and then use separate smaller probe(s) to do the sampling and return to mothership.
Complicated, for sure, but any sort of back to earth sample return will be as complicated.
Title: Re: Proposed Europa Missions
Post by: a_langwich on 12/26/2013 01:24 AM
The other challenge--really more of a drawback--is that you get essentially zero science return until the sample gets back to Earth. And it is a long mission. So do you fund a mission knowing that you will wait 18 years for ANY data, and that it could fail at any point during those 18 years? There are much less risky missions you could fund.

What about Curiosity-style spectrometry, mass spec and other instruments for sample analysis?   Hang around, collect some, analyze it, store that sample group if you like it for sample return, or perhaps adjust your fly-by patterns if you don't to get something better.


Quote
Fourth, how could SLS change this equation? I am an SLS agnostic. Although I think that HLV is necessary for many human missions, and it _can_ be enabling for some robotic missions, I'm skeptical of the cost in the current political environment. However, SLS might be the only viable way to do sample return at Europa, so I think that this would be worth studying.

Well, SLS isn't going to be doing much until well into the 2020s, given the first 2-3 missions are spoken for, right?  I think regarding cost, it will only happen if NASA provides the SLS at no cost to the science budget, and that still implies a commitment on the level of JWST and Hubble:  unsinkable flagship.  (Not sure whether Europa can inspire that much determination in HQ, or more importantly in the public imagination which is where Hubble and JWST have gathered strength.  But also in the science community:  is this so valuable to the planetary community they'd forego many, many other opportunities as astro has done since JWST?  I'm thinking Mars projects have more pull than that.) 

Even so, there would still be the question of launch slots.  Every SLS DRM seems to involve groups of SLS launches, which involves committing years of SLS production to a mission set.  While it might be handy to have a different mission to slide in if there were delays--even the asteroid mission is extremely schedule-risky--a Europa mission, with outer planet launch windows, isn't a good candidate for moving around to fill gaps.

Title: Re: Proposed Europa Missions
Post by: savuporo on 12/26/2013 02:58 AM
What about Curiosity-style spectrometry, mass spec and other instruments for sample analysis?
In-situ science around jupiter will always be severely hindered by what kind of instruments and electronics you can subject to the radiation.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/26/2013 04:03 AM
What I was referring to boils down to this: up until now, nobody has discussed Europa sample return missions. They have discussed Enceladus sample return missions. A-what would be the parameters of a Europa sample return mission?

ARC/JPL studied Europa sample return before under the Ice Clipper concept for a ~$250M Discovery proposal back in 1996/7.  The idea was to create an "ice geyser" with a 20kg copper impactor sent ahead of the spacecraft and then fly through the cloud with an aerogel screen (think Deep Impact crossed with Stardust).  The "ice geyser" would not get very high, and the risk of flying that close to Europa on first approach was deemed too high and the proposal was rejected.  But if confirmed, persistent, and of the right height, a naturally occurring Europa geyser may solve this problem.

APL revisited the concept a decade later with a bigger, 100kg impactor and spectroscopy instead of sample return (think Deep Impact on steroids).  But if applied to a sample return mission, the larger impactor had the twin benefits of allowing the capture spacecraft to fly higher and safer while also accessing deeper and more interesting ice layers from Europa.

Not much exists on the web, but here's an article on both studies:

http://www.marsdaily.com/reports/Go_Flagship_Class_By_Jove_999.html

And some random Ice Clipper abstracts:

http://trs-new.jpl.nasa.gov/dspace/handle/2014/27403

http://archive.is/BdqH

http://www.sciencedirect.com/science/article/pii/S0273117702004805

Quote
B-could SLS make any difference for that mission given its difficult parameters (like delta-vee)?

No, totally unnecessary.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/26/2013 09:16 AM
Could the JUICE mission be reconfigured to if not do sample return then to fly through these plumes & do in situ science on them?
Title: Re: Proposed Europa Missions
Post by: ugordan on 12/26/2013 03:16 PM
Could the JUICE mission be reconfigured to if not do sample return then to fly through these plumes & do in situ science on them?

Almost certainly not. It's an entirely different mission with entirely different goals. They might be able to shift their observation strategy a bit, but they couldn't really change the main parameters of the mission without it being an entirely different mission--and maybe not workable.

There ought to be some freedom in tweaking the sub s/c point to move it to higher southern latitudes, but I wonder if flying through the plumes would be considered too hazardous to the solar panels. Even if they wanted to rotate them to present the lowest cross-section to the plume flux, I'd imagine the uncertainty in the actual plume/particle velocities would make predicting the "ram" direction difficult.
Title: Re: Proposed Europa Missions
Post by: ugordan on 12/26/2013 05:37 PM
There's probably not real reason to go through the plumes. What you'd want is some kind of assessment, particularly looking for organics. Cassini has done that at Saturn with Enceladus.

Yes, I was too lazy to check if JUICE will be carrying something similar to Cassini's INMS - which apparently it won't. I agree there's little added value in flying through the plumes in this case.
Title: Re: Proposed Europa Missions
Post by: ugordan on 12/26/2013 06:11 PM
One thing that just occurred to me is that there might be a benefit to turning JUICE to look at Europa at a point where the plumes might be illuminated by the sun. They might not have considered that yet, and the new data might cause them to reevaluate.

I cannot imagine them *not* doing that or, for that matter, monitoring all other satellites once on the Jovian tour.

Regular distant monitoring was IIRC something the Galileo mission was also originally supposed to do. Imagine if the HGA hadn't failed and we saw glimpses of these plumes (in forward-scattered light, too!) 15 years sooner than we did...
Title: Proposed Europa Missions
Post by: Star One on 12/26/2013 09:47 PM
There ought to be some freedom in tweaking the sub s/c point to move it to higher southern latitudes, but I wonder if flying through the plumes would be considered too hazardous to the solar panels. Even if they wanted to rotate them to present the lowest cross-section to the plume flux, I'd imagine the uncertainty in the actual plume/particle velocities would make predicting the "ram" direction difficult.

There's probably not real reason to go through the plumes. What you'd want is some kind of assessment, particularly looking for organics. Cassini has done that at Saturn with Enceladus.

But JUICE is only supposed to have a few observations of Europa, so it simply may lack any flexibility to expand the Europa observations without substantially impacting the Ganymede science objectives.

Are they targeting Ganymede because it's the only moon with a magnetosphere?

Also will Juno be able to do any observations of Jupiter's moons?
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/27/2013 12:37 AM
One thing that just occurred to me is that there might be a benefit to turning JUICE to look at Europa at a point where the plumes might be illuminated by the sun. They might not have considered that yet, and the new data might cause them to reevaluate.
The JUICE mission was planning to search for plumes at Europa prior to the AGU announcement.  There's a paper or abstract that discussed the plans using the ultraviolet spectrometer in the ~1 year in Jupiter orbit prior to the Europa flybys.
Title: Re: Proposed Europa Missions
Post by: mdatb on 12/28/2013 07:53 PM
Could the JUICE mission be reconfigured to if not do sample return then to fly through these plumes & do in situ science on them?
So the U.S. has a lot of Mars scientists, and therefore generates a lot of interest in more Mars missions. There are positives to this and negatives. The positive is that it results in great expertise and focus on a subject. The negative is that it results in slower response to new discoveries, and even neglect of potentially great scientific subjects. For instance, the ice giants remain the last major unexplored objects in our solar system (after New Horizons flies by Pluto), but there is still limited interest in them, meaning that it will probably be 30-40 years before we mount a robotic mission to Uranus or Neptune.
I agree. Mars gets a lot of interest and focus due to the many scientists who focus on mars. Thus, we get a lot of information on the subject and focus on putting missions there, but other objects get exploration-starved and projects focusing on them get cut or canceled.

This comment somewhat helped me understand why we have a 2020 mars rover.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/29/2013 12:34 PM

1-I agree. Mars gets a lot of interest and focus due to the many scientists who focus on mars. Thus, we get a lot of information on the subject and focus on putting missions there, but other objects get exploration-starved and projects focusing on them get cut or canceled.

2-This comment somewhat helped me understand why we have a 2020 mars rover.

1-But that is not the ONLY reason Mars gets a lot of attention. Mars is a high-value scientific target. There is no way to deny that. Mars is also easily accessible, with regular launch windows and relatively short transit times compared to just about every other target in the solar system. Finally, Mars has always occupied a greater public role than any other planet, a fact that goes back centuries.

2-It's not that easy. The Mars 2020 rover was the right decision. The decadal survey prioritized the MAX-C rover mission and the Mars 2020 rover is going to do what MAX-C laid out. That's the way it is supposed to happen. Any other decision would have been in defiance of the wishes of the scientific community. And the only reason that MAX-C came out ahead of a Europa mission was because the Europa mission presented to the decadal survey was both too expensive to recommend, and could not be downscoped by the decadal survey committee itself.

But now that the Mars rover has been commissioned there should be no further Mars projects initiated when Europa is clearly the next target to be investigated.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/29/2013 04:27 PM
Yes, I was too lazy to check if JUICE will be carrying something similar to Cassini's INMS - which apparently it won't. I agree there's little added value in flying through the plumes in this case.
JUICE will carry what appears to be a very good mass spectrometer as part of its PEP instrument, which is really six different particle instruments.  This is from an abstract on the NIM sensor presented at the last European Planetary Science Conference:

"NIM is a highly sensitive neutral gas and ion mass spectrometer designed to measure the exospheric neutral gas and thermal plasma at Jupiter’s moons with a very high mass resolution and unprecedented sensitivity. The detection level for neutral gas is 1 ·10−16 mbar for a 5-second accumulation time (Wurz
et al., 2012), which corresponds to a particle density of about 1 cm−3. The mass resolution is M/M >
1100 in the mass range 1–1000 amu and NIM’s energy range is  5e V for neutrals and <10 eV for ions."

I'm not a mass spectrometer guy (give me a LiDAR or multi-spectral instrument any day), but this looks to be a very respectable mass spectrometer.  I believe that the Rosetta ROSINA MS only goes to 300 amu.
Title: Proposed Europa Missions
Post by: Star One on 12/29/2013 09:58 PM
But now that the Mars rover has been commissioned there should be no further Mars projects initiated when Europa is clearly the next target to be investigated.

Where does it say that?

That's what I am saying.

Sample collection has effectively been agreed for Mars with MSL 2 so let's start looking down the list so to speak.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/30/2013 01:04 AM
Sample collection has effectively been agreed for Mars with MSL 2 so let's start looking down the list so to speak.
Whoa, interesting. I just read the AO Q&A doc doc here (http://soma.larc.nasa.gov/mars2020/pdf_files/Mars2020AO_QAs_131224.pdf) and learned that an ISRU O2 experiment by HEOMD is one of highest prio payloads. The 2020 rover should probably get its own thread here, esp as preproposal materials (http://soma.larc.nasa.gov/mars2020/prepropwkshop.html) etc get posted now.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/30/2013 03:36 AM
... then maybe NASA could get started on a Europa mission by 2020 or so. But that should only happen after the overall balance has been restored to the program.
I have followed the fate of the four Decadal Surveys for each of NASA's science programs.  In terms of being able to implement the proposed program, the Earth Sciences program is perhaps in the worst shape and the astrophysics program perhaps is in the best shape (but only because the expectations were set so low).

Given much smaller budgets than anticipated, the managers of each of the programs are doing their best to implement the science priorities of the Surveys as best their resources allow.  I don't think it will be a question of returning the Decadal implementation plans, but rather what new plans will emerge.  (The science priorities identified by each Survey continue to be relevant. however.)

Jim Green was pretty specific about why Mars received the priority it did.  OMB told NASA it could have X dollars for a Mars program, and if it didn't accept it, then there were other places to put the funding.  I think that we under estimate the influence of mid-level budget officials at OMB in how roadmap decisions are being made.

Perhaps Blackstar knows more and let us know if my reading of the situation differs from what he's hearing.

Title: Re: Proposed Europa Missions
Post by: savuporo on 12/30/2013 04:10 AM
Mars sample return has been a high priority for decades and is only now being implemented.

Every document on 2020 rover goes out of it's way to explain that MSR is not being implemented. Sample caching is. But MSR is not, and 2020 rover's sample caching applicability to eventual MSR is not established, either.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/30/2013 04:48 AM
I agree with everything that Blackstar says (which means I find sources of information that may give me a fraction of what he hears :> ).  Just a couple of observations: The focus on Mars was, I believe, OMB directed.  If left to its own devices and with the same budgets as have occurred, Jim Green's folks might be talking about how sorry they are that they couldn't do a Flagship mission this decade but look at all the Discovery and New Frontiers missions they will select.  Green et al.'s genius was in turning a dictate into a mission that fit the Decadal plan.

And as an example of putting together what I meant by a new program, NASA appears to have made the decision to do a New Frontiers selection instead of two Discovery selections on its own.  I'm confident that they have a good reason, and I'll nod when I hear it.  The pieces come from the Decadal Survey, but the final mix will of necessity be different.  Look at all the missions that have been dropped or severely descoped in the Earth Science program to see a more extreme case (including one I wanted very much, a vegetation-oriented LiDAR instrument).

As for the mid-term assessment, I'm clearly less knowledgeable than Blackstar.  However, a parallel 2008 review, Opening New Frontiers in Space: Choices for the Next New Frontiers Announcement of Opportunity, did review the list of New Frontiers missions and recommended expanding the list to include a larger set previously identified by the full Survey.

The 2011 Survey identified the top scientific missions doable within the scope of a New Frontiers mission for each of the major types of destinations in the solar system: Inner planets (Venus Atmospheric Probe and Lander, Lunar South Pole-Aitken Basin Sample Return, Lunar Geophysical Network), small bodies (Comet Surface Sample Return, Trojan Asteroid Tour and Rendezvous), outer planets (Saturn probe, Io observer).  I don't see this list being overturned by the mid-term review.

What may get interesting is how NASA interprets the priority of a Europa mission (close #2 Flagship choice to a Mars caching rover) vis-a-vis the New Frontiers program.  Does it start the Europa Clipper in 2020 (~3 years before the next Decadal Survey takes effect) in place of New Frontiers 5 & 6 (assuming New Frontiers 4 starts ~2017)?  If Grunsfeld follows through with his idea to look at a New Frontiers or New Frontiers+25% mission for Europa and it comes through with a credible proposal, how would that fall into the mix?  NASA may ask the mid-term assessment team for advice on questions such as this for this one destination. 

Otherwise, short of Dawn finding spots on Ceres to be covered in complex organics or something equally solar system-shattering, I think the 2011 Survey priorities will stand.  The question will be how much of it can be implemented given the budgets provided and any more mandates from OMB or Congress.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/30/2013 04:55 AM
Every document on 2020 rover goes out of it's way to explain that MSR is not being implemented. Sample caching is. But MSR is not, and 2020 rover's sample caching applicability to eventual MSR is not established, either.
In one of the Decadal Survey meetings, Squyres said that this (the 2011) Survey doesn't have to decide on the full sample return mission since the latter missions would fall into the following decade.

We have a mission that will provide great science and enables MSR.  I'm happy to wait and see if the 2020 mission finds great samples to return or not, especially since pushing for approval of all of the MSR program is likely to get the OMB guys all excited.  The debates on this topic in the next Survey will make great reading, and they will know whether or not the rover is finding samples that are high priority to return.
Title: Proposed Europa Missions
Post by: Star One on 12/30/2013 09:20 AM
I suppose the larger question is we cannot discount other nations carrying out missions to the outer planets next decade aside from JUICE. So if NASA cannot do it maybe somebody else will put a project on the table that if not doing as envisioned here does at least cover the Jupiter system.

As far as next decade is concerned I think we can mostly count NASA out from planetary exploration to any great extend and instead see what others do in this area. I agree with what someone I saw wrote in the comments on another site that if NASA are happy to continue investing money in a dead ball of rock then let them and let's see who else comes to the table.
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 12/30/2013 12:07 PM
2-No. NASA doesn't really have the freedom to go off and do its own thing, ignoring the decadal. Congress doesn't let them do that, which is why the decadal surveys are required by law.

This is true in theory, but not always in practice.  For example, NASA ignored the prior to last solar and space physics decadal, and initiated Solar Probe Plus ahead of several smaller missions, violating that decadal's decision rules.  The follow-on solar and space physics mid-term assessment emphatically pointed out NASA's error, but the White House and Congress did nothing to correct it.

Quote
(If you ask me, this was just OMB wasting time.)

Or OMB forcing NASA to do its homework for once and get its arms around flagship options and costs before jumping into design decisions and development -- an understandable position for the budget agency given cost growth on Curiousity and other flagships.
Title: Re: Proposed Europa Missions
Post by: Star One on 12/30/2013 12:32 PM
Is such a focus on Mars scientifically being driven at a financial level by an expectation of manned missions as if it is this seems an unfortunate state of affairs as I have no confidence we will see any person on Mars any time soon?
Title: Re: Proposed Europa Missions
Post by: Star One on 12/30/2013 04:02 PM
Not seen this article before.

http://www.planetary.org/blogs/guest-blogs/van-kane/20131227-nasa-planetary-new-mission-woes.html
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/30/2013 05:02 PM
Is such a focus on Mars scientifically being driven at a financial level by an expectation of manned missions as if it is this seems an unfortunate state of affairs as I have no confidence we will see any person on Mars any time soon?

No. It's driven by scientific questions. The scientists have very little expectation of human missions to Mars in the next decades. I'm sure that many would love to see it, but they don't expect it to happen, and they don't want any expectation for human missions to affect their scientific goals. (For instance, some Mars scientists are unhappy that an ISRU experiment is taking up real estate on the Mars 2020 rover that they would prefer be devoted to scientific instrumentation.)

This is a very simplistic view, seeing as MSL 2 has joint SMD and HEOMD sponsorship. I dont think it has been established that the MSL 2 selection was a result of scientific priorities, at all - and i know you are going to say "decadal survey" about two dozen times more. In addition to OMB and SMD, there are obviously other decision influencers here. The real question is who and where. Rep. Adam Schiff and Sen. Dianne Feinstein may have a little something to do with it, too.

At the time of announcement, sample caching was very much not decided upon, even though apparently now that decision has been made. What Emily Lakdawalla wrote at the time (http://www.planetary.org/blogs/emily-lakdawalla/2012/12051226-response-2020-rover.html):
Quote
The rover that NASA announced yesterday is absolutely not the mission described in the Decadal Survey. It is not a small one based on MER with a lower science value than Curiosity because the science will happen back on Earth with samples returned through two later missions. It may not even cache samples at all. We actually don't know what it's going to do, because no scientific goals for the mission were mentioned in the announcement. The reason they weren't mentioned is because NASA doesn't know what the scientific goals are yet; those are yet to be defined, by a Science Definition Team.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/30/2013 05:39 PM
And it's an SMD mission, not an HEOMD mission (look who is paying for it).
Its cosponsored. HEOMD is paying for things like MEDLI+, the ISRU experiment and a few other things. Like i said this probably warrants its own thread.

( i was off by at least 4x by guessing two dozen , you only said "decadal survey" 6 times in your post. Its not a bible you know )

Btw here was the news piece (http://www.spacenews.com/article/figueroa-rules-out-another-nasa-mars-rover-2020)
Quote
Figueroa reiterated previous statements that his team will consider only missions that contribute in some way to an eventual Mars sample-return mission, which is the U.S. planetary science community’s top priority for flagship-class Mars exploration endeavors.

The White House in February sent Congress a 2013 budget request that would reduce the Planetary Science division’s budget from $1.5 billion to $1.2 billion. An appropriations bill drafted in the House of Representatives recommended giving the division $1.4 billion for 2013 and would require that NASA either create a Mars Next Decade mission that works toward sample return or scrap it in favor of sending an orbiter to Jupiter’s moon Europa.

The White House on May 7 threatened to veto the House proposal, which funds NASA at $17.6 billion as part of a broader $51.1 billion appropriations bill that funds several agencies.

Jim Green, director of NASA’s Planetary Science Division, warned that the White House could pull the plug on Mars Next Decade if the agency cannot decide on a mission that fulfills science, human exploration and space technology objectives.

“We are given an opportunity by this administration to craft a new Mars program,” Green said at the May 8 meeting. “If we are not able to do that, or if we are not able to show the synergies and move this agency forward both in human exploration and science, we may not be able to retain that budget.”

And another earlier one here (http://www.spacenews.com/article/former-mars-czar-tapped-lead-nasas-mars-reboot)
Quote
“With sample return, they didn’t mince the words in the decadal survey,” Figueroa said, acknowledging that his group must design a mission that not only supports Mars sample return but also passes muster with the White House budget hawks who nixed NASA’s involvement in such a campaign because it would tie up too much funding for too long.
...
Some scientists here, however, raised doubts that NASA could afford a rover capable of contributing to an eventual sample-return mission for $700 million.
..
Delaying a Mars Next Generation launch until 2020 would give Grunsfeld two more years over which to spread the mission’s development cost, but it would also mean a loss of 150 kilograms of payload due to the less-favorable relative positions of the Earth and Mars as they orbit the sun.
..
The MPPG is setting the stage for meaningful collaborations in the exploration of the red planet. To that end we have representation from the Science Mission Directorate, Human Exploration and Operations Mission Directorate, Office of the Chief Technologist, and Office of the Chief Scientist in our endeavor.

Its pretty easy to see that this was not a decadal survey/SMD and OMB fight alone

And this from the MPPG final report (http://www.nasa.gov/pdf/691580main_MPPG-Integrated-v13i-Summary%20Report-9-25-12.pdf):
Quote
The MPPG finds that sample return architectures provide a promising intersection of objectives and integrated strategy for long term SMD/HEOMD/STP collaboration

Title: Re: Proposed Europa Missions
Post by: savuporo on 12/30/2013 06:59 PM
As for MEDLI, the ISRU thing, they're minimal. They don't cost much, and they aren't the focus of the mission. The Science Mission Directorate is paying the vast majority of the cost of the Mars 2020 mission. It's a science mission first and foremost, with science priorities.

So you keep saying, but these claims are not supported by MPPG stated charter and results. MPPG charter explicitly said that the strategy has to be integrated HEOMD/STP/SMD goals. The selected 2020 rover mission is effectively Figueroa's "Rover C" , with the stated advantage of "Substantial HEO/STP payload opportunity"
HEOMD/STP sponsored payload total is a significant percentage of the estimated budget here, im not sure if you have looked at the docs at all.
The O2 experiment is at $55M, MEDLI up to $30M, potential weather station another $20M.

SMD instrument budget total is not to exceed $100M !

Atlas 5 launch is pinned at $400M.

Science driven ? Hmmm ..

EDIT: just for reference the docs where the numbers came from
http://www.nasa.gov/pdf/691580main_MPPG-Integrated-v13i-Summary%20Report-9-25-12.pdf
http://mars.jpl.nasa.gov/mars2020/files/m2020/SDT_Appendices_Final_v6.pdf
And
http://www.thk.edu.tr/~nsengil/feb13.pdf - page 32
Title: Re: Proposed Europa Missions
Post by: Star One on 12/30/2013 07:01 PM
How much of this confusion is down to political meddling? Would things be a lot easier if politicians didn't keep requiring x,y & z of NASA where x & z contradict one another?

It would be nice maybe if the politicians kept out of things full stop & let NASA fully allocate its own budget to its requirements & needs.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/31/2013 12:04 AM
In my opinion, I think we've mined the topic of how/why the 2020 rover mission (and I'm hearing 2022, too, as a possibility) as much as we can.  It's done.

I would still like to see a Europa mission.  In a few days, I'll post to my blog the results of a thought experiment I did to see if Grunsfeld's idea of a Europa New Frontiers mission seemed to make sense.  I took the instrument package from the Io Observer and asked whether a package of instruments from the Clipper within the same mass, power, and data requirements would fulfill one or more of the Europa science objectives.  From this simplistic analysis, there appears to be at least a few subsets.  So the Clipper may not be the final word in lower cost viable Europa missions.  However, if you read the post, you'll see why I concluded that the Clipper is the mission I think we should fly.  If we look at the total Decadal spending time frame (2013 through 2022 or 2023), then NASA will have the ability to build the Clipper (or a cheaper Europa mission if it decides that is viable).  (This gets harder if the 2020 Mars mission becomes the 2022 Mars mission.)

My only other big regret about Decadal priorities that don't look like they would be flown is an Ice Giants mission.  I wish the Decadal had specified an outer planets atmospheric mission rather than specifying Saturn.  The arguments in the Survey report for a Uranus probe were equally compelling (and the report did prioritize Uranus, but Flagships opportunities have gone away), and I'd like the scientific community to have an opportunity to propose for either one.  Oh well.




Title: Re: Proposed Europa Missions
Post by: Star One on 01/04/2014 04:23 PM
New article from the New Scientist about missions to Europa.

http://www.newscientist.com/article/mg22129502.700-water-plumes-spark-a-race-to-jupiter-moon-europa.html
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/04/2014 05:22 PM
New article from the New Scientist about missions to Europa.

http://www.newscientist.com/article/mg22129502.700-water-plumes-spark-a-race-to-jupiter-moon-europa.html
Some of the CubeSat guys keep suggesting that they can return to Europa faster than any other option.  We have yet to have any interplanetary CubeSats, and so this represents planning to run ultramarathons before taking baby steps.

CubeSats will find a role in planetary missions, but Europa is about as hard a target as you can pick for your first one.  At the very basics, what instrument (~1 kg) are you going to fly that will tell us something interesting?  How are you going to implement a radiation vault? 

I love the idea of CubeSats, but for nearby targets (NEOs, lunar) or a auxiliary instrument platforms for larger missions.

The New Scientist article, by the way, ignored JUICE's (at least) two Europa flybys plus long term distant observation campaign.  Any mission proposed for Europa has to exceed what is already planned by ESA.
Title: Re: Proposed Europa Missions
Post by: savuporo on 01/04/2014 06:19 PM
Yep, a cubesat plan to anywhere further than a simple deep space test or a lunar orbit at this point is just not reasonable. There are many technical issues that have to be figured out and tested as of yet. Radiation issues and communication being the most critical.
Title: Proposed Europa Missions
Post by: Star One on 01/04/2014 06:55 PM
For a start how would you even effectively radiation shield a cubesat in that kind of environment.

Quote from: vjkane
The New Scientist article, by the way, ignored JUICE's (at least) two Europa flybys plus long term distant observation campaign.  Any mission proposed for Europa has to exceed what is already planned by ESA.

I wonder if there is any possibility for them to increase the number of Europa flybys it does?
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/04/2014 07:31 PM
I wonder if there is any possibility for them to increase the number of Europa flybys it does?
It's likely a tradeoff of radiation hardening $s and risk assumed for later portions of the mission (radiation accumulated during the Europa flybys will be added to radiation accumulated later and could put later operations at risk).

The JUICE team is properly, a decade before launch, talking only about their committed Europa flyby number, 2.  I would not be surprised to see that increased closer to launch and the effectiveness of the radiation hardening is better understood.  I don't think that 5 flybys would surprise me.  10 would.  At 20, I'd be really worried about chemical stimulants during their analysis.  :>

One of the challenges to Grunsfeld suggestion of a New Frontiers[+] to Europa is that it has to add significantly to what some small number of JUICE flybys would.  More on my blog later this weekend.
Title: Re: Proposed Europa Missions
Post by: Star One on 01/04/2014 08:33 PM

I wonder if there is any possibility for them to increase the number of Europa flybys it does?
It's likely a tradeoff of radiation hardening $s and risk assumed for later portions of the mission (radiation accumulated during the Europa flybys will be added to radiation accumulated later and could put later operations at risk).

The JUICE team is properly, a decade before launch, talking only about their committed Europa flyby number, 2.  I would not be surprised to see that increased closer to launch and the effectiveness of the radiation hardening is better understood.  I don't think that 5 flybys would surprise me.  10 would.  At 20, I'd be really worried about chemical stimulants during their analysis.  :>

One of the challenges to Grunsfeld suggestion of a New Frontiers[+] to Europa is that it has to add significantly to what some small number of JUICE flybys would.  More on my blog later this weekend.

There must be a lot of competing pressures on the mission planning team of JUICE as at this time it's the only definite game in town as far as looking into such matters in situ.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/05/2014 06:10 PM
At the last NAC Planetary Sciences Subcommittee meeting, John Grunsfeld (NASA Associate Administrator for Science) discussed the possibility of looking at New Frontiers or New Frontiers +25% $s as an alternative to the Europa Clipper.  This got me curious as to whether this was a brain dead idea or not.

I took the Io Observer spacecraft study from the Decadal Survey as a credible spacecraft that could study a Jovian moon and looked at what some of the key questions would be for a similar spacecraft with equivalent instruments to study Europa.  I also look at the questions that this type of idea would raise given that JUICE will make at least two Europa flybys.  (I only raise questions because I'm not a mission architect, but there are some obvious questions a professional study team would look at; my post hopefully raises some of the major ones.  This is blog journalism, not mission design.)

This board has lots of informed readers.  I'd be interested in your thoughts on what a New Frontiers-class Europa mission might do and whether it might  be a credible alternative.

You can read the post at http://futureplanets.blogspot.com/2014/01/europa-new-frontiers-mission-or-why-i.html (http://futureplanets.blogspot.com/2014/01/europa-new-frontiers-mission-or-why-i.html)
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 01/05/2014 08:10 PM
For a start how would you even effectively radiation shield a cubesat in that kind of environment.


Maybe placing cubesat components inside a sphere of water. :) Of course that still leaves the sensors exposed to the harsh rad environment.
Title: Re: Proposed Europa Missions
Post by: savuporo on 01/05/2014 09:42 PM
For a start how would you even effectively radiation shield a cubesat in that kind of environment.


Maybe placing cubesat components inside a sphere of water. :) Of course that still leaves the sensors exposed to the harsh rad environment.
Do the math, it doesn't work. And i think thats off topic here.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/06/2014 03:56 PM
Europa Ice Clipper.
Title: Re: Proposed Europa Missions
Post by: Star One on 01/06/2014 08:36 PM

Europa Ice Clipper.

Thanks for that.
Title: Re: Proposed Europa Missions
Post by: jongoff on 01/06/2014 09:50 PM
CubeSats will find a role in planetary missions, but Europa is about as hard a target as you can pick for your first one.  At the very basics, what instrument (~1 kg) are you going to fly that will tell us something interesting?  How are you going to implement a radiation vault? 

I love the idea of CubeSats, but for nearby targets (NEOs, lunar) or a auxiliary instrument platforms for larger missions.

It'll be interesting to see where "interplanetary" cubesat missions go. If by "auxiliary instrument platforms" you mean having the cubesats as distributed sensor platform free-fliers supporting a more traditionally-sized "mothership" spacecraft, that's along the lines of what I've been thinking too.

~Jon
Title: Re: Proposed Europa Missions
Post by: jongoff on 01/06/2014 10:08 PM
Newbie question--the radiation we're talking about here is basically like Van Allen Belt radiation around earth (mostly high energy/fast electrons and protons/light nuclei), just more intense, correct?

~Jon
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/06/2014 10:51 PM
Newbie question--the radiation we're talking about here is basically like Van Allen Belt radiation around earth (mostly high energy/fast electrons and protons/light nuclei), just more intense, correct?
Far more intense than the Van Allen belts and concentrated more in the ecliptic.  The ions come primarily, I believe, from Io's erruptions.

Intensity increases as you approach Jupiter until just a few 10Ks kilometers above the cloud tops where they drop in intensity.  (Juno will sneak through this gap during its closest to avoid the worst of the radiation.  Even so, the spacecraft has extensive shielding.) 

The radiation at Europa would be lethal to humans and will fry electronics without shielding or specialty high radiation electronics (the latter are expensive and in some cases not available).
Title: Re: Proposed Europa Missions
Post by: jongoff on 01/07/2014 02:07 PM
Newbie question--the radiation we're talking about here is basically like Van Allen Belt radiation around earth (mostly high energy/fast electrons and protons/light nuclei), just more intense, correct?
Far more intense than the Van Allen belts and concentrated more in the ecliptic.  The ions come primarily, I believe, from Io's erruptions.

Intensity increases as you approach Jupiter until just a few 10Ks kilometers above the cloud tops where they drop in intensity.  (Juno will sneak through this gap during its closest to avoid the worst of the radiation.  Even so, the spacecraft has extensive shielding.) 

The radiation at Europa would be lethal to humans and will fry electronics without shielding or specialty high radiation electronics (the latter are expensive and in some cases not available).

Interesting, thanks. Is the higher intensity due to higher energy levels of particles (relative to earth's Van Allen Belts), or higher particle density, or both? I've got an idea that *might* work for protecting a cubesat from the worst of it, but I'm trying to make sure I understand the problem first.

~Jon
Title: Re: Proposed Europa Missions
Post by: Robotbeat on 01/07/2014 04:06 PM
Cubesats can be ready faster only because they're smaller and cheaper. The whole process of building them and picking a flight is just WAY easier because of that. So I don't take the claim that they can be ready faster as too outrageous. Yeah, no one has demonstrated an interplanetary cubesat, but what fundamentally would be the reason it couldn't be done?

A big issue with cubesats is communication over interplanetary distances. Some sort of relay using a larger vehicle (like we do on Mars with landers and rovers) is a great way to overcome that.

Anyway, the cubesat people have a huge advantage in nimbleness that may off-set their equally huge disadvantage of not demonstrating an interplanetary mission, yet. But it wouldn't be as capable as a real spacecraft, that much is certain, and I don't think we need to kid ourselves about that, yet.
Title: Re: Proposed Europa Missions
Post by: Star One on 01/07/2014 05:23 PM

Cubesats can be ready faster only because they're smaller and cheaper. The whole process of building them and picking a flight is just WAY easier because of that. So I don't take the claim that they can be ready faster as too outrageous. Yeah, no one has demonstrated an interplanetary cubesat, but what fundamentally would be the reason it couldn't be done?

A big issue with cubesats is communication over interplanetary distances. Some sort of relay using a larger vehicle (like we do on Mars with landers and rovers) is a great way to overcome that.

Anyway, the cubesat people have a huge advantage in nimbleness that may off-set their equally huge disadvantage of not demonstrating an interplanetary mission, yet. But it wouldn't be as capable as a real spacecraft, that much is certain, and I don't think we need to kid ourselves about that, yet.

I would have thought the most effective way of achieving interplanetary missions with them would be by using a swarm of them combined together using collective intelligence. This would allow for redundancy. Also scientific payloads along with items such as long range communications could be distributed amongst them.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/07/2014 06:45 PM
Anyway, the cubesat people have a huge advantage in nimbleness that may off-set their equally huge disadvantage of not demonstrating an interplanetary mission, yet. But it wouldn't be as capable as a real spacecraft, that much is certain, and I don't think we need to kid ourselves about that, yet.
I think that the challenge of putting science quality instruments on a CubeSat, navigate it to fly past Europa, and return science is daunting.  If all we needed were a few snap shots of the surface to answer the compelling questions, Galileo already did that.  Just getting some piece of (in this case, really small) hardware to Europa doesn't address the science questions.

There is a serious concept to add CubeSats to a Europa multi-flyby mission to perform very high resolution imaging a la the lunar Rangers.  But the CubeSats don't have to propel themselves to Jupiter, navigate precisely, and return many megabytes of data to Earth (the mother craft serves as data storage and relay). 
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 01/07/2014 08:14 PM
The 2012 JPL paper linked at the bottom of this post summarizes a study of interplanetary cubesat missions, including:

1. Mineral Mapping of Asteroids [Small Body Science]
2. Solar System Escape Technology Demonstration [Tech Demo]
3. Earth–Sun Sub-L1 Space Weather Monitor [Heliophysics and Terrestrial Applications]
4. Phobos Sample Return [Planetary Science]
5. Earth–Moon L2 Radio Quiet Observatory [Astrophysics]
6. Out-of-Ecliptic Missions [Heliophysics]

It probably represents the "state-of-the-art" in cubesat mission concepts beyond LEO.  None are outer planets missions, and Europa would be especially challenging given the low solar flux and extremely high radiation.  That said, if you look sideways and squint really hard at the Phobos sample return mission and assume a couple different or newer approaches than what JPL baselined here, then maybe a simple, independent Europa geyser sample return would be possible within 6U.

In terms of enabling technologies for interplanetary cubesat missions, here's JPL's list:

1. CubeSat electronics and subsystems extended and improved from their low Earth orbit implementations in order to operate in the interplanetary environment, with particular attention to surviving increased radiation and
duration of operation.
2. Optical telecommunications to enable very compact, low-power uplink/downlink over interplanetary distances.
3. Solar sail propulsion to enable major maneuvers and rendezvous with multiple targets using no propellant.
4. Navigation of the Interplanetary Superhighway to enable multiple destinations over reasonable mission durations with achievable dV.
5. Small, highly capable instrumentation (such as a miniature imaging spectrometer) enabling acquisition of high quality scientific and exploration information.
6. Onboard storage and processing of raw instrument data and navigation information to enable maximum utility
of uplink and downlink telecom capacity, and minimal operations staffing.

I'd add alpha and/or betavoltaic power sources, passive optical comm, metamaterial and/or genetically engineered antennas, and microfluidic electrospray propulsion to that list for more capable future missions and potentially enabling for the outer planets.

Here's the PDF paper and live presentation:

http://www.nasa.gov/pdf/716078main_Staehle_2011_PhI_CubeSat.pdf

http://www.youtube.com/watch?v=WMSxBuyGoO0

And here's a somewhat technical PowerPoint presentation on the various missions:

http://mstl.atl.calpoly.edu/~bklofas/Presentations/DevelopersWorkshop2012/Staehle_Interplanetary_CubeSat.pdf

And here's another paper that delves more deeply into the Phobos sample return and variations on it:

http://www.lpi.usra.edu/meetings/marsconcepts2012/pdf/4123.pdf

FWIW...

Title: Re: Proposed Europa Missions
Post by: savuporo on 01/08/2014 03:22 AM
Great summary of technical issues. Deep space environmental issues are really quite different from LEO and before a single cubesat has been even to a lunar distance for an extended period, it's way too premature to talk about outer planets.
Would be awesome if there was a funded cubesat launch opportunities program to GEO altitudes first
Title: Re: Proposed Europa Missions
Post by: plutogno on 03/03/2014 07:48 PM
the next NASA budget may at last fund initial work on an Europa mission
http://www.aviationweek.com/Article.aspx?id=%2Farticle-xml%2Fawx_03_03_2014_p0-668360.xml
Title: Re: Proposed Europa Missions
Post by: EE Scott on 03/04/2014 02:49 AM
Yes, but is NASA able to be that thoughtful?  That sounds like the best way to spend the resources, guaranteed to contribute to the Europa mission, or many others should Europa not come to be.
Title: Re: Proposed Europa Missions
Post by: baldusi on 03/04/2014 02:57 AM
Don't they need like four MMRTG? Is there enough weaved fabric?
Title: Re: Proposed Europa Missions
Post by: redliox on 03/04/2014 07:33 AM
Although it's doubtful the Europa Clipper will do anything too inventive (i.e. using what's available now like chemical engines, solar panels, RTGs, instrument rebuilds), I have had thoughts on what would assist a future Jupiter mission (or possibly a Saturn/Titan mission)....

Both Galileo's and Juno's missions were driven partly by their mass.  More specifically, JOI propellant.  Galileo weighed about 2.4 metric tons, of which 0.9 was fuel/oxidizer.  However during the 8 years it orbited Jupiter Galileo used scarcely a hundred pounds.  If JOI could be scratched, any Jupiter spacecraft would weigh no more than a Martian one, giving room for thicker rad shielding and instruments.

Since SEP is a bit of a stretch at Jupiter and nuclear , an idea Arthur C. Clarke implemented comes to mind...
(http://mossfilm.files.wordpress.com/2013/12/2010-leonov.jpg)

Aerocapture is no doubt a stretch, but the technology is maturing.  Titan is an easier target compared to Jupiter's turbulence and radiation, but it's also a heck of a lot farther.  Jupiter with 4 large moons has the greater science payout for operation time, its just getting around JOI.  Something akin to a shielded Mariner probe could be stuffed in a cylinder and a tough inflatable utilized to get it into an orbit spanning out to Callisto (or Ganymede or Europa itself depending on mission needs), and from there pops out of its can and gravity assists its way among the moons.

So how much of a pain would it be to aerocapture a probe at Jupiter?
Title: Re: Proposed Europa Missions
Post by: Drkskywxlt on 03/04/2014 10:50 PM
I take back what I just wrote. Wait until the budget comes out. You'll be surprised.

Do you think this ~$15M in FY15 is enough to count as a new start?  Sounds more like they're relenting to the fact that Rep. Culbertson is going to put money into the budget anyway (and likely more than this).
Title: Re: Proposed Europa Missions
Post by: redliox on 03/05/2014 02:40 AM
Do you think this ~$15M in FY15 is enough to count as a new start?  Sounds more like they're relenting to the fact that Rep. Culbertson is going to put money into the budget anyway (and likely more than this).

It's enough to give inquires into.  It is already on a promising arc and just needs a boost of attention from Congress.

One way that might ensure it gets funded is flying it aboard SLS.  With complaints about it lacking a payload or purpose beyond Orion, advocate to Bolden "Here one!"  Some projects survived by pulling on strings of others, such as Cassini dodging an ax because of it's heavy international ties or Galileo onboard the shuttle (granted Challenger's mishap delayed it quite a bit).  Something you have to fight politics with politics, since science alone can't do much without a crowd behind it.
Title: Proposed Europa Missions
Post by: vjkane on 03/05/2014 05:28 AM
I take back what I just wrote. Wait until the budget comes out. You'll be surprised.

Which post should we forget? The out year funding or the mmrtg post?
Title: Re: Proposed Europa Missions
Post by: darkbluenine on 03/05/2014 02:07 PM
Also heard some info about an "enhanced" MMRTG and a small nuclear reactor. The former is new to me and I don't know any details. The latter has been talked for awhile, but I did not realize that they had done some work on that (namely identifying a Nevada site where they could test a small reactor).

A couple papers/presentations on these "kilopower" uranium reactor concepts.  First addresses testing.  I've seen the cost estimates for the second.  They're in the $1-2B range.

http://local.ans.org/trinity/files/mcclure-130920.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120001793.pdf

FWIW...
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/06/2014 04:45 PM
Here you go.
Title: Re: Proposed Europa Missions
Post by: Star One on 03/06/2014 07:27 PM
Thanks for that. Be interesting to see which way they go on both the power supply and launcher.
Title: Re: Proposed Europa Missions
Post by: yg1968 on 03/06/2014 07:57 PM
SN is reporting that Bolden is looking for a Europa mission that would cost less than $1B:
http://www.spacenews.com/article/civil-space/39756nasa-to-seek-ideas-for-1-billion-mission-to-europa
Title: Re: Proposed Europa Missions
Post by: redliox on 03/06/2014 08:08 PM
SN is reporting that Bolden is looking for a Europa mission that would cost less than $1B:
http://www.spacenews.com/article/civil-space/39756nasa-to-seek-ideas-for-1-billion-mission-to-europa

Heard about that.  I think a New Frontiers-class probe would have some potential, but understandably it'd be limited compared to a flagship.  If it has to be prioritized and limited, giving it a goal of mapping the surface and finding the ocean should be it - i.e. visible cameras and the radar but no spectrometers.  If we can't do everything, at least ensuring we can put a lander down later isn't a bad goal to settle for.

Here you go.

Great find Blackstar!  It's good to see more details and plans for E.C. emerging.  I just hope sometime this year they finally commit to it or establish a solid "plan B", be it flagship or N.F.
Title: Re: Proposed Europa Missions
Post by: baldusi on 03/06/2014 08:24 PM
I do wonder, thou. What if the final budget looks to be something like 1.5B?
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 03/06/2014 08:41 PM
So how much of a pain would it be to aerocapture a probe at Jupiter?

I'd like an answer to this too, especially considering the recent discussion (http://forum.nasaspaceflight.com/index.php?topic=34127.0). :)
Title: Re: Proposed Europa Missions
Post by: Star One on 03/06/2014 08:59 PM

I do wonder, thou. What if the final budget looks to be something like 1.5B?

I could put all of this into italics for emphasis, but instead, just consider this to be a helpful reminder:

Your best bet (for your own peace of mind) is to not speculate too much and just watch the process play itself out. There is a lot of stuff that is in play, and a lot of things that will have to work themselves out, but not all the details are public (nor should be). But there is some reason to be optimistic about the way things may turn out. No guarantees, but for the first time the trend arrows are pointing in the right direction.

I really hope it all goes positively.

I posted about this mission on a general forum and there was a high level of enthusiasm for it. I know that isn't a very scientific survey but Europa does seem to capture people's minds in the same way Mars appears too.
Title: Re: Proposed Europa Missions
Post by: yg1968 on 03/06/2014 09:07 PM
SN is reporting that Bolden is looking for a Europa mission that would cost less than $1B:
http://www.spacenews.com/article/civil-space/39756nasa-to-seek-ideas-for-1-billion-mission-to-europa

You can probably ignore Bolden's comments on these things.

Grunsfeld said the same thing.

Quote
John Grunsfeld, the former astronaut turned associate administrator for NASA’s Science Mission Directorate, said at the symposium. NASA will ask for Europa mission concepts that could be done “for around a billion dollars.”
Title: Re: Proposed Europa Missions
Post by: baldusi on 03/06/2014 10:16 PM
From what I get they have estimated that for 2B they'll get a good idea of the surface and the undelying structures (i.e. if there are oceans and what type). But if they have to do away with the deep radar, they might end with a 1B mission that only tells them about the surgace and the interior will be left as an excercise for the PI.
Title: Re: Proposed Europa Missions
Post by: baldusi on 03/07/2014 12:16 AM
I
But can you do an assessment of the plumes? And can you do high-resolution imaging of the surface to enable an eventual lander?
I see the plumes as a bet. If it's a recurrent process, they can hit a jackpot. But if not a lot of expensive instrument will be wasted.
Regarding the resolution, I understand that it might require a level of resolution that's not possible ( like sub meter), and many flybys might not get a global coverage. But more importantly, we don't know how it changes or regenerate. That's my understanding. I might be widely wrong.
But given that a follow up missions might be 15 to 20 years after this one, I think it's better to get enough information to know if Europa should be the biggest priority (probably after Mars) or not.
Title: Re: Proposed Europa Missions
Post by: redliox on 03/07/2014 06:59 AM
So how much of a pain would it be to aerocapture a probe at Jupiter?

I'd like an answer to this too, especially considering the recent discussion (http://forum.nasaspaceflight.com/index.php?topic=34127.0). :)

Right now the goal is to get the cost of such a mission lower, and adding new and untested technologies is not a good way to lower costs. So it is not going to happen.

Correct, which I admitted to when mentioning it.  Still, with aerocapture being considered for outer planet targets like Neptune and Titan, it would make sense to test it closer to home, making Jupiter the first atmosphere in the outer solar system.  I just know that radiation belt and (to a lesser extent) rings would be a heck of a landmine field.

Other than another orbiter, a more specific probe that would get the maximum benefit from Jovian aerocapture would be a future Europa lander.  Timed correctly, it could arc from Jupiter directly to Europa without a massive JOI or months of gravity assists to guide it down the gravity well.  Aerocapture is too big a leap for Europa Clipper, but whatever it's successor is, that craft could attempt it.

...I'm just curious what kind of hellish geometry is needed.  ;)
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/07/2014 11:55 AM

And part of the way that you have to look at that question is with regards to any follow-on missions. If you do the $1 billion mission, but in order to answer the key questions you still have to do another $1.5 billion mission (say, a Europa orbiter), then you haven't made a wise choice, because you've spent more money in the long run rather than doing the first mission right. Of course, there are all kinds of trades here, and it requires judgement calls. But it ultimately points to the fact that the goal should not be to do a Europa mission simply to do a Europa mission, the goal should be to do a Europa mission that answers the key questions that people want to answer.
In support of what Blackstar is saying, the science definition team has specified several science goals: icy she'll, surface composition, surface geology, ocean depth and composition, and landing site reconnaissance. The plumes, if confirmed, would be an additional goal.

Each goal has one or two instruments (with several instruments shared between goals). Each also needs a specific number and geometries of encounters.

To me, a credible mission needs to knock of the two highest priority goals, the ice shell characterization (ice penetrating radar and topographic imager) and surface composition (add short wave IR spectrometer with a mass spectrometer as a desired instrument). For plumes you'd want the MS spectrometer and some remote sensing instrument to locate the plumes and their sources, maybe a UV spectrometer.

The instrument list looks reasonable, but the real challenge is likely to be surviving the radiation the achieve a sufficient number of encounters.
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/07/2014 12:51 PM


I see the plumes as a bet. If it's a recurrent process, they can hit a jackpot. But if not a lot of expensive instrument will be wasted.
The key instrument for the plumes would be a mass spectrometer. That instrument also would be highly desired for measuring surface composition.

For a uv spectrometer, perhaps NASA could collaborate with ESA. The JUICE mission is planning an extensive search with their uv instrument.
Title: Re: Proposed Europa Missions
Post by: Star One on 03/07/2014 01:46 PM


And part of the way that you have to look at that question is with regards to any follow-on missions. If you do the $1 billion mission, but in order to answer the key questions you still have to do another $1.5 billion mission (say, a Europa orbiter), then you haven't made a wise choice, because you've spent more money in the long run rather than doing the first mission right. Of course, there are all kinds of trades here, and it requires judgement calls. But it ultimately points to the fact that the goal should not be to do a Europa mission simply to do a Europa mission, the goal should be to do a Europa mission that answers the key questions that people want to answer.
In support of what Blackstar is saying, the science definition team has specified several science goals: icy she'll, surface composition, surface geology, ocean depth and composition, and landing site reconnaissance. The plumes, if confirmed, would be an additional goal.

Each goal has one or two instruments (with several instruments shared between goals). Each also needs a specific number and geometries of encounters.

To me, a credible mission needs to knock of the two highest priority goals, the ice shell characterization (ice penetrating radar and topographic imager) and surface composition (add short wave IR spectrometer with a mass spectrometer as a desired instrument). For plumes you'd want the MS spectrometer and some remote sensing instrument to locate the plumes and their sources, maybe a UV spectrometer.

The instrument list looks reasonable, but the real challenge is likely to be surviving the radiation the achieve a sufficient number of encounters.

How many encounters would it need to make with Europa at a minimum to get an effective set of science results?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/07/2014 06:02 PM
Two papers from 2008 on exactly what their titles indicate.
Title: Re: Proposed Europa Missions
Post by: redliox on 03/07/2014 07:21 PM
Other than another orbiter, a more specific probe that would get the maximum benefit from Jovian aerocapture would be a future Europa lander.  Timed correctly, it could arc from Jupiter directly to Europa without a massive JOI or months of gravity assists to guide it down the gravity well.


You sure of that?

It would be possible, but a more conservative approach using aerocapture would do its best to just graze the Jovian atmosphere and enter ~100 day orbit.  Naturally the longer a craft aerobrakes, the more speed it burns off so long as the heatshield holds.  Something wanting an orbit whose apogee touches Europa's would be ~7 days or less, and that would be on the higher end of entry speeds.

We've had heat shields, landers, and sample-return capsules for decades now, the only new elements to apply are inflatables and composites.  The only issue I see is calculating a right angle and whether or not the vehicle needs more aggressive autonomous programming (Curiosity's descent at Mars might be good example of this).
Title: Re: Proposed Europa Missions
Post by: Star One on 03/07/2014 10:05 PM
Space Politics article.

http://www.spacepolitics.com/2014/03/07/europa-on-five-hundred-thousand-dollars-a-day/
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/08/2014 07:37 AM



Quote from: baldusi link=
[/quote


How many encounters would it need to make with Europa at a minimum to get an effective set of science results?

The number of encounters is a complex question. From the Clipper presentations, my reading of a complex slide suggests that some investigations might get by with as few as 20-30 flybys, others perhaps as many as 50.

However, the Clipper goals are for full global coverage, tries to replicate with flybys what an orbiter would do, and assumes a ~$2b budget. 

An alternative strategy might be to remotely study  a handful of interesting locations instead. (Each interesting region would have a dedicated fly over during one of the encounters,).

Imagine that a ~$1b mission could do 12 flybys. You might budget them this way:

3 plume encounters
6 interesting regions such as the maculas
3 average areas

I'm not saying I favor this strategy, but it is a valid option to consider.   The targets chosen could also be coordinated with the ones the Juice mission will target
Title: Re: Proposed Europa Missions
Post by: redliox on 03/08/2014 08:06 AM
An alternative strategy might be to remotely study  a handful of interesting locations instead. (Each interesting region would have a dedicated fly over during one of the encounters,).

Imagine that a ~$1b mission could do 12 flybys. You might budget them this way:

3 plume encounters
6 interesting regions such as the maculas
3 average areas

I'm not saying I favor this strategy, but it is a valid option to consider.   The targets chosen could also be coordinated with the ones the Juice mission will target

That would sound like a still viable plan.  Naturally not as elaborate or in depth, but the point is to establish some answers.  Kepler, for example, couldn't scan the whole sky but from what it could see and record has now confirmed hundreds of planets, supplying information that can give solid numbers for the Drake equation.  For Europa the least we can do is answer "Is there a liquid ocean down there?"
Title: Re: Proposed Europa Missions
Post by: Star One on 03/08/2014 10:05 AM




Quote from: baldusi link=
[/quote


How many encounters would it need to make with Europa at a minimum to get an effective set of science results?

The number of encounters is a complex question. From the Clipper presentations, my reading of a complex slide suggests that some investigations might get by with as few as 20-30 flybys, others perhaps as many as 50.

However, the Clipper goals are for full global coverage, tries to replicate with flybys what an orbiter would do, and assumes a ~$2b budget. 

An alternative strategy might be to remotely study  a handful of interesting locations instead. (Each interesting region would have a dedicated fly over during one of the encounters,).

Imagine that a ~$1b mission could do 12 flybys. You might budget them this way:

3 plume encounters
6 interesting regions such as the maculas
3 average areas

I'm not saying I favor this strategy, but it is a valid option to consider.   The targets chosen could also be coordinated with the ones the Juice mission will target

Thanks for that. I assume you would want these encounters at different altitudes, or would that make a more simple mission too complex. How difficult is it too vary a perimeter such as this.
Title: Re: Proposed Europa Missions
Post by: redliox on 03/08/2014 07:31 PM
For Europa the least we can do is answer "Is there a liquid ocean down there?"

Scientists are already 99% sure there is a liquid ocean down there. A Europa mission would have to do a lot more to be worthwhile.

Scientists were sure about a lot of things, from the Earth being flat to Venus being a tropical paradise...until they got direct data.  There is still speculation it might be all ice.  IPR is a must whatever gets sent to Europa for that reason.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/08/2014 07:58 PM
For Europa the least we can do is answer "Is there a liquid ocean down there?"

Scientists are already 99% sure there is a liquid ocean down there. A Europa mission would have to do a lot more to be worthwhile.

Scientists were sure about a lot of things, from the Earth being flat to Venus being a tropical paradise...until they got direct data.  There is still speculation it might be all ice.  IPR is a must whatever gets sent to Europa for that reason.

The issue is not the presence of water, it is how much of it there is (as opposed to ice).
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/09/2014 05:39 AM


That would sound like a still viable plan.  Naturally not as elaborate or in depth, but the point is to establish some answers.  Kepler, for example, couldn't scan the whole sky but from what it could see and record has now confirmed hundreds of planets, supplying information that can give solid numbers for the Drake equation.  For Europa the least we can do is answer "Is there a liquid ocean down there?"
The Kepler analogy doesn't quite work. There are billions of stars in our galaxy and so a sample from thousands of stars is statistically valid. 

There's only one Europa with heterogenously distributed features. Fortunately, we have Galileo data to give us some idea where to look. However, without global coverage, we would miss many potentially interesting spots. Imagine if we only had coarse resolution Viking images and the Mars Reconnaissance orbiter could look at only a dozen locations.  We would have missed most of the exciting story that has emerged.

Galileo all but confirmed the ocean. My understanding is that the megnetometer and gravity measurements that would further would require a large number of flybys.
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/09/2014 05:45 AM



[quote author=Star One link=topic=27871.msg1168993#msg1168993 date=

Thanks for that. I assume you would want these encounters at different altitudes, or would that make a more simple mission too complex. How difficult is it too vary a perimeter such as this.
I believe that the Clipper strategy is to keep the flyby altitudes similar.  What the make clear is that they would distribute to locations of the closest approach across the Europan globe
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/09/2014 07:36 AM
The issue is not the presence of water, it is how much of it there is (as opposed to ice).
And the salinity of the ocean, which gives a lot of clues about the composition and the nature of the water-rocky surface interface

Edit/Lar: Fix quotes
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/15/2014 03:02 AM
Here you go.
Title: Re: Proposed Europa Missions
Post by: redliox on 03/15/2014 07:37 AM
Interesting reading through the older EL specifications, but it felt like a mix of pie-in-sky, irritating, and yet a touch of intrigue all at once.

The 2 bits that caught my attention most were locations for a relay orbiter and their (brief) thoughts on aerocapture:

Relay): Although I doubt NASA would devote an orbiter purely for relay, it would be an obvious side-function for a long lived observer orbiter meant for medium-range observations or plume observations (of either Europa or Io).  A LaGrange position would be easier to settle into, although, aside from radiation at one at Europa, the gravity-play of 4 moons and a giant planet might make it tricky.  A relay at either Ganymede's or Callisto's L-points or a distant Jovian orbit might be the best compromise, if your priority is avoiding radiation at least.

Aerocapture: Not an enabling technology my *&@$$#!!!  was my instinctive reaction.  JOI is also NOT a small burn, ITS HUGE!  Both Galileo and Juno devoted easily half their weight for just those events, which says a lot for finding a way to get around the burden.  Aside from electric propulsion (both ION and VASMIR), which they did point out was too power-hungry to be practical at Jupiter, aerocapture is the best way to slow down without giant fuel loads.  This was, of course, all written before experiments like IRVEE began, so I read this with a grain of salt.  Still I felt very disappointed, as I consider myself an advocate of aerobraking/capture (you can blame 2010 and the Leonov for that  ;D :P ).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/15/2014 03:50 PM
Here's another one. I have not checked to see if this differs from the others. I have a 150 meg movie animation of this design, but it's too big to load here.
Title: Re: Proposed Europa Missions
Post by: redliox on 03/15/2014 04:21 PM
Aerocapture: Not an enabling technology my *&@$$#!!!  was my instinctive reaction. 

SNIP

Still I felt very disappointed, as I consider myself an advocate of aerobraking/capture (you can blame 2010 and the Leonov for that  ;D :P ).

I've seen a bunch of Europa presentations and none of them ever talk about aerocapture with Jupiter.

And likewise none of us have seen a Europa spacecraft, discounting perhaps Galileo.

Specifically for aerocapture, I have read into it from the 1980s' Race to Mars and Mark Zubrin's The Case for Mars, and more recently the IRVEE tests.  So many sources are advocating it as a means for reducing mass on Martian missions; on top of that both Titan and Neptune are being cited as future targets.  If the technology expands into the outer solar system, Jupiter is the closet body where it could be used.

A handy link full of data from the University of Houston: http://www.uh.edu/sicsa/library/media/Student%20Projects/Deceleraters (http://www.uh.edu/sicsa/library/media/Student%20Projects/Deceleraters)

The technology just needs to be demonstrated, just as Pathfinder used airbags and Deep Space 1 used ion propulsion, each later used by MER and Dawn respectively in full-fledged science missions.

I'm just seeing a logical use for it at Jupiter and the Outer Solar System as a means for reducing weight and size.  When you need 1,000 pounds+ of fuel to slow down....is it any wonder nothing but flagships are insisted upon whereas smaller, Discovery-sized missions in the Inner Solar System have made significant discoveries?
Title: Re: Proposed Europa Missions
Post by: Spiff on 03/15/2014 06:42 PM
Nice article on SpaceflightNow

http://spaceflightnow.com/news/n1403/14europa/#.UySenYX3ip0

Title: Re: Proposed Europa Missions
Post by: redliox on 03/15/2014 08:20 PM
Nice article on SpaceflightNow

http://spaceflightnow.com/news/n1403/14europa/#.UySenYX3ip0

Not a bad find Spiff.  :)  It at least establishes what the overall 'mood' of the Europa situation is.

Quote
   
NASA Administrator Charlie Bolden said March 5 that officials envision a mission to Europa with about the same cost as the agency's New Frontiers line, which carries a cost cap of approximately $1 billion. NASA has launched two New Frontiers mission to date, with the New Horizons probe on the way to the first flyby of Pluto and the Juno spacecraft cruising to Jupiter.

Another New Frontiers mission, OSIRIS-REx, is due for launch in late 2016 to return samples from an asteroid.

Green said that while NASA aims to design a Europa probe in the mold of a New Frontiers mission, it will be a standalone project. The National Research Council's planetary science decadal survey, which sets NASA's strategy in robotic exploration of the solar system, outlined specific concepts the space agency will choose from when crafting the next New Frontiers program.

"Everyone has been saying New Frontiers-class, but what they really mean is at about a billion dollars," Green said. "Could we really do Europa science at about a billion dollars?"

Engineers could design the spacecraft to be solar-powered instead of putting plutonium power generators on the probe, a design change that would cut costs. International partnerships are also an option, officials said.

Sadly budgets will drive this mission, but I am optimistic regarding what an official study for a New Frontiers-Europa probe could say.  Mapping Europa will certainly be a priority, but the plume discovery will be the new wild card now:

Quote
The discovery of the plumes drove NASA to ask "what out of our concepts could take advantage of flying through the plumes," Green said. "Is the orbiter or the multiple-flyby option in a better position to be able to study the plumes, make measurements, actually get samples, analyze those and be able to tell us what's in those? Is it just water, are there organics, what is Europa processing and how is that ocean communicating with the surface?"

The Europa Clipper concept, which carries a cost of about $2 billion, was designed before the plume discovery.

"Clipper wasn't designed to fly through plumes with the right instruments," Green said. "We're in the process of validating that. We're in the process of asking what could have Clipper done, or do we need to follow up with Clipper to do that. That's one option, but we're also looking at what can we do of value with the plumes at an even lower cost. We don't know for a fact that we can, but that's what pre-formulation is all about. Let's study that."

Lets hope the new round of studies bring promise to Europa exploration.
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/16/2014 04:38 AM
If NASA decided to cancel New Frontiers and do a cheapish Europa mission instead, they would be explicitly going against the direction of the decadal sururovey and the scientists would make a lot of noise complaining. NASA knows this, Congress certainly knows this, and OMB, depending upon the time of day and the phase of the Moon, knows this.

The Decadal Survey said that *global* mapping of Europa is the goal.  A $1B mission certainly would build on our knowledge of Europa.  Consider, though, that our current knowledge about Europa probably falls somewhere between what we knew of Mars between Mariner 9 and the Viking orbiters.  Imagine if we studied only a few percent of Mars at high resolution based on what we knew from Viking.  We would have missed so much that turned out to be important.  We need a good analysis of Europa as a world. 

If you read the original paper on the moons or the better stories reporting on it, the signal for the plumes is just above the noise level.  They may be real or not.

I suspect that NASA is using the plumes and the hopes for a credible $1B mission to get a mission approved earlier than the current mid-2020s.  It might work.  It did for Mars.
Title: Re: Proposed Europa Missions
Post by: Star One on 03/16/2014 10:06 AM
A question if Atlas isn't available to launch this mission should it go ahead, SLS is too expensive, would it have to be launched on a Delta 4H and if that was the case what would the cost implications be?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/16/2014 11:26 AM
The Decadal Survey said that *global* mapping of Europa is the goal.  A $1B mission certainly would build on our knowledge of Europa.  Consider, though, that our current knowledge about Europa probably falls somewhere between what we knew of Mars between Mariner 9 and the Viking orbiters.  Imagine if we studied only a few percent of Mars at high resolution based on what we knew from Viking.  We would have missed so much that turned out to be important.  We need a good analysis of Europa as a world. 


We should also keep in mind that there are science goals and also programmatic goals. The programmatic goals are longer term, but essentially boil down to: what can we do with this first mission that makes further missions easier/better?

For example, if a flyby mission does not gather enough data to go straight to a lander mission, then that means that NASA will have to fly an orbiter next before a lander. What that means is that if they do the flyby mission wrong (to save a few hundred million dollars), they may have to spend an extra $2.5+ billion for an orbiter mission before a lander, and delay flying a lander for many decades.

You could spin out two scenarios:

Scenario 1
$1 billion (cheap) flyby mission in the 2020s--->$2.5+ billion orbiter mission in the 2030s-->lander mission 2040s/50s

Scenario 2
$2.1 billion Europa Clipper mission in the 2020s-->lander mission in the 2030s

Title: Re: Proposed Europa Missions
Post by: Blackstar on 03/16/2014 11:27 AM
A question if Atlas isn't available to launch this mission should it go ahead, SLS is too expensive, would it have to be launched on a Delta 4H and if that was the case what would the cost implications be?

Yeah, or maybe Falcon Heavy, if it is available.

But there's no reason to assume that Atlas V will not be available.
Title: Re: Proposed Europa Missions
Post by: Star One on 03/16/2014 12:09 PM

A question if Atlas isn't available to launch this mission should it go ahead, SLS is too expensive, would it have to be launched on a Delta 4H and if that was the case what would the cost implications be?

Yeah, or maybe Falcon Heavy, if it is available.

But there's no reason to assume that Atlas V will not be available.

Well there is the possible RD-180 supply issue with the Atlas V. I know we are talking a long way off but I am not convinced whether the relevant decisions to fix this will take place. But that's a whole other thread.
Title: Re: Proposed Europa Missions
Post by: vjkane on 03/16/2014 03:23 PM
We should also keep in mind that there are science goals and also programmatic goals. The programmatic goals are longer term, but essentially boil down to: what can we do with this first mission that makes further missions easier/better?

For example, if a flyby mission does not gather enough data to go straight to a lander mission, then that means that NASA will have to fly an orbiter next before a lander. What that means is that if they do the flyby mission wrong (to save a few hundred million dollars), they may have to spend an extra $2.5+ billion for an orbiter mission before a lander, and delay flying a lander for many decades.

You could spin out two scenarios:

Scenario 1
$1 billion (cheap) flyby mission in the 2020s--->$2.5+ billion orbiter mission in the 2030s-->lander mission 2040s/50s

Scenario 2
$2.1 billion Europa Clipper mission in the 2020s-->lander mission in the 2030s
I just finished posting my analysis of the FY15 budget proposal.  http://futureplanets.blogspot.com/2014/03/2015-planetary-science-proposed-budget.html (http://futureplanets.blogspot.com/2014/03/2015-planetary-science-proposed-budget.html)

At the end of FY19, NASA will be spending ~$740M a year on mission development/operations, split between the Discovery program and a ramping down Mars 2020 rover.  If that level of spending continues through the following decade, my back of the envelope calculation suggests that NASA could fly the ~$2B Europa Clipper, a New Frontiers mission, and five Discovery missions (assuming NASA's total mission costs are 33% higher than the PI mission costs).

Other than an aversion to Flagship missions, I don't see a good reason to push studying a cheaper New Frontiers class mission now.  A mid 2020's mission would begin development around 2020.  It would arrive after JUICE does, which would already fulfill many of the goals that a cut rate dedicated Europa mission might do.

Deciding to fly a mission now to scout out the system might make sense (but recall the plumes are not confirmed).  A Discovery-class mission could make remote observations from the relatively benign region of Ganymede's orbit to verify the plumes.  It might even be able to fly once or twice through the plumes (although I don't know if radiation hardened instruments are doable on a Discovery budget). 

BUT committing to a Discovery mission based on a single unconfirmed observation does not seem sensible to me. 
Title: Re: Proposed Europa Missions
Post by: grondilu on 03/22/2014 02:04 AM

Not sure it's related, but this article about a new kind of radiation-proof transistor made me think of Europa:

http://phys.org/news/2014-03-tiny-transistors-extreme-environs-plasma.html#ms
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/04/2014 12:52 PM
Here is a 1997 proposal for a Europa orbiter. This may be the first Europa orbiter proposal. This was a Discovery proposal. Note that it would have used solar and not RTGs.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/07/2014 09:48 PM
Jeff Foust's new article on this subject. I haven't read it yet, but Jeff is pretty good at understanding these things:

http://www.thespacereview.com/article/2483/1

Europa on the cheap
by Jeff Foust
Monday, April 7, 2014

For decades, scientists have dreamed of sending a mission to Europa, one of Jupiter’s four large Galilean moons. The fleeting flybys of the moon by Voyagers 1 and 2 in 1979, and the more frequent flybys of Galileo in the 1990s, revealed a world with a icy crust, crisscrossed by fractures and other complex features. Those and other observations led scientists to conclude that Europa has, below that icy crust, a subterranean ocean of liquid water that, combined with the energy from tidal heating that keeps that ocean liquid and organic compounds, provide the basic requirements for life.

As compelling as the scientific case is for Europa, NASA has yet to send a dedicated mission there. Part of that is due to the technical challenges involved in launching a spacecraft to Jupiter and operating in the high radiation environment created by Jupiter’s powerful magnetic field. Those technical obstacles drive up the costs of those proposed, and reduce the chances they can be funded. NASA has studied Europa orbiter mission proposals since the late 1990s, but those efforts typically foundered on costs and shifting priorities.



Title: Re: Proposed Europa Missions
Post by: kris on 04/14/2014 09:12 AM
Hello sorry to go off topic but this seemed like the best thread and if the information is already in it, I can't find it.

I've read that it's possible that their is oxygen in the oceans of Europa trough the interaction of sunlight hitting the icy surface changing H2O into H2O2 that can get recycled under the ice changing it into H2O and O2. This prediction are pretty vague altough optimist says it could be enough to support Multi cellular life forms. I wonder if there would be any instrument that could potentially measure the O2 concentration (from orbit or flyby).
also as a gues could their be enough dissolved O2 (on Europe) to add 210 milliebar of O2 to a place like mars



http://phys.org/news174918239.html (http://phys.org/news174918239.html)
Title: Re: Proposed Europa Missions
Post by: redliox on 04/26/2014 09:06 AM
An interesting idea suggested by Andrew LePage involves a Europa-Io Sample Return by flying through the plumes of each respective moon: http://www.drewexmachina.com/2014/03/27/a-europa-io-sample-return-mission/ (http://www.drewexmachina.com/2014/03/27/a-europa-io-sample-return-mission/)

Quote
With the announcement in December of the possible detection of plume activity over the southern polar region of the Jovian moon, Europa [2, 3], the possibility exists of using a spacecraft essentially identical to that employed in the proposed LIFE mission to secure samples from the Europan plume(s).  And as an added bonus, it may prove possible during the same mission to sample one or more volcanic plumes of Io (the next moon in from Europa) which have been observed to reach as high as 500 km above this active moon’s surface – easily within the reach of a passing spacecraft.

-----

Once at Jupiter, the spacecraft would use its propulsion system to enter an elongated Jovian orbit to keep the spacecraft away from the worst of Jupiter’s radiation belt for most of the mission.  Using repeated gravity assists from Europa, Ganymede and Callisto, the spacecraft’s orbit would be gradually decreased in size to allow multiple, relatively low velocity encounters with Europa’s polar plumes so that samples could be gathered using an aerogel collector.  With a spacecraft perijove distance equal to Europa’s mean orbital distance from Jupiter, encounter speeds of 3.7 to 4.0 km/s (the Enceladus encounter speed in the LIFE mission scenarios) are possible if the apojove is ~2.0 to ~2.4 million km – just beyond the orbit of Callisto.  By coincidence, this potential Europa encounter orbit would be in a 3:1 resonance with Europa (i.e. Europa would orbit Jupiter three times for every orbit of the spacecraft allowing repeated encounters with minimal orbit adjustments) with a apojove of ~2.1 million km.  Such a resonance would facilitate repeated encounters with Europa if the orbit is properly phased.

After months of observation from a safe distance to spot the most promising target, one final close pass by Io located deep inside Jupiter’s radiation belt could be made to sample one of its volcanic plumes.  This encounter with Io and (probably) during insertion into Jovian orbit would be the only two times this spacecraft would be required to pass through the most intense portions of Jupiter’s radiation belts thus helping to minimize the spacecraft’s total radiation exposure.  Keeping the encounter velocity with Io down to ~4 km/s will be more difficult but perhaps a greater velocity would be acceptable since the mineral grains from Io’s plumes will be more robust than any icy particles from Europa’s plume.  Depending on any limitations on the spacecraft’s orbit around Jupiter, it might even prove possible to sample Jupiter’s outer Gossamer Rings associated with Jovian moons Amalthea and Thebe thus allowing indirect sampling of these bodies as well (since these rings are believed to originate from material that has escaped these small inner moons).

Outside of the miracle of Europa Clipper getting full funding, a Europan sample return might be a worthy silver prize.  Naturally there are numerous considerations....

Firstly, the possibility is based on the plumes Hubble seems to have spotted.  What's needed next is confirmation, follow-up observations to make sure these aren't flukes of course.  Considering how Europa is a prime target and the excitement generated by the initial discovery...I believe there will be confirmation before the end of the 2010s.  So before the first nut and bolt is twisted on any Jovian craft, we will know about the plumes.

Second, funding issues.  Bolden has already admitted he's bite at a billion dollar probe, so odds now favor a scheme that fits a New Frontier budget.  Obviously this isn't a good fit for 'Clipper.  However, a plume-catcher might be more straightforward; already we have OSIRIS-REX, a fairly complex asteroid SR in the NF bracket, and Stardust before excelled at Discovery levels.  Most of the billion give to a ESR would focus on the flyby hardware, with 2 supplemental instruments like a more robust mass spectrometer and a color camera for PR (heck this is the rationale for JunoCam's existence).  In short, I could see a compact can-like ESR fitting into New Frontiers better than the mega-Christmas-tree designs (both figuratively and schematically) of typical Jovian orbiters.

Third, engineering.  Stardust has pretty much demonstrated what's needed for plume-catching, and with those huge speeds comets sweep at it was no small challenge they faced to catch a handful of comet stuff.  A Giotto-like bus with thickened aluminum for shielding and a capsule behind it is the gist of a ESR.  It wouldn't need to linger for dozens of flybys to finish its job, and while at Jupiter fetching fire from Io or ring material may be further options.  No booms, no spanning antennas.

Four, science.  Of course we want more photos in better detail, and answers to the ocean and life enigmas.  But when you say you have a piece of that moon, you'll get an avalanche of eager scientists storming in.  A few samples of ocean salt won't answer everything, but it will definitely help answer some of the bigger questions around Europa.

If it becomes adamant that a Europa mission must be on the cheap, well this might be one of the answers the project teams come up with, and while not as photogenic as Europa Clipper (which I do root for) this concept may be just as exciting.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/28/2014 02:54 AM
An interesting idea suggested by Andrew LePage involves a Europa-Io Sample Return by flying through the plumes of each respective moon:

I read that a couple of weeks ago and although it is an interesting idea, I think he misses a key point--the U.S. scientific community said to go to Europa and do specific kinds of science. The community did not say go to Europa and collect samples from the plumes. Now if somebody wants to propose doing that with a Discovery class mission they are free to do so (good luck at fitting that in the cost cap). But it is not a recommended New Frontiers mission, nor is it a recommended flagship mission and therefore should not, and will not get funded out of those budgets.

Put another way, that sample return mission has not been recommended or vetted by the U.S. scientific community. And the way things work in the U.S. is that only science missions that are vetted get the necessary money to proceed.

And once again this highlights the key fact: what is important is not where you go, but what you do when you get there. The recent discussion of a Europa mission has sometimes lost sight of the fact that the reason that scientists said to go to Europa in the first place is to do specific science there, not to simply say that "we've gone to Europa." It's about science, not planting a flag. There's no point in doing the mission at all unless it focuses on the important science.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/28/2014 03:02 AM
1-Second, funding issues.  Bolden has already admitted he's bite at a billion dollar probe, so odds now favor a scheme that fits a New Frontier budget. 

2-Four, science.  Of course we want more photos in better detail, and answers to the ocean and life enigmas.  But when you say you have a piece of that moon, you'll get an avalanche of eager scientists storming in.  A few samples of ocean salt won't answer everything, but it will definitely help answer some of the bigger questions around Europa.

1-Bolden doesn't really matter in this (and in fact, his comments are somewhat out of tune with the comments made by Grunsfeld and others). It ultimately comes down to OMB, Congress, and the scientific community. All three matter in this issue, and I'd note that if a significant part of the scientific community comes out and says "a plume sampling mission is not worth the cost of doing it and is no substitute for flagship-class science," then the political support will evaporate. As I heard one senior person put it, it's better to wait an extra decade and do the mission right than to do a lousy mission now and then have to try again two decades after that.

2-That's really looking at the science issues in a weird way. A sample return mission would provide particles. That's not going to satisfy the people interested in the geology, the water circulation, the entire Europa system dynamics. That's like saying to a weatherman "We could not afford to give you a satellite that will show where the hurricanes and tornadoes are, but here are a few raindrops instead. I'm sure you'll be happy with these."

There's a framework that has been developed over many decades: flyby, orbit, land, rove. Skipping all those steps to go straight to sample return doesn't produce the scientific knowledge that justifies spending the money in the first place.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/29/2014 06:19 PM
http://www.spacepolicyonline.com/news/house-appropriators-propose-substantial-increase-for-nasa-including-europa

House Appropriators Propose Substantial Increase for NASA, Including Europa
Marcia S. Smith
Posted: 29-Apr-2014
Updated: 29-Apr-2014 02:08 PM

The House Appropriations Committee released a draft of the FY2015 Commerce-Justice-Science (CJS) bill that will be marked up by the CJS subcommittee tomorrow (April 30).   It proposes a substantial increase for NASA compared to the President's request and funding for a robotic mission to Jupiter's moon Europa would be one beneficiary of the increased spending.

SNIP

The funding figures in the House CJS subcommittee draft bill are as follows

    Science:   $5,193 million.  That is $221 million more than the President requested, and $42 million more than the FY2014 amount.  Of the $5,193 million, $100 million is for the Europa mission.  The President requested $15 million for FY2015.   The President requested zero for Europa in FY2013 and FY2014, but Congress appropriated $75 million in FY2013 (subject to rescissions and the sequester, which left about $69 million) and $80 million in FY2014.
Title: Re: Proposed Europa Missions
Post by: redliox on 04/29/2014 08:20 PM
It looks like NASA will be taking a look at cheaper missions soon: http://www.space.com/25672-jupiter-moon-europa-nasa-mission-ideas.html (http://www.space.com/25672-jupiter-moon-europa-nasa-mission-ideas.html)

Quote
NASA is asking the scientific community to help it devise a relatively low-budget mission to Jupiter's moon Europa, perhaps the solar system's best bet to host alien life.

The space agency announced Monday (April 28) that it has issued a Request for Information (RFI), officially seeking ideas from outside researchers for a mission to study Europa and its subsurface ocean for less than $1 billion (excluding the launch vehicle).

"This is an opportunity to hear from those creative teams that have ideas on how we can achieve the most science at minimum cost," John Grunsfeld, associate administrator for the NASA Science Mission Directorate at the agency's headquarters in Washington, said in a statement.

"Europa is one of the most interesting sites in our solar system in the search for life beyond Earth," Grunsfeld added. "The drive to explore Europa has stimulated not only scientific interest but also the ingenuity of engineers and scientists with innovative concepts."

The deadline to submit ideas under the RFI is May 30, officials said.

So come June there'll at least be a few ideas on the table in addition to Europa Clipper.  The increase in Planetary Science is excellent but without that full $2 billion for 'Clipper we need to find what other options are possible.  Whatever those options will be the Decadal Survey that recommended Europa to begin with may be the guide (although naturally a smaller mission might only sate a few goals):

Quote
The Decadal Survey deemed a mission to the Jupiter moon as among the highest priority scientific pursuits for NASA. It lists five key science objectives in priority order that are necessary to improve our understanding of this potentially habitable moon.

The mission will need to:

• Characterize the extent of the ocean and its relation to the deeper interior

• Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange

• Determine global surface, compositions and chemistry, especially as related to habitability

• Understand the formation of surface features, including sites of recent or current activity, identify and characterize candidate sites for future detailed exploration

• Understand Europa's space environment and interaction with the magnetosphere.

So, going by priority, finding the depth and extent of the subsurface ocean comes first followed by chemistry.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/29/2014 09:44 PM
So come June there'll at least be a few ideas on the table in addition to Europa Clipper.  The increase in Planetary Science is excellent but without that full $2 billion for 'Clipper we need to find what other options are possible.  Whatever those options will be the Decadal Survey that recommended Europa to begin with may be the guide (although naturally a smaller mission might only sate a few goals):


I thought that the explanation as to what is going on appeared earlier in the thread.

This is OMB pushing the issue. OMB wants NASA to see what is possible at the $1 billion level. I know a lot of people who think that the answer is that decadal level science cannot be accomplished at that lower level. (One former Voyager/Galileo scientist was recently asked at a conference what $1 billion could buy at Jupiter and he replied "A lot of radiation shielding.") Remember that the reason why Europa is on the table, and why people have been talking about it, is to do the science described in the decadal survey, not simply to go and plant a flag at Europa (flipping that on its head, there's no reason to do a Europa mission if it is not going to accomplish that level of science; might as well just wait another decade and try again).

Now I don't think this is necessarily a bad thing to do. After all, we might get some interesting mission proposals out of it, and there is value to doing mission proposals, because--as an example--the next time there is a decadal survey it helps to know some of the options ahead of time. But there is a risk to this. The risk is that the politicians will go off and approve a mission just so they can say "We are doing Europa!" when that mission doesn't accomplish interesting science. There is also a risk that this could kill the next New Frontiers opportunity, and that would annoy a lot of people with interests in the Moon, Venus, Saturn, comets, and other targets. It would also lead to a lot of programmatic chaos.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/29/2014 11:46 PM
So, going by priority, finding the depth and extent of the subsurface ocean comes first followed by chemistry.

As a senior NASA planetary science official recently explained, in addition to the science goals, there are also programmatic goals for any Europa mission. The key programmatic goal is that the mission should minimize the amount of science/data that has to be collected for the next mission.

Put more succinctly, if you do a flyby mission, it should provide enough data so that you can go to a lander mission next and not have to repeat another flyby or orbiter mission. That means that the mission should gather high resolution imagery of the surface to enable a lander.
Title: Re: Proposed Europa Missions
Post by: redliox on 04/30/2014 12:32 AM
This is OMB pushing the issue. OMB wants NASA to see what is possible at the $1 billion level. I know a lot of people who think that the answer is that decadal level science cannot be accomplished at that lower level. And the reason why Europa is on the table, and why people have been talking about it, is to do the science described in the decadal survey (flipping that on its head, there's no reason to do a Europa mission if it is not going to accomplish that level of science; might as well just wait another decade and try again).

Now I don't think this is necessarily a bad thing to do. After all, we might get some interesting mission proposals out of it, and there is value to doing mission proposals, because--as an example--the next time there is a decadal survey it helps to know some of the options ahead of time.

That's why I see this more as a positive.  It opens opportunities.  Everyone says it must be a flagship...but only because nobody seriously looked into what a smaller spacecraft might do.  That's not engineering, that's presumption.

We've had spacecraft with modest instrumentation that served well.  A great example would be Mars Odyssey: an 800kg orbiter with 3 instruments, only 2 of which remote sensing.  Its THERMIS instrument singled out the MER landing sites, including the hematite Opportunity found, not to mention mapped the whole of Mars at resolutions only MRO surpassed.  Never underestimate the small guys.

Quote
The risk is that the politicians will go off and approve a mission just so they can say "We are doing Europa!" when that mission doesn't accomplish interesting science. There is also a risk that this could kill the next New Frontiers opportunity, and that would annoy a lot of people with interests in the Moon, Venus, Saturn, comets, and other targets. It would also lead to a lot of programmatic chaos.

Err...that already happened when EJSM won over TSSM, only to get canceled (i.e. the annoying everyone part).  Frankly as much as I retroactively wish TSSM won instead of EJSM (presuming its budget could fit better), if any mission deserves the next New Frontiers slot it should be the Uranus Orbiter, which was 3rd on the Decadal-to-do-list.  Of course this thread is about Europa, not to mention wishful thinking should be kept to a minimum.

Quote
Put more succinctly, if you do a flyby mission, it should provide enough data so that you can go to a lander mission next and not have to repeat another flyby or orbiter mission. That means that the mission should gather high resolution imagery of the surface to enable a lander.

Definitely agreed there.  Whatever gets sent, large or small, must be able to find safe ground for landing.  At worst, an orbiter with a camera system ought to be sent; more so coupled with the ice radar; Van Kane mentioned that as a suggestion for a New Frontiers fitting.  If we end up flying New Frontiers-class, it should be functional yet conservative.

Europa needs options, least we all end up waiting forever.  'Clipper is an excellent option, but shouldn't be exclusive in case Congress' generosity runs low.  I'm eager to see what's suggested by June, that way we all can better judge the choice between flagships and 'frontiers.  I'm hoping to be pleasantly surprised either way!
Title: Re: Proposed Europa Missions
Post by: Blackstar on 04/30/2014 02:47 AM
That's why I see this more as a positive.  It opens opportunities.  Everyone says it must be a flagship...but only because nobody seriously looked into what a smaller spacecraft might do.  That's not engineering, that's presumption.

No, that's not what happened.
Title: Re: Proposed Europa Missions
Post by: Star One on 07/28/2014 03:07 PM
Europa Clipper Would Wash Out Other Nuclear-powered Missions.

Quote
BETHESDA, Md. — If NASA sends a nuclear-powered probe to Jupiter’s moon Europa, it would launch no sooner than 2024, and effectively rule out other nuclear missions to the outer solar system before then by tying up the specialized infrastructure required to produce plutonium-powered spacecraft batteries, a senior NASA official said here.

“If the Europa mission goes nuclear, it needs four or five [Multi-Mission Radioisotope Thermoelectric Generators],” Curt Niebur, a program scientist at NASA headquarters in Washington, said in a July 23 interview here during a meeting of the NASA-chartered Outer Planets Assessment Group. “That’s quite a few. If Europa needs that many, that sucks up all the output for the production line between now and 2024. There’s no more left."

Clipper will likely need such a power source, but the U.S. Department of Energy, which owns and operates all the equipment needed to refine plutonium-238 and press it into pellets usable by an MMRTG, now plans to shut down its aging pellet-stamping hot press at the Los Alamos National Laboratory in Los Alamos, New Mexico, after 2015, when the department plans to produce one last batch of pellets for the single MMRTG needed for Mars 2020, a sample-caching rover based on Curiosity and slated to launch in 2020.

Len Dudzinski, program executive for radioisotope power systems at NASA headquarters, said in an interview here that the Department of Energy “won’t promise us to be able to support Europa without a new hot press.” NASA, not the Department of Energy, is on the hook to pay for the new equipment.


http://www.spacenews.com/article/civil-space/41399europa-clipper-would-wash-out-other-nuclear-powered-missions
Title: Re: Proposed Europa Missions
Post by: Alpha_Centauri on 07/28/2014 05:16 PM
What other realistic nuclear-powered outer solar system mission before 2024 is there to sacrifice?!
Title: Re: Proposed Europa Missions
Post by: GalacticIntruder on 07/28/2014 05:26 PM
Might need to add the last part of the SpaceNews article.

Quote
That process will likely start in 2015, Carroll said. When it is done, the press will be taken offline until a new one can be installed. The Department of Energy hopes the new machine will be online by 2017. After that, the department could press enough fuel to prepare one flight-ready MMRTG a year, Carroll said.

2017 is probably optimistic for these things, but nevertheless, it is not a permanent end of Pu pellet production.

Title: Proposed Europa Missions
Post by: Star One on 07/28/2014 06:34 PM
Might need to add the last part of the SpaceNews article.

Quote
That process will likely start in 2015, Carroll said. When it is done, the press will be taken offline until a new one can be installed. The Department of Energy hopes the new machine will be online by 2017. After that, the department could press enough fuel to prepare one flight-ready MMRTG a year, Carroll said.

2017 is probably optimistic for these things, but nevertheless, it is not a permanent end of Pu pellet production.

I wasn't sure if too add as it wasn't a definitive response on the issue.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/29/2014 02:04 PM
This is not a surprise to anybody who has been following either the Pu-238 subject or Europa mission plans closely. They've been saying things like this--although not loudly--for almost a year now. The context is that a lot of the Pu-238 production infrastructure is in poor shape and they need to replace equipment. I was talking to one person familiar with the whole issue. He said that NASA was initially concerned that they were getting stuck with too much cost, but after a group looked at the infrastructure, they said that if anything, NASA is getting off easy, because there are a lot of associated infrastructure costs that are hidden, and fortunately NASA is not being charged for them.
Title: Re: Proposed Europa Missions
Post by: Star One on 07/29/2014 03:02 PM

This is not a surprise to anybody who has been following either the Pu-238 subject or Europa mission plans closely. They've been saying things like this--although not loudly--for almost a year now. The context is that a lot of the Pu-238 production infrastructure is in poor shape and they need to replace equipment. I was talking to one person familiar with the whole issue. He said that NASA was initially concerned that they were getting stuck with too much cost, but after a group looked at the infrastructure, they said that if anything, NASA is getting off easy, because there are a lot of associated infrastructure costs that are hidden, and fortunately NASA is not being charged for them.

So it will be the DOE who picks up the majority of the cost of updating this equipment.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/29/2014 06:37 PM

This is not a surprise to anybody who has been following either the Pu-238 subject or Europa mission plans closely. They've been saying things like this--although not loudly--for almost a year now. The context is that a lot of the Pu-238 production infrastructure is in poor shape and they need to replace equipment. I was talking to one person familiar with the whole issue. He said that NASA was initially concerned that they were getting stuck with too much cost, but after a group looked at the infrastructure, they said that if anything, NASA is getting off easy, because there are a lot of associated infrastructure costs that are hidden, and fortunately NASA is not being charged for them.

So it will be the DOE who picks up the majority of the cost of updating this equipment.

I would not say that. For this specific equipment, NASA may get stuck with most of the bill. I was saying that for the overall cost of doing all of this stuff, NASA may be getting a deal. Now I don't know why that is. One possibility is that if you had to run all of this entirely separate from DoE, then NASA would have to duplicate security, handling, staff, etc. that is currently being covered by DoE overhead. It gets squiggly when you start trying to figure out cross-agency costs.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/29/2014 08:45 PM
I did not make it to OPAG last week, but a colleague did. I asked him about the "$1 billion Europa missions" in response to NASA's RFI. He said that there were 6 proposals. They are all being CATEd right now. NASA would not say anything more than that. Nothing about who proposed them or what they are about.
Title: Re: Proposed Europa Missions
Post by: sdsds on 07/29/2014 10:05 PM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?
Title: Re: Proposed Europa Missions
Post by: Jim on 07/30/2014 12:31 AM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?

yes, that is why it could fly on SLS or Atlas V
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2014 03:52 AM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?

Er, this is a weird question. No matter what the cost of the mission, it still has to get to Europa. So it's either going to launch on an Atlas or an SLS. Now some people argue that taking a VEEGA trajectory is going to cost more in operations costs than a direct trajectory, because you have to spend $X per year and it is more years to go that way than directly. So maybe you save $80 million in operating costs with the direct trajectory vs. the VEEGA trajectory (but do you pay more for the launch vehicle?).

But that whole discussion is essentially irrelevant to the $1 billion mission issue. The $1 billion cost goal came from OMB, which is opposed to an expensive mission (which they define as "more than $1 billion") and so they told NASA to see what could be done for $1 billion. I suspect that the answer to that question is going to be "you cannot do much."

Title: Re: Proposed Europa Missions
Post by: vjkane on 07/30/2014 04:43 AM
Europa Clipper Would Wash Out Other Nuclear-powered Missions.

SpaceNews generally writes does very good reporting, and this article is except for one omission.  The Clipper mission can also be done (based on current engineering assessments) with solar panels.  There are various engineering and budget trades (solar panels are heavier and must always point toward the sun; but the solar option is cheaper than the Pu-238 option). 

So far as I know, there's been no decision on which direction to go.

If the Clipper doesn't use Pu-238, then NASA could make MMRTGs available to Discovery and New Horizon missions.  There are a number of concepts that either depend on a plutonium power supply or would benefit from it.
Title: Re: Proposed Europa Missions
Post by: metaphor on 07/30/2014 03:18 PM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?

Er, this is a weird question. No matter what the cost of the mission, it still has to get to Europa. So it's either going to launch on an Atlas or an SLS. Now some people argue that taking a VEEGA trajectory is going to cost more in operations costs than a direct trajectory, because you have to spend $X per year and it is more years to go that way than directly. So maybe you save $80 million in operating costs with the direct trajectory vs. the VEEGA trajectory (but do you pay more for the launch vehicle?).


Is there also an additional cost due to the thermal insulation needed because of the higher temperatures at Venus?  I seem to remember that being an advantage of a straight-to-Jupiter trajectory.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2014 04:44 PM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?

Er, this is a weird question. No matter what the cost of the mission, it still has to get to Europa. So it's either going to launch on an Atlas or an SLS. Now some people argue that taking a VEEGA trajectory is going to cost more in operations costs than a direct trajectory, because you have to spend $X per year and it is more years to go that way than directly. So maybe you save $80 million in operating costs with the direct trajectory vs. the VEEGA trajectory (but do you pay more for the launch vehicle?).


Is there also an additional cost due to the thermal insulation needed because of the higher temperatures at Venus?  I seem to remember that being an advantage of a straight-to-Jupiter trajectory.

I've heard something about that too, but I suspect that it's not a big cost. Really, it's just insulation (plus the engineering evaluation). Shouldn't cost much.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2014 04:48 PM
Europa Clipper Would Wash Out Other Nuclear-powered Missions.

SpaceNews generally writes does very good reporting, and this article is except for one omission.  The Clipper mission can also be done (based on current engineering assessments) with solar panels.  There are various engineering and budget trades (solar panels are heavier and must always point toward the sun; but the solar option is cheaper than the Pu-238 option). 

So far as I know, there's been no decision on which direction to go.

If the Clipper doesn't use Pu-238, then NASA could make MMRTGs available to Discovery and New Horizon missions.  There are a number of concepts that either depend on a plutonium power supply or would benefit from it.


There's also a hybrid solar/RTG option that was going to be evaluated as of a few months ago. But RTGs are the lowest risk option. I suspect that for an expensive mission they will want the lowest risk option.
Title: Re: Proposed Europa Missions
Post by: baldusi on 07/30/2014 05:50 PM
Europa Clipper Would Wash Out Other Nuclear-powered Missions.

SpaceNews generally writes does very good reporting, and this article is except for one omission.  The Clipper mission can also be done (based on current engineering assessments) with solar panels.  There are various engineering and budget trades (solar panels are heavier and must always point toward the sun; but the solar option is cheaper than the Pu-238 option). 

So far as I know, there's been no decision on which direction to go.

If the Clipper doesn't use Pu-238, then NASA could make MMRTGs available to Discovery and New Horizon missions.  There are a number of concepts that either depend on a plutonium power supply or would benefit from it.


There's also a hybrid solar/RTG option that was going to be evaluated as of a few months ago. But RTGs are the lowest risk option. I suspect that for an expensive mission they will want the lowest risk option.
If they go with SLS, RTG also mean nuclear-rating it.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2014 06:13 PM
If they go with SLS, RTG also mean nuclear-rating it.

Yes. But I think that's something that is going to have to happen eventually. If you assume that SLS will become operational and that it will be used for decades to launch human missions, then it will eventually carry RTGs for human missions.

So I think the most important/relevant question is who pays for that nuclear certification: the science community or the human spaceflight community?
Title: Re: Proposed Europa Missions
Post by: a_langwich on 07/30/2014 06:49 PM
Europa Clipper Would Wash Out Other Nuclear-powered Missions.

SpaceNews generally writes does very good reporting, and this article is except for one omission.  The Clipper mission can also be done (based on current engineering assessments) with solar panels.  There are various engineering and budget trades (solar panels are heavier and must always point toward the sun; but the solar option is cheaper than the Pu-238 option). 

So far as I know, there's been no decision on which direction to go.

If the Clipper doesn't use Pu-238, then NASA could make MMRTGs available to Discovery and New Horizon missions.  There are a number of concepts that either depend on a plutonium power supply or would benefit from it.


There's also a hybrid solar/RTG option that was going to be evaluated as of a few months ago. But RTGs are the lowest risk option. I suspect that for an expensive mission they will want the lowest risk option.

I would think the hybrid option would be pretty competitive on risk.  You can get just enough RTGs to support a baseline science level, so that even if the solar completely disappeared you could get most of the science done.  And, truth is, solar panels aren't too shabby in reliability themselves.  If solar panels are safe enough to risk for the $8 billion JWSC and Hubble, they are probably okay for a measly $1 - $2 billion mission.

But the hybrid option would carry all the complication, cost, size, and weight of both the RTGs and solar and then some.  Maybe not a problem if you are launching on SLS and you don't have the money to fill the size/weight envelope with instruments, but could be trouble for an Atlas.  Still, it might be worth it, IF it enables another small mission or two to take place (meaning there is some assurance the RTG capability wouldn't just sit unused for the entire time frame).

It will be interesting, once Falcon Heavy gets going, to see what its payload/C3 graph looks like. 
Title: Re: Proposed Europa Missions
Post by: Jim on 07/30/2014 07:02 PM
  If solar panels are safe enough to risk for the $8 billion JWSC and Hubble, they are probably okay for a measly $1 - $2 billion mission.


Not the same trade.  The issue is getting enough power which does not apply to JWST and HST and not reliability.
The risk for Europa is holding to a spacecraft power level and then having the mass for large enough panels with margin to supply the required levels.

Europa needs more power than other probes because of the radar mapper.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/30/2014 07:02 PM
I would think the hybrid option would be pretty competitive on risk.  You can get just enough RTGs to support a baseline science level, so that even if the solar completely disappeared you could get most of the science done.  And, truth is, solar panels aren't too shabby in reliability themselves.  If solar panels are safe enough to risk for the $8 billion JWSC and Hubble, they are probably okay for a measly $1 - $2 billion mission.

But the hybrid option would carry all the complication, cost, size, and weight of both the RTGs and solar and then some.  Maybe not a problem if you are launching on SLS and you don't have the money to fill the size/weight envelope with instruments, but could be trouble for an Atlas.  Still, it might be worth it, IF it enables another small mission or two to take place (meaning there is some assurance the RTG capability wouldn't just sit unused for the entire time frame).

It will be interesting, once Falcon Heavy gets going, to see what its payload/C3 graph looks like. 

I don't think they would count risk in this case as "solar plus RTG." Instead, the risk comes in integrating those two technologies. That might seem easy to us, who don't know anything about doing it, but I would note that it has not been done before. There could be all kinds of complications that come from running two different power supplies into the bus.

My impression, and I've said this before, is that if you put 100 Europa scientists into a room and told them they could vote for either Atlas or SLS, you would probably get 99 people voting for Atlas. SLS comes with all kinds of unknown and murky political and budgetary risks. Better to go with the known quantity, which is Atlas. So I think that the hybrid RTG/solar option is being evaluated for Atlas, because that's what most of the Europa scientists and engineers believe is the most likely launch vehicle.
Title: Re: Proposed Europa Missions
Post by: metaphor on 07/30/2014 08:28 PM

It will be interesting, once Falcon Heavy gets going, to see what its payload/C3 graph looks like.

Extrapolating from the 21.2 tons to GTO and 13.2 tons to Mars on the SpaceX website, and the second stage stats here (http://www.spacelaunchreport.com/falcon9v1-1.html), the Falcon Heavy would only be able to take about 1-2 tons on a trajectory straight to Jupiter.  Adding a solid upper booster stage like a Star 48 would increase the payload to about 3-4 tons.  The payload would go up to 13-14 tons using a VEEGA.
Title: Re: Proposed Europa Missions
Post by: denis on 07/30/2014 11:58 PM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?

Er, this is a weird question. No matter what the cost of the mission, it still has to get to Europa. So it's either going to launch on an Atlas or an SLS. Now some people argue that taking a VEEGA trajectory is going to cost more in operations costs than a direct trajectory, because you have to spend $X per year and it is more years to go that way than directly. So maybe you save $80 million in operating costs with the direct trajectory vs. the VEEGA trajectory (but do you pay more for the launch vehicle?).


Is there also an additional cost due to the thermal insulation needed because of the higher temperatures at Venus?  I seem to remember that being an advantage of a straight-to-Jupiter trajectory.

I've heard something about that too, but I suspect that it's not a big cost. Really, it's just insulation (plus the engineering evaluation). Shouldn't cost much.
That's a pretty wild statement. How do you know it would just need "extra insulation" ? It depends a lot on the spacecraft design. Maybe it's just insulation? Maybe it will need a new attitude "BBQ-like" mode? Maybe it will need active thermal control?

As for the cost of engineering evaluation, it is one of the main reason all these missions cost billions.

Title: Re: Proposed Europa Missions
Post by: denis on 07/31/2014 12:03 AM

If they go with SLS, RTG also mean nuclear-rating it.

What does nuclear-rating a launcher mean ?

I thought the RTG were designed to survive intact even an explosion of the launcher.  Isn't it the case ?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/31/2014 02:30 AM
Sorry for asking a rather basic question but: could the "$1 billion" Europa missions be designed (like Clipper) to take either a VEEGA trajectory after launch on Atlas or a direct trajectory after launch on SLS? Or is there something about $1b that makes that not possible?

Er, this is a weird question. No matter what the cost of the mission, it still has to get to Europa. So it's either going to launch on an Atlas or an SLS. Now some people argue that taking a VEEGA trajectory is going to cost more in operations costs than a direct trajectory, because you have to spend $X per year and it is more years to go that way than directly. So maybe you save $80 million in operating costs with the direct trajectory vs. the VEEGA trajectory (but do you pay more for the launch vehicle?).


Is there also an additional cost due to the thermal insulation needed because of the higher temperatures at Venus?  I seem to remember that being an advantage of a straight-to-Jupiter trajectory.

I've heard something about that too, but I suspect that it's not a big cost. Really, it's just insulation (plus the engineering evaluation). Shouldn't cost much.
That's a pretty wild statement. How do you know it would just need "extra insulation" ? It depends a lot on the spacecraft design. Maybe it's just insulation? Maybe it will need a new attitude "BBQ-like" mode? Maybe it will need active thermal control?

As for the cost of engineering evaluation, it is one of the main reason all these missions cost billions.



Please, tell me some more. I don't know much about this subject.
Title: Re: Proposed Europa Missions
Post by: sdsds on 07/31/2014 03:22 AM
if you put 100 Europa scientists into a room and told them they could vote for either Atlas or SLS, you would probably get 99 people voting for Atlas.

I understand why today's researchers are the population one would first think to poll. For them, now, arrival dates in 2025 and 2028 don't look that far apart. Nor do departure dates in 2022 and 2021. But as the departure dates get closer the calculus might change. Engineers might want those extra few months of time to assure the spacecraft is ready. And a student in 2021 is going to see a meaningful difference between a 2025 arrival and a 2028 arrival.

In any case, the notion that a mission in development can "maintain dual launch capability through CDR" seems in the current political reality to mandate that it do so.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 07/31/2014 01:23 PM
I understand why today's researchers are the population one would first think to poll.

Yeah, because they're the only ones that actually have the knowledge and expertise.
Title: Re: Proposed Europa Missions
Post by: a_langwich on 07/31/2014 07:38 PM
I would think the hybrid option would be pretty competitive on risk.  You can get just enough RTGs to support a baseline science level, so that even if the solar completely disappeared you could get most of the science done.  And, truth is, solar panels aren't too shabby in reliability themselves.  If solar panels are safe enough to risk for the $8 billion JWSC and Hubble, they are probably okay for a measly $1 - $2 billion mission.

But the hybrid option would carry all the complication, cost, size, and weight of both the RTGs and solar and then some.  Maybe not a problem if you are launching on SLS and you don't have the money to fill the size/weight envelope with instruments, but could be trouble for an Atlas.  Still, it might be worth it, IF it enables another small mission or two to take place (meaning there is some assurance the RTG capability wouldn't just sit unused for the entire time frame).

It will be interesting, once Falcon Heavy gets going, to see what its payload/C3 graph looks like. 

I don't think they would count risk in this case as "solar plus RTG." Instead, the risk comes in integrating those two technologies. That might seem easy to us, who don't know anything about doing it, but I would note that it has not been done before. There could be all kinds of complications that come from running two different power supplies into the bus.

My impression, and I've said this before, is that if you put 100 Europa scientists into a room and told them they could vote for either Atlas or SLS, you would probably get 99 people voting for Atlas. SLS comes with all kinds of unknown and murky political and budgetary risks. Better to go with the known quantity, which is Atlas. So I think that the hybrid RTG/solar option is being evaluated for Atlas, because that's what most of the Europa scientists and engineers believe is the most likely launch vehicle.


Re: Atlas vs SLS, seems pretty reasonable to me.  ANY never-flown rocket would of course be riskier, and the large size and development cost and schedule of SLS, and the fickleness of using a manned rocket for an unmanned mission and depending essentially on the manned program for that impetus--yes, it's more risky.

Re: combining solar and RTGs, having built voltage converters and power management buses, I think combining them would be fairly easy.  AFAIK there will still be a layer of voltage conversion to the bus voltage chosen for instruments; the input to that voltage conversion usually has a wide latitude/tolerance for different sources and voltages.  Especially for a solar panel system, the combination would be simple.  The RTG would just look like another battery, permanently charged.  It IS just another battery.

I don't know how feasible or practical solar power by itself is; I guess Juno will retire a lot of that risk when it starts returning science?  But Juno's panels were 340 kg...that's a pretty big chunk out of a probe's weight budget, isn't it?  That doesn't include the batteries.  340 kg for 420 W (EOM)...a little more than 2 MMRTGs, right?  To me, that's the trade, along with the difficulties of stowing/unfurling, figuring out how to point your probe at the target while your arrays point toward the sun and try to maximize insolation, arranging your instruments and comm to avoid being blocked by the panels, etc. 
Title: Re: Proposed Europa Missions
Post by: vjkane on 07/31/2014 08:17 PM
Another issue with solar is that much of the power goes to running heaters in the spacecraft (about 50% in the case of Juno if memory serves me right). Mmrtg's have heat to spare
Title: Re: Proposed Europa Missions
Post by: a_langwich on 07/31/2014 08:22 PM
But as the departure dates get closer the calculus might change.

Well, sure, because "future risk" is being retired.  By 2021, if all goes well, SLS will have flights under its belt.  There will presumably be much lower risk that it could get cancelled between mission selection and mission launch.  A lot more people would bet on the high-wire artist after, or even 2/3 of the way through, his walk over the {landmark of interest}.

At the same time, if we are prognosticating the future, I'd bet 99 out of 100 Europa scientists would pick Falcon Heavy in 2021 over SLS.  Possibly even if it still has crappy high-energy mission performance.

In any case, the notion that a mission in development can "maintain dual launch capability through CDR" seems in the current political reality to mandate that it do so.

This may not be so hard for the Clipper concepts, if the mass launched by SLS direct is similar to Atlas VEEGA mass.  The Venus environment should be trivially easy to handle with shading and minor thermal design, since the probe isn't trying to do any science there.

The problem with using SLS for a $1 billion probe is that to halve the price of the budget, you are going to have to throw out instruments, which will reduce both weight and power.  That won't make any significant difference in travel time, either direct or VEEGA, but it means you will be seriously underusing SLS.  And it won't help SLS for people to be talking about cutting half of a $2 billion probe's cost in tight budget times, while flying it on an LV which has cost tens of billions.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/01/2014 04:02 PM
But as the departure dates get closer the calculus might change.

Well, sure, because "future risk" is being retired.  By 2021, if all goes well, SLS will have flights under its belt.


But that's not really it. It's not the danger that SLS will get canceled between now and then, it's all the programmatic instability that would come with using an SLS instead of an Atlas V. Simply put, if the Science Mission Directorate buys an Atlas V for a Europa mission, then they own it. It's theirs. Everybody knows that. But if they go with an SLS, the program managers are always going to be worried that they are at risk from larger political and bureaucratic forces. For instance, if HEOMD decides to change their bookkeeping for SLS and unexpectedly shifts more costs onto the payload side. If I was a Europa scientist, I would want the launch vehicle that is a 100% known variable and where I'm the full owner. There won't be any surprises.
Title: Re: Proposed Europa Missions
Post by: baldusi on 08/01/2014 04:07 PM
There's no internal equivalent to an insurance or warranty?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/01/2014 06:11 PM
There's no internal equivalent to an insurance or warranty?

We're talking about a bureaucracy here. If somebody from the government promised you something would you believe them?

I will pose a theoretical example: suppose when HEOMD and the Science Mission Directorate (SMD) are negotiating over using SLS for the Europa mission HEOMD says that they (HEOMD) will pay the cost of nuclear rating the SLS. Suppose that they say this because they expect that in a few years they are going to have to nuclear rate the SLS for HEOMD missions. So SMD says yes. And then a few years later, HEOMD slips its plans and no longer plans to fly its own nuclear payloads on SLS in the next few years. And so, because they do not need to nuclear rate SLS for their own purposes, they say "SMD, you are the only user who needs the nuclear capability, so you should pay for nuclear rating the SLS." And then SMD gets stuck with an added cost that they were told that they would not have to pay. Surprise!

I am not saying that this is the kind of thing that will happen. What I am saying is that it is the kind of thing that can happen. And people know it.*

So when a program selects a launch vehicle, or anything else, they try to maximize the things that they can control within their own office, and minimize the things that other people control. If I was a Europa scientist, I would want to use the rocket that has a high flight rate, high reliability rate, and that my people have a lot of experience with.







*I am sure that if you talked to principal investigators who ran missions in the past you could get lots of similar horror stories. I remember New Horizons PI Alan Stern explaining once about how after his mission was selected his team wanted to pick a launch vehicle and start designing their spacecraft for that vehicle. However, because of some contracting policy issue at NASA, NASA told New Horizons that they could not pick a single launch vehicle at that time. That forced New Horizons to design for both Atlas and Delta for much of their development, which Stern claimed cost them a lot of money in the design phase. Eventually, NASA picked an Atlas. My point is that these are the kinds of decisions that program managers like to nail down quickly, and they want to go with the safest and most well-known choice. They do not necessarily want the highest performance option. Thus, even when Falcon Heavy starts flying, I suspect it will take a long time before program managers will embrace it. They will all want to see a lot of successful flights before they agree to use it. "Cheap" is not really cheap if the launch vehicle fails.
Title: Re: Proposed Europa Missions
Post by: baldusi on 08/01/2014 07:43 PM
Thanks for your reply Blackstar. But I meant that if NASA signs a contract with some other entity, if they don't perform, they are in breach of contract and can be taken to court, if necessary. But was wondering if they could have legally binding contracts within divisions of the same entity (NASA). I understand from your answer that no.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/02/2014 12:04 PM
Thanks for your reply Blackstar. But I meant that if NASA signs a contract with some other entity, if they don't perform, they are in breach of contract and can be taken to court, if necessary. But was wondering if they could have legally binding contracts within divisions of the same entity (NASA). I understand from your answer that no.

I am no federal contracting expert (and despite what you see on this forum, I doubt that there is more than one person who _is_ a federal contracting expert here), but the government can write contracts that allow it to cancel them at any time. Usually there is a penalty clause of some kind in there, but it happens all the time.

My point is that the science side which runs the Europa mission would rather own their rocket, meaning that they control almost everything about it. With SLS that would not be the case, because primary authority for the SLS rests with the HEOMD.
Title: Re: Proposed Europa Missions
Post by: John-H on 08/02/2014 01:01 PM
If the contractor doesn't perform, you can take him to court. But you have missed the launch window. How often does a window to Jupiter occur?
Title: Re: Proposed Europa Missions
Post by: Jim on 08/02/2014 01:38 PM
If the contractor doesn't perform, you can take him to court. But you have missed the launch window. How often does a window to Jupiter occur?

The contractor is a NASA center
Title: Re: Proposed Europa Missions
Post by: ugordan on 08/02/2014 01:41 PM
How often does a window to Jupiter occur?

For a direct insertion to Jupiter, every 13 months or so. VEEGA-type trajectories are more complex so there's no single answer, the launch C3 cost can vary a lot between different opportunities.
Title: Re: Proposed Europa Missions
Post by: baldusi on 08/02/2014 02:48 PM

How often does a window to Jupiter occur?

For a direct insertion to Jupiter, every 13 months or so. VEEGA-type trajectories are more complex so there's no single answer, the launch C3 cost can vary a lot between different opportunities.
But now that we think of it, there might be some intermediate LV. Let's say a DIVH with a Star 48GXV. Or eventually a Falcon Heavy with a kick stage. What if the extra performance requires just a VEGA maneuver? It may cut a year from the trip and almost pay for itself. And whomever wins the Solar Probe Plus mission will have every certification save the nuclear rating.
Title: Re: Proposed Europa Missions
Post by: sdsds on 08/02/2014 10:58 PM
Starting this post with an observation: Europa is of high interest to people on the internet. See the attached "google fight" results below. "mars 64 100 000 résultats, europa 89 600 000 résultats." Europa is the "winner!" Of course that's not very scientific, but it gives a sense of the potential "popularity" of a Europa mission.

I think it's fair to contrast that popularity with the rather esoteric nature of the Europa science community. I was interested in the comment earlier that suggested putting 100 Europa scientists in a room and polling them on their preferences for a mission. My first reaction was, "Wait! Do that many dedicated Europa scientists really exist?"

Several times in the past when I have had some expertise in an esoteric topic that suddenly became popular I have been disappointed in how the unwashed masses "played with my toys." I'm sure others have experienced similar feelings. Maybe the coming years will be like that for Europa scientists. (Indeed, the threat of "cooperation" from NASA's HEOMD might have many in the SMD area feeling that way already!)

Going back some way in this thread:
ARC/JPL studied Europa sample return before under the Ice Clipper concept for a ~$250M Discovery proposal back in 1996/7.

With that as background, is there in principle a reason why two different Clipper missions, one in the ~$2B range and one in the ~$250M range, would be unable to share launch on an SLS?
Title: Re: Proposed Europa Missions
Post by: belegor on 08/03/2014 01:06 AM
Starting this post with an observation: Europa is of high interest to people on the internet. See the attached "google fight" results below. "mars 64 100 000 résultats, europa 89 600 000 résultats." Europa is the "winner!" Of course that's not very scientific, but it gives a sense of the potential "popularity" of a Europa mission.

Have you considered that "Europa" is the way Europe (the continent) is written in German, Italian and Spanish? How do you know that you're not actually comparing Mars (the planet) with Europe (the planet + the continent)?
Title: Re: Proposed Europa Missions
Post by: sdsds on 08/03/2014 08:04 AM
Have you considered that "Europa" is the way Europe (the continent) is written in German, Italian and Spanish? How do you know that you're not actually comparing Mars (the planet) with Europe (the planet + the continent)?

Oh, you're right: it probably isn't comparing references to the planet Mars and references to the moon Europa! To make the case I would need some other evidence that "Europa the moon of Jupiter" is a hot topic right now. Would a quotation from the movie 2010: Odyssey Two count? "All these worlds are yours, except Europa. Attempt no landing there!" ;)

Title: Re: Proposed Europa Missions
Post by: Oli on 08/03/2014 05:02 PM

Regarding the popularity of Mars vs Europa, I think this is more relevant:

http://www.google.com/trends/explore?hl=en-US#q=/m/0bv05,%20/m/09cws&cmpt=q
Title: Re: Proposed Europa Missions
Post by: vjkane on 08/04/2014 01:40 AM
"With that as background, is there in principle a reason why two different Clipper missions, one in the ~$2B range and one in the ~$250M range, would be unable to share launch on an SLS?"

$250m is not credible. The most similar mission, Deep Impact, would cost in the neighborhood of $450m plus today. A mission to Europa would have substantially higher costs: longer flight, low light levels, etc.
Title: Re: Proposed Europa Missions
Post by: vjkane on 08/04/2014 02:23 AM
Oops, actually the closest analogy is a mixture of Deep Impact and Stardust, driving the cost even higher
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/04/2014 03:34 AM
This discussion of "the popularity" of a Europa vs. Mars mission is a whole lotta silliness. These missions are not selected via a popularity contest. The general public doesn't get to vote.

There is in fact a well-established process for prioritizing space science missions. It works. And in fact it is working at this very moment, which is why Europa is even being discussed as a possible future flagship class mission.

Title: Re: Proposed Europa Missions
Post by: sdsds on 08/04/2014 04:52 AM
This discussion of "the popularity" of a Europa vs. Mars mission is a whole lotta silliness. These missions are not selected via a popularity contest. The general public doesn't get to vote.

No one but you has suggested that, Blackstar. You are fighting against a straw-man opponent!

What you don't seem able to accept is the true sentiment beneath, which your belittling mis-interpretation disregards. I do understand your defense of the way science missions have been selected in recent years; it has worked well! Do you understand that SMD is not an empire unto itself?
Title: Re: Proposed Europa Missions
Post by: TakeOff on 08/04/2014 11:38 AM
The problem with using SLS for a $1 billion probe is that to halve the price of the budget, you are going to have to throw out instruments, which will reduce both weight and power.  That won't make any significant difference in travel time, either direct or VEEGA, but it means you will be seriously underusing SLS.
Couldn't the extra payload be used for cheap and heavy payloads, such as fuel and radiation shielding material? A probe actually orbiting Europa requires good shielding from Jupiter's radiation. And fuel to manage the unstable gravitational environment.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/04/2014 01:23 PM
This discussion of "the popularity" of a Europa vs. Mars mission is a whole lotta silliness. These missions are not selected via a popularity contest. The general public doesn't get to vote.

No one but you has suggested that, Blackstar. You are fighting against a straw-man opponent!

What you don't seem able to accept is the true sentiment beneath, which your belittling mis-interpretation disregards. I do understand your defense of the way science missions have been selected in recent years; it has worked well! Do you understand that SMD is not an empire unto itself?

Silliness.
Title: Re: Proposed Europa Missions
Post by: a_langwich on 08/07/2014 06:46 PM
My point is that these are the kinds of decisions that program managers like to nail down quickly, and they want to go with the safest and most well-known choice. They do not necessarily want the highest performance option. Thus, even when Falcon Heavy starts flying, I suspect it will take a long time before program managers will embrace it. They will all want to see a lot of successful flights before they agree to use it. "Cheap" is not really cheap if the launch vehicle fails.


Yes, I would expect they would wait at least 3 missions.  And something like Solar Probe Plus, where a mission gets bumped onto Falcon Heavy because there aren't any good alternatives, will probably be the first SMD payload.  But the enormous capability FH opens up, for a price that is cheaper than what they've been paying for Atlas 5's...that's going to drive proposals toward it.  At the end of the day, when the proposal is more likely to win because of the extra goodies it can achieve, than lose because it uses a Falcon Heavy LV, then it will go with FH.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/27/2014 05:07 PM
I just had an interesting discussion with somebody who has helped review the Europa Clipper study progress and he had some interesting things to say. I should add that he's an engineer, not a scientist, and not a Europa hugger or SLS hugger or anything like that. He's also highly credible (a well-respected guy, by me and others).

He said that the solar power case for Europa is looking really good. He said that current experience with Juno is already giving them a lot of confidence. He also added a really subtle point--if you consider the timeline for developing a Europa mission, they will not enter full-scale development until after Juno has flown its full mission. That will give them really good confidence in the engineering data. In other words, starting to design EC they will not have to guess about solar panels at Jupiter (cold and radiation) they will have real-world data to use.

There's a complicated issue that I don't totally understand concerning the RTG availability. I didn't catch all of it, but apparently the production rate for Pu-238 is so low that they'll be really pressed for power on the mission. I imagine that this has to do with both how old the Pu-238 is at launch and when the spacecraft eventually reaches Europa. He said that this is one of the things that is making solar look even better. He also said that they have looked at a hybrid solar/RTG mission, and it has some advantages, but the way he put it, if you're going to use solar anyway, why mess with RTGs at all? I think that's a valid point, because you can save money by not having to certify the rocket, etc.

He said that the SLS option looks pretty good. You can save a lot of money on the spacecraft because of both the shorter transit time and the fact that you don't have to deal with thermal issues flying past Venus. That's nothing new (reported numerous places before). However, he was pretty impressed with it. The problem, of course, is that it depends upon the mission essentially getting an SLS for free. He did say that using an Atlas V and a VEEGA trajectory provides more mass for the spacecraft than SLS, because the SLS is just shooting it out and has less C3.

He confirmed what I've believed and I've heard from numerous other people that the $1 billion Europa mission concept is not viable.

Of course, the politics on this has to play out, but I've been a skeptic on both solar power and SLS for Europa Clipper, and the fact that somebody I highly respect considers them both viable and positive is something that I'll accept.
Title: Re: Proposed Europa Missions
Post by: veblen on 08/27/2014 05:44 PM

He confirmed what I've believed and I've heard from numerous other people that the $1 billion Europa mission concept is not viable.

Of course, the politics on this has to play out, but I've been a skeptic on both solar power and SLS for Europa Clipper, and the fact that somebody I highly respect considers them both viable and positive is something that I'll accept.

Very interesting. However, to be clear, are you saying that there are multiple Europa mission concepts and the one that has the $1B price tag is not viable? And another (cheaper&solar?) one is?


The reg process for missions with RTG is lengthy = expensive. Correct?
Title: Re: Proposed Europa Missions
Post by: Star One on 08/27/2014 05:57 PM
Being solar powered of course also saves the time and expense of certifying the SLS for nuclear carriage.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 08/27/2014 06:11 PM
1-Very interesting. However, to be clear, are you saying that there are multiple Europa mission concepts and the one that has the $1B price tag is not viable? And another (cheaper&solar?) one is?

2-The reg process for missions with RTG is lengthy = expensive. Correct?

1-There is the Europa Clipper mission proposal, which currently runs in the $2.4 billion range. Earlier this year OMB directed NASA to see what could be possible to do at Europa for about $1 billion. NASA put out a request for information and apparently received back six proposals for ~$1 billion Europa missions. The question is if it is possible to do decadal survey level science for $1 billion. I don't know anybody who thinks it is (although whoever proposed those six missions may believe it is possible).

2-Yes. There's really two aspects to this, as I understand. The first is an engineering assessment of the specific payload and specific vehicle to determine what would happen in various launch accident scenarios. The second is a legal certification, essentially somebody going through all the paperwork and assessing that all the procedures are done properly. Neither one is cheap. Now Atlas V is already nuclear certified. My guess is that this means that both the engineering assessment and the legal certification are easier. SLS is not nuclear certified, so there would have to be an initial major engineering assessment of the overall vehicle, then the other two steps that I mentioned above.

My colleague mentioned something that I had not thought of--the SLS's solid boosters are more dangerous to a payload than the Atlas. They can produce a more energetic explosion (and presumably more debris, because you could get pieces of rocket casing blasted at the payload). So SLS is a trickier vehicle to certify for nuclear payloads.

However, as I have mentioned before in this thread, if SLS is eventually going to carry humans into deep space, they're going to have to get a nuclear certification of some kind, because those missions will eventually carry RTGs. So I think the question becomes whether you do the certification five years from now or 15 years from now. You don't do it until you need to do it.
Title: Re: Proposed Europa Missions
Post by: simonbp on 08/28/2014 02:56 PM
He said that the solar power case for Europa is looking really good. He said that current experience with Juno is already giving them a lot of confidence. He also added a really subtle point--if you consider the timeline for developing a Europa mission, they will not enter full-scale development until after Juno has flown its full mission. That will give them really good confidence in the engineering data. In other words, starting to design EC they will not have to guess about solar panels at Jupiter (cold and radiation) they will have real-world data to use.

I heard something similar from someone who should know recently. Though, you have to remember that Juno's primary mission is pretty short (14 months), and terminates with Juno impacting Jupiter, which obviously limits the amount of engineering data we'll get on how solar works at Jupiter.

That said, RTGs are such a production to pull off that if there is any chance to make a solar Europa mission work, they will try. Especially with all the Pu238 production issues, even a nominal-RTG mission proposal needs a solar backup option in their back pocket.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/02/2014 07:24 PM
These are not strictly Europa presentations, but they're close. They were made at the July meeting of the Outer Planets Assessment Group (OPAG).

They can also be found at the OPAG site.
Title: Re: Proposed Europa Missions
Post by: vjkane on 09/03/2014 08:15 PM
I think that opag's plan to pre-prioritize New Frontiers missions well ahead of the next Decadal Survey will help them out especially if they can get some money to flesh out the details.

Any news from today's pas meeting on Europa planning? I had to drop off the call
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/03/2014 09:32 PM
I think that opag's plan to pre-prioritize New Frontiers missions well ahead of the next Decadal Survey will help them out especially if they can get some money to flesh out the details.


Huh?

That's actually not up to OPAG. According to NASA, it is the NRC's CAPS committee that is "the keeper of the decadal survey." OPAG can provide input to CAPS, and they could voice their opinion to NASA on this subject, but NASA would not be inclined to listen to them on that, and it would create problems (for instance, all the other AGs would complain).
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 09/03/2014 11:42 PM
Why is the SLS being push as a launch vehicle?
Title: Re: Proposed Europa Missions
Post by: Kryten on 09/03/2014 11:57 PM
Why is the SLS being push as a launch vehicle?
Because it needs payloads. There's not much else to it.
Title: Re: Proposed Europa Missions
Post by: veblen on 09/04/2014 12:10 AM
Why is the SLS being push as a launch vehicle?
Be cause it needs payloads. There's not much else to it.

To make up for the cratering of Planetary science over several years, resulting in a paucity of science missions in particular to the outer solar system, by JWST budget balloon.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2014 01:22 AM
Why is the SLS being push as a launch vehicle?
Be cause it needs payloads. There's not much else to it.

To make up for the cratering of Planetary science over several years, resulting in a paucity of science missions in particular to the outer solar system, by JWST budget balloon.

That's not really it. Planetary has ultimately done better than people expected a few years ago (you can thank Congress for that). There are currently three outer planets missions underway: Cassini, New Horizons, and Juno. And Europa is under study. The outer planets community likes to cry into its milk a lot, but the reality was that their missions are inherently expensive and Cassini ballooned in costs, and so it was not realistic for them to expect to get everything they wanted.
Title: Re: Proposed Europa Missions
Post by: vjkane on 09/04/2014 01:42 AM
But they can prepare their input for the *next* Decadal Survey. Starting now is smart.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2014 02:42 AM
But they can prepare their input for the *next* Decadal Survey. Starting now is smart.

I don't think that's what they're doing. It wouldn't make sense to start preparing their input for a decadal survey that is not going to happen for another 7 years. Think about the science changes that will happen in that time.

What will happen in the interim is the mid-term assessment of the planetary program. That will probably kick off sometime later next year. There are some people who naively think that the mid-term can be used to change the New Frontiers list. That won't happen. There is a long and healthy list of New Frontiers candidates and it won't be reevaluated just because some people don't like the options.
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 03:19 AM
These are not strictly Europa presentations, but they're close. They were made at the July meeting of the Outer Planets Assessment Group (OPAG).

They can also be found at the OPAG site.

Excellent find Blackstar.  A lot of the OPAG's site material is dated, but quite relevant.

I heartily support a Europa mission, but they should refocus on Uranus/Neptune (most likely Uranus) next presuming their priority is on new science.  Lord knows outside of Hubble observations they've been left out colder than Pluto.  One would think the Uranus Orbiter would be the cheapest option between it, MSR, and Europa...but I'm guessing it's study hasn't been as involved as either Mars or Europa, that a good assumption Blackstar?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2014 04:08 AM
1-Excellent find Blackstar.  A lot of the OPAG's site material is dated, but quite relevant.

2-I heartily support a Europa mission, but they should refocus on Uranus/Neptune (most likely Uranus) next presuming their priority is on new science.  Lord knows outside of Hubble observations they've been left out colder than Pluto.  One would think the Uranus Orbiter would be the cheapest option between it, MSR, and Europa...but I'm guessing it's study hasn't been as involved as either Mars or Europa, that a good assumption Blackstar?

1-Just look up all the AGs: LEAG, VEXAG, OPAG, MEPAG, SBAG. Go find their presentations. Usually they have a separate presentation link, but sometimes you can also look via their agenda. They hold two meetings a year, and the most recent stuff was July, so it should be quite current. I think the next meeting is LEAG in October. I'm hoping to go myself (not that far from me). VEXAG should have an upcoming meeting too.

Keep in mind that the slides are just that, slides. You really need to hear the talks, but they don't record these meetings (nor should they). You can listen in live if you want.

2-Well, I sorta cringe when I see people post on boards saying what "should" happen. Really, these decisions are made through a process, i.e. meetings and rules and lots and lots of deliberation. We can all have our own opinions, but it is really best if the community makes those decisions based upon their understanding of the science.

Now I actually agree that an ice giant mission is a logical next high priority. But it's going to take awhile for that to really happen. The decision on what to do next--for big missions--is not going to happen until after the next decadal survey, which will probably kick off around 2019 or so. (I was one of the people who ran the last one and it was one of the most fun and inspiring studies I've ever run. Really smart people working hard to come up with a good plan.)

Now an ice giants mission came in third on the last list (technically, the Mars rover and Europa tied for second place, so the ice giants mission really came in second). Such a mission will be a good contender next time. Certainly the science return on the dollar will be high because we've never studied either planet in detail, so everything will be new and revelatory.

But, the next step for Mars after a caching rover is bringing the cache back. So the Mars community is going to push hard for a return vehicle and a Mars Ascent Vehicle to be in first place. That will be an expensive mission. And if a Europa mission gets underway, the next logical step at Europa is a lander. And by then Cassini will be dead, so the people who study Titan will clamor for a Titan mission (and maybe they'll wise up and not ask for such a flipping big mission next time). So an ice giants mission might still get stuck in the number 3 priority list next time.

There was an ice giants workshop held in late July in Laurel, Maryland at APL. Unfortunately, it required paid registration and I didn't have the money to attend. They'll be producing some kind of proceedings, of course. So we'll learn what their science priorities are for such a mission. That workshop was in some ways a direct result of the decadal survey ranking an ice giants mission so high. But you can look at any large planetary science mission and you can trace back its origins 2-3 decades at least. These things take a long time to go from initial idea to flight.

Personally, I want to see a Neptune mission happen, but I expect that will not happen for many decades.
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 04:44 AM
-Well, I sorta cringe when I see people post on boards saying what "should" happen. Really, these decisions are made through a process, i.e. meetings and rules and lots and lots of deliberation. We can all have our own opinions, but it is really best if the community makes those decisions based upon their understanding of the science.

Correct; wasn't trying to be presumptuous.  If anything, the Decadal Study suggestion that if neither MSR or a EO were affordable, that UO was 'plan C'.  Otherwise, just logical option.

Now I actually agree that an ice giant mission is a logical next high priority. But it's going to take awhile for that to really happen. The decision on what to do next--for big missions--is not going to happen until after the next decadal survey, which will probably kick off around 2019 or so. (I was one of the people who ran the last one and it was one of the most fun and inspiring studies I've ever run. Really smart people working hard to come up with a good plan.)

Now an ice giants mission came in third on the last list (technically, the Mars rover and Europa tied for second place, so the ice giants mission really came in second). Such a mission will be a good contender next time. Certainly the science return on the dollar will be high because we've never studied either planet in detail, so everything will be new and revelatory.

But, the next step for Mars after a caching rover is bringing the cache back. So the Mars community is going to push hard for a return vehicle and a Mars Ascent Vehicle to be in first place. That will be an expensive mission. And if a Europa mission gets underway, the next logical step at Europa is a lander. And by then Cassini will be dead, so the people who study Titan will clamor for a Titan mission (and maybe they'll wise up and not ask for such a flipping big mission next time). So an ice giants mission might still get stuck in the number 3 priority list next time.

Everyone wants a piece of the pie...  ;)

Frankly Mars has been hogging the frickn' pie long enough, and if humans are coming well it's time to shift the Martian paradigm to serve man, literally for the crewed missions.  Once (or if) MSR is accomplished, leave the fossil hunting to the humans.

In fairness, I know there will always be high-priority targets like Europa and Titan (in their cases for exobiology), but every planet deserves a turn.  Aside from the Ice Giants, Venus is another prime example.  Whereas Uranus and Neptune are just hard to reach, Venus is literally Hellish to endure.  In their case I'd rank Uranus, Neptune, and Venus in order of the technology to study (good luck landing on Venus long enough for seismology, a much-needed science for Earth's sister).

Personally, I want to see a Neptune mission happen, but I expect that will not happen for many decades.
Outside of aerocapture (and lord knows we've both exchanged remarks on that technology), my bet would be a fly-by/probe mission using available technology. 

This post probably flew well beyond the topic...but still strengthens importance of the Outer Planets with Europa included.
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 09/04/2014 04:51 AM
Why is the SLS being push as a launch vehicle?
Be cause it needs payloads. There's not much else to it.

To make up for the cratering of Planetary science over several years, resulting in a paucity of science missions in particular to the outer solar system, by JWST budget balloon.

That's not really it. Planetary has ultimately done better than people expected a few years ago (you can thank Congress for that). There are currently three outer planets missions underway: Cassini, New Horizons, and Juno. And Europa is under study. The outer planets community likes to cry into its milk a lot, but the reality was that their missions are inherently expensive and Cassini ballooned in costs, and so it was not realistic for them to expect to get everything they wanted.
But using the SLS and certifying it to carry nukes for outer system missions will balloon the budget astronomically. Wouldn't that make the mission less likely to be selected?
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 05:20 AM
But using the SLS and certifying it to carry nukes for outer system missions will balloon the budget astronomically. Wouldn't that make the mission less likely to be selected?

If so, they technically still list the Atlas as their primary choice.  However, if the solar option is used worrying about certifying the SLS for carrying plutonium becomes irrelevant.  It becomes more like a technological chicken-and-the-egg game: if we so solar we get there faster for a shorter study; if we go nuclear we have to so slow for a longer study...

I hate the unnecessary wait times cruises impose, not to mention the need to accommodate a Venus fry-by is counterproductive for an Outer Solar System expedition.  Short and sweet is better; Juno's Earth fly-by should be the most at least a Jupiter-bound probe should ensure - the whole Galileo VEEGA bit was just an improvised scheme thanks to space shuttle nonsense.

They'll figure out something; regarding "nukes" it will just depend on RTG availability and the power needs of the spacecraft.
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 09/04/2014 05:31 AM
But using the SLS and certifying it to carry nukes for outer system missions will balloon the budget astronomically. Wouldn't that make the mission less likely to be selected?

If so, they technically still list the Atlas as their primary choice.  However, if the solar option is used worrying about certifying the SLS for carrying plutonium becomes irrelevant.  It becomes more like a technological chicken-and-the-egg game: if we so solar we get there faster for a shorter study; if we go nuclear we have to so slow for a longer study...

I hate the unnecessary wait times cruises impose, not to mention the need to accommodate a Venus fry-by is counterproductive for an Outer Solar System expedition.  Short and sweet is better; Juno's Earth fly-by should be the most at least a Jupiter-bound probe should ensure - the whole Galileo VEEGA bit was just an improvised scheme thanks to space shuttle nonsense.

They'll figure out something; regarding "nukes" it will just depend on RTG availability and the power needs of the spacecraft.
Hmm. Don't think solar power is variable beyond the orbit of Jupiter.
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 09:54 AM
But using the SLS and certifying it to carry nukes for outer system missions will balloon the budget astronomically. Wouldn't that make the mission less likely to be selected?

If so, they technically still list the Atlas as their primary choice.  However, if the solar option is used worrying about certifying the SLS for carrying plutonium becomes irrelevant.  It becomes more like a technological chicken-and-the-egg game: if we so solar we get there faster for a shorter study; if we go nuclear we have to so slow for a longer study...

I hate the unnecessary wait times cruises impose, not to mention the need to accommodate a Venus fry-by is counterproductive for an Outer Solar System expedition.  Short and sweet is better; Juno's Earth fly-by should be the most at least a Jupiter-bound probe should ensure - the whole Galileo VEEGA bit was just an improvised scheme thanks to space shuttle nonsense.

They'll figure out something; regarding "nukes" it will just depend on RTG availability and the power needs of the spacecraft.
Hmm. Don't think solar power is variable beyond the orbit of Jupiter.

Tell that to the CURRENTLY FLYING Juno mission...
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 09:55 AM
Finally found a link to the Europa workshop:

http://soma.larc.nasa.gov/europa/conf_wkshop.html (http://soma.larc.nasa.gov/europa/conf_wkshop.html)

From one of the PEA slides comes a breakdown of the immediate schedule:
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 09/04/2014 10:14 AM
...
Hmm. Don't think solar power is variable beyond the orbit of Jupiter.

Tell that to the CURRENTLY FLYING Juno mission...

The Juno mission is not flying beyond the orbit of Jupiter.
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 10:24 AM
...
Hmm. Don't think solar power is variable beyond the orbit of Jupiter.

Tell that to the CURRENTLY FLYING Juno mission...

The Juno mission is not flying beyond the orbit of Jupiter.

Correct, but there have been proposals to the Trojans, Saturn (with Titan), and even Uranus using large and advanced solar arrays.  It depends on the mission needs, and especially for Uranus much of the solar power goes toward ion propulsion.  With the 2020 Rover in the works and a Europa mission in consideration, even with the restarted enrichment program the cupboards are going to be thin for some time...and even weak solar power is going to be considered.  It's an option and it tends to be cheaper at the expense of mass.

p.s.
I believe you meant viable beyond the orbit of Jupiter.
Title: Re: Proposed Europa Missions
Post by: Dalhousie on 09/04/2014 11:56 AM

Regarding the popularity of Mars vs Europa, I think this is more relevant:

http://www.google.com/trends/explore?hl=en-US#q=/m/0bv05,%20/m/09cws&cmpt=q

Running the cursor over it shows that this is still picking up Europa the continent hits.

A simple Mars + planet Google search yields 53,900,000 hits

A simple Europa + moon Google search yields 23,900,000 hits
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2014 12:52 PM
But using the SLS and certifying it to carry nukes for outer system missions will balloon the budget astronomically. Wouldn't that make the mission less likely to be selected?

It depends upon what part of NASA pays for the SLS. I've said this before, but it's worth repeating: there's no great enthusiasm within the planetary community for using SLS for Europa. They would all be perfectly happy with Atlas or whatever rocket is available. SLS is an expensive rocket, but if the human side pays for it, it could actually lower the cost of a Europa mission for the science side.
Title: Re: Proposed Europa Missions
Post by: redliox on 09/04/2014 08:09 PM
It depends upon what part of NASA pays for the SLS. I've said this before, but it's worth repeating: there's no great enthusiasm within the planetary community for using SLS for Europa. They would all be perfectly happy with Atlas or whatever rocket is available. SLS is an expensive rocket, but if the human side pays for it, it could actually lower the cost of a Europa mission for the science side.

If it weren't for a fear of a new rocket blowing up it's be an excellent match for the Outer Solar System.  The Voyagers and Cassini both needed the heft of a Titan rocket to do their jobs, and ULA/Boeing/Lockheed have yet to speak of successors to either Delta 4 or Atlas 5...so beyond Falcon 9 Heavy SLS is the most obvious heavy-duty rocket coming to market.

i.e. if push comes to shove and if NASA seriously wants a new probe to show off it's new rocket, in the end the science community will be the fussy baby getting the spoon shoved in it's mouth.
Title: Re: Proposed Europa Missions
Post by: Jim on 09/04/2014 08:18 PM

If it weren't for a fear of a new rocket blowing up it's be an excellent match for the Outer Solar System.  The Voyagers and Cassini both needed the heft of a Titan rocket to do their jobs, and ULA/Boeing/Lockheed have yet to speak of successors to either Delta 4 or Atlas 5......so beyond Falcon 9 Heavy SLS is the most obvious heavy-duty rocket coming to market.


Not so.   

NASA is not lacking for performance from launch vehicles for unmanned mission.  There has been no need for successors to either Delta 4 or Atlas 5, there hasn't been a science payload that needs a Delta IV Heavy (which has more capability than any Titan configuration and Atlas V 551 has more than any Titan III configuration).   And Falcon Heavy can't do some of the high energy missions.

i.e. if push comes to shove and if NASA seriously wants a new probe to show off it's new rocket, in the end the science community will be the fussy baby getting the spoon shoved in it's mouth.


Not so again.  NASA isn't going to build a probe just for SLS.  Europa can fly without it.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/04/2014 08:46 PM
See one of my earlier posts. One of the ironic things is that for this mission, Atlas V can actually carry a little more payload than the SLS. That's because the SLS spends all its energy shooting the thing there directly, whereas the Atlas V gets a gravity assist. So if they need to add a little mass, the Atlas V offers more margin.
Title: Re: Proposed Europa Missions
Post by: Star One on 09/04/2014 09:23 PM

See one of my earlier posts. One of the ironic things is that for this mission, Atlas V can actually carry a little more payload than the SLS. That's because the SLS spends all its energy shooting the thing there directly, whereas the Atlas V gets a gravity assist. So if they need to add a little mass, the Atlas V offers more margin.

But don't you to loose some payload because of the additional shielding needed for a Venus flyby?
Title: Re: Proposed Europa Missions
Post by: veblen on 09/04/2014 09:25 PM
Yeah AtlasV is great hopefully it will remain available for science missions, probably will but who knows? FH can't do a Europa mission? Disappointing non-option. Interesting to read, from wiki, that Magellan and Galileo s/c were basically spin-offs of the Voyager missions, plus other parts of other s/c programs. Why weren't they launched on Delta or some other medium lift (?) rocket? Why did they get launched on STS?
Title: Re: Proposed Europa Missions
Post by: Jim on 09/05/2014 12:51 AM
Why weren't they launched on Delta or some other medium lift (?) rocket? Why did they get launched on STS?

Because the shuttle was to be the only launch vehicle.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/05/2014 01:29 AM
Yeah AtlasV is great hopefully it will remain available for science missions, probably will but who knows? FH can't do a Europa mission? Disappointing non-option. Interesting to read, from wiki, that Magellan and Galileo s/c were basically spin-offs of the Voyager missions, plus other parts of other s/c programs. Why weren't they launched on Delta or some other medium lift (?) rocket? Why did they get launched on STS?

There are some good books you can read that discuss this.
Title: Re: Proposed Europa Missions
Post by: Zed_Noir on 09/05/2014 03:00 AM
...

Correct, but there have been proposals to the Trojans, Saturn (with Titan), and even Uranus using large and advanced solar arrays.  It depends on the mission needs, and especially for Uranus much of the solar power goes toward ion propulsion.  With the 2020 Rover in the works and a Europa mission in consideration, even with the restarted enrichment program the cupboards are going to be thin for some time...and even weak solar power is going to be considered.  It's an option and it tends to be cheaper at the expense of mass.

p.s.
I believe you meant viable beyond the orbit of Jupiter.
It is highly unlikely such solar powered missions can done for New Frontier level budgets, IMO. However a flagship program might be possible, if NASA approve one in the mid term.

p.s.
I meant viable beyond the orbit of Jupiter. Auto-correct strikes again.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/05/2014 03:05 AM
There was actually some brief discussion about that during the OPAG presentation to PSS/CAPS this morning. I don't think it is reflected in the slides, but they did say that they are interested in exploring if solar is viable beyond Jupiter and also what can be done on a New Frontiers budget at the outer planets. They said that they were inspired by the TiME mission, which implied that Saturn distance science could be done even on a Discovery budget. (I think the key term is "implied.")

That was just the OPAG chair expressing an opinion, but the opinion is held by somebody who knows their stuff.
Title: Re: Proposed Europa Missions
Post by: vjkane on 09/05/2014 05:02 AM
Regarding solar power missions to the outer planets, I've chatted with a JPL architect on this subject.  His take is that solar power at Jupiter's distance from the sun is a proven technology.  There are some challenges.  Extensive testing of the candidate lots of solar panels must be done to find those that can operate at the low temperatures.  Significant amounts of power has to be diverted to run heaters of for the spacecraft.  (Almost half of Juno's power at Jupiter goes to the heaters.)  And the panels are heavy and bulky.  (And while we didn't discuss this, the bulk is the likely reason for the fine stability problems if the Europa Clipper goes solar.  During the encounters, the spacecraft has to torque rapidly to point its instruments, and the panels likely express Newton's first law by vibrating.  I just saw a Cirque de Soleil show, and the high wire artists' poles were vibrating rapidly at their ends in response to each movement.)

Given this, solar power missions can be done for Jupiter and the Trojan asteroids.  Flying even one MMRTG to provide heat would dramatically lower the size of the panels, but would also incur all the costs of using radioactive material on the mission.

His take was that for Saturn, solar cells that would operate at Jupiter would probably also operate there.  But the bulk and weight problem would be four times greater than at Jupiter to make up for the lower sunlight.

At Uranus and beyond, current solar panel technology is simply impractical.  There are groups working on really advanced cells that may solve this problem, but my impression is that they aren't very far along.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/05/2014 01:17 PM
Regarding solar power missions to the outer planets, I've chatted with a JPL architect on this subject.  His take is that solar power at Jupiter's distance from the sun is a proven technology.  There are some challenges.  Extensive testing of the candidate lots of solar panels must be done to find those that can operate at the low temperatures.  Significant amounts of power has to be diverted to run heaters of for the spacecraft.  (Almost half of Juno's power at Jupiter goes to the heaters.)  And the panels are heavy and bulky.  (And while we didn't discuss this, the bulk is the likely reason for the fine stability problems if the Europa Clipper goes solar.  During the encounters, the spacecraft has to torque rapidly to point its instruments, and the panels likely express Newton's first law by vibrating.  I just saw a Cirque de Soleil show, and the high wire artists' poles were vibrating rapidly at their ends in response to each movement.)

Given this, solar power missions can be done for Jupiter and the Trojan asteroids.  Flying even one MMRTG to provide heat would dramatically lower the size of the panels, but would also incur all the costs of using radioactive material on the mission.

His take was that for Saturn, solar cells that would operate at Jupiter would probably also operate there.  But the bulk and weight problem would be four times greater than at Jupiter to make up for the lower sunlight.

At Uranus and beyond, current solar panel technology is simply impractical.  There are groups working on really advanced cells that may solve this problem, but my impression is that they aren't very far along.


Thanks for that detailed explanation.

I know it has commented that running solar + RTG makes little sense, and going with strictly one or the other just makes sense, but I wonder if there truly is something to be gained by having RTGs employed strictly for thermal issues, leaving Solar for the instruments/spacecraft ops.

Of course in my little world, I would also have a cross-connect feature in case one had an issue (to add redundancy), but I know that introduces a whole complex set of issues, not least of which is additional mass & failure points.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/05/2014 05:16 PM
I know it has commented that running solar + RTG makes little sense, and going with strictly one or the other just makes sense, but I wonder if there truly is something to be gained by having RTGs employed strictly for thermal issues, leaving Solar for the instruments/spacecraft ops.

If all they need is heat they would not use an RTG. They would use RHUs, or radioisotope heating units. Less Pu-238 required.
Title: Re: Proposed Europa Missions
Post by: robertross on 09/06/2014 12:02 AM
I know it has commented that running solar + RTG makes little sense, and going with strictly one or the other just makes sense, but I wonder if there truly is something to be gained by having RTGs employed strictly for thermal issues, leaving Solar for the instruments/spacecraft ops.

If all they need is heat they would not use an RTG. They would use RHUs, or radioisotope heating units. Less Pu-238 required.

You learn something new every day, thanks.
I would say this could be a consideration?

http://en.wikipedia.org/wiki/Radioisotope_heater_unit

"Radioisotope heater units (RHU) are small devices that provide heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of a few grams of plutonium-238—although other radioactive isotopes could be used."

So another isotope can be used (and that makes sense). It notes less Pu-238 is required, so that may make it a desirable approach due to the shortage. I wonder if it has been considered?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/06/2014 01:30 AM
"Radioisotope heater units (RHU) are small devices that provide heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of a few grams of plutonium-238—although other radioactive isotopes could be used."

So another isotope can be used (and that makes sense). It notes less Pu-238 is required, so that may make it a desirable approach due to the shortage. I wonder if it has been considered?

Yeah, there are other options. They're just not good. Some are gamma emitters, which is yucky. Some have short half-lives, which is icky. And some dissolve in water, which is not good if you need to launch them from a planet that is 70% covered with water.

There's another thing that I didn't really appreciate until I hung around Ralph McNutt for a long time (he will talk your ear off about this stuff): we have a LOT of experience with Pu-238. Decades. That means that just about every possible question has been answered. Somebody can go look it up in their big 3-ringed binder at the lab. They know all the procedures and all of the behaviors of the material. That's not true for any of the other isotopes. So if somebody asks something like "How will material X react when it is heated and shocked by a rocket explosion at 30,000 feet?" they won't have an answer and they'll have to go model it. That's expensive and time consuming. Better the devil you know...
Title: Re: Proposed Europa Missions
Post by: robertross on 09/06/2014 02:00 AM
"Radioisotope heater units (RHU) are small devices that provide heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of a few grams of plutonium-238—although other radioactive isotopes could be used."

So another isotope can be used (and that makes sense). It notes less Pu-238 is required, so that may make it a desirable approach due to the shortage. I wonder if it has been considered?

Yeah, there are other options. They're just not good. Some are gamma emitters, which is yucky. Some have short half-lives, which is icky. And some dissolve in water, which is not good if you need to launch them from a planet that is 70% covered with water.

There's another thing that I didn't really appreciate until I hung around Ralph McNutt for a long time (he will talk your ear off about this stuff): we have a LOT of experience with Pu-238. Decades. That means that just about every possible question has been answered. Somebody can go look it up in their big 3-ringed binder at the lab. They know all the procedures and all of the behaviors of the material. That's not true for any of the other isotopes. So if somebody asks something like "How will material X react when it is heated and shocked by a rocket explosion at 30,000 feet?" they won't have an answer and they'll have to go model it. That's expensive and time consuming. Better the devil you know...

Yes, the devil you know, but not as readily available as one would hope (not that we haven't seen this coming for years). I do agree Pu-238 is the right material for the job. At least they're working on harnessing more.

Well, I still think a lot of 'alignments' need to happen to pull off this Europa mission.
It's a super cool destination however.
Title: Re: Proposed Europa Missions
Post by: sdsds on 09/06/2014 02:18 AM
Americium 241 (Am-241) is apparently a fairly virtuous RHU option.
Quote
Am-241 is available at around 1 kg/yr commercially, [...] produces 59 kev gammas which are stopped readily by tungsten so the radiation field is very low, [and] has a half-life that is approximately five times greater than that of Pu-238.
Preliminary Analysis: Am-241 RHU/TEG Electric Power Source for Nanosatellites. Glen A. Robertson et al.
http://hdl.handle.net/2060/20140008746



Title: Re: Proposed Europa Missions
Post by: baldusi on 09/06/2014 03:59 AM
AM-241 need heavier insulation, and itself weight like four times more for the same heat output. And the extra life would be unnecessary given the solar panels natural degradation in space?
Title: Proposed Europa Missions
Post by: Star One on 09/08/2014 05:21 PM
Plate Tectonics May Increase Chances for Life on Europa.

Quote
Jupiter’s moon Europa is a fascinating little world, but particularly so for one reason: water. It’s deep alien ocean underneath the surface ice is reminiscent of our own planet, and since our oceans and seas are teeming with life, even beneath the ice at the poles, could Europa’s ocean also harbor life of some kind? Now, another discovery shows that Europa may be similar to Earth in yet another way, and one that could bolster the chances of life even more: plate tectonics. The new results were just published in Nature Geoscience on Sep. 7, 2014.

Why is this significant? It means that the icy surface may be connected to the ocean below; plate tectonics can provide a way for nutrients to be carried from the surface down into the waters below, just as they do on Earth. Even microbes themselves might be able to make that journey.

Learning more about Europa’s tectonics and the ocean below will require follow-up missions such as the proposed Europa Clipper, which would make repeated flybys of the moon while studying its surface and interior. Other missions have also been proposed, although it is likely that costs may be a limiting factor. There is, however, a big push happening now for a return mission to Europa that could help answer some of the long-standing questions—primarily, is or was there ever life there?



http://www.americaspace.com/?p=67147
Title: Re: Proposed Europa Missions
Post by: jongoff on 09/08/2014 11:10 PM
...
Hmm. Don't think solar power is variable beyond the orbit of Jupiter.

Tell that to the CURRENTLY FLYING Juno mission...

The Juno mission is not flying beyond the orbit of Jupiter.

Correct, but there have been proposals to the Trojans, Saturn (with Titan), and even Uranus using large and advanced solar arrays.  It depends on the mission needs, and especially for Uranus much of the solar power goes toward ion propulsion.  With the 2020 Rover in the works and a Europa mission in consideration, even with the restarted enrichment program the cupboards are going to be thin for some time...and even weak solar power is going to be considered.  It's an option and it tends to be cheaper at the expense of mass.

p.s.
I believe you meant viable beyond the orbit of Jupiter.

Under our MIDAS SBIR at Altius we're looking at a system for enabling a 6U cubesat mission to Titan using solar power (with ~2U worth of useable payload space). We're about 1/3 of the way through the Phase 1 study, and while things don't close yet, we're making progress. Won't be a lot of power available, but our aerocapture system requires huge batteries, so we may be able to make it close by doing some things in pulsed-mode (ie where you trickle charge the batteries over the course of a few days and then do something power intensive for a few hours using battery power to augment the solar power).

Obviously we'll be limited in how far we can analyze this in a Phase 1/Phase 2 SBIR, but we're hoping to retire some of the key risks. Figured it might be relevant.

~Jon
Title: Re: Proposed Europa Missions
Post by: truth is life on 09/09/2014 08:43 PM
Yeah, there are other options. They're just not good. Some are gamma emitters, which is yucky. Some have short half-lives, which is icky. And some dissolve in water, which is not good if you need to launch them from a planet that is 70% covered with water.

There's another thing that I didn't really appreciate until I hung around Ralph McNutt for a long time (he will talk your ear off about this stuff): we have a LOT of experience with Pu-238. Decades. That means that just about every possible question has been answered. Somebody can go look it up in their big 3-ringed binder at the lab. They know all the procedures and all of the behaviors of the material. That's not true for any of the other isotopes. So if somebody asks something like "How will material X react when it is heated and shocked by a rocket explosion at 30,000 feet?" they won't have an answer and they'll have to go model it. That's expensive and time consuming. Better the devil you know...
I thought we had a pretty good handle on americium? I mean, they use the stuff in smoke detectors, so they've got to have a huge amount of information about how it behaves under different circumstances (not least HOT circumstances, for obvious reasons).
Title: Re: Proposed Europa Missions
Post by: a_langwich on 09/09/2014 10:06 PM
Americium 241 (Am-241) is apparently a fairly virtuous RHU option.
Quote
Am-241 is available at around 1 kg/yr commercially, [...] produces 59 kev gammas which are stopped readily by tungsten so the radiation field is very low, [and] has a half-life that is approximately five times greater than that of Pu-238.
Preliminary Analysis: Am-241 RHU/TEG Electric Power Source for Nanosatellites. Glen A. Robertson et al.
http://hdl.handle.net/2060/20140008746



"Stopped readily by tungsten" -- ie, a very dense, heavy material
vs
"stopped by a thin sheet of paper"  for alpha particles

That is, the current power supply does not need to waste much mass on radiation shielding.  Very important because W/kg is the key metric.  Given the longer half-life, just the americium already will weigh much more than plutonium, and now you are looking at heavy shielding, which means an even heavier structure.  The larger size (required by the lower decay rate) will mean less heat density.

Still, given the huge costs of producing plutonium 238, there is probably a lot of leeway for much less ideal (but also possibly much less expensive) alternatives.  Solar arrays are increasingly viable, but for landers/rovers/floaters/subs (beyond Mars) an RTG option still seems needed.

Aren't the Europeans pursuing Americium?  That's a good thing, because the options right now are clearly too limited, and NASA SMD is stretched out just trying to recreate the Pu238 production.

Who knows?  It may be the much heavier structure (sturdier in overpressure), plus the disappearance of the name "plutonium", and the whole concept of "nuclear rating" a rocket might quietly be ditched.  Similar to the calmness with which people face MRIs vs the dreaded Nuclear Magnetic Resonance imaging (as the chemistry community still calls it).  Or there may be other silver linings to choosing a second-best RTG material.  Maybe it will force the development of much higher efficiency electrical conversion systems.  I hear there's a Stirling engine option out there somewhere... ::)

For me, that's the fantastic thing about having the Europeans, Japanese, Chinese, Indians, and Russians all capable of tackling scientific missions:  there's a wonderful diversity of approaches, which together accomplish much more than a single mindset.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/18/2014 03:28 PM
I thought I had posted these here. They are from the recent OPAG meeting.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 09/18/2014 03:29 PM
Ah, yes, I did previously post those. But here they are again so you can enjoy them all the more...
Title: Re: Proposed Europa Missions
Post by: baldusi on 10/02/2014 07:44 PM
From Stephen Clark Tweeter at IAC2014

Quote
Stephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
Might the LV have determined the power source? Could it have been that with extra throw weight they could add solar panels without much penalty?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/02/2014 08:38 PM
From Stephen Clark Tweeter at IAC2014

Quote
Stephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
Might the LV have determined the power source? Could it have been that with extra throw weight they could add solar panels without much penalty?

I am skeptical of this comment. There's no approved Europa Clipper program right now, let alone one scheduled for a 2022 launch (where's the money going to come from?).

And as I mentioned earlier, SLS has lower throw weight than Atlas V for this mission.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/02/2014 09:01 PM
They just held a mission concept review.
Title: Re: Proposed Europa Missions
Post by: redliox on 10/02/2014 09:02 PM
From Stephen Clark Tweeter at IAC2014

Quote
Stephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
Might the LV have determined the power source? Could it have been that with extra throw weight they could add solar panels without much penalty?

I am skeptical of this comment. There's no approved Europa Clipper program right now, let alone one scheduled for a 2022 launch (where's the money going to come from?).

And as I mentioned earlier, SLS has lower throw weight than Atlas V for this mission.

I'm likewise skeptical about this comment and the source, who appears to be another random space enthusiast.  I'm emailing one of the outer planet managers to verify this; based on what I heard they are still reviewing missions concepts, although this month they might unveil what instruments will be used.
Title: Re: Proposed Europa Missions
Post by: veblen on 10/02/2014 09:13 PM
Stephen Clark of SFN? I don't know if I would describe him as "another random space enthusiast", that would be me!
Title: Re: Proposed Europa Missions
Post by: Jim on 10/02/2014 11:42 PM
I'm likewise skeptical about this comment and the source, who appears to be another random space enthusiast.  I'm emailing one of the outer planet managers to verify this; based on what I heard they are still reviewing missions concepts, although this month they might unveil what instruments will be used.

Like I said they held a mission concept review.  SLS is prime and EELV is backup.  The basic instruments included in the review.
Title: Re: Proposed Europa Missions
Post by: sdsds on 10/03/2014 01:32 AM
SLS has lower throw weight than Atlas V for this mission.

Disingenuous. To the same sub-optimal trajectory an Atlas V mission would use, SLS has a better throw weight. Atlas V cannot launch the mission on the better trajectory SLS would use.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/03/2014 02:17 AM
SLS has lower throw weight than Atlas V for this mission.

Disingenuous. To the same sub-optimal trajectory an Atlas V mission would use, SLS has a better throw weight. Atlas V cannot launch the mission on the better trajectory SLS would use.

I'm disingenuous?
Title: Re: Proposed Europa Missions
Post by: sdsds on 10/03/2014 03:45 AM
I'm disingenuous?

We're in agreement?
Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/03/2014 04:22 PM

I am skeptical of this comment. There's no approved Europa Clipper program right now, let alone one scheduled for a 2022 launch (where's the money going to come from?).

The planetary science mission slots in 2022+ are basically to be decided. The internet meme that NASA no longer has money to do anything is rather annoying. The budget is bigger than ISRO, JAXA, Roscosmos, ESA and CNSA combined. The last manifested and defined planetary science mission is Mars 2020. Everything past that in the NASA FY2014 AMPM are placeholders for Mars, Discovery and New Frontier class missions. The house budget is 100 million, 80 million was the budget in 2014 and 75 million was the budget for Europa in 2013. It has congressional support if not presidential support and congressmen don't have term limits.
Title: Re: Proposed Europa Missions
Post by: GClark on 10/03/2014 05:32 PM
It's good that Congress is giving NASA money for this.  Polite applause.

Someone better convince OMB to authorize a new start for it, otherwise it's going nowhere fast.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/03/2014 08:36 PM

I am skeptical of this comment. There's no approved Europa Clipper program right now, let alone one scheduled for a 2022 launch (where's the money going to come from?).

The planetary science mission slots in 2022+ are basically to be decided. The internet meme that NASA no longer has money to do anything is rather annoying. The budget is bigger than ISRO, JAXA, Roscosmos, ESA and CNSA combined. The last manifested and defined planetary science mission is Mars 2020. Everything past that in the NASA FY2014 AMPM are placeholders for Mars, Discovery and New Frontier class missions. The house budget is 100 million, 80 million was the budget in 2014 and 75 million was the budget for Europa in 2013. It has congressional support if not presidential support and congressmen don't have term limits.

That's not how the budgeting system works at all. Congress cannot make a space mission happen without the executive branch's cooperation (beginning with a formal new program start). Congress, for example, cannot write contracts to build hardware. So they can stuff all the money they want into a bill, but that doesn't write the contracts to build stuff.

Write a letter to NASA and ask them if they are planning on launching a Europa mission in 2022. They're not. The funding profiles don't support it and the administration has not approved any such mission.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/03/2014 09:07 PM
I'm disingenuous?

We're in agreement?

Was it really necessary to just pop in here and be all grumpy? Have some coffee, you'll feel better.

NASA has two basic Europa Clipper missions under study. The SLS one doesn't use gravity assist. It has slightly lower throw weight to Jupiter.


Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/04/2014 08:18 AM

I am skeptical of this comment. There's no approved Europa Clipper program right now, let alone one scheduled for a 2022 launch (where's the money going to come from?).

The planetary science mission slots in 2022+ are basically to be decided. The internet meme that NASA no longer has money to do anything is rather annoying. The budget is bigger than ISRO, JAXA, Roscosmos, ESA and CNSA combined. The last manifested and defined planetary science mission is Mars 2020. Everything past that in the NASA FY2014 AMPM are placeholders for Mars, Discovery and New Frontier class missions. The house budget is 100 million, 80 million was the budget in 2014 and 75 million was the budget for Europa in 2013. It has congressional support if not presidential support and congressmen don't have term limits.

That's not how the budgeting system works at all. Congress cannot make a space mission happen without the executive branch's cooperation (beginning with a formal new program start). Congress, for example, cannot write contracts to build hardware. So they can stuff all the money they want into a bill, but that doesn't write the contracts to build stuff.

Write a letter to NASA and ask them if they are planning on launching a Europa mission in 2022. They're not. The funding profiles don't support it and the administration has not approved any such mission.

Quote
Impoundment is an act by a President of the United States of not spending money that has been appropriated by the U.S. Congress. Thomas Jefferson was the first president to exercise the power of impoundment in 1801. The power was available to all presidents up to and including Richard Nixon, and was regarded as a power inherent to the office. The Congressional Budget and Impoundment Control Act of 1974 was passed in response to perceived abuse of the power under President Nixon. Title X of the act, and its interpretation under Train v. City of New York, essentially removed the power. The president's ability to reject congressionally approved spending thus became severely inhibited.[1]

The Impoundment Control Act of 1974 provides that the president may propose rescission of specific funds, but that rescission must be approved by both the House of Representatives and Senate within 45 days. In effect, the requirement removed the impoundment power, since Congress is not required to vote on the rescission and, in fact, has ignored the vast majority of presidential requests
http://en.wikipedia.org/wiki/Impoundment_of_appropriated_funds


Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/04/2014 09:07 PM
Er, yeah, still doesn't work like that when it comes to creating new programs (as opposed to stuffing money into an ongoing project).

Look, I know the guy who is in charge of the planetary program. He has said in public on several occasions that he cannot pursue a new program without a formal new program start from OMB. Just cannot do it. For starters, the money provided by Congress is only there for one year (technically, they usually have two years to spend it), without any promise of further money. Thus, NASA cannot sign contracts for programs that would require many years to pay for them. Go ask him.

All NASA programs are part of the discretionary budget, which is funded on an annual basis. Are you suggesting that NASA can't sign contracts for long term projects because the funds for a year out are not there? How did NASA sign a contract with Boeing and SpaceX for crew access to ISS when no funds have been appropriated? I presume contracts have the ability to be cancelled. If funds are zeroed out in the future, as so often occurs for NASA programs, the contract is cancelled.

In fact, there is actually still money left over in the Europa account from when Congress first appropriated it. That's because it was a huge chunk of money for "studies" and there's only so much that you can spend on studies without actually bending metal. It's a rather sloppy and inefficient way to run a program (in part because that money is not free, but is being taken from other things that NASA has on its plate, like another New Frontiers mission). What it does do, however, is send a message to the OMB that if OMB doesn't get in front of the horse on a Europa mission, it will continue to be behind the horse on a Europa mission, and nobody really wants to be behind the horse.

The joint Omnibus spending bill in 2013 had Planetary Science funded at 127 million over the administration's request. Of that 127 million, 80 million was set aside for Europa "formulation" work. I don't see how this could be seen as taking away funds from other programs when not even counting this money, it was above the administration's request. Stretching the defination of "formulation" to include detailed design, build and test activities is more consistent with the law than effectively impounding the funds which can't be reconciled at all.

Quote
When NASA has a real program for building a Europa Clipper you will know it because they will talk about it as a development program. They don't have it now, and Congress cannot make it happen on its own.

Perhaps taking the example that caused Congress and the Supreme Court to strip the President of the impounding power could be illustrative.

Quote
And overridden it was. On October 18, 1972, first the Senate, then the House overrode Nixon's veto and the bill became law. After the veto override, Nixon refused to spend the money appropriated by Congress, using his presidential powers to impound half of the money. For a time, members of the House considered impeachment proceedings against Nixon and his actions were eventually challenged in the Supreme Court. In Train v. City of New York (1975), the court ruled "that the president had no authority to withhold funds provided by Congress in the Clean Water Act of 1972," stating essentially, "The president cannot frustrate the will of Congress by killing a program through impoundment." In addition, the Impoundment Control Act of 1974 provided a means of controlling the President's ability to impound funds for programs that they don't support.
http://www.huffingtonpost.com/robin-madel/nixons-clean-water-act-im_b_1372740.html

You suggest that Congress doesn't have the power to create a program. The example with the Clean Water Act strongly suggests that the President doesn't have the power not to implement programs funded by Congress.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/05/2014 05:09 PM

 How did NASA sign a contract with Boeing and SpaceX for crew access to ISS when no funds have been appropriated?


Because of the contract structure, they have not obligated the gov't for any real money.
Title: Re: Proposed Europa Missions
Post by: redliox on 10/05/2014 08:30 PM
From Stephen Clark Tweeter at IAC2014

Quote
Stephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014

Let's presume what Thomas Magner divulged from the concept review is true or at least heavily favored.  Would going solar benefit a Europa spacecraft enough to out-weigh nuclear?  Is SLS wiser to use than Atlas V?  Both are options I could get behind personally, but I know there's always a downside to everything.  Let's debate...

Title: Re: Proposed Europa Missions
Post by: baldusi on 10/05/2014 11:13 PM
Since I didn't new this was so preliminary, I assumed that solar would have been chose, in part to avoid nuclear rating the SLS. Also, since they don't have to go through Venus orbit, they don't have to rate the panels and heat rejection system for anything hotter than Earth. And since they are leaving fast, they could tolerate some degradation at Earth orbit.
The only issue is that Atlas V as backup means a lot of adaptation on those systems.
Title: Re: Proposed Europa Missions
Post by: vjkane on 10/07/2014 05:42 AM

The SLS thing is not at all assured. They have studied it because they were _told_ to study it. But I know a lot of people in the planetary program who just roll their eyes whenever it comes up. That's not because it is a bad engineering choice, but because they think the politics is very sketchy. Nobody wants to go down that road and get burned.


We've been down the road where planetary missions were tied to a new launch system.  NASA didn't pursue a Voyager Uranus probe mission because they were phasing out the Titan launch system and the shuttle wouldn't be ready in time.  We all know the story of how Galileo was repeatedly delayed because of its dependence on the shuttle.
Title: Re: Proposed Europa Missions
Post by: baldusi on 10/07/2014 02:34 PM
Blackstar, when would you expect an Europa Clipper Authorization to Start? I'm guessing "not with this OMB". But that's gonna change soon enough.
Title: Re: Proposed Europa Missions
Post by: arachnitect on 10/08/2014 05:05 PM
Jeff Foust reports from IAC in Toronto:

http://www.spacenews.com/article/civil-space/42121europa-clipper-opts-for-solar-power-over-nuclear

Quote
In an Oct. 3 presentation at the 65th International Astronautical Congress here, Europa Clipper deputy project manager Thomas Magner of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said that using large solar panels for the mission was both technically viable and less expensive than a radioisotope thermoelectric generator (RTG).

EC is an APL project?
Title: Re: Proposed Europa Missions
Post by: redliox on 10/08/2014 10:03 PM
http://www.spacenews.com/article/civil-space/42121europa-clipper-opts-for-solar-power-over-nuclear

Quote
In an Oct. 3 presentation at the 65th International Astronautical Congress here, Europa Clipper deputy project manager Thomas Magner of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said that using large solar panels for the mission was both technically viable and less expensive than a radioisotope thermoelectric generator (RTG).

Saw that article too, and it's great to see a news update that confirms what Stephen Clark heard about earlier (my apologies to him if I came off a bit harsh).

So whatever degradation the panels may endure, apparently they decided it's easier to handle versus acquiring plutonium, the paperwork to utilize it, and the environmental risks to both Europa and Earth.  At least there won't be any no-nuke-protestors like there were for Galileo and Cassini.  I've never been fond of nuclear power, but it is steadfast and necessary in the deeper parts of the solar system; on that note I'd hope whatever plutonium that isn't used for Mars 2020 can be applied to a new outer planet mission (my guess would be to either Saturn's moons or Uranus).

So that leaves two further factors for a new Europa mission: official funding (and between the forthcoming Congressional elections and the next Presidential one this is definitely a wild card not to underestimate) and choice of launch vehicle. 

Going by what Magner stated from APL, the SLS is recognized as an option but, as Blackstar elucidated upon, scientists likely find it more a political ploy than an vehicle at this point.  Still, it wouldn't be the first time politics came into play; recall Galileo and Magellan and their ties to the shuttle.  As complicated as that relationship was, it simultaneously preserved them (they were the only major planetary missions launched in the '80s after all).  The SLS, more so under a new administration, will need to justify its development and utility.  Considering EC was examined alongside ARM, that implies there already are political currents that will nudge spacecraft towards SLS.  Ultimately however, I would call it a 50/50 chance with Atlas V as well (then again, with politics in play, there could be frowns regarding 'relying on Russian technology'). 

It is still too soon to be certain.  With the OPAG having a meeting next February, I believe that is when we'll get firmer answers on the nature of a Europa mission.
Title: Re: Proposed Europa Missions
Post by: redliox on 10/08/2014 10:18 PM

The SLS thing is not at all assured. They have studied it because they were _told_ to study it. But I know a lot of people in the planetary program who just roll their eyes whenever it comes up. That's not because it is a bad engineering choice, but because they think the politics is very sketchy. Nobody wants to go down that road and get burned.


We've been down the road where planetary missions were tied to a new launch system.  NASA didn't pursue a Voyager Uranus probe mission because they were phasing out the Titan launch system and the shuttle wouldn't be ready in time.  We all know the story of how Galileo was repeatedly delayed because of its dependence on the shuttle.

The death of the Titan definitely put limits on probes, with the multiple fly-bys that keep the spacecraft away from their targets nearly as long as issues (technical and political) on the ground.  The shuttle, at least for anything beyond LEO, was a half-assed launcher because of design.  The SLS at least is a vehicle that combines the strengths of both; just shove the Orion out of the way and you have a big rocket with some of the most thoroughly tested parts (since mere humans are so squishy).

I don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising.  And you only improvise when you don't have the best tools for the job.  It is wise to keep both an EELV and a HLV open, but if the HLV is ready by the launch date don't hesitate to use it.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/08/2014 10:46 PM

The death of the Titan definitely put limits on probes,

Huh?  Delta IV has more capability than Titan IV and cheaper.
Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/09/2014 03:10 AM
I don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising. 
You cannot simply throw a large launch vehicle at every mission. That's expensive. That is money better spent on instruments.

Has anyone proposed doing something like using an HLV for every mission?

Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total. Not sure how you would spend the money on an HLV on instruments. Most of the money goes to the logistics of getting the instruments where they need to go with the resources available to them to get the job done. The reason space science is so much more expensive than earth science is the logistics, not the lab equipment. Instruments could probably use a few extra kgs of mass budget, a few more watts in the power budget rather than a few million in the dollar budget.
Title: Re: Proposed Europa Missions
Post by: Star One on 10/09/2014 06:27 AM
If the mission was solar powered rather than nuclear would there be any advantage to using a Delta IVH for it rather than the Atlas 551?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/09/2014 01:49 PM
I don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising. 
You cannot simply throw a large launch vehicle at every mission. That's expensive. That is money better spent on instruments.

Has anyone proposed doing something like using an HLV for every mission?

Instruments are usually a small portion of a mission's budget.


Launch vehicle size, and cost, has been a factor in the selection and non-selection of many planetary missions over the years. Look at Voyager-Mars as the classic example. Of course, size of the spacecraft (and cost) usually tracks with size of the rocket, but as a general rule, planetary missions have sought to keep the launch vehicle size as small as possible and mission designers are not automatically given the option of the largest rocket (there's a reason why Curiosity and Juno did not launch on Delta IVs, for instance).

There are lots of examples, but I'll mention just one: In the 1970s NASA considered a Mercury orbiting mission. But the mission would have required a large launch vehicle, and that (among other things) made it more expensive than people were willing to spend on such a mission. It wasn't until somebody was able to successfully propose a Mercury orbiter mission that could fly on a Delta II that the mission became viable and affordable.

The elimination of the Delta II and the increase in launch costs has materially hit the planetary program. It is one of the major factors in the reduction in Discovery missions.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 01:51 PM

Has anyone proposed doing something like using an HLV for every mission?


Too expensive.  You can fund a whole Discovery class mission for the cost of just the SLS.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 01:56 PM

Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.

Wrong.  They are not a small portion.  A lander is the wrong example.  MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.



Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/09/2014 02:19 PM

Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.

Wrong.  They are not a small portion.  A lander is the wrong example.  MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.

Also, the Curiosity instrument suite cost more than that. I think the cost was more like $170-$190 million. After all, the cost of the instrument suite for Mars 2020--not including the sample cacher--is over $130 million.
Title: Re: Proposed Europa Missions
Post by: baldusi on 10/09/2014 03:04 PM

Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.

Wrong.  They are not a small portion.  A lander is the wrong example.  MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.

Also, the Curiosity instrument suite cost more than that. I think the cost was more like $170-$190 million. After all, the cost of the instrument suite for Mars 2020--not including the sample cacher--is over $130 million.
And that's for a rover, for telescopes is much more (like 200M per instrument for a big one). And I wonder about something like Cassini which should be the closest match for this mission.
Title: Re: Proposed Europa Missions
Post by: vjkane on 10/09/2014 03:13 PM
The direct costs of instruments often runs 10-15% of the total cost of a mission. Accommodations on the spacecraft to provide power, stable pointing, space, data return, mission operations, etc can be much more. 

I've heard that if one wanted to just have a spacecraft flyby Europa many times with no instruments, the cost would be about $1B.   If you want to do great science, too, about double that price
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/09/2014 04:39 PM
And that's for a rover, for telescopes is much more (like 200M per instrument for a big one). And I wonder about something like Cassini which should be the closest match for this mission.

I'd quibble with counting a telescope that way. When it comes to a telescope, I don't think it is totally fair to divide it in terms of "instruments" and everything else. The telescope itself should in some way be considered a scientific instrument. It's not just support equipment.

Title: Re: Proposed Europa Missions
Post by: baldusi on 10/09/2014 04:50 PM
And that's for a rover, for telescopes is much more (like 200M per instrument for a big one). And I wonder about something like Cassini which should be the closest match for this mission.

I'd quibble with counting a telescope that way. When it comes to a telescope, I don't think it is totally fair to divide it in terms of "instruments" and everything else. The telescope itself should in some way be considered a scientific instrument. It's not just support equipment.
They include a deep radar. The whole craft has to act as an instrument. Similar concept can be made for the rest of the instruments. A craft with no instruments would have minimum power and heat rejection, basic comm, no pointing and stability needs, etc. So, I concur with vjkane that the instrument cost is the instrument itself plus the incremental cost to the craft.
But I concede that the telescope case is pretty particular.
Title: Re: Proposed Europa Missions
Post by: metaphor on 10/09/2014 04:55 PM
I've heard that if one wanted to just have a spacecraft flyby Europa many times with no instruments, the cost would be about $1B.   If you want to do great science, too, about double that price

If you add instruments, you're adding mass to the payload, plus additional power/thermal/communications requirements, so that makes the rest of the spacecraft cost more.  So the cost of the instruments themselves would not be equal to the difference in cost between a full-science Europa flyby mission and a Europa flyby mission with no instruments.  (edit--misread that post, I agree with your point)

According to this source (http://"http://orion.asu.edu/Additional%20Reading/Cassini_resource-margin_trade.pdf")(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 05:22 PM


According to this source (http://"http://orion.asu.edu/Additional%20Reading/Cassini_resource-margin_trade.pdf")(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.

$400M for the TIV, so 1/5 of the spacecraft cost.
Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/09/2014 05:30 PM
I don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising. 
You cannot simply throw a large launch vehicle at every mission. That's expensive. That is money better spent on instruments.

Has anyone proposed doing something like using an HLV for every mission?

Instruments are usually a small portion of a mission's budget.


Launch vehicle size, and cost, has been a factor in the selection and non-selection of many planetary missions over the years. Look at Voyager-Mars as the classic example. Of course, size of the spacecraft (and cost) usually tracks with size of the rocket, but as a general rule, planetary missions have sought to keep the launch vehicle size as small as possible and mission designers are not automatically given the option of the largest rocket (there's a reason why Curiosity and Juno did not launch on Delta IVs, for instance).

I've heard it argued here that Curiosity maxes out NASA's EDL technology for downmass(i.e. they can't make the parachutes any bigger). If this is the case, more upmass wouldn't enable much more rover. This doesn't apply to Europa Clipper. Delta IVs are generally never used for NASA missions, partly due to not being a NASA certified launch vehicle. For whatever reason, ULA/Boeing/Lockheed generally push Atlas over Delta for NASA/commercial.


Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.

Wrong.  They are not a small portion.  A lander is the wrong example.  MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.


Also, the Curiosity instrument suite cost more than that. I think the cost was more like $170-$190 million. After all, the cost of the instrument suite for Mars 2020--not including the sample cacher--is over $130 million.

If a lander is a wrong example, maybe JIMO would be a better example given that it was also a Jupiter moon mission. It includes multiple mission elements assembled in orbit via multiple launches, a nuclear reactor, electric drive, massive radiators, etc. All of that is logistics and is just as complicated as MSL if not more so.

Anyways, the constraint for a Jupiter moon mission needs to be the ability to equip a full power, full scale ground penetrating radar. I'm not sure it would be hugely expensive, but it will be power hungry and heavy. What is going on below the surface is the whole point after all.

As far as budget for Mars 2020:
Quote
The 19-member SDT, headed by Brown University geologist Jack Mustard, has been told NASA will have about $80 million for rover science instruments, Meyer said, adding that at least one and possibly two more instruments, with a total value of about $20 million, also should be coming from participating international or other partners.
http://www.spacenews.com/article/civil-space/34035nasa-outlines-budget-scope-for-next-mars-rover-in-2020

MSL budget was about what I said, but ended up significantly over budget resulting in the ~170 million.

Quote
Although Curiosity’s initial budget for science instruments was $85 million in 2004 dollars, the agency ended up spending roughly twice that amount.
http://www.spacenews.com/article/civil-space/34035nasa-outlines-budget-scope-for-next-mars-rover-in-2020

Still, we are talking about 7% of the mission cost even after going over-budget(more so than the mission overall) which some people here have pointed out might be on the low end of the spectrum given it is a lander. I'm having a bit of trouble finding cost figures for the instruments on Cassini, but the linked page below says the UVIS instrument cost 12.5 million and is one of 12 while the whole mission cost 3.3 billion. Extrapolating this towards all twelve would yield 150 million out of 3.3 billion or 4.5%. I would characterize this as a small portion. Anyone with better numbers and more expert google-fu, feel free to post.

http://lasp.colorado.edu/cassini/education/faqs.htm

p.s. Yes, I see someone posted numbers above me. I am just going to push the button anyways.

Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/09/2014 05:44 PM


According to this source (http://"http://orion.asu.edu/Additional%20Reading/Cassini_resource-margin_trade.pdf")(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.

$400M for the TIV, so 1/5 of the spacecraft cost.

You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander. If the 200 million is right, it is 200 million out of 3.3 billion or 6%.
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 05:51 PM


According to this source (http://"http://orion.asu.edu/Additional%20Reading/Cassini_resource-margin_trade.pdf")(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.

$400M for the TIV, so 1/5 of the spacecraft cost.

You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander. If the 200 million is right, it is 200 million out of 3.3 billion or 6%.

TIV is Titan IV.  $1.4B total mission cost - $400M LV = $1B spacecraft.  Instruments are 1/5 of it.
Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/09/2014 06:13 PM


According to this source (http://"http://orion.asu.edu/Additional%20Reading/Cassini_resource-margin_trade.pdf")(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.

$400M for the TIV, so 1/5 of the spacecraft cost.

You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander. If the 200 million is right, it is 200 million out of 3.3 billion or 6%.

TIV is Titan IV.  $1.4B total mission cost - $400M LV = $1B spacecraft.  Instruments are 1/5 of it.

Cassini-Huygens was a lot more expensive than that:

Quote
The total cost of this scientific exploration mission is about US$3.26 billion, including $1.4 billion for pre-launch development, $704 million for mission operations, $54 million for tracking and $422 million for the launch vehicle. The United States contributed $2.6 billion (80%), the ESA $500 million (15%), and the ASI $160 million (5%).
http://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

Your 1.4 Billion is only "pre-launch development".
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 06:23 PM


Your 1.4 Billion is only "pre-launch development".

So 1/7 of the spacecraft, which is still a sizable portion.
Title: Re: Proposed Europa Missions
Post by: ncb1397 on 10/09/2014 06:40 PM


Your 1.4 Billion is only "pre-launch development".

So 1/7 of the spacecraft, which is still a sizable portion.


Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.

Wrong.  They are not a small portion.  A lander is the wrong example.  MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.

Now calculating the "portion" to be the percentage of the spacecraft vs the percentage of the mission is moving the goal post. 200 million is ~1/16th of 3.3 billion. Still, let's say a big LV costs 1 billion(no idea how much SLS costs). I still haven't heard what the instrument developers would spend 1 billion on in the same mass and power constraints(R&D for science instrument optimization?). No other probes have ever spent this amount of money on instrumentation.
Title: Re: Proposed Europa Missions
Post by: veblen on 10/09/2014 07:54 PM
$422M in 1997 for Cassini TitanIV-Centaur launch vehicle. $625M today with inflation factored in. How much more expensive for SLS, add another $375M =$1B? AtlasV 541 $226M, good price but availability?
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 08:10 PM

Now calculating the "portion" to be the percentage of the spacecraft vs the percentage of the mission is moving the goal post.

Yes, it is.  That is why is it part of the spacecraft.  Mission operations costs are mainly driven by time on station and not during cruise.  Mission extensions increase mission costs.  Cassini operations are around $80m per year. 
Title: Re: Proposed Europa Missions
Post by: Jim on 10/09/2014 08:13 PM

You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander.

yes, Huygen's probe would be counted as an instrument/payload of the spacecraft.
Title: Re: Proposed Europa Missions
Post by: redliox on 10/09/2014 08:31 PM
$422M in 1997 for Cassini TitanIV-Centaur launch vehicle. $625M today with inflation factored in. How much more expensive for SLS, add another $375M =$1B? AtlasV 541 $226M, good price but availability?

Good point.  The Atlas V is supposed to have enough spare Russian engines to last a few years, but I would presume by the early 2020s that supply would be at an end.  It's a good rocket but they will eventually need to upgrade or replace it.

I wonder how a Falcon Heavy compares; if SLS is "too fantastic" and the Atlas too underpowered for a direct flight, could an FH deliver something to Jupiter with a single Earth fly-by? 
Title: Re: Proposed Europa Missions
Post by: redliox on 10/09/2014 08:59 PM
Another update for Europa: Cubesat proposals!
http://www.astrowatch.net/2014/10/jet-propulsion-laboratory-selects.html (http://www.astrowatch.net/2014/10/jet-propulsion-laboratory-selects.html)

If they can get those things into Europa orbit, they could be a boost for gravity and magnetic mapping, but aside from what instruments could get crammed in, the question I ponder is how they'd be placed in orbit while, presumably, the long-lived mothership (Europa Clipper or otherwise) continues circling Jupiter.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/10/2014 12:44 AM
Another update for Europa: Cubesat proposals!
http://www.astrowatch.net/2014/10/jet-propulsion-laboratory-selects.html (http://www.astrowatch.net/2014/10/jet-propulsion-laboratory-selects.html)

If they can get those things into Europa orbit, they could be a boost for gravity and magnetic mapping, but aside from what instruments could get crammed in, the question I ponder is how they'd be placed in orbit while, presumably, the long-lived mothership (Europa Clipper or otherwise) continues circling Jupiter.

This stuff is tossed around as an idea, but I have real doubts about its practicality. Small spacecraft don't have any shielding. How long are they going to last in that radiation hell? And is that the best use of that limited mass?
Title: Re: Proposed Europa Missions
Post by: vjkane on 10/10/2014 01:06 AM


This stuff is tossed around as an idea, but I have real doubts about its practicality. Small spacecraft don't have any shielding. How long are they going to last in that radiation hell? And is that the best use of that limited mass?

Hey, if you think cubesats lack shielding, how about Draper Labs Europa chipsets?

I suspect that most of the cubesats are for short life, deploy from a shielded canister, missions.   The might be deployed for imaging specific areas a la Ranger or for gravity tracking a la Grail.  They are also likely to be battery powered. I suspect that any solar panels would have more volume than the cubesat

I think of these as short-lived deployed instruments.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/10/2014 02:09 AM
Yeah, that is how they would have to be used--short life. But that itself is an issue. If you are a mission designer and somebody says "I want 10 kg of payload to operate some cubesats for about 1 hour of data and there is high risk that they will fail immediately," will you sit there and say "Go on..." or will you kick that person out of your office?

Put more diplomatically, are short-lived cubesats the proper way to spend mass? Is it a good idea to spend many years to send an instrument to Europa that is only going to last a very short time?

I have a friend who is currently a PI for a NASA-led planetary cubesat mission and they have noted that many of the things that keep cubesat costs down--short lives, high risk, limited testing--are things that you don't want on an expensive planetary mission.

So if you're going to use them, they better be really really worth it. Otherwise, that mass could probably be put to better use as shielding.
Title: Re: Proposed Europa Missions
Post by: metaphor on 10/10/2014 05:23 AM
I'm guessing with the cubesats they're just exploring all the options right now.  There's only so much you can spend $100 million dollars on for "studies".


I wonder how a Falcon Heavy compares; if SLS is "too fantastic" and the Atlas too underpowered for a direct flight, could an FH deliver something to Jupiter with a single Earth fly-by? 

The FH might be able to get about 6 tons to a 2-year solar orbit so the spacecraft could do an Earth flyby to Jupiter, like Juno.  But in that case you would need more fuel on the spacecraft itself for the needed deep-space maneuver of about 600 m/s delta-v.  Also, it wouldn't save much time compared to a VVE/VEE gravity assist transfer (about 5 years instead of 6).
Title: Re: Proposed Europa Missions
Post by: baldusi on 10/10/2014 11:29 AM

I'm guessing with the cubesats they're just exploring all the options right now.  There's only so much you can spend $100 million dollars on for "studies".


I wonder how a Falcon Heavy compares; if SLS is "too fantastic" and the Atlas too underpowered for a direct flight, could an FH deliver something to Jupiter with a single Earth fly-by? 

The FH might be able to get about 6 tons to a 2-year solar orbit so the spacecraft could do an Earth flyby to Jupiter, like Juno.  But in that case you would need more fuel on the spacecraft itself for the needed deep-space maneuver of about 600 m/s delta-v.  Also, it wouldn't save much time compared to a VVE/VEE gravity assist transfer (about 5 years instead of 6).
Adding fuel is cheap, and 1 year of operations might cost 80M (like Cassini). Which is about same the difference from F9 to FH. But this would need an Atlas V 551 otherwise, so if FH actually pans out, it could mean a cheaper and faster mission. Less than 3% overall i. The whole mission cost, but good enough none the less.
If FH does launches by 2015, it should be able to be certified by PDR, at least. If this delays a bit more, it might be certifiable by SDR, in fact.
Title: Re: Proposed Europa Missions
Post by: robertross on 10/10/2014 01:17 PM
Yeah, that is how they would have to be used--short life. But that itself is an issue. If you are a mission designer and somebody says "I want 10 kg of payload to operate some cubesats for about 1 hour of data and there is high risk that they will fail immediately," will you sit there and say "Go on..." or will you kick that person out of your office?

Put more diplomatically, are short-lived cubesats the proper way to spend mass? Is it a good idea to spend many years to send an instrument to Europa that is only going to last a very short time?

I have a friend who is currently a PI for a NASA-led planetary cubesat mission and they have noted that many of the things that keep cubesat costs down--short lives, high risk, limited testing--are things that you don't want on an expensive planetary mission.

So if you're going to use them, they better be really really worth it. Otherwise, that mass could probably be put to better use as shielding.

In retrospect to my original 'like' for this concept, I have to agree with your assessment. I could envision the mass being better spent on additional instruments on the spacecraft, or more fuel, than to have to give up mass & space for the Cubesats, deployment mechanism, and possibly the coms requirement.

My original 'like' was to help out the universities & students for these types of cutting edge missions.
Title: Re: Proposed Europa Missions
Post by: metaphor on 10/10/2014 07:04 PM
If the Europa Clipper does launch on the SLS, which version would it use?  Block 1 with the ICPS or Block 1B with the exploration upper stage?  Which version did the mission concept study consider?  By 2022 I'm guessing both would be available.

From my calculations the ICPS could get about 5 tons to Jupiter, and the exploration upper stage could get about 7-8 tons to Jupiter.  If using a third stage such as a solid kick stage, the payload for the EUS to Jupiter could be improved to about 12-15 tons.  I'm not sure if that much mass is really needed, but it's possible.

Atlas V payload to Venus is about 5 tons.
Title: Re: Proposed Europa Missions
Post by: baldusi on 10/11/2014 12:09 AM
The faster it reaches Jupiter, the more braking propellant it will need. There's not such a thing as too much performance.
Title: Re: Proposed Europa Missions
Post by: ugordan on 10/17/2014 08:37 AM
There is an interesting drawback to the RTG design (I'm guessing that this is peculiar to the MMRTG design that we now have). It loses power at a greater rate, so long flight times (or mission times) are greater problems.

Interesting. One could naively expect that, once in the Jovian radiation environment, solar arrays would degrade much faster than an MMRTG, although the latter would have a big head start right from launch. Kind of a rabbit and turtle story situation. Modern solar arrays must be more resilient than I expected.
Title: Re: Proposed Europa Missions
Post by: redliox on 10/17/2014 08:55 AM
He explained the trades over solar and RTGs. Ultimately, the decision on power is going to be a headquarters decision, although the project can recommend one over the other. Solar is cheaper, although solar is also a problem for the VEEGA trajectory because near Venus it is awfully hot and this presents thermal design problems. There is an interesting drawback to the RTG design (I'm guessing that this is peculiar to the MMRTG design that we now have). It loses power at a greater rate, so long flight times (or mission times) are greater problems. That is one of the things that made solar more appealing. But he also emphasized that solar is particular to this mission design and that if you wanted to do other things out at Jupiter solar may not be an option at all. So don't think that "we now can do solar at Jupiter." No, we can do it in some specific mission implementations.

I wager the power needs of the IPR will drive the minimum size of the arrays in addition to 'life support' functions like communication and heating.  If a smaller payload is used it might get by, but naturally that's why they're debating this: quality versus cost issues.  However, I distinctly feel they won't let the probe launch without the radar; did your source say much on payload considerations?

Venus...ugh.  With those thermal issues it'd make more sense just to use exclusively Earth fly-bys instead.  Useful gravity well, hellish location (in just about every sense) especially for an outer planet probe.
Title: Re: Proposed Europa Missions
Post by: kevin-rf on 10/17/2014 12:20 PM
Venus...ugh.  With those thermal issues it'd make more sense just to use exclusively Earth fly-bys instead.  Useful gravity well, hellish location (in just about every sense) especially for an outer planet probe.
Or use a bigger rocket...
Title: Re: Proposed Europa Missions
Post by: simonbp on 10/17/2014 07:56 PM
So don't think that "we now can do solar at Jupiter." No, we can do it in some specific mission implementations.

Well, ever since we launched a solar-powered mission to Jupiter (that will arrive less than two years), the question will always be raised. ;)

IIRC, the missions that solar really fails on right now involve lots of time in the radiation belt (i.e. Io Observer-style mission) and/or high-power ground-penetrating radar. Either of those is an expensive proposition in and of itself, which is exactly why Clipper came to be...
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/18/2014 05:38 AM
IIRC, the missions that solar really fails on right now involve lots of time in the radiation belt (i.e. Io Observer-style mission) and/or high-power ground-penetrating radar. Either of those is an expensive proposition in and of itself, which is exactly why Clipper came to be...

It's not just that. It is overall mission design. If you need to operate multiple instruments at once, or even some instruments for a long time, solar may not work very well.
Title: Re: Proposed Europa Missions
Post by: Nilof on 10/18/2014 10:35 PM
What about using an electrodynamic tether for power to complement solar? Could that be viable?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/19/2014 12:30 AM
There is a rule of space mission design (that seems to go out the window here on NSF): you are allowed only one miracle technology per mission.

Multiplying technologies that have not been proven by other technologies that have not been proven increases your chance of failure.
Title: Re: Proposed Europa Missions
Post by: redliox on 10/19/2014 02:42 AM
There is a rule of space mission design (that seems to go out the window here on NSF): you are allowed only one miracle technology per mission.

Multiplying technologies that have not been proven by other technologies that have not been proven increases your chance of failure.

Agreed.  There are some technologies that are on the cusp, such as aerocapture that I'd love to see demonstrated, but the maturation of those technologies can eat up the budget.  Deep Space 1, which pioneered SEP, flew a slew of new mechanisms but only had 2 intruments: a hybrid spectrometer/camera and a plasma detector (a third instrument was improvised from a device meant to monitor the ions from the propulsion).

This is why both MAVEN and OSIRIS-REX both borrow the 'body' of MRO, to keep costs down, and likewise with InSight using Phoenix's setup.  If there's a design, and tech, that works, improvise with what you got.  The JIMO concept from the early 2000s fell flat on its face because they thought they could shove nuclear reactor technology into space with a high-powered NEP at a warp-speed-pace.  Baby steps are best taken; even in the Apollo era there was Mercury and Gemini beforehand along with missions set to test incrementally.

For Europa, there could be a lot of heritage drawn upon from Cassini, Juno, and New Horizons that would serve very well.  The only 'experimental' tech that could be utilized would be solar arrays and cubesats.  Both are being considered and have been utilized before; the real trick to both is adapting them to the extreme radiation at Jupiter.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/19/2014 08:25 PM
Agreed.  There are some technologies that are on the cusp, such as aerocapture that I'd love to see demonstrated, but the maturation of those technologies can eat up the budget.  Deep Space 1, which pioneered SEP, flew a slew of new mechanisms but only had 2 intruments: a hybrid spectrometer/camera and a plasma detector (a third instrument was improvised from a device meant to monitor the ions from the propulsion).

This is why both MAVEN and OSIRIS-REX both borrow the 'body' of MRO, to keep costs down, and likewise with InSight using Phoenix's setup.  If there's a design, and tech, that works, improvise with what you got.  The JIMO concept from the early 2000s fell flat on its face because they thought they could shove nuclear reactor technology into space with a high-powered NEP at a warp-speed-pace.  Baby steps are best taken; even in the Apollo era there was Mercury and Gemini beforehand along with missions set to test incrementally.

For Europa, there could be a lot of heritage drawn upon from Cassini, Juno, and New Horizons that would serve very well.  The only 'experimental' tech that could be utilized would be solar arrays and cubesats.  Both are being considered and have been utilized before; the real trick to both is adapting them to the extreme radiation at Jupiter.

I would make an important distinction here: DS1 was a technology demonstration spacecraft. NASA doesn't really do that anymore. There's a long story behind that, but the quick version is that there has always been a tendency at NASA to raid the R&D budget to feed the flight programs, and so dedicated R&D/tech demo spacecraft like DS1 are really hard to fund. So they don't happen.

On the other things, there's a constant desire to minimize risk in order to make the mission successful, but also to increase the chance that it will not go over budget or get canceled. MAVEN is an example of a mission that took no risks and the PI for that mission has been totally open about that. Last year I saw him give a talk where he was asked about it and he was pretty blunt: "I wanted to get funded." And advancing technology decreased his chances of that.

With big flagship class missions you can develop some new technology if it is necessary for the mission, but program managers always want to reduce that. If you look at JWST, one of the big reasons that JWST went so obscenely over budget is that it needed all new technology in several key areas such as very low temperature electronics, a folding mirror, and the sunshade. They may not qualify as "miracles," but each of them is relatively immature. That creates problems--which drive up costs--and it also requires more simulation and testing--which drive up costs.

(more later)
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/19/2014 08:28 PM
So for Europa Clipper, what mission designers want to do is to reduce the new technologies that they need to carry with them. In fact, that is why solar power is now seriously being considered, because it is no longer considered "new" after Juno flies.

But keep in mind the timeline--Juno has not reached Jupiter yet, and has not operated at Jupiter yet. There are going to be senior people (at NASA HQ, OMB, elsewhere) who are going to be nervous about entrusting a $2.5 billion mission to solar panels. So they will not get comfortable with it until after Juno operates and collects a lot of data.

In fact, if Juno's solar panels are still working great at the end of the mission, solar panels for Europa Clipper will probably be an easy sell, assuming that the mission designers are able to convince the powers that be that there is not a big difference between the two missions.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/28/2014 08:58 PM
The Wernher von Braun Symposium is going on in Huntsville right now. This afternoon featured a panel on SLS (not only the rocket, but ground systems, Orion, etc.). One thing that has changed with SLS is that they are now talking about mass and volume available below the Orion that could carry other payloads. I saw a presentation about that last week at a workshop, but I don't remember seeing anybody discuss is very publicly before now. (See attached image for some examples.)

No, you cannot stick a Europa Clipper underneath an Orion.

There was one question (from somebody from the Planetary Society) about putting Europa Clipper on an SLS. The SLS guy's response was actually quite reasonable. He said that this was a planetary decision, of course, but he also thought that the smart thing for the EC program to do was to not make a decision until just before their preliminary design review. Instead, they should be studying their trades, trying to figure out what all their options are. For example, if they see themselves running into a mass/cost issue (with Atlas) they might be able to solve it by switching vehicles and using SLS instead and throwing mass at the problem. (I'd note that this is the kind of problem that might only show up long after PDR, but he made a reasonable point.)

If the sessions end up on the internet, you might want to watch that one.

Title: Re: Proposed Europa Missions
Post by: baldusi on 10/28/2014 10:47 PM
Very interesting opportunity for validating any Moon technology (like landers, LCT sats and such). I also wonder about some habitat module. It appears to rest against Orion's main engines, so it might have to do a maneuver (like Apollo) to retrieve the module. But for the rest it seems like a very real possibility.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/28/2014 11:10 PM
I don't want to derail this thread to discuss payloads that can fly below Orion. I have some better slides about that, but won't post them. I assume that Chris will do some SLS update article eventually and will mention this.
Title: Re: Proposed Europa Missions
Post by: jongoff on 10/29/2014 03:42 AM
I would make an important distinction here: DS1 was a technology demonstration spacecraft. NASA doesn't really do that anymore. There's a long story behind that, but the quick version is that there has always been a tendency at NASA to raid the R&D budget to feed the flight programs, and so dedicated R&D/tech demo spacecraft like DS1 are really hard to fund. So they don't happen.

On the other things, there's a constant desire to minimize risk in order to make the mission successful, but also to increase the chance that it will not go over budget or get canceled. MAVEN is an example of a mission that took no risks and the PI for that mission has been totally open about that. Last year I saw him give a talk where he was asked about it and he was pretty blunt: "I wanted to get funded." And advancing technology decreased his chances of that.

With big flagship class missions you can develop some new technology if it is necessary for the mission, but program managers always want to reduce that. If you look at JWST, one of the big reasons that JWST went so obscenely over budget is that it needed all new technology in several key areas such as very low temperature electronics, a folding mirror, and the sunshade. They may not qualify as "miracles," but each of them is relatively immature. That creates problems--which drive up costs--and it also requires more simulation and testing--which drive up costs.

(more later)

It's kind of frustrating to have a big budget space science program like what NASA has that is so scared of putting money into new technologies and technology demonstrations. That should be one of the points of having a national space program--to make the far-sighted technology investments that are too risky for industry to invest in. Have you seen any good suggestions for how to solve this problem? Because a failure to properly invest in  up-front new technology maturation and demonstration is basically a tax on future programs. By not investing now, you guarantee future programs will deliver less for a given amount of money. Unmanned space science seems less neurotic than HSF at NASA, but this is still a pretty serious neuroses that's going to keep cutting into what we can do in the future if we don't find a way of solving it.

May not be the best specific thread for this discussion, but I wanted to get your take on it, since you're more up-to-the-elbows in this sort of space policy issue.

~Jon
Title: Re: Proposed Europa Missions
Post by: Oli on 10/29/2014 11:47 AM
It's kind of frustrating to have a big budget space science program like what NASA has that is so scared of putting money into new technologies and technology demonstrations. That should be one of the points of having a national space program--to make the far-sighted technology investments that are too risky for industry to invest in. Have you seen any good suggestions for how to solve this problem? Because a failure to properly invest in  up-front new technology maturation and demonstration is basically a tax on future programs. By not investing now, you guarantee future programs will deliver less for a given amount of money. Unmanned space science seems less neurotic than HSF at NASA, but this is still a pretty serious neuroses that's going to keep cutting into what we can do in the future if we don't find a way of solving it.

May not be the best specific thread for this discussion, but I wanted to get your take on it, since you're more up-to-the-elbows in this sort of space policy issue.

~Jon

I think the goal of the space science program should be to maximize the scientific return. Technology is secondary. Maybe the fact that unmanned space science has a more or less clearly defined goal makes it less 'neurotic' than HSF?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/29/2014 01:13 PM
It's kind of frustrating to have a big budget space science program like what NASA has that is so scared of putting money into new technologies and technology demonstrations. That should be one of the points of having a national space program--to make the far-sighted technology investments that are too risky for industry to invest in. Have you seen any good suggestions for how to solve this problem? Because a failure to properly invest in  up-front new technology maturation and demonstration is basically a tax on future programs. By not investing now, you guarantee future programs will deliver less for a given amount of money. Unmanned space science seems less neurotic than HSF at NASA, but this is still a pretty serious neuroses that's going to keep cutting into what we can do in the future if we don't find a way of solving it.

May not be the best specific thread for this discussion, but I wanted to get your take on it, since you're more up-to-the-elbows in this sort of space policy issue.

~Jon

I've got no good answer. If you look at the planetary decadal survey, they made a recommendation for devoting a percentage of the budget for technology. PSD wanted to do that. They recognize how important it is. But they got their budget whacked, and all the budget categories are tight. No matter what you cut somebody gets hurt. And even cutting things like flight programs now can have long-term down the road impacts. For instance, reducing the number of Discovery missions drives people out of the program and scares away young and innovative people. That's a long term hit as a result of a near-term cut. The same is true for the research and analysis (R&A) funding, which keeps alive many scientists. Cut R&A and you lose a lot of graduate students and your future people base.

Now there are different ways to approach the problem. I'm no expert on it, but on one extreme you have the approach typified by DS-1 (I forget the name of the overall program it was part of). That approach is a separate R&D budget and demo missions. Although that seems like the ideal, it is just too vulnerable to getting cut. So it doesn't work. Another method is to offer incentives to mission PIs. For example, in the previous Discovery call, NASA actually offered the ASRG (replacement for the RTG) "free" to the mission so that they might use it and therefore demonstrate it in space. That allowed PIs to propose new and exciting missions and not have to pay for their power source. (I think I heard that the PIs were less than thrilled about this in the end, because they got stuck with unexpected ASRG integration costs, so it was not really "free" to them. But I don't know about the details.)

But yeah, it's a perpetual struggle, and nobody thinks that R&D is winning.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/29/2014 01:19 PM
1-I think the goal of the space science program should be to maximize the scientific return. Technology is secondary.

2-Maybe the fact that unmanned space science has a more or less clearly defined goal makes it less 'neurotic' than HSF?


1-Except that, as Jon noted, if you rob the tech base, over time you can produce less and less science. If nobody invests in the things you need for future missions, then those missions won't happen.

2-Robotic space science does a really good job of defining its goals and eventually achieving them. The space geeks who populate this board generally don't care about the robotic stuff, but I think that if you looked at the space science priority lists for the 1970s, 80s, 90s and 00s, you would see that the science community did a remarkably good job of achieving the goals they established for themselves. Accomplishment rates above 80-90% by some measures.
Title: Re: Proposed Europa Missions
Post by: jongoff on 10/29/2014 02:24 PM
It's kind of frustrating to have a big budget space science program like what NASA has that is so scared of putting money into new technologies and technology demonstrations. That should be one of the points of having a national space program--to make the far-sighted technology investments that are too risky for industry to invest in. Have you seen any good suggestions for how to solve this problem? Because a failure to properly invest in  up-front new technology maturation and demonstration is basically a tax on future programs. By not investing now, you guarantee future programs will deliver less for a given amount of money. Unmanned space science seems less neurotic than HSF at NASA, but this is still a pretty serious neuroses that's going to keep cutting into what we can do in the future if we don't find a way of solving it.

May not be the best specific thread for this discussion, but I wanted to get your take on it, since you're more up-to-the-elbows in this sort of space policy issue.

~Jon

I think the goal of the space science program should be to maximize the scientific return. Technology is secondary. Maybe the fact that unmanned space science has a more or less clearly defined goal makes it less 'neurotic' than HSF?

I think the problem that I was highlighting was that avoiding technology maturation/demonstration doesn't maximize long-term scientific return. So long as the technologies are legitimately enabling, it's a standard consumption (flying missions using existing technology) vs. investment (developing and demonstrating new technologies) economics story. You might be able to consumer more today by not investing, but in the long run you can't consume as much as you could if you had sacrificed a little today for more consumption in the future.

Basically, I'm saying that the approach we're taking appears to be myopic, sacrificing long-term benefits for near-term gratification... Which ironically is the kind of "market failure" a government program is supposed to avoid.

~Jon
Title: Re: Proposed Europa Missions
Post by: jongoff on 10/29/2014 02:27 PM
But yeah, it's a perpetual struggle, and nobody thinks that R&D is winning.

Thanks Blackstar. I have noticed several recent solicitations where they do incentivize optional, non-mission critical, bonus tech maturation/demos on solicitations. But yeah, this is a fundamental challenge. The good news is that if we can ever find a way to make this work (ie find a way to increase R&D and tech demo spending), we'll likely be able to get a lot more out of SMD in the future.

~Jon
Title: Re: Proposed Europa Missions
Post by: Blackstar on 10/29/2014 02:43 PM
But yeah, it's a perpetual struggle, and nobody thinks that R&D is winning.

Thanks Blackstar. I have noticed several recent solicitations where they do incentivize optional, non-mission critical, bonus tech maturation/demos on solicitations. But yeah, this is a fundamental challenge.

Tech demo happens on flagship missions which usually are ambitious and have money so they can spend money on it. So Curiosity developed the skycrane, and JWST is developing lots of things like low-temperature sensors and the foldable mirrors which may eventually get used on future telescopes.

However, those missions develop the technologies that they specifically need and not broader technologies that can be used for other things, like in-space propulsion. So the goal for R&D has been to fund tech that can be used by several different future missions. Either create a program that does that, or encourage it to happen on smaller missions. That's the problem.

Now it is not all bad news. Skycrane is getting re-used for Mars 2020. Juno is demonstrating low temperature solar cells that may get used for Europa Clipper as well as rad-hardened systems. The thermal management techniques developed for MESSENGER are being applied to Solar Probe Plus (and the MESSENGER team has aided the Europeans with Bepi-Columbo). So new tech does get developed and re-used.
Title: Re: Proposed Europa Missions
Post by: GClark on 10/29/2014 06:09 PM
...you have the approach typified by DS-1 (I forget the name of the overall program it was part of).

New Millennium program
Title: Re: Proposed Europa Missions
Post by: redliox on 11/21/2014 08:42 PM
I emailed Curt Niebur, whose in charge of both Cassini and the efforts tied to Europa.  I asked the following regarding solar power to get a straight answer:

Quote
I wrote to you previously regarding the schedule for a Europa mission's planning.  This time I write because a surprising rumor has popped up on twitter, stating that solar power has been chosen for the mission.  I thought it prudent to get straight answers from a legitimate source rather than rumor.
 
 This is what was stated via twitter: APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
 
 I find it doubtful this could be true, mainly because mission concepts are still being viewed.  I believe solar power could be both useful and practical, so long as radiation decay can be mitigated.  However I'm more concerned this is just a rumor and I don't like the idea of amateurs making assumptions while your colleagues are making though choices and evaluations.  Please look into this if you can.

Niebur replied:
Quote
Yes, this is true.  While we haven’t decided on a final concept, for the Clipper concept in particular we have baselined solar.  We did look at the radiation effect on the panels, which degrades their power output.  But testing shows that the panels are good for over 200 flybys, well beyond the 45 flybys in the Clipper concept.

Presuming the panels can retain the better part of their power production, this would be good news for mission extensions.  Considering Galileo held up reasonably well during its Jupiter cruise, sans the antenna and tape recorder issues (neither of which related to radiation), it should be safe to presume 'Clipper could live through it's primary mission and one mission extension; I don't go so far as to say two since even Galileo didn't as long as this potential successor will in the radiation belts.

Hopefully we'll hear good news for Europa.  Obviously much is still in the air but I'm feeling good vibes.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/21/2014 09:19 PM
Yeah, I got the same thing from a colleague who talked to another member of the EC team: they have baselined both solar and SLS.

That said, you have to ask what "baseline" actually means, because, a) this is not yet an approved mission, it's only a study, so no final decisions have been made, and b) those decisions ultimately are made at the HQ level, not by the study team, and they depend on lots of things such as funding.

So at some future point if EC gets approved as a mission, then somebody at NASA Headquarters has to approve both the choice of solar (which could still be rejected because of risk), and the use of SLS (which all depends upon who is paying the cost of the rocket--if the Science Mission Directorate has to shell out $1 billion, or even $500 million for an SLS launch they are not going to do it).

Title: Re: Proposed Europa Missions
Post by: rcoppola on 11/21/2014 09:37 PM
Has there been any discussions to include a small robotic lander to a Europa mission? If we're going to go into orbit, might as well land on it as well. We've proven damn capable of doing both. And if you're going to hitch a ride on a $500 Million HLV, may as well go all the way to bright.
Title: Re: Proposed Europa Missions
Post by: NovaSilisko on 11/21/2014 09:50 PM
Has there been any discussions to include a small robotic lander to a Europa mission? If we're going to go into orbit, might as well land on it as well. We've proven damn capable of doing both. And if you're going to hitch a ride on a $500 Million HLV, may as well go all the way to bright.

I do wonder what's the minimum mass you can get away with for a lander with decent payload. The proposed Mercury Surface Element of BepiColumbo was only 44 kg for the entire lander package, and used airbags for braking on the surface at ~30 m/s to reduce propulsion needs.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/21/2014 09:53 PM
Has there been any discussions to include a small robotic lander to a Europa mission? If we're going to go into orbit, might as well land on it as well. We've proven damn capable of doing both. And if you're going to hitch a ride on a $500 Million HLV, may as well go all the way to bright.

No. Keep in mind that the goal of EC has been to get the cost down to something that is affordable and doing that required keeping out of Europa orbit entirely. A lander would blow the cost sky high.

Plus, JPL did a Europa lander study in 2012 that indicated that a necessary precursor to a lander was high resolution photos of the potential landing sites. You cannot do that on the same mission with any degree of confidence.
Title: Re: Proposed Europa Missions
Post by: Star One on 11/21/2014 10:24 PM

Has there been any discussions to include a small robotic lander to a Europa mission? If we're going to go into orbit, might as well land on it as well. We've proven damn capable of doing both. And if you're going to hitch a ride on a $500 Million HLV, may as well go all the way to bright.

No. Keep in mind that the goal of EC has been to get the cost down to something that is affordable and doing that required keeping out of Europa orbit entirely. A lander would blow the cost sky high.

Plus, JPL did a Europa lander study in 2012 that indicated that a necessary precursor to a lander was high resolution photos of the potential landing sites. You cannot do that on the same mission with any degree of confidence.

Also if you're going to do a lander you might as well do it properly with a full up dedicated mission not something bolted onto a completely different one.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/21/2014 11:44 PM

Has there been any discussions to include a small robotic lander to a Europa mission? If we're going to go into orbit, might as well land on it as well. We've proven damn capable of doing both. And if you're going to hitch a ride on a $500 Million HLV, may as well go all the way to bright.

No. Keep in mind that the goal of EC has been to get the cost down to something that is affordable and doing that required keeping out of Europa orbit entirely. A lander would blow the cost sky high.

Plus, JPL did a Europa lander study in 2012 that indicated that a necessary precursor to a lander was high resolution photos of the potential landing sites. You cannot do that on the same mission with any degree of confidence.

Also if you're going to do a lander you might as well do it properly with a full up dedicated mission not something bolted onto a completely different one.

Well, it's not clear that you could do anything worthwhile with a small lander. What will it be able to take with it that can do anything useful?
Title: Re: Proposed Europa Missions
Post by: redliox on 11/22/2014 08:44 AM
Also if you're going to do a lander you might as well do it properly with a full up dedicated mission not something bolted onto a completely different one.

Well, it's not clear that you could do anything worthwhile with a small lander. What will it be able to take with it that can do anything useful?

Lord knows we're having enough arguments on scaling a (flyby) orbiter down to fit into a smaller budget...

As ambitious the folks supporting the Antarctic drilling are, I don't think we're quite at the readiness to send a submersible down there - just enough to scratch the surface a bit.  I definitely would wait until we have at least global and regional maps of Europa; as is they're still spotty as heck and would make maps of Mars in the early '70s look more accurate.

A lander would be great to send down, but I'd expect something that'd be a mix of both the Martian missions, Phoenix and InSight, in terms of science and function: analyzing surface chemistry, drilling and probing the near-surface ice, seismology, and good-old-fashion pictures for PR.  A probe using an updated version of their experiments would serve well, not to mention fit into a budget better.
Title: Re: Proposed Europa Missions
Post by: Jim on 11/22/2014 12:59 PM
Has there been any discussions to include a small robotic lander to a Europa mission? If we're going to go into orbit, might as well land on it as well. We've proven damn capable of doing both. And if you're going to hitch a ride on a $500 Million HLV, may as well go all the way to bright.

 "might as well land on it as well" is out of the question."  It is not going into orbit around Europa.  It will be in orbit around Jupiter and then perform flyby's of Europa.  The delta V for orbit is too high and landing is a non starter.  Anyways, going into orbit does not mean landing is just a simple step.  That completely ignore the additional complexities.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/22/2014 03:50 PM
This is from JPL's 2012 Europa Lander study.
Title: Re: Proposed Europa Missions
Post by: Torbjorn Larsson, OM on 11/23/2014 02:04 PM
A lander would be great to send down, but I'd expect something that'd be a mix of both the Martian missions, Phoenix and InSight, in terms of science and function: analyzing surface chemistry, drilling and probing the near-surface ice, seismology, and good-old-fashion pictures for PR.  A probe using an updated version of their experiments would serve well, not to mention fit into a budget better.

That they have to include seismology, especially now that it seems Europa has an ice analog to plate tectonics going on (which would be only the second such known instance in the solar system), may mean that they would like to land a set of smaller probes sometime in the future. Say, with a follow up through-the-ice drill mission. But the first lander should be more generalist along the lines proposed here.

Speaking of future science, since ice moon oceans may be the largest type of biosphere out there (certainly by volume and perhaps by bioproductivity considering all the water), the end game would have us drilling most or all of found ones for habitability and habitation. That may include debris disk objects such as Ceres and Charon. (The latter has potentially a similar ocean kept open after its collisional formation with proto-Pluto.)

That may be the only way to get a firmer grip on the frequency of life in the universe, since we can mostly probe the surface habitable zone only from afar. Europa would be an important prerunner to that major task, and the better the initial science program the faster that goal could be realized. Reusing integration of experiments would be a robust way forward, even as drill and organics analysis subsystems presumably would  be advancing fast. (E.g. Rosetta looked for chirality, thus far lacking in martian missions.)
Title: Re: Proposed Europa Missions
Post by: vjkane on 11/23/2014 03:55 PM
There have been proposals for fairly simple hard Europa landers or penetrators (see for example, http://futureplanets.blogspot.com/2010/05/europaganymede-penetrator.html).  Even a simple lander could provide valuable data on seismology and composition.

HOWEVER, even these simple landers would be expensive (we learned from the Beagle 2 experience that short cuts don't work in designing landers) and would not fit within the budget of the Europa Clipper.  That said, if the Europa Clipper launches on the SLS (which I personally do not ever expect to see fly) there would be plenty of mass margin for a simple contributed lander.  But mission creep is a dangerous thing.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/25/2014 11:46 AM
HOWEVER, even these simple landers would be expensive (we learned from the Beagle 2 experience that short cuts don't work in designing landers) and would not fit within the budget of the Europa Clipper.  That said, if the Europa Clipper launches on the SLS (which I personally do not ever expect to see fly) there would be plenty of mass margin for a simple contributed lander.  But mission creep is a dangerous thing.

Actually, I talked to one of the people involved in the SLS/EC evaluation and he said that the surprising thing is that there is less mass margin for the SLS version than one using an Atlas. The reason is that SLS puts all its energy into velocity, whereas the gravity assist version using Atlas trades speed for a bit more payload capability.

An interesting question, however, concerns the next steps after EC. I've heard that there is some grumbling over this among the outer planets community. They want Europa to be treated somewhat like Mars, with a "campaign" of missions to Europa--EC with its flybys followed by an orbiter followed by a lander. But the problem with that is that every mission to Europa is going to be expensive, in the multi-billions class. So they're making an argument that they should get a whole bunch of flagships. Meanwhile, there is an argument from elsewhere that they should do EC right so that it will enable a Europa lander as the follow-on mission. And considering the time between these missions, you gotta admit that it makes sense to go to a lander next, because going to an orbiter (unless you really really have to) means that the lander won't happen for another 30 years at least.
Title: Re: Proposed Europa Missions
Post by: baldusi on 11/25/2014 12:50 PM
So, the Atlas V551 v SLS is one of payload against mission time (and Venus thermal environment requirements?). It would still seems like the SLS will enable a faster turnaround for a lander. Any idea how much work can be advanced into a lander before we have the actual data from the flybys? BTW, has anybody actually got a planetary lander for a body without atmosphere? Philae is the closest I can think of.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/25/2014 03:45 PM
So, the Atlas V551 v SLS is one of payload against mission time (and Venus thermal environment requirements?). It would still seems like the SLS will enable a faster turnaround for a lander. Any idea how much work can be advanced into a lander before we have the actual data from the flybys? BTW, has anybody actually got a planetary lander for a body without atmosphere? Philae is the closest I can think of.

The only thing I can really speculate on is the first one, and it would be interesting to learn if eliminating the Venus flyby and thermal requirements actually saves any mass, or of it is just a complexity thing. More precisely: if SLS can throw less mass to Europa, how much mass are you saving by eliminating the Venus flyby and does that matter?

But these things might be in the margins, only a few kilos or tens of kilos.

Faster transit times and return of data are good things (although that has to be compared to cost). But I would add that a major pacing item between missions is funding. You might be able to throw EC at Europa faster, but that doesn't mean you can fund the follow-on mission any faster. You still have to pay for it. And presumably you have to let the Decadal Survey choose the priorities.
Title: Re: Proposed Europa Missions
Post by: baldusi on 11/25/2014 04:14 PM
Faster transit times and return of data are good things (although that has to be compared to cost). But I would add that a major pacing item between missions is funding. You might be able to throw EC at Europa faster, but that doesn't mean you can fund the follow-on mission any faster. You still have to pay for it. And presumably you have to let the Decadal Survey choose the priorities.
Well, but that might well mean that a faster mission might generate enough interest to accelerate funding for a follow up mission. It will clearly miss the 2023 Survey, but may be by a couple of years. If what they find is interesting enough, they might get their money faster (because of shorter transit times). I know that the SLS cost is quite a difficult matter. So I'm not speculating on the probabilities of each scenario, just on the consequences.
BTW, given that this mission isn't even approved, aren't they speculating on a FH service? It might save a gravity assist. Or be cheap enough to procure a Star 48GXV to add some extra delta-v margin. Again, this mission is so far in the future that even the next ULA's LV might well be an option.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/25/2014 05:53 PM
Faster transit times and return of data are good things (although that has to be compared to cost). But I would add that a major pacing item between missions is funding. You might be able to throw EC at Europa faster, but that doesn't mean you can fund the follow-on mission any faster. You still have to pay for it. And presumably you have to let the Decadal Survey choose the priorities.
Well, but that might well mean that a faster mission might generate enough interest to accelerate funding for a follow up mission. It will clearly miss the 2023 Survey, but may be by a couple of years. If what they find is interesting enough, they might get their money faster (because of shorter transit times). I know that the SLS cost is quite a difficult matter. So I'm not speculating on the probabilities of each scenario, just on the consequences.
BTW, given that this mission isn't even approved, aren't they speculating on a FH service? It might save a gravity assist. Or be cheap enough to procure a Star 48GXV to add some extra delta-v margin. Again, this mission is so far in the future that even the next ULA's LV might well be an option.

They are only evaluating SLS as an option because they were told to do that. Until other rockets fly, I don't think they will really consider them in their trade studies.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/25/2014 08:52 PM
JUICE
JUpiter ICy moons Explorer
Exploring the emergence of habitable worlds around gas giants
Definition Study Report
Title: Re: Proposed Europa Missions
Post by: baldusi on 11/25/2014 09:18 PM
So, when the FH gets in the NLS II contract, they will be able to study its use? That might be available by 2016. and the Delta IV Heavy is being used for EFT-1 and (probably) Solar Probe Plus. So it might be quite available, too. So it would seem like the SLS option is purely political. In your experience, would this mission receive an ATP before 2017? And could it be politically married to the SLS?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/26/2014 12:29 AM
1-So, when the FH gets in the NLS II contract, they will be able to study its use?

2-and the Delta IV Heavy is being used for EFT-1 and (probably) Solar Probe Plus. So it might be quite available, too.

3-So it would seem like the SLS option is purely political.

4-In your experience, would this mission receive an ATP before 2017?

5-And could it be politically married to the SLS?

1-They could probably study it before then. However, I believe that FH lacks an upper stage required for planetary missions. In fact, a few weeks ago I met some guy from some company that I forget (Aerojet-Rocketdyne?) that is currently studying an upper stage for Falcon Heavy so that it can be offered for Solar Probe Plus. Maybe there is more information about that elsewhere on this site. However, keep in mind that SpaceX's cost savings are exaggerated, and the fainting phanboys on this site don't understand the actual costs. The best comparison is what NASA pays for a Falcon 9 and what it pays for an Atlas V of similar capability under the launch services contract. Falcon is cheaper, but not THAT much cheaper. The same will be true comparing a Falcon Heavy to a Delta IV Heavy, especially if that Falcon Heavy is equipped with a new upper stage.

2-Yeah, but it's expensive. When we did the DS, the Aerospace Corp guys who were doing the CATE for Europa Orbiter warned us that it was at risk of moving from an Atlas V to a Delta IV, which would substantially increase launch costs. Nobody wants a big expensive rocket if they can avoid it.

3-I would not say "purely political." I would say "mostly" political. But yes.

4-What do you mean "ATP"? Is that a new start? I think that it is possible. But there's a window--It is possible it can get a new start during the next few years, but I think that the likelihood drops later in the decade when people start saying "Let's wait and see if the new decadal survey says that we should do a Europa mission." There is still a large uncertainty factor, however. Culberson is a new important ally for the Europa mission. But how powerful is he? Also, it would be VERY BAD if we got a Europa Clipper mission at the expense of New Frontiers and Discovery. New Frontiers is already unfunded. There are important missions in New Frontiers and they are competed. They deserve a chance.

5-Yes.

Title: Re: Proposed Europa Missions
Post by: HIP2BSQRE on 11/26/2014 12:53 AM
How much does NASA pay for a Falcon 9 and a comparable Atlas?
Title: Re: Proposed Europa Missions
Post by: baldusi on 11/26/2014 02:26 AM
ATP: Authorization To Proceed, that was what I understand was a new start.
Regarding the numbers, I believe that a F9 is about 160M for a NASA mission and an Atlas V 551 was expected to be 320M. Or those are the numbers from the MSR missin trades I remember. If I'm not mistaken those numbers include everything, from LV to integration, certification and mission specific mods. I expected a FH to cost 250M with better than 551 performance. But the FH high C3 curve will probably fall a lot faster than a Delta IV Heavy/ AV551. The question is where does it crosses. FH is expected to throw more than 10tonnes to a 13km2/s2 C3, which I believes trumps both ULA LV. But I have no comparison for the DIVH nor the Europa C3 requirement.
Title: Re: Proposed Europa Missions
Post by: rcoppola on 11/26/2014 02:41 AM
ATP: Authorization To Proceed, that was what I understand was a new start.
Regarding the numbers, I believe that a F9 is about 160M for a NASA mission and an Atlas V 551 was expected to be 320M. Or those are the numbers from the MSR missin trades I remember. If I'm not mistaken those numbers include everything, from LV to integration, certification and mission specific mods. I expected a FH to cost 250M with better than 551 performance. But the FH high C3 curve will probably fall a lot faster than a Delta IV Heavy/ AV551. The question is where does it crosses. FH is expected to throw more than 10tonnes to a 13km2/s2 C3, which I believes trumps both ULA LV. But I have no comparison for the DIVH nor the Europa C3 requirement.
Doesn't the F9 160M number for NASA you mentioned include Dragon? 
Title: Re: Proposed Europa Missions
Post by: ncb1397 on 11/26/2014 08:41 AM
How much does NASA pay for a Falcon 9 and a comparable Atlas?

Quote
CAPE CANAVERAL, Fla. -- NASA has selected Space Exploration Technologies (SpaceX) of Hawthorne, Calif., to launch the National Oceanic and Atmospheric Administration's (NOAA) Jason-3 spacecraft in December 2014 aboard a Falcon 9 v1.0 rocket from Complex 4 at Vandenberg Air Force Base in California.

The total value of the Jason-3 launch service is approximately $82 million. This estimated cost includes the task ordered launch service for the Falcon 9 v1.0, plus additional services under other contracts for payload processing, launch vehicle integration, mission-unique launch site ground support and tracking, data and telemetry services. NASA is the procurement agent for NOAA.
http://www.nasa.gov/home/hqnews/2012/jul/HQ_C12-029_RSLP-20_Launch_Services.html

Quote
CAPE CANAVERAL, Fla. -- NASA has selected United Launch Services, LLC of Littleton, Colo., to launch the Mars Atmosphere and Volatile Evolution spacecraft known as MAVEN. MAVEN will launch in November 2013 aboard an Atlas V 401 rocket from Complex 41 at Cape Canaveral Air Force Station, Fla.

The total cost value for the MAVEN launch service is approximately $187 million. This estimated cost includes the task ordered launch service for the Atlas plus additional services under other contracts for payload processing; launch vehicle integration; mission unique launch site ground support; and tracking, data and telemetry services.
http://www.nasa.gov/home/hqnews/2010/oct/HQ_C10-065_Maven_Services.html

82 million vs 187 million...(counting other launch related costs not part of the launch contract)

edit: more recent data points

Quote
InSight will launch in March 2016 aboard an Atlas V 401 rocket from Space Launch Complex 3E at Vandenberg Air Force Base in California.
The total cost for NASA to launch InSight is approximately $160 million, including spacecraft processing, payload integration, tracking, data and telemetry and other launch support requirements.
http://www.nasa.gov/press/2013/december/nasa-awards-launch-services-contract-for-insight-mission/#.VHWzINLF_X4

Quote
NASA has selected United Launch Services LLC of Centennial, Colo., to launch the Solar Orbiter Collaboration mission to study the sun in July 2017. The Solar Orbiter will launch on an Atlas V 411 rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida.
The total cost for NASA to launch the Solar Orbiter is approximately $172.7 million, which includes the launch service, spacecraft processing, payload integration, tracking, data and telemetry and other launch support requirements.
http://www.nasa.gov/press/2014/march/nasa-awards-launch-services-contract-for-solar-orbiter-mission/#.VHWzW9LF_X4
Title: Re: Proposed Europa Missions
Post by: Proponent on 11/26/2014 09:40 AM
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 11/26/2014 02:09 PM
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?

The place to start would be with the cost for New Horizons.
Title: Re: Proposed Europa Missions
Post by: vjkane on 11/26/2014 04:20 PM
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?

In various OPAG meetings, a cost of $7-10M a year has been quoted in the context of the penalty that outer planet (and any mission with a long cruise) faces in Discovery mission proposals.  (The newest Discovery Announcement of Opportunity has NASA picking up the cost of "reasonable" cruise costs to level the playing field.)
Title: Re: Proposed Europa Missions
Post by: vjkane on 11/26/2014 08:21 PM
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?

In various OPAG meetings, a cost of $7-10M a year has been quoted in the context of the penalty that outer planet (and any mission with a long cruise) faces in Discovery mission proposals.  (The newest Discovery Announcement of Opportunity has NASA picking up the cost of "reasonable" cruise costs to level the playing field.)
Title: Re: Proposed Europa Missions
Post by: Vultur on 11/27/2014 01:30 AM
HOWEVER, even these simple landers would be expensive (we learned from the Beagle 2 experience that short cuts don't work in designing landers) and would not fit within the budget of the Europa Clipper.  That said, if the Europa Clipper launches on the SLS (which I personally do not ever expect to see fly) there would be plenty of mass margin for a simple contributed lander.  But mission creep is a dangerous thing.

Actually, I talked to one of the people involved in the SLS/EC evaluation and he said that the surprising thing is that there is less mass margin for the SLS version than one using an Atlas. The reason is that SLS puts all its energy into velocity, whereas the gravity assist version using Atlas trades speed for a bit more payload capability.

An interesting question, however, concerns the next steps after EC. I've heard that there is some grumbling over this among the outer planets community. They want Europa to be treated somewhat like Mars, with a "campaign" of missions to Europa--EC with its flybys followed by an orbiter followed by a lander. But the problem with that is that every mission to Europa is going to be expensive, in the multi-billions class. So they're making an argument that they should get a whole bunch of flagships. Meanwhile, there is an argument from elsewhere that they should do EC right so that it will enable a Europa lander as the follow-on mission. And considering the time between these missions, you gotta admit that it makes sense to go to a lander next, because going to an orbiter (unless you really really have to) means that the lander won't happen for another 30 years at least.

That would make sense. I think there's a very good argument for Europa being the top priority of planetary science (or Enceladus, but Juno is demonstrating solar at Jupiter's distance so no RTGs needed, and it's much closer/quicker).
Title: Re: Proposed Europa Missions
Post by: redliox on 11/29/2014 08:53 AM
While Europa Clipper's under debate, it now looks like ESA's JUICE may soon be under construction (quoted from ESA's webpage):

Quote
The European Space Agency's JUICE (JUpiter ICy moons Explorer) mission has been given the green light to proceed to the next stage of development. This approval is a milestone for the mission, which aims to launch in 2022 to explore Jupiter and its potentially habitable icy moons.

JUICE gained approval for its implementation phase from ESA’s Science Programme Committee during a meeting at the European Space Astronomy Centre near Madrid, Spain, on 19 and 20 November 2014.

---------

At the November 2014 meeting of the SPC, the multilateral agreement for JUICE was also approved. This agreement provides the legal framework for provision of payload equipment and ongoing mission support between funding agencies. The parties to the agreement are the European Space Agency and the funding agencies of the European countries leading the instrument developments in the JUICE mission: the Agenzia Spaziale Italiana (Italy); the Centre National d’Etudes Spatiales (France); the Deutsches Zentrum für Luft- und Raumfahrt e.V. (Germany); the Swedish National Space Board, and the United Kingdom Space Agency. Austria, Belgium, the Czech Republic, Greece, Poland, and Switzerland participate via the PRODEX programme.
Title: Re: Proposed Europa Missions
Post by: Targeteer on 11/30/2014 07:01 AM
A really good article on how Pu-238 production is restarting, slowly

http://www.nature.com/news/nuclear-power-desperately-seeking-plutonium-1.16411

"NASA has 35 kilograms of plutonium-238 to power its deep-space missions — but that will not get it very far."
Title: Proposed Europa Missions
Post by: Star One on 12/03/2014 05:30 PM
Well at least one politician seems keen on a Europa mission.

Quote
Culberson — the only lawmaker who attended the public portion of the Planetary Society’s program in the Dirksen Senate office building here — was especially keen on funding a mission to Europa: Jupiter’s ice-encrusted moon with a subterranean ocean of briny water that many scientists believe harbors the heat and chemical elements necessary for life as we know it.

Culberson, for his part, is already a step beyond scientific skepticism.

“I’m convinced that when we discover life on another world, it will be in the oceans of Europa. I want to be there to be a part of that,” Culberson said in a two-minute speech that served as the unofficial kickoff for the society’s event.

Officially, NASA has no Europa mission on the books. However, instrument and mission studies on the so-called Clipper concept have been ongoing since 2012 at the NASA’s Jet Propulsion Laboratory in Pasadena, and the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. The solar-powered Clipper ship would launch in the 2020s and enter orbit around Jupiter, where it would fly by Europa multiple times to map the icy moon in greater detail than ever before.

NASA teams have said the Clipper mission would cost about $2 billion. The White House, as part of the 2015 budget request it released in April, asked the agency to study whether the mission could be done for $1 billion. In a November meeting of the NASA Advisory Council’s planetary science subcommittee, Jim Green, head of NASA’s Planetary Science Division, said NASA probably could not answer important scientific questions with a $1 billion Europa orbiter.

After the White House unveiled a 2015 budget request earlier this year that sought $15 million for Europa mission studies, Culberson bumped that figure to $100 million in the 2015 Commerce, Justice, Science spending bill that passed the full House in May. The Senate’s version of the bill, which has not made it to the floor, prescribed only $79 million for NASA’s entire outer planets program, of which Europa is only one part.

The Senate mentioned Europa by name only in the report accompanying their stalled bill, which said any mission to the icy moon should launch on the Space Launch System heavy-lift rocket NASA is building.

http://www.spacenews.com/article/civil-space/42823rep-culberson-drops-in-to-pledge-planetary-science-support
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/08/2014 11:25 PM
Europa Clipper electronics vault mockup. Photo from Twitter.
Title: Re: Proposed Europa Missions
Post by: Malderi on 12/10/2014 12:32 AM
For a mission that doesn't exist, that's a nice picture.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/10/2014 02:11 AM
JPL does some interesting mockup work. This is obviously very low fidelity, probably just to prove that they can fit things where they need to.

I've got some interesting pictures of a lunar lander design that has not yet been built. They built a full scale mockup of the thing, and a high fidelity mockup of an important part.
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 12/10/2014 02:37 PM
I've got some interesting pictures of a lunar lander design that has not yet been built. They built a full scale mockup of the thing, and a high fidelity mockup of an important part.

Can they be posted?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/12/2014 04:14 PM
I've got some interesting pictures of a lunar lander design that has not yet been built. They built a full scale mockup of the thing, and a high fidelity mockup of an important part.

Can they be posted?

I'm saving them for an article I'm going to publish.
Title: Re: Proposed Europa Missions
Post by: rcoppola on 12/16/2014 04:15 PM
Not sure if this was listed in another thread but as of last Saturday night through final passage of the the so-called Cromnibus bill for FY 2015 Govt funding, NASA received that $100Million to begin designing a Europa mission.

Our next great planetary (well, moon actually) mission. If there is current life in our planetary system, liquid water, under ice with warm vents providing heat energy from internal friction caused by the massive gravitational pulls of Jupiter, may very well be the place to finally find it.

So the next of many questions...will it be designed for SLS to launch?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2014 04:35 PM
1-Our next great planetary (well, moon actually) mission. If there is current life in our planetary system, liquid water, under ice with warm vents providing heat energy from internal friction caused by the massive gravitational pulls of Jupiter, may very well be the place to finally find it.

2-So the next of many questions...will it be designed for SLS to launch?

1-Maybe. Or maybe not. Congress can keep stuffing money into the Europa budget, but without a formal "new start" from OMB the mission won't happen.

2-Not yet. They'll hold off on a launch decision as long as they can. Unfortunately, holding off the design to be able to launch on either an Atlas V or SLS can become increasingly expensive (ask Alan Stern about their experience with New Horizons when they were forced to do the same for Atlas or Delta).

At the moment, it is probably easier and cheaper to design for an Atlas V launch because all the performance specs for Atlas V are well known. That cannot be said for SLS. For example, what is the acoustic environment inside the SLS payload shroud?
Title: Re: Proposed Europa Missions
Post by: rcoppola on 12/16/2014 04:40 PM
1-Our next great planetary (well, moon actually) mission. If there is current life in our planetary system, liquid water, under ice with warm vents providing heat energy from internal friction caused by the massive gravitational pulls of Jupiter, may very well be the place to finally find it.

2-So the next of many questions...will it be designed for SLS to launch?

1-Maybe. Or maybe not. Congress can keep stuffing money into the Europa budget, but without a formal "new start" from OMB the mission won't happen.

2-Not yet. They'll hold off on a launch decision as long as they can. Unfortunately, holding off the design to be able to launch on either an Atlas V or SLS can become increasingly expensive (ask Alan Stern about their experience with New Horizons when they were forced to do the same for Atlas or Delta).

At the moment, it is probably easier and cheaper to design for an Atlas V launch because all the performance specs for Atlas V are well known. That cannot be said for SLS. For example, what is the acoustic environment inside the SLS payload shroud?
Thanks for the response. In reference to the launcher decision... I imagine that "if" the SLS could cut the transit time in half, that would certainly alter how they architect the systems? Or no?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/16/2014 05:54 PM
Thanks for the response. In reference to the launcher decision... I imagine that "if" the SLS could cut the transit time in half, that would certainly alter how they architect the systems? Or no?

Absolutely. First of all, if EC does not have to do the Venus flybys, then they can take off the thermal protection. So how long do they keep designing the vehicle with thermal protection and without it? That's two designs, more money, etc.

Also, a much shorter trip time may affect how much they have to test the spacecraft. But that could be a tricky issue. I'll provide a caveat that I'm not an expert on any of that stuff (remember, I'm a policy wonk), but generally a lot of testing is for lifetime. So they test something to see how long it will last. And if they can test it for a shorter lifetime that costs less.

So an EC that only has to last, say, three years is going to cost less to test than an EC that has to last nine years. That said, I suspect that for EC the dominant issue for testing is the radiation environment at Jupiter, and that's going to be the same no matter how long it takes to get to Europa. (I could be wrong about that. Spacecraft get tested for overall radiation dose, and flying for 5-7-9 years through the inner solar system still gives the spacecraft a lot of galactic cosmic radiation to deal with before it ever gets to Jupiter.) Bottom line is that I should stop talking about this and go find an expert.
Title: Re: Proposed Europa Missions
Post by: JasonAW3 on 12/16/2014 07:09 PM
Thanks for the response. In reference to the launcher decision... I imagine that "if" the SLS could cut the transit time in half, that would certainly alter how they architect the systems? Or no?

Absolutely. First of all, if EC does not have to do the Venus flybys, then they can take off the thermal protection. So how long do they keep designing the vehicle with thermal protection and without it? That's two designs, more money, etc.

Also, a much shorter trip time may affect how much they have to test the spacecraft. But that could be a tricky issue. I'll provide a caveat that I'm not an expert on any of that stuff (remember, I'm a policy wonk), but generally a lot of testing is for lifetime. So they test something to see how long it will last. And if they can test it for a shorter lifetime that costs less.

So an EC that only has to last, say, three years is going to cost less to test than an EC that has to last nine years. That said, I suspect that for EC the dominant issue for testing is the radiation environment at Jupiter, and that's going to be the same no matter how long it takes to get to Europa. (I could be wrong about that. Spacecraft get tested for overall radiation dose, and flying for 5-7-9 years through the inner solar system still gives the spacecraft a lot of galactic cosmic radiation to deal with before it ever gets to Jupiter.) Bottom line is that I should stop talking about this and go find an expert.

In regards to the thermal protection;  Not quite true.  The Europa Mission would be heading out into a very could region of space, so while SOME thermal protection could be removed, you're still going to have to protect a lot of very sensitive equipment from the cold out around Europa. Most thermal protection blankets work both ways, keeping heat out or cold out.

Assuming a similar but shorter mission, the mass savings is likely to be insignificant, other for power supplies.  Essentially, the same instrunments that would be for the short duration mission would be the ones that would be used on the longer term mission.

While radiation is an issue using more expensive radiation and EM hardened circuits and systems, while more expensive, would assure a longer lasting and more reliable while adding an insignicant amount of mass to the overall craft.  (Note: This only applies to hardened systems that do not require a specialized radiation shielded compartment, which could require a variety of materials from PEC to alloyed aluminium.)

Overall; a probe with the correct set of instrunments could not only be used for going simply to Europa, but could be used, using an ION drive, to do comprehensive comparitive studies of the other Jovian moons.  And perhaps beyond.  Spaghettie orbits aroundthe primary and associated moons could build up the velocity needed for orbit changes that could include the outer planets, the Kuiper belt, or possibly even the Oort cloud. 

Title: Re: Proposed Europa Missions
Post by: Jim on 12/16/2014 08:00 PM

1.  In regards to the thermal protection;  Not quite true.  The Europa Mission would be heading out into a very could region of space, so while SOME thermal protection could be removed, you're still going to have to protect a lot of very sensitive equipment from the cold out around Europa. Most thermal protection blankets work both ways, keeping heat out or cold out.

2.  Assuming a similar but shorter mission, the mass savings is likely to be insignificant, other for power supplies.  Essentially, the same instrunments that would be for the short duration mission would be the ones that would be used on the longer term mission.

3.  Overall; a probe with the correct set of instrunments could not only be used for going simply to Europa, but could be used, using an ION drive, to do comprehensive comparitive studies of the other Jovian moons.  And perhaps beyond.  Spaghettie orbits aroundthe primary and associated moons could build up the velocity needed for orbit changes that could include the outer planets, the Kuiper belt, or possibly even the Oort cloud. 


1.  Yes, quite true and you got it wrong.   There are differences in thermal blankets for keeping out heat vs holding it in

2.  Longer mission can carry more mass than the shorter mission.

3.  Not true for many reasons
a.  The instruments are specific to Europa.
b.  They are useless for outside of the Jovian system
c.  The spacecraft is not going to have the energy to leave the system
d.  There is no power for the ion drive
e. there is no power to operate past Jupiter.  You do realize that this is a solar powered mission.

These comments don't a show a knowledge of spacecraft design.
Title: Re: Proposed Europa Missions
Post by: arachnitect on 12/16/2014 10:26 PM

1-Maybe. Or maybe not. Congress can keep stuffing money into the Europa budget, but without a formal "new start" from OMB the mission won't happen.


I don't know if the answer to this is publicly available but I'm curious, who makes spaceflight decisions/recommendations at OMB? Do they have in house people who do only that, or is it a committee, or like 1 person who talks to John Holdren or something?

A certain amount of our space policy seems to be coming out of "OMB,"  presumably there are people doing this stuff but I have no idea who they actually are.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/17/2014 01:54 AM
They have divisions within OMB. And then they have "examiners" within those divisions. There are about 4-5 people at OMB responsible for overseeing the NASA budget. That's it. The only advice they get is from their senior political appointees at OMB. They also interact with NASA.
Title: Re: Proposed Europa Missions
Post by: Proponent on 12/17/2014 04:44 PM
You do realize that this [Europa Clipper] is a solar powered mission.

I thought that was only for the SLS version, in order to avoid having to nuclear-rate SLS.

Am I wrong?  If so (entirely possible), is the Atlas V version of the spacecraft driven to use solar entirely for intrinsic reasons, or is limiting the number of differences between the two versions a significant factor?
Title: Re: Proposed Europa Missions
Post by: Proponent on 12/17/2014 04:51 PM
Thanks for the response. In reference to the launcher decision... I imagine that "if" the SLS could cut the transit time in half, that would certainly alter how they architect the systems? Or no?

Absolutely. First of all, if EC does not have to do the Venus flybys, then they can take off the thermal protection. So how long do they keep designing the vehicle with thermal protection and without it? That's two designs, more money, etc.

Also, a much shorter trip time may affect how much they have to test the spacecraft. But that could be a tricky issue. I'll provide a caveat that I'm not an expert on any of that stuff (remember, I'm a policy wonk), but generally a lot of testing is for lifetime. So they test something to see how long it will last. And if they can test it for a shorter lifetime that costs less.

So an EC that only has to last, say, three years is going to cost less to test than an EC that has to last nine years. That said, I suspect that for EC the dominant issue for testing is the radiation environment at Jupiter, and that's going to be the same no matter how long it takes to get to Europa. (I could be wrong about that. Spacecraft get tested for overall radiation dose, and flying for 5-7-9 years through the inner solar system still gives the spacecraft a lot of galactic cosmic radiation to deal with before it ever gets to Jupiter.) Bottom line is that I should stop talking about this and go find an expert.

Thanks a lot -- that's very interesting.  Two big take-aways for me.  First is the point about the faster mission possibly having significantly cheaper testing.  Obviously, that's a factor in favor of the SLS version.  It seems to me that could easily constitute a bigger savings than the reduction the cost of support for support during cruise that is afforded by the faster trajectory (which I doubt would be very significant).

The other point is that even just considering SLS increases costs, because two designs must be pursued until one is selected (assuming the mission is ever approved).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/17/2014 04:52 PM
You do realize that this [Europa Clipper] is a solar powered mission.

I thought that was only for the SLS version, in order to avoid having to nuclear-rate SLS.

Am I wrong?  If so (entirely possible), is the Atlas V version of the spacecraft driven to use solar entirely for intrinsic reasons, or is limiting the number of differences between the two versions a significant factor?

Right now, at this moment, Europa Clipper is baselined for SLS, and baselined for solar.

But it's still a study. It's not in Phase A development. And in fact, I imagine that some people would argue that it's not even in "pre-Phase A" development. (But I'm guessing that the definitions of that are kinda squishy.) Until it actually gets a new start and gets into Phase A development things like the launch vehicle and the power supply are not set in stone. And those are decisions that will be made ABOVE the level of the people currently doing the study, at NASA Headquarters. A group of senior NASA officials are going to say at some point "Come to Washington and sit with us in a room for 10 hours and convince us that solar can do the job and is not too risky for a $2.5 billion space mission." And they'll want to be convinced before they say okay.

Now I think it will be easier to convince people after Juno's solar panels operate in Jupiter's radiation for awhile. So it is an argument that is easier to make in 2017 than it is right now.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/17/2014 04:55 PM
Is the current estimate really $2.5B?  Last I heard, it was hovering around $2B.  Is the larger figure with launch vehicle?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/17/2014 04:56 PM
The other point is that even just considering SLS increases costs, because two designs must be pursued until one is selected (assuming the mission is ever approved).

Well, right now the cost increase is probably not all that great. They don't have hundreds of engineers working on it. The cost of considering two launch vehicles increases over time, so that's the kind of thing that they really want to nail down as soon as possible. But they probably don't have to nail it down for awhile.

As a sidenote, the EC team was at one point considering RTG, solar, and ASRG for power. They stopped considering ASRG and one of the reasons was that the ASRG program was put on hold, but another was that they didn't have the resources (people) to keep evaluating three options. So they eliminated one because of cost. That's an example of the kinds of decisions they have to make in the study phase.

Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/17/2014 04:58 PM
Is the current estimate really $2.5B?  Last I heard, it was hovering around $2B.  Is the larger figure with launch vehicle?

I'm spitballing it. It's going to be in that range. And of course the cost depends upon launch vehicle, power supply, and when they actually start it. Money costs more in 2020 than it does in 2019, for example.
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 12/17/2014 06:55 PM
But it's still a study. It's not in Phase A development. And in fact, I imagine that some people would argue that it's not even in "pre-Phase A" development.

As I recall, this was one of the arguments against dribbling out funds earmarked for Europa Clipper in increments of $12-15 million.  At some point you have to fish or cut bait; you can't hold course on a $2.5 billion program with only $15 million per year.

And now that they have $100 million to do pretty much the same thing, can they really do anything besides run in place a little faster?

Such as:

They stopped considering ASRG and one of the reasons was that the ASRG program was put on hold, but another was that they didn't have the resources (people) to keep evaluating three options. So they eliminated one because of cost.

Well the $100 million should remove that constraint, at least for the study.  Can they use any sort of programmatic maneuvering* to take the ASRG off hold status with the justification to use it for Europa Clipper?  Advancing ASRG is a tangible benefit that would be more valuable than more studies and paperwork, IMAO (in my armchair opinion).


* For clarity: yes, I know the $100 million is earmarked specifically for Europa Clipper and isn't money that NASA can reallocate to whatever program it wants on an as-needed basis.  That's why I asked if it could be maneuvered under the Europa Clipper umbrella.  Bureaucratic sleight-of-hand happens all the time; one example was the rationale to continue processing MAVEN despite the government shutdown.
Title: Re: Proposed Europa Missions
Post by: MP99 on 12/17/2014 07:44 PM
NASA has two basic Europa Clipper missions under study. The SLS one doesn't use gravity assist. It has slightly lower throw weight to Jupiter.

If the SLS verions used the gravity assist, wouldn't it then have the higher throw weight?

cheers, Martin
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/17/2014 08:36 PM
re: $100M for Europa Clipper

I am suspecting that soon JPL is going to run out of pre-project activities it can do for the mission.  At this point, there's been something like $200M over 2-3 years.

You can't build this mission drips and drabs (even ignoring the requirement for an OMB-sanctioned new start).  At peak funding, the project probably will require something around $500M a year for a couple of years.

Short of a major increase in the planetary science budget, there just isn't room in the budget until the peak spending passes on the 2020 rover (and that's assuming that there's no New Frontiers missions).

I think that Congress has made its desire known.  At this point, it's up to OMB.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/17/2014 11:24 PM
NASA has two basic Europa Clipper missions under study. The SLS one doesn't use gravity assist. It has slightly lower throw weight to Jupiter.

If the SLS verions used the gravity assist, wouldn't it then have the higher throw weight?

cheers, Martin

Yeah, but the important issue is not mass to Europa. The trade is really time and the costs associated with that.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/17/2014 11:31 PM
re: $100M for Europa Clipper

I am suspecting that soon JPL is going to run out of pre-project activities it can do for the mission.  At this point, there's been something like $200M over 2-3 years.

Yeah, I think that it would be interesting to see the accounting for this so far. What has JPL done with all that money? There's really only so much you can spend without bending metal. It's things like contracts and purchasing instruments that spends real money.

I have heard--don't know how true this is--that JPL up until a year or so ago still had a lot of money left over in the Europa account. They just couldn't spend it all, or at least they couldn't spend it all on stuff that was legitimately Europa-related. So it was sitting around in the account, unspent. If you think about it, that's a really inefficient way to run a planetary program, because that money could certainly be used for other things, but instead it's sitting unused.

This is all just obscure budget politics, but what Congress has been doing for several years is not funding a Europa program, but trying to force OMB to start one. And until OMB does, it's just a really inefficient way to spend money that could be used for other things.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/18/2014 12:25 AM
re: $100M for Europa Clipper

I am suspecting that soon JPL is going to run out of pre-project activities it can do for the mission.  At this point, there's been something like $200M over 2-3 years.

Yeah, I think that it would be interesting to see the accounting for this so far. What has JPL done with all that money? There's really only so much you can spend without bending metal. It's things like contracts and purchasing instruments that spends real money.

My guess is that JPL is banking the money they can't spend (as far a permissible) against the day that the mission is approved.  The other alternative I can think of is that they design and build 'prototypes' of the higher risk elements of the mission.  Any portion of the instruments outside the radiation vault would certainly count.  They could also, for example, design in the new space-borne atomic clock to vastly improve the gravity measurements, for example, which is a subsystem that is flight ready but never flown, so there's always more risk.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/18/2014 03:36 AM
My guess is that JPL is banking the money they can't spend (as far a permissible) against the day that the mission is approved.

They can't really do that. Money lasts for two years, then it has to go back to the Treasury.
Title: Re: Proposed Europa Missions
Post by: baldusi on 12/18/2014 04:00 AM
What about funding technology development, like high efficiency solar cells, validating the atomic clock in a cubesat, etc.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/18/2014 04:06 AM
My guess is that JPL is banking the money they can't spend (as far a permissible) against the day that the mission is approved.

They can't really do that. Money lasts for two years, then it has to go back to the Treasury.

For the federal agencies that fund my research, they have 'spent' their funding (which expires annually) once there is a signed contract with my university, but I have up to five years (depending on the initial term and any extensions) to draw on the funds.  JPL/NASA may have similar options to commit the funds to outside organizations.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/18/2014 05:08 AM
As a sidenote, the EC team was at one point considering RTG, solar, and ASRG for power. They stopped considering ASRG and one of the reasons was that the ASRG program was put on hold, but another was that they didn't have the resources (people) to keep evaluating three options. So they eliminated one because of cost. That's an example of the kinds of decisions they have to make in the study phase.

This was another case of chicken, egg, and screw technology development
http://www.planetary.org/blogs/casey-dreier/2013/20130905-no-asrgs-for-europa.html
Quote
A planned long-duration mock mission of the ASRG was canceled this summer due to budget cuts related to the sequester..According to the presented slides, the lack of any previous missions using ASRGs, as well as reliability questions of the moving piston within harsh radiation environment around Europa created an unacceptable risk engineering and cost risk for the mission.
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 12/18/2014 04:38 PM
I'll repeat the question I asked yesterday...

Can they use any sort of programmatic maneuvering to take the ASRG off hold status with the justification to use it for Europa Clipper?  Advancing ASRG is a tangible benefit that would be more valuable than more studies and paperwork, IMAO (in my armchair opinion).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/18/2014 09:26 PM
I'll repeat the question I asked yesterday...

Can they use any sort of programmatic maneuvering to take the ASRG off hold status with the justification to use it for Europa Clipper?  Advancing ASRG is a tangible benefit that would be more valuable than more studies and paperwork, IMAO (in my armchair opinion).

No. No money. ASRG got put on hold for a couple of reasons: the cost had started to increase (after it had been steady), and NASA's planetary budget got whacked. Something had to go. They weren't willing to shut off working missions or kill something in development. It was not an easy decision, but they had to make a decision.

I also suspect that JPL would not really want to put money into the ASRG because it's not under their roof. So they're not going to advocate for something like that.
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 12/19/2014 04:30 AM
No. No money.

There's $100 million that Europa Clipper has now that it didn't have before.  That's why I was so pedantic here (http://forum.nasaspaceflight.com/index.php?topic=27871.msg1303965#msg1303965) about saying under the umbrella of Europa Clipper.

Quote
I also suspect that JPL would not really want to put money into the ASRG because it's not under their roof. So they're not going to advocate for something like that.

That part makes sense.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/19/2014 05:07 PM
No. No money.

There's $100 million that Europa Clipper has now that it didn't have before.  That's why I was so pedantic here (http://forum.nasaspaceflight.com/index.php?topic=27871.msg1303965#msg1303965) about saying under the umbrella of Europa Clipper.



Except that ASRG is not Europa Clipper. If NASA tried to spend the money designated for EC on the ASRG program, they'd be in violation of the Anti-Deficiency Act. Couldn't do it.
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 12/20/2014 08:43 PM
Except that ASRG is not Europa Clipper. If NASA tried to spend the money designated for EC on the ASRG program, they'd be in violation of the Anti-Deficiency Act. Couldn't do it.

I'm not saying take money from one program and move it to another, as I made clear here:

* For clarity: yes, I know the $100 million is earmarked specifically for Europa Clipper and isn't money that NASA can reallocate to whatever program it wants on an as-needed basis.  That's why I asked if it could be maneuvered under the Europa Clipper umbrella.  Bureaucratic sleight-of-hand happens all the time; one example was the rationale to continue processing MAVEN despite the government shutdown.

I said "put it under the umbrella", not "swap the programs".  Another way to think of it is to imagine a program manager saying "We've determined that ASRG is one of the enabling technologies for Europa Clipper and we are going to investigate it in parallel with solar".  A funding of "technology development" as baldusi said here (http://forum.nasaspaceflight.com/index.php?topic=27871.msg1304325#msg1304325).
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/20/2014 11:10 PM
I said "put it under the umbrella", not "swap the programs".  Another way to think of it is to imagine a program manager saying "We've determined that ASRG is one of the enabling technologies for Europa Clipper and we are going to investigate it in parallel with solar".  A funding of "technology development" as baldusi said here (http://forum.nasaspaceflight.com/index.php?topic=27871.msg1304325#msg1304325).
If the Europa Clipper required ASRGs to do it's mission, like it depends on radiation hardened electronics, then NASA could do this.  But the Clipper mission can be done with solar panels or MMRTGs.

Also, the ASRG program hit technical problems and was about to have a major cost overrun when it was cancelled.  It would take considerably more than $100M to complete the program.  And to what purpose?  The gating factor on producing any new radioisotope units (MMRTGs, ASRGs) is rebuilding the manufacturing equipment that turns out to be severely degraded.

There are also plans to significantly improve the performance of MMRTGs.  30% sticks in my mind, but the specific number is likely wrong. 
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/20/2014 11:47 PM
I said "put it under the umbrella", not "swap the programs".  Another way to think of it is to imagine a program manager saying "We've determined that ASRG is one of the enabling technologies for Europa Clipper and we are going to investigate it in parallel with solar".  A funding of "technology development" as baldusi said here (http://forum.nasaspaceflight.com/index.php?topic=27871.msg1304325#msg1304325).

Why don't you write a "Dear NASA" letter and suggest that to them?
Title: Re: Proposed Europa Missions
Post by: Sesquipedalian on 12/21/2014 02:15 AM
Why don't you write a "Dear NASA" letter and suggest that to them?

Because the people on this forum are generally more knowledgeable and responsive, even when -- as in this case -- it takes several attempts to actually get a question answered.  Back in the DIRECT days, I wrote my Congressional representatives in support of the program.  From the three people, I got a) no response, b) a form letter, and c) a self-congratulatory letter about the person's support for a NASA program totally unrelated to DIRECT.

Anyway, vjkane's post mostly answers my question.
Title: Re: Proposed Europa Missions
Post by: redliox on 12/21/2014 08:24 AM
Amazing how much banter EC is generating...but that just proves how ecstatic we all are about it.

Looking at the OPAG's web page, they have a meeting coming up in February at the Ames Research Center.  Does anyone know how much of EC will be discussed then and there?  Understandably it wouldn't be the sole topic, although for the near future it's pretty much EC, Juno, and Cassini for choices.  I'd love to hear more regarding Uranus and Neptune, but Europa, Titan, and Enceladus understandably have precedence.
Title: Re: Proposed Europa Missions
Post by: redliox on 12/21/2014 08:45 AM
Regarding cubesats at Europa, would they be sufficiently large enough to host a short-lived mass spectrometer experiment (ion, neutral, both)?

If they could be placed into orbit around Europa and able to operate for a few days (presuming modest miracles of technology of course), I could see them being decent candidates for observing the particle environment around the satellite.  Cameras or radar are far to huge for any cubsat to handle, but particle antennas and magnetometers are far less demanding.  The next step up would be sniffing the air and verifying by "scent" whether or not plumes exist.

If a mass spectrometer leans a bit hard on demands, perhaps the Europan cubsats could be put in a cluster of 2 sets: a set for gas analysis and a set for fields.  Again, this would depend on Europa Clipper's mass budget (and in turn SLS' if used).  As for their funding...foreign partners and universities; ESA's done well with small craft (sans Beagle 2) and cubesats are pretty much fitted for university budgets to begin with.
Title: Re: Proposed Europa Missions
Post by: kato on 12/21/2014 10:47 AM
Regarding cubesats at Europa, would they be sufficiently large enough to host a short-lived mass spectrometer experiment (ion, neutral, both)?
Simple experiment:

Take the only cubesat currently on a interplanetary piggyride mission (MASCOT on Hayabusa 2, by dimensions effectively a 12U cubesat) and use its weight reserve to wrap it in shielding, and functionally replace the hopping excenter arm with some thrust system for attitude control.

The shielding would be comparable to what Juno carries. The payload would be about 3.5 kg, enough to host a single instrument comparable to Rosetta's ALICE UV imaging spectrometer (3.0 kg / 5.6 W).

With magnetometers, radio/plasma experiments or full ion spectrometers, you're usually looking at 10-15 kg weight and 10-15 W power consumption minimum with current systems.

The first downside? You have 220 Watt hours in the batteries. With ALICE you could conceivably at most squeeze 20 hours of operations out of this. Probably would end up more like 10. Then you're dead.

The second downside? Do you want a couple of them up there? With even just six of the above you're looking at 150 kg deadweight. Plus probably around 20 kg in extra blackbox equipment on your spacecraft for them for comms and for pushing them off in the first place. That's 170 kg that you could use for decent instruments. Or exactly the entire scientific payload of Juno.

If you want 'em to carry a decent ion spectrometer or magnetometer with operating times of 3-4 days, you're looking at something in the upper-end region of "cubesats", at around 75 kg. Or half a ton deadweight for carrying a 6-sat cluster. And that's assuming your host spacecraft can spare the fuel to place them in their intended orbits in the first place.

Title: Re: Proposed Europa Missions
Post by: redliox on 12/21/2014 03:27 PM
Regarding cubesats at Europa, would they be sufficiently large enough to host a short-lived mass spectrometer experiment (ion, neutral, both)?
Simple experiment:

Take the only cubesat currently on a interplanetary piggyride mission (MASCOT on Hayabusa 2, by dimensions effectively a 12U cubesat) and use its weight reserve to wrap it in shielding, and functionally replace the hopping excenter arm with some thrust system for attitude control.

The shielding would be comparable to what Juno carries. The payload would be about 3.5 kg, enough to host a single instrument comparable to Rosetta's ALICE UV imaging spectrometer (3.0 kg / 5.6 W).

With magnetometers, radio/plasma experiments or full ion spectrometers, you're usually looking at 10-15 kg weight and 10-15 W power consumption minimum with current systems.

The first downside? You have 220 Watt hours in the batteries. With ALICE you could conceivably at most squeeze 20 hours of operations out of this. Probably would end up more like 10. Then you're dead.

So a standard cubesat could operate 'nominally' for a handful of orbits about Europa; not an entire Europan orbit.  Not totally surprised but it confirms they'd be a short-lived experiment.

The second downside? Do you want a couple of them up there? With even just six of the above you're looking at 150 kg deadweight. Plus probably around 20 kg in extra blackbox equipment on your spacecraft for them for comms and for pushing them off in the first place. That's 170 kg that you could use for decent instruments. Or exactly the entire scientific payload of Juno.

If you want 'em to carry a decent ion spectrometer or magnetometer with operating times of 3-4 days, you're looking at something in the upper-end region of "cubesats", at around 75 kg. Or half a ton deadweight for carrying a 6-sat cluster. And that's assuming your host spacecraft can spare the fuel to place them in their intended orbits in the first place.

That 170 kg isn't an entire showstopper regarding a cubesat addition.  The Galileo probe was about 340kg and Huygens about 320, and both could be classified as short-lived probes.  However, your list of needs confirms they'd have to be designed as a dedicated part of the mission, not like the ill-fated Beagle 2 or MINERVA on the first Hayabusa.

Of course that 150kg now needs to be placed in orbit around Europa.  The real burden would be how much propellant that labor requires.  To minimize that burden on 'Clipper (or any other mother craft), I'd presume these sats would enter into a mildly elliptical orbit near the equator, inclined slightly but only along the parent's flight path, something along the lines of a 2-hour orbit; just stable enough for the 4 day mission max.  A solid motor or monopropellant stage could put the cluster into orbit then pop each sat off one-by-one, operating basically by a timer after the parent craft aims the whole package just prior to flyby.

Suffice to say it'd be a challenge and need to be taken seriously.  So odds are the Europa Clipper would need to be generously favored with a stronger justification from the scientists interested in Europa's atmosphere and geysers.  So the whole things would be a long-shot, though not impossible.
Title: Re: Proposed Europa Missions
Post by: TakeOff on 12/21/2014 05:03 PM
What about a flyby mission to take some close up images of potential landing sites on Europa and if lucky sample a plume, and then follow up with a lander mission? A flyby wouldn't need much radiation protection because of the short exposure, neither would a lander which is shielded by Europa itself. All probes which have been sent beyond Jupiter, have used Jupiter for gravity assist. A flyby could continue to maybe a comet, Uranus and/or a KBO. A flyby also has the advantage of getting there several years sooner than an orbiter or lander.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/21/2014 05:27 PM
Regarding cubesats at Europa, would they be sufficiently large enough to host a short-lived mass spectrometer experiment (ion, neutral, both)?
Simple experiment:

Take the only cubesat currently on a interplanetary piggyride mission (MASCOT on Hayabusa 2, by dimensions effectively a 12U cubesat) and use its weight reserve to wrap it in shielding, and functionally replace the hopping excenter arm with some thrust system for attitude control...

So a standard cubesat could operate 'nominally' for a handful of orbits about Europa; not an entire Europan orbit.  Not totally surprised but it confirms they'd be a short-lived experiment.
Well, not really no. First, MASCOT-size 12U is not a "standard" cubesat by any means. Second, MASCOT is designed to remain in close proximity to mothership, greatly simplifying the communications relay problem. (http://solarsystem.nasa.gov/docs/p456.pdf)
From spacecraft engineering perspective, i dont think you could make a ~10kg sat usefully work in Jupiters environment.

EDIT: a more up to date link : http://smsc.cnes.fr/MASCOT/GP_mascot.htm
EDIT2:
Earlier trade space analysis ( 2009 ): http://sci.esa.int/science-e/www/object/doc.cfm?fobjectid=45177
How it was built (2012) : http://www.congrexprojects.com/docs/12c12_docs/1325-lange.pdf
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/21/2014 06:00 PM
The cubesats that operate in Earth orbit have it easy in many ways.  Communication is easy since ground stations are near by. Orientation can be done either using the Earth's magnetic field or the gravity gradient.  No propulsion is needed.  The sun is bright, so solar cells can be fairly small.

It is really hard to get all the functions of a fully independent spacecraft into a cubesat format.  The toughest are long distance communications and propulsion.  The first still doesn't have a really good solution.  The technologies I've seen would return a tiny stream of data even from the moon or a near Earth asteroid encounter.  The propulsion solutions tend to be low impulse, long running engines, exactly what you don't want in the harsh radiation environment around Europa.  At Europa, the solar cells needed to power a cubesat would need to be large.

JPL has solicited and received a number of proposals for cubesats that could be carried by the Europa Clipper.  Few details have been released on their goals or designs.  The only statement is, "The universities' Europa science objectives for their CubeSats would include reconnaissance for future landing sites, gravity fields, magnetic fields, atmospheric and plume science, and radiation measurements."

We can make some guesses about the designs.  I suspect that the cubesats would be released on their trajectories by the mother ship (no propulsion needed).  Communication would be to the nearby mother ship.  Batteries would supply power.

We can imagine some science scenarios.  During each pass over Europa, the Clipper craft will image a very narrow swath of terrain immediately below it.  A cubesat flying some tens of kilometers away could image an nearby swath.  A cubesat could be released ahead or behind the Clipper craft to allow spaceship to spaceship tracking for high precision gravity measurements similar to what the GRACE and GRAIL missions did.  A cubesat could be released to fly through a plume, assuming any are available.

What I don't think is being proposed is a fully independent spacecraft that would enter Europa orbit and operate independently.

On a side note, if an daughter orbiter was considered (much bigger than a cubesat), I suspect that the priorities would be simple radio tracking for gravity measurements and a magnetometer and plasma probe to study the magnetic induction of the ocean.  But with propulsion, a good radio system, solar cells, radiation vaulting, etc., you probably are looking at hundreds of kilograms and hundreds of millions of dollars.
Title: Re: Proposed Europa Missions
Post by: Jim on 12/21/2014 06:18 PM
1.  What about a flyby mission to take some close up images of potential landing sites on Europa and if lucky sample a plume, and then follow up with a lander mission?

2.   A flyby wouldn't need much radiation protection because of the short exposure, neither would a lander which is shielded by Europa itself.

3.All probes which have been sent beyond Jupiter, have used Jupiter for gravity assist. A flyby could continue to maybe a comet, Uranus and/or a KBO.

4. A flyby also has the advantage of getting there several years sooner than an orbiter or lander.

A lot of wrong here

1.  Not viable, because it is not worth the cost.  a flyby is not enough coverage for landing site scouting.

2.  Wrong on both accounts.  Deep flyby needs protection because of the intensity and it isn't a valid mission as stated in #1.    Europa would not protect a lander.

3.  not workable.  Gravity assists are targeted for the follow on trajectory.   A flyby of Europa is not going to lead to any relevant follow on mission.

4.  Not true at all.  There isn't much difference in the trajectories.

Title: Re: Proposed Europa Missions
Post by: TakeOff on 12/21/2014 07:30 PM
4.  Not true at all.  There isn't much difference in the trajectories.
Voyager and New Horizons flew by Jupiter 1½ and 1 years after launch. The only two orbiters, Galileo and Juno, take 6 and 5 years to reach Jupiter. A close flyby could very well detect suitable landing sites. And of course the mass of Europa provides radiation protection for a lander. Besides, the budget doesn't seem to allow for any orbiter. And the Jupiter orbiter like Galileo just made a few flybys of Europa anyway, as is the European JUICE mission proposed to do. Might then as well have a fast cheap dedicated flyby Europa mission. Its equipment will be 5 years more modern and science would return 5 years earlier, than an orbiter, so that a more ambitious follow on mission can be planned.
Title: Re: Proposed Europa Missions
Post by: redliox on 12/21/2014 07:58 PM
The cubesats that operate in Earth orbit have it easy in many ways.  Communication is easy since ground stations are near by. Orientation can be done either using the Earth's magnetic field or the gravity gradient.  No propulsion is needed.  The sun is bright, so solar cells can be fairly small.

It is really hard to get all the functions of a fully independent spacecraft into a cubesat format.  The toughest are long distance communications and propulsion.  The first still doesn't have a really good solution.  The technologies I've seen would return a tiny stream of data even from the moon or a near Earth asteroid encounter.  The propulsion solutions tend to be low impulse, long running engines, exactly what you don't want in the harsh radiation environment around Europa.  At Europa, the solar cells needed to power a cubesat would need to be large.

Naturally a challenge.  A lot of demands for something typically the size of a desktop computer.

We can make some guesses about the designs.  I suspect that the cubesats would be released on their trajectories by the mother ship (no propulsion needed).  Communication would be to the nearby mother ship.  Batteries would supply power.

We can imagine some science scenarios.  During each pass over Europa, the Clipper craft will image a very narrow swath of terrain immediately below it.  A cubesat flying some tens of kilometers away could image an nearby swath.  A cubesat could be released ahead or behind the Clipper craft to allow spaceship to spaceship tracking for high precision gravity measurements similar to what the GRACE and GRAIL missions did.  A cubesat could be released to fly through a plume, assuming any are available.

So they'd be like cousins to JAXA's mini-sats SELENE brought with, at best that is.
(http://global.jaxa.jp/projects/sat/selene/images/selene_main_001.jpg)

On a side note, if an daughter orbiter was considered (much bigger than a cubesat), I suspect that the priorities would be simple radio tracking for gravity measurements and a magnetometer and plasma probe to study the magnetic induction of the ocean.  But with propulsion, a good radio system, solar cells, radiation vaulting, etc., you probably are looking at hundreds of kilograms and hundreds of millions of dollars.

Have to agree with the notion of a daughter orbiter versus the cubesats, especially if there's no means to put them into Europa orbit.  We may not be ready for a lander, but a tiny orbiter could be sent and sacrificed to gain some useful knowledge, namely the plumes but also the oceans.

Ultimately, again, this depends on if a future Europa mission can take on such a burden.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/21/2014 08:03 PM
A lot of demands for something typically the size of a desktop computer.
More like the size of a loaf of bread.
Title: Re: Proposed Europa Missions
Post by: savuporo on 12/21/2014 08:49 PM
Have to agree with the notion of a daughter orbiter versus the cubesats, especially if there's no means to put them into Europa orbit.  We may not be ready for a lander, but a tiny orbiter could be sent and sacrificed to gain some useful knowledge, namely the plumes but also the oceans.
The problem, as outlined above is power and communications. Running on primary batteries is pretty much the only feasible power option in that size category at Jovian distance, solar cells wont hack it - this means very limited lifetime after separation from the carrier spacecraft. Communication is the next big issue as only relaying is feasible, and to lesser extent tracking and guidance due to distance.
For a useful lander or even just atmospheric entry probe, you'd need a lot more mass.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2014 08:54 PM
4.  Not true at all.  There isn't much difference in the trajectories.
Voyager and New Horizons flew by Jupiter 1½ and 1 years after launch. The only two orbiters, Galileo and Juno, take 6 and 5 years to reach Jupiter. A close flyby could very well detect suitable landing sites. And of course the mass of Europa provides radiation protection for a lander. Besides, the budget doesn't seem to allow for any orbiter. And the Jupiter orbiter like Galileo just made a few flybys of Europa anyway, as is the European JUICE mission proposed to do. Might then as well have a fast cheap dedicated flyby Europa mission. Its equipment will be 5 years more modern and science would return 5 years earlier, than an orbiter, so that a more ambitious follow on mission can be planned.

This was ruled out years ago. It costs a lot of money to send something to Jupiter. The cost-benefit ratio of a flyby is bad. NASA is not going to spend 75% of the cost of an orbiting mission for 2% of the return.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2014 09:02 PM
JPL has solicited and received a number of proposals for cubesats that could be carried by the Europa Clipper.  Few details have been released on their goals or designs.  The only statement is, "The universities' Europa science objectives for their CubeSats would include reconnaissance for future landing sites, gravity fields, magnetic fields, atmospheric and plume science, and radiation measurements."

We can make some guesses about the designs.  I suspect that the cubesats would be released on their trajectories by the mother ship (no propulsion needed).  Communication would be to the nearby mother ship.  Batteries would supply power.

A colleague of mine is currently running an approved interplanetary cubesat mission. I asked them what they thought about the prospect for cubesats for Europa and they essentially scoffed and rolled their eyes.

The qualities that make cubesats attractive in Earth orbit--and the drawbacks that make them at least acceptable for Earth orbit missions--really work against them for interplanetary missions. For example, no shielding, short lifetimes, and very low testing requirements combined with a high acceptance of risk. Simply put, they're throwaway spacecraft. But when you send something out to Mars or Europa you spend a lot of money to get it there. That alone demands longer lifetimes, higher reliability, more shielding, redundancy, and more testing. You don't want to spend a lot of money, not to mention transit time, sending something to Europa only to have it die two hours after leaving the carrier spacecraft.

So it's really doubtful you'll see cubesats at Europa, and highly unlikely you'll see them at Mars. They're just too small to perform anything worthwhile or worth the cost.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/21/2014 09:30 PM
They're just too small to perform anything worthwhile or worth the cost.
I think that JPL's SmallSat concept (~50kg and ~$50Mish) has much more potential for planetary missions. 

Current cubeSat technology is at best minimally useful for the moon and near Earth asteroids.  I view cubesats today like the home built personal computer industry of the late 1970s.  Interesting, fun, not yet very practical.

But I've learned not to scoff at the march of technology.  Cubesats will never replace major planetary spacecraft (there's a reason for larger instruments), but may in a couple of decades have their own niche.  In another 10 years or so, the quality and radiation hardening needed for deep space operations will progress.  Their capabilities will still be severely limited by the form factor (even 6U and 12U cubesats).  I expect that they eventually will play small roles as the planetary equivalent of sounding rockets to train young scientists and engineers or two deploy simple instruments at a distance from a mother craft.

Note, though, that my timeline puts useful cubesats outside the time frame of the Europa Clipper.
Title: Re: Proposed Europa Missions
Post by: hop on 12/21/2014 09:47 PM
Voyager and New Horizons flew by Jupiter 1½ and 1 years after launch. The only two orbiters, Galileo and Juno, take 6 and 5 years to reach Jupiter.
Jim, as usual, is correct. The difference between Voyager and Galileo wasn't flyby vs orbiter, it was direct vs using multiple gravity assists. The Voyagers were launched on something close to a Hohmann transfer to Jupiter, they only ended up on solar escape trajectories thanks to gravity assist.

Title: Re: Proposed Europa Missions
Post by: baldusi on 12/21/2014 09:57 PM
BTW, the radiation environment in Europa is terrible. Cubesat usually have it easy because they are deployed below the Van Allen Belt. But sending something that will last the deep space trip and won't fry during the close approach would require rad-hard electronics. So most of the savings of a cube sat are gone.
Title: Re: Proposed Europa Missions
Post by: kato on 12/21/2014 10:11 PM
Well, not really no. First, MASCOT-size 12U is not a "standard" cubesat by any means. Second, MASCOT is designed to remain in close proximity to mothership, greatly simplifying the communications relay problem. (http://solarsystem.nasa.gov/docs/p456.pdf)
Sure. Think about it as more of a standard black box approach though, we're not straightout designing something here.

A 12U cubesat has a weight margin of 24 kg. Within that you can pack exactly the weight of MASCOT and the weight of titanium shielding of around 9-10mm thickness on all sides. Using MASCOT simply allows you to have a baseline model regarding:
a) functional payload package
b) power package
c) movement package
d) communications package
In this model think about the "packages" more as size/weight/power shares awarded.

Yeah, you'll need to enlarge the communications package for operations over there. Not that much, we're not going deep-space after all, but significantly. Realistically, one would have to calculate whether stepping down to a downlink-only system could counter this enough.

We could probably make it work. In theory. With the given restriction of extremely short lifetime, and the space/weight on the host spacecraft better used for useful internal payload.

So it's really doubtful you'll see cubesats at Europa, and highly unlikely you'll see them at Mars.
Only way I could see someone spending the effort is if the weight is carried as ballast anyway. See the NASA solicitation regarding a certain Mars lander that could afford that. Of course that one has the additional benefit of a communications infrastructure in place.

If there's ever a concerted effort to land on Jupiter's moons with similar communications infrastructure in place, I could see a couple cubesats and flyby probes being taken along as similar ballast. Give it half a century or so.
Title: Re: Proposed Europa Missions
Post by: Jim on 12/21/2014 11:42 PM

1.  Voyager and New Horizons flew by Jupiter 1½ and 1 years after launch. The only two orbiters, Galileo and Juno, take 6 and 5 years to reach Jupiter.

2.  A close flyby could very well detect suitable landing sites.

3.   And of course the mass of Europa provides radiation protection for a lander. Besides, the budget doesn't seem to allow for any orbiter.

4.  And the Jupiter orbiter like Galileo just made a few flybys of Europa anyway, as is the European JUICE mission proposed to do.

5.   Might then as well have a fast cheap dedicated flyby Europa mission. Its equipment will be 5 years more modern and science would return 5 years earlier, than an orbiter, so that a more ambitious follow on mission can be planned.

More wrong on top of wrong (a recurring theme)

1.  That is a function of the spacecraft mass and not the mission.

2.  quite wrong.  You really shouldn't make statements about topics you don't know about. 

3.  It is not " of course the mass of Europa provides radiation protection"  It has nothing to do with the mass of the moon.   Radiation at Europa will cause problems and just getting there will also cause problems.

4.  And your point is?  It doesn't matter, it is insufficient for landing site selection.

5.  Wrong conclusion. again, it would not be worth the effort.

edit: added after review of other posts.
Other people have chimed in, so "maybe" it is not just me.   But then again, I have worked on 8 planetary missions, so what do I know.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/21/2014 11:54 PM
But I've learned not to scoff at the march of technology.  Cubesats will never replace major planetary spacecraft (there's a reason for larger instruments), but may in a couple of decades have their own niche.  In another 10 years or so, the quality and radiation hardening needed for deep space operations will progress.  Their capabilities will still be severely limited by the form factor (even 6U and 12U cubesats).  I expect that they eventually will play small roles as the planetary equivalent of sounding rockets to train young scientists and engineers or two deploy simple instruments at a distance from a mother craft.

Note, though, that my timeline puts useful cubesats outside the time frame of the Europa Clipper.

Well, I think there are two general issues involved with cubesats. One is technology, the other is engineering philosophy. Certainly the technology has advanced a lot. But even with improvements with technology, what makes cubesats possible is that people are willing to accept the severe limitations like low quality data, limited lifetimes, high risk, etc. I guess what I'm saying is that the technology improved to the point where some people have been willing to say that they are "good enough" for some applications. But there has been no fundamental technological leap that makes something that we call "a cubesat" possible now when it was not before. Really small satellites have been around a long time. Look at Vanguard 1.

But even if the technology marches on, the equation is not going to fundamentally change for planetary missions because it is so hard and expensive to get to the planets. Imagine if NASA launched five cubesats to Mars or Jupiter and all failed because of their limited redundancy and capabilities. The headlines the next day would be "Five NASA spacecraft fail at Mars" and the agency would take a publicity hit. Is the higher risk worth the reward? (Note that the two Mars spacecraft that NASA lost in 1999 were smaller and cheaper, and the agency had accepted greater risk. And yet none of that mattered when all the stories in the media were "NASA is filled with idiots who lost two spacecraft at Mars.")

I'm not going to say "never" on this, but I do think it is unlikely.

But I also think that this is missing the point. The point is not cubesats themselves. The point is (some of) the technology making them possible. What's happening is that electronics are being miniaturized. And for planetary missions that does not require that the spacecraft itself get smaller, but it can allow for greater capabilities to be carried within that spacecraft. So rather than thinking of a cubesat being launched to Mars, think in terms of far more electronics and processing capability being launched to Mars. Or Europa. Don't get caught up on the object itself, but what makes it possible. That's the important aspect.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2014 12:56 AM
What about a flyby mission to take some close up images of potential landing sites on Europa and if lucky sample a plume, and then follow up with a lander mission? A flyby wouldn't need much radiation protection because of the short exposure, neither would a lander which is shielded by Europa itself. All probes which have been sent beyond Jupiter, have used Jupiter for gravity assist. A flyby could continue to maybe a comet, Uranus and/or a KBO. A flyby also has the advantage of getting there several years sooner than an orbiter or lander.

A flyby has the disadvantage of not spending enough time at the system to collect much useful data. Flybys, for instance, can image a very small area of the surface of a planet or moon at high resolution. (Quick homework exercise: go look up the highest resolution of any planetary surface achieved by the Voyager missions. Then report back here.) So what happens if your spacecraft flies past Europa, takes a high resolution photo of a really small area, and all of it is too jagged to land on? Wasted money and opportunity since you won't get the opportunity to fly another mission for 10-20 years.

This is actually part of the debate with Europa Clipper. I don't know the current status of the discussion, but as of this past spring there was disagreement over the inclusion of a high resolution camera on the EC. I don't know why anybody would really oppose it, but certainly it costs money, mass, and could have a big impact on the mission design. But as it was told to me by somebody who had some better info than I did, there were scientists arguing that a high-resolution camera was not needed for Europa Clipper because they wanted an orbiter to follow EC and that would have the camera. He thinks that the proponents of this view assumed that they could get both an orbiter and lander in the same decade after Europa Clipper. Neither of us considers this to be a realistic belief.

As the person who told me this pointed out, and I agreed, putting off the high-res camera and hoping for an orbiter essentially means delaying any Europa lander by another two decades after Europa Clipper. If you're going to do Europa Clipper, you have to do it right, maximizing the data return to enable a lander, which is going to be an expensive and difficult mission.

Title: Re: Proposed Europa Missions
Post by: vjkane on 12/22/2014 02:55 AM
Imagine if NASA launched five cubesats to Mars or Jupiter and all failed because of their limited redundancy and capabilities. The headlines the next day would be "Five NASA spacecraft fail at Mars" and the agency would take a publicity hit. Is the higher risk worth the reward?
I think only the most optimistic or ill-informed would propose launching a cubesat to Mars or Europa anytime in the foreseeable future.  What I do see is cubesats to the moon or near Earth asteroids as the planetary equivalent of sounding rockets. 

You are probably aware that NASA has just issued a request for proposals for a planetary cubesat mission responsive to Decadal Survey priorities with a $5.6M price cap.  A great way to train future lead scientists and engineers.

I also see cubesats as daughter spacecraft that deploy instruments remotely from the main spacecraft.  This will probably take awhile since, as you point out, reliability is not yet up to standards for instruments NASA funds.  However, since the weight is low, NASA may decide to carry cubesats on missions as the equivalent of sounding rockets.  The pool of experienced potential lead engineers and scientists has gotten smaller as planetary launch rates have decline.
Title: Re: Proposed Europa Missions
Post by: QuantumG on 12/22/2014 02:57 AM
I think only the most optimistic or ill-informed would propose launching a cubesat to Mars or Europa anytime in the foreseeable future.  What I do see is cubesats to the moon or near Earth asteroids as the planetary equivalent of sounding rockets. 

Sounding rockets provide new and affordable scientific and engineering results every day.

Is that what you mean?
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/22/2014 03:03 AM
Sounding rockets provide new and affordable scientific and engineering results every day.

Is that what you mean?
Sounding rockets are great investments.  They allow testing of new instruments, provide training, and produce good but limited results (otherwise, we'd only fly only sounding rockets and give up on dedicated satellites :> ).  A great investment.  Planetary science and to a degree Earth science hasn't had the equivalent (although instruments carried in planes can provide a lot of proving for Earth-focused instruments).  I believe that cubesats can grow  into that role for planetary science.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2014 04:29 AM
Sounding rockets are great investments.  They allow testing of new instruments, provide training, and produce good but limited results (otherwise, we'd only fly only sounding rockets and give up on dedicated satellites :> ).  A great investment.  Planetary science and to a degree Earth science hasn't had the equivalent (although instruments carried in planes can provide a lot of proving for Earth-focused instruments).  I believe that cubesats can grow  into that role for planetary science.

Apropos of nothing...

Of course, the value of sounding rockets has changed a lot over time. Before satellites they were of course the only way to get data from space altitudes. During the 1960s they were used for all kinds of research, from Earth sensing to heliophysics to upper atmosphere science (a lot of that) to even planetary observations. But the numbers launched dropped a lot starting in the 1970s and through to today. I had some statistics about that a few years ago, but I think that the number of U.S. launches was in the 40s in the 1990s and then dropped to about 20 per year after 2000 and has been somewhat stuck there. That's because of limited utility but also high costs. They're not cheap and unfortunately a big chunk of that cost is overhead.

I think that the engineering value certainly dropped a lot with the drop in science value. They just don't fly long enough to provide good engineering value. (Sidenote: A friend of mine met up with a sounding rocket scientist a few years ago and was impressed by the unique characteristics of sounding rocket payloads. They have to operate instantly. No checkout. No time to deal with outgassing, etc. He said that for his huge observatory, Chandra, they spent months getting it up and running, but this guy's sounding rocket payload had to be operating and stabilized in seconds.)

I do think that the training value of sounding rockets has been undervalued for many years. I even worked on a NASA workforce study some years ago that advocated using them for systems engineering training because a person developing a sounding rocket payload had to address all aspects of design and it gave them a lot of experience useful for working on much more complex payloads. Cubesats may have some of that value, but I have my doubts that they are as good as sounding rockets, perhaps because they are so small that the designer doesn't face all of the engineering choices that are possible with a slightly bigger payload, and a rocket. For example, cubesats are stuck with a ride to orbit and get no say at all in the launch vehicle's performance. It's sorta like learning to ride a bike but you're only allowed to make right turns; you need greater freedom in order to really develop the skills.

I'm rambling. I'll stop.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2014 04:43 AM
1-You are probably aware that NASA has just issued a request for proposals for a planetary cubesat mission responsive to Decadal Survey priorities with a $5.6M price cap.  A great way to train future lead scientists and engineers.

2-I also see cubesats as daughter spacecraft that deploy instruments remotely from the main spacecraft.  This will probably take awhile since, as you point out, reliability is not yet up to standards for instruments NASA funds. 

3-However, since the weight is low, NASA may decide to carry cubesats on missions as the equivalent of sounding rockets.  The pool of experienced potential lead engineers and scientists has gotten smaller as planetary launch rates have decline.


1-Yeah, I'm aware. I also have my doubts. I tend to suspect that this is the equivalent of dangling a hook and seeing if they catch anything worthwhile. It doesn't inherently indicate confidence in a positive outcome.

2-But is there real value to this? It's not just reliability, it's utility. Is there something that can be done by separating an instrument that is worth doing? And considering that this comes with penalties (instruments on cubesats have to be smaller, you're carrying parasitic mass like additional guidance and comm instead of simply using that already on the main spacecraft) it may not be worth it compared to using all that mass and money to make the primary spacecraft better. I worry that some of the motivation right now is a case of people having decided that cubesats are the answer and now they're looking for the question.

3-On planetary missions? There's usually not much mass to spare on planetary missions. And if you tell a mission PI that they have to carry an extra 20 kg along to their destination, I think the PI is going to argue that it should go for fuel.

I'm not opposed to them per se, I just have real doubts about their utility for planetary missions. Maybe for a few niches, but it just seems really hard to figure out where they will fit in. I do think they're interesting and have potential for Earth orbital missions. But once you have to start adding in radiation hardening, redundancy, better pointing accuracy and things like that for planetary missions, you quickly end up with something that is no longer a cubesat.
Title: Re: Proposed Europa Missions
Post by: jongoff on 12/22/2014 06:19 AM
Well, not really no. First, MASCOT-size 12U is not a "standard" cubesat by any means. Second, MASCOT is designed to remain in close proximity to mothership, greatly simplifying the communications relay problem. (http://solarsystem.nasa.gov/docs/p456.pdf)

For what it's worth, part of the SBIR Phase I my company just finished on Friday included a deployable cubesat patch array antenna that looked like it could theoretically close a link from Saturn/Titan back to DSN in X-Band (very low data rate though--only about 250bps at Saturn, 4kbps at Mars, didn't run the numbers on Jupiter, but somewhere in the middle). So the comms issue may be solvable.

~Jon
Title: Re: Proposed Europa Missions
Post by: mikelepage on 12/22/2014 06:27 AM
I do enjoy reading the informed opinions in these threads.  I might have come to the same conclusion about including cubesats on planetary missions after a bit of thought, but thank you for putting the reasons against doing so succinctly.

The question that's been nagging me (and I hope I can get an expert response to) is: there is much enthusiasm around Europa mission concepts, but isn't it true that Callisto, being futher away from (outside?) Jupiter's radiation belts, would be a much easier candidate to design a mission for?  I understand Europa is generally considered a more interesting moon for a number of reasons, but I remember reading that Ganymede and Callisto have many of the same characteristics and possible subsurface oceans too.  Is the preference for Europa a matter of degree, or is there some characteristic I've missed that makes Europa a categorically more interesting moon than the others (particularly Callisto)? Cheers.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/22/2014 01:39 PM
The question that's been nagging me (and I hope I can get an expert response to) is: there is much enthusiasm around Europa mission concepts, but isn't it true that Callisto, being futher away from (outside?) Jupiter's radiation belts, would be a much easier candidate to design a mission for?  I understand Europa is generally considered a more interesting moon for a number of reasons, but I remember reading that Ganymede and Callisto have many of the same characteristics and possible subsurface oceans too.  Is the preference for Europa a matter of degree, or is there some characteristic I've missed that makes Europa a categorically more interesting moon than the others (particularly Callisto)? Cheers.

Well, consider that ESA is planning a Ganymede mission. If, as you say, Ganymede and Callisto are essentially the same, then the ESA mission has it covered.

But yes, the U.S. scientific community views Europa as significantly more interesting than the other moons, for a number of reasons.
Title: Re: Proposed Europa Missions
Post by: kato on 12/22/2014 04:00 PM
The sole reason Europa is considered more interesting is because its subsurface ocean has a simple ice cover a couple km thick, with likely ducts and cracks in the ice to connect it to the surface. Insofar it would be (comparably) easy to breach to get down to that ocean.
That's actually what part of JUICE's mission is, characterizing Callisto's and Ganymede's (likely) subsurface oceans and examining the lithosphere above. Insofar Europa is simply one step ahead of Callisto and Ganymede right now.

Title: Re: Proposed Europa Missions
Post by: ugordan on 12/22/2014 04:06 PM
Europa being thought to have its ocean in direct contact with the rock below is considered to be a big advantage from an astrobiological standpoint.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/22/2014 04:54 PM
There is a gradient of tidal effects from Jupiter on each of the major moons.  Io gets the most extreme baking and modification.  Europa is warm enough to keep its outer H2O layer almost entirely liquid (and there's a good chance that the rocky core is warm enough to support some degree of volcanic activity, which would replicate the thermal vents on the Earth's ocean floors).  Ganymede is less heated, but between that and its large size, it became internally differentiated.  Callisto is cold and appears not to have differentiated.

An explicit goal of the JUICE mission is to explore the results of the gradient on the three icy moons.  Ganymede will receive the most attention since it is the more evolved of the two moons (Callisto being the other) that lies outside the intense radiation fields.

If the extreme radiation fields didn't exist, I'm sure that ESA would have done a Europa orbiter instead of a Ganymede orbiter.  However, the radiation hardening roughly doubles the cost of the mission, and ESA doesn't have a mission class for that expensive of a mission.
Title: Re: Proposed Europa Missions
Post by: mikelepage on 12/23/2014 02:52 AM
There is a gradient of tidal effects from Jupiter on each of the major moons.  Io gets the most extreme baking and modification.  Europa is warm enough to keep its outer H2O layer almost entirely liquid (and there's a good chance that the rocky core is warm enough to support some degree of volcanic activity, which would replicate the thermal vents on the Earth's ocean floors).  Ganymede is less heated, but between that and its large size, it became internally differentiated.  Callisto is cold and appears not to have differentiated.

An explicit goal of the JUICE mission is to explore the results of the gradient on the three icy moons.  Ganymede will receive the most attention since it is the more evolved of the two moons (Callisto being the other) that lies outside the intense radiation fields.

If the extreme radiation fields didn't exist, I'm sure that ESA would have done a Europa orbiter instead of a Ganymede orbiter.  However, the radiation hardening roughly doubles the cost of the mission, and ESA doesn't have a mission class for that expensive of a mission.

Very interesting! Thanks for the replies. I hadn't realised Ganymede was also outside the worst of the belts, so with its internal differentiation of course they would go for that.

Thinking out loud and going back to what some of the posters above were wanting to try with cube sats, (or at least, the principle of having "mother" and "daughter" craft), I wonder how worthwhile it would be to have a mothership insert itself into Ganymede orbit, and using this as the staging point from which a smaller orbiter (radiation hardened) to go to Europa to map possible landing sites. Then a second, daughter landing craft would be launched to that spot to start digging. Probably too complicated, but wondering if the mass saved by having a mothership without radiation hardening but that could serve as relay would be worth it.
Title: Re: Proposed Europa Missions
Post by: vjkane on 12/23/2014 02:54 AM
Thinking out loud and going back to what some of the posters above were wanting to try with cube sats, (or at least, the principle of having "mother" and "daughter" craft), I wonder how worthwhile it would be to have a mothership insert itself into Ganymede orbit, and using this as the staging point from which a smaller orbiter (radiation hardened) to go to Europa to map possible landing sites. Then a second, daughter landing craft would be launched to that spot to start digging. Probably too complicated, but wondering if the mass saved by having a mothership without radiation hardening but that could serve as relay would be worth it.
Those daughtercraft would need to be full fledged interplanetary spacecraft.  That's far, far from where cubesats are now.  Maybe in two to three decades. 
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/23/2014 03:49 AM
Thinking out loud and going back to what some of the posters above were wanting to try with cube sats, (or at least, the principle of having "mother" and "daughter" craft), I wonder how worthwhile it would be to have a mothership insert itself into Ganymede orbit, and using this as the staging point from which a smaller orbiter (radiation hardened) to go to Europa to map possible landing sites. Then a second, daughter landing craft would be launched to that spot to start digging. Probably too complicated, but wondering if the mass saved by having a mothership without radiation hardening but that could serve as relay would be worth it.

The smaller the spacecraft, the less capable it is. The less it can do. Things like redundancy get thrown away because you don't have the mass budget.

So, no.
Title: Proposed Europa Missions
Post by: Star One on 12/30/2014 09:24 PM
Now those water plumes at Europa seem less certain.

-- Data from Cassini's 2001 Jupiter flyby show Europa contributes less material to its surrounding environment than previously thought.

-- Unlike Saturn's known-active moon Enceladus, Europa is surrounded by very tenuous hot, excited gas.

A fresh look at data collected by NASA's Cassini spacecraft during its 2001 flyby of Jupiter shows that Europa's tenuous atmosphere is even thinner than previously thought and also suggests that the thin, hot gas around the moon does not show evidence of plume activity occurring at the time of the flyby. The new research provides a snapshot of Europa's state of activity at that time, and suggests that if there is plume activity, it is likely intermittent.

The Europa results are being presented today at the American Geophysical Union fall meeting in San Francisco and published in the Astrophysical Journal. Europa is considered one of the most exciting destinations in the solar system for future exploration because it shows strong indications of having an ocean beneath its icy crust.

Members of Cassini's ultraviolet imaging spectrograph (UVIS) team analyzed data collected by their instrument during the brief time it observed Europa in 2001, as Cassini sped through the Jupiter system en route to Saturn. The observations show that most of the hot, excited gas, or plasma, around Europa originates not from the moon itself, but from volcanoes on the nearby moon Io. In fact, from their data, the researchers calculated that Europa contributes 40 times less oxygen than previously thought to its surrounding environment.

"Our work shows that researchers have been overestimating the density of Europa's atmosphere by quite a bit," said Don Shemansky, a Cassini UVIS team member with Space Environment Technologies in Pasadena, California, who led the study. The team found that the moon's tenuous atmosphere, which was already thought to be millions of times thinner than Earth's atmosphere, is actually about 100 times less dense than those previous estimates.

A downward revision in the amount of oxygen Europa pumps into the environment around Jupiter would make it less likely that the moon is regularly venting plumes of water vapor high into orbit, especially at the time the data was acquired.

Scientists would expect that ongoing plume activity at Europa, as Cassini has observed at Saturn's moon Enceladus, would inject large amounts of water vapor into the area around Europa's orbit if the plumes were large enough, but that is not what UVIS observed.

"We found no evidence for water near Europa, even though we have readily detected it as it erupts in the plumes of Enceladus," said Larry Esposito, UVIS team lead at the University of Colorado at Boulder.

"It is certainly still possible that plume activity occurs, but that it is infrequent or the plumes are smaller than we see at Enceladus," said Amanda Hendrix, a Cassini UVIS team member with the Planetary Science Institute in Pasadena, who co-authored the new study. "If eruptive activity was occurring at the time of Cassini's flyby, it was at a level too low to be detectable by UVIS."

Indications of possible plume activity were reported in 2013 by researchers using NASA's Hubble Space Telescope, launching a wave of interest in searching for additional signs, including this effort by the UVIS team. Cassini's 2001 Jupiter flyby provided UVIS the opportunity to directly measure the environment near Europa, which is not possible with Hubble.

For more than a decade, Cassini's UVIS has observed the cold, dense doughnut of gas that encloses the orbit of Enceladus. There, the massive amount of gas being breathed into orbit around Saturn by the Enceladus plumes acts like a brake on electrons being dragged through it by Saturn's magnetic field, which rotates with the planet. This braking helps to keep down the temperature of the plasma. Apparently there is no such brake at Europa.

Since UVIS saw a hot plasma, rather than a cold one, around Europa's orbit, it suggests Europa is not outputting large amounts of gas -- including water.

Snapshots provided by missions that visited Jupiter prior to Cassini provided strong indications that Io is the major contributor of material to the environment around Jupiter, and indicated a hot, low density plasma surrounding Europa. The new results confirm that. "Io is the real monster here," Shemansky said.

"Europa is a complex, amazing world, and understanding it is challenging given the limited observations we have," said Curt Niebur, Outer Planets program scientist at NASA Headquarters in Washington. "Studies like this make the most of the data we have and help guide the kinds of of science investigations NASA should pursue in the future."

Scientists are currently using the Hubble Space Telescope to conduct an extensive six-month long survey looking for plume activity, and NASA is also studying various possible Europa missions for future exploration.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. JPL designed, developed and assembled the Cassini orbiter. The UVIS team is based at the University of Colorado, Boulder, where the instrument was designed and built.

More information about Cassini:

http://www.nasa.gov/cassini

and

http://saturn.jpl.nasa.gov

More information about Europa:

http://solarsystem.nasa.gov/europa


Media Contact

Preston Dyches
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-7013
[email protected]

2014-436

http://www.jpl.nasa.gov/news/news.php?feature=4417
Title: Re: Proposed Europa Missions
Post by: Blackstar on 12/31/2014 12:00 AM
NASA was always careful when discussing the plumes on Europa, using "possible" or some other qualifier. Of course, lots of people didn't do that and dropped the qualifiers. But the possible plumes is what helped get OMB to put the $15 million in the budget for Europa studies. Sometimes that's how science works.
Title: Re: Proposed Europa Missions
Post by: redliox on 12/31/2014 06:47 PM
NASA was always careful when discussing the plumes on Europa, using "possible" or some other qualifier. Of course, lots of people didn't do that and dropped the qualifiers. But the possible plumes is what helped get OMB to put the $15 million in the budget for Europa studies. Sometimes that's how science works.

Right.  Regarding plumes this definitely deepens the mystery.  It is a matter still worth investigating but not one on the top of the list.

Since we are talking gas and plasma around Europa, how does a neutral mass spectrometer's performance compare with an ion-neutral version?  I wondered how huge a downgrade in data there's be.
Title: Re: Proposed Europa Missions
Post by: the_other_Doug on 01/08/2015 04:06 AM
So -- just as a curiosity, here, not being a physicist, what would hot, low-density plasma from Io do to occasional water plumes from Europa?  Would this impact how long the indicators of water plumes would remain detectable?
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/09/2015 02:45 AM
NASA was always careful when discussing the plumes on Europa, using "possible" or some other qualifier. Of course, lots of people didn't do that and dropped the qualifiers. But the possible plumes is what helped get OMB to put the $15 million in the budget for Europa studies. Sometimes that's how science works.

Right.  Regarding plumes this definitely deepens the mystery.  It is a matter still worth investigating but not one on the top of the list.


And science can be persnickety. Look at the issue of methane on Mars. The readings have been ambiguous for a long time, barely sticking out of the noise. And then Curiosity makes a discovery. These can be very difficult things to extract from noisy data.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/09/2015 02:49 AM
I listened in on a presentation by Jim Green, head of NASA’s Planetary Science Division at this week’s Small Bodies Assessment Group.  Dr. Green says that NASA hopes that it will be able to use the $100M Congress added to NASA’s budget for a Europa mission to enable a New Start for the Europa Clipper program.  This is the term for when a mission goes from the wish list to an approved program.  This is the first that I had heard that NASA’s management was looking to commit to a Europa mission.  This isn’t a done deal: the President’s Office of Budget and Management (OMB) must also approve a new start, and in the past they have not been.  (Congress must also approve a new start, but the substantial funding it has already supplied suggests that it would.) We will see with the release of the Fiscal Year 2016 budget request whether OMB’s stance has changed.  IF a new start is given, then the important questions will be the total budget for the mission and when launch is planned (which might be in the mid-2020’s).
Title: Re: Proposed Europa Missions
Post by: redliox on 01/09/2015 09:17 AM
I listened in on a presentation by Jim Green, head of NASA’s Planetary Science Division at this week’s Small Bodies Assessment Group.  Dr. Green says that NASA hopes that it will be able to use the $100M Congress added to NASA’s budget for a Europa mission to enable a New Start for the Europa Clipper program.  This is the term for when a mission goes from the wish list to an approved program.  This is the first that I had heard that NASA’s management was looking to commit to a Europa mission.

SWEET!

Pardon my premature enthusiasm, but it's about time we heard something both new and good.

There's a meeting for the OPAG in February.  That would be the next likely burst of news we hear specifically for Europa Clipper.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/09/2015 10:46 AM
There's a meeting for the OPAG in February.  That would be the next likely burst of news we hear specifically for Europa Clipper.

No, you would hear it in the budget release, which is likely to happen in early March.
Title: Re: Proposed Europa Missions
Post by: redliox on 01/09/2015 11:41 AM
There's a meeting for the OPAG in February.  That would be the next likely burst of news we hear specifically for Europa Clipper.

No, you would hear it in the budget release, which is likely to happen in early March.

Pointer appreciated.  Do you know what would be discussed, EC and otherwise then?
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/09/2015 05:10 PM
I'm hoping that at the OPAG meeting, we get a high level summary of the results of the $1B mission exercise.  There have been enough comments in public to establish that the proposals could not meet all the scientific goals, but it would be interesting to hear the 15 minute summary.  We won't get many details since the proposals were promised confidentiality.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/10/2015 02:32 AM
I'm hoping that at the OPAG meeting, we get a high level summary of the results of the $1B mission exercise.  There have been enough comments in public to establish that the proposals could not meet all the scientific goals, but it would be interesting to hear the 15 minute summary.  We won't get many details since the proposals were promised confidentiality.

I think you will hear that they did not meet the criteria and that is all. Nothing more. I think NASA and other parties would like all of that to be forgotten, quickly.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/10/2015 02:36 AM
There's a meeting for the OPAG in February.  That would be the next likely burst of news we hear specifically for Europa Clipper.

No, you would hear it in the budget release, which is likely to happen in early March.

Pointer appreciated.  Do you know what would be discussed, EC and otherwise then?

Either it will be a new start in the president's budget or it won't.

What you have to understand is that there's a political game going on here: Congress keeps earmarking in Europa money, and OMB keeps trying to ignore it. But as long as it is in appropriations bills (that become law) the money has to be spent on some Europa-like activities, but not actual spacecraft design and hardware. It is enormously wasteful and inefficient to do things this way. But what some members of Congress are hoping is that OMB will realize that they cannot keep opposing it (i.e. "the will of the Congress") and will finally start the program. It's like playing a game of chicken, except that, well, the stakes are different and the loser just ends up wasting money as opposed to putting it into an actual mission.

Title: Re: Proposed Europa Missions
Post by: JH on 01/14/2015 09:29 PM
Back on the topic of cubesat parasite payloads as a part of EC, I am familiar with several of the proposals that have been funded as part of the JPL program. There are unquestionably instruments that can significantly increase scientific return and can fit onto a cubesat. To add a few details about the program: 10 studies from various institutions were funded and the proposals are targeting a 3U size with the possibility of expanding to 6U if it can be justified. Depending on the proposal's goals, either a solar powered, long(ish) lived cubesat or a battery powered, short duration cubesat might be acceptable. I can confirm that at least one proposal team is considering solar power; it is not impossible at Jupiter given the low power requirements of some of the instruments in question.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/14/2015 09:44 PM
I am familiar with several of the proposals that have been funded as part of the JPL program.
Can you say whether any propose to orbit Europe itself?

Title: Re: Proposed Europa Missions
Post by: JH on 01/14/2015 11:14 PM
Not that I am aware of. I doubt you could even fit enough Delta V into a 3U cubesat (or a 6U for that matter). Assuming you deployed the cubesat from EC shortly after JOI and were willing to wait a few years, you'd need over 600 m/s of Delta V. I think the most that I've heard of being crammed into a cubesat (not using EP, obviously) is 100-200 m/s and that takes up about half of the cubesat. Also, for planetary protection reasons you probably wouldn't want a cubesat orbiting Europa.

On the other hand, it would take relatively little Delta V (~10's of m/s) to do a series of flybys.

-typo
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/15/2015 12:29 AM
Not that I am aware of. I doubt you could even fit enough Delta V into a 3U cubesat (or a 6U for that matter). Assuming you deployed the cubesat from EC shortly after JOI and were willing to wait a few years, you'd need over 600 m/s of Delta V. I think the most that I've heard of being crammed into a cubesat (not using EP, obviously) is 100-200 m/s and that takes up about half of the cubesat. Also, for planetary protection reasons you probably wouldn't want a cubesat orbiting Europa.
I didn't think anyone would propose a Europa orbiter (peace, Draper Labs :> ); if the delta V didn't get you, the radiation would.  I can think of a number of non-Europa long-lived CubeSat missions -- monitoring the magnetosphere in a second (or even 3rd) location, watching the weather on Jupiter, watching the volcanoes on Io.  For multiple Europa flybys, the most obvious options are to increase the number of flybys to collect magnetic induction measurements (magnetometer and simple plasma probe), collect gravity data (ultrastable oscillator), or collect imagery (think Planetary Lab's CubeSats).  My betting is on the first two; the last requires significant data rates, and even with the mother craft for relay, that may be stretching what is reasonable.  However, any long-lived multi-flyby craft would require optical navigation, and the star trackers are very good cameras that could be made more useful for science with different filter strips on the sensor.


Title: Re: Proposed Europa Missions
Post by: JH on 01/15/2015 12:46 AM
There have been orbiter proposals (flagship missions) but their durations have only been 30 days in orbit due to the rad environment. I've heard recently that longer missions may be possible. I don't remember if it is because our understanding of the environment has changed or because of technical advances.

Incidentally, your bet is good.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/15/2015 04:20 PM
There have been orbiter proposals (flagship missions) but their durations have only been 30 days in orbit due to the rad environment. I've heard recently that longer missions may be possible. I don't remember if it is because our understanding of the environment has changed or because of technical advances.

Incidentally, your bet is good.

I think that the later iterations of Europa orbiter missions were at 60+ days for the mission. A big part of that was a better understanding of the actual radiation doses that they would get (for instance, Europa itself shields part of the radiation, so can the orbit be maximized to take advantage of that). You'd have to look at the JPL Europa orbiter study from around 2012 or so and see what it says.
Title: Re: Proposed Europa Missions
Post by: Malderi on 01/15/2015 04:23 PM
Question about the radiation - as an software guy I should know more about this. I know some types of radiation can be more easily shielded against than others. What's the problem around Europa, then? Is the radiation something that can be shielded against, if we only had a bunch more mass to throw at the problem (impractical amounts given current launch/propulsion technology?) Or is it tougher than that? I know Juno has a "vault" for all the electronics - but not sure if that's something that can just be scaled up with more mass to solve the problem.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/15/2015 05:42 PM
Question about the radiation - as an software guy I should know more about this. I know some types of radiation can be more easily shielded against than others. What's the problem around Europa, then? Is the radiation something that can be shielded against, if we only had a bunch more mass to throw at the problem (impractical amounts given current launch/propulsion technology?) Or is it tougher than that? I know Juno has a "vault" for all the electronics - but not sure if that's something that can just be scaled up with more mass to solve the problem.
The problem at Jupiter is the combination of a very strong magnetic field (supplied by Jupiter) and a source of a humongous amount of ions (supplied by Io's volcanoes primarily).  The result is highly energetic ions that are very good at penetrating matter (unlike some kinds of radiation (vague memory says alpha radiation) where a piece of paper is good shielding).  All current Jupiter-mission designs include a vault that puts most of the sensitive electronics behind shielding (instrument sensors remain a problem because they need to be outside the vault).  There appears to be a limit as to how much shielding a spacecraft can reasonably carry - probably weight.

The other approach that Jupiter missions use is to avoid the radiation.  Juno slips past Jupiter in a relatively radiation free zone that is just above the atmosphere and has a polar orbit.  JUICE stays away from the inner Jovian system except for two brief passes by Europa.  Europa Clipper would do many flybys to limit its time in the inner system.  An Io mission would both do a limited number of flybys (most concepts seem to do 6 to 8) and has a polar orbit around Jupiter where the radiation is much less (the radiation is most concentrated in the equatorial plane).  The Europa Clipper wouldn't use a polar orbit because the encounter speeds are too high for good spectroscopy work -- the signals they need to see are faint and they need all the time they can get to collect photons.
Title: Re: Proposed Europa Missions
Post by: Malderi on 01/15/2015 05:44 PM
Question about the radiation - as an software guy I should know more about this. I know some types of radiation can be more easily shielded against than others. What's the problem around Europa, then? Is the radiation something that can be shielded against, if we only had a bunch more mass to throw at the problem (impractical amounts given current launch/propulsion technology?) Or is it tougher than that? I know Juno has a "vault" for all the electronics - but not sure if that's something that can just be scaled up with more mass to solve the problem.
The problem at Jupiter is the combination of a very strong magnetic field (supplied by Jupiter) and a source of a humongous amount of ions (supplied by Io's volcanoes primarily).  The result is highly energetic ions that are very good at penetrating matter (unlike some kinds of radiation (vague memory says alpha radiation) where a piece of paper is good shielding).  All current Jupiter-mission designs include a vault that puts most of the sensitive electronics behind shielding (instrument sensors remain a problem because they need to be outside the vault).  There appears to be a limit as to how much shielding a spacecraft can reasonably carry - probably weight.

The other approach that Jupiter missions use is to avoid the radiation.  Juno slips past Jupiter in a relatively radiation free zone that is just above the atmosphere and has a polar orbit.  JUICE stays away from the inner Jovian system except for two brief passes by Europa.  Europa Clipper would do many flybys to limit its time in the inner system.  An Io mission would both do a limited number of flybys (most concepts seem to do 6 to 8) and has a polar orbit around Jupiter where the radiation is much less (the radiation is most concentrated in the equatorial plane).  The Europa Clipper wouldn't use a polar orbit because the encounter speeds are too high for good spectroscopy work -- the signals they need to see are faint and they need all the time they can get to collect photons.


I guess what I'm asking is - if/when launch costs come down significantly - would it be possible for a longer-lived Europa orbiter mission, just by throwing a bunch more mass at the shielding problem? I know there's diminishing returns, but I'm not sure how much.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/15/2015 08:21 PM
I guess what I'm asking is - if/when launch costs come down significantly - would it be possible for a longer-lived Europa orbiter mission, just by throwing a bunch more mass at the shielding problem? I know there's diminishing returns, but I'm not sure how much.

I don't think it buys you all that much. You'd need a lot more shielding. Plus, as VJkane noted, the instruments are outside the shielding.

The radiation is hell. It just screws you over bad. The only decent way to deal with it is to avoid it.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/15/2015 08:55 PM
The radiation is hell. It just screws you over bad. The only decent way to deal with it is to avoid it.

Maybe instead of moving an asteroid, NASA should move Europa.
Title: Re: Proposed Europa Missions
Post by: JH on 01/15/2015 08:57 PM
I think that the later iterations of Europa orbiter missions were at 60+ days for the mission. A big part of that was a better understanding of the actual radiation doses that they would get (for instance, Europa itself shields part of the radiation, so can the orbit be maximized to take advantage of that). You'd have to look at the JPL Europa orbiter study from around 2012 or so and see what it says.

I'm fairly certain that the 2012 orbiter study was still assuming 30 days. There is depletion of hot electrons in the corotational plasma wake of Europa. I'm pretty sure that beta radiation is the most hazardous to electronics, so I would think that spending as much time as possible orbiting in the wake would be beneficial.

I just double checked and it is 30 days. If anyone is interested, the report has a section on the radiation environment and measures to shield against it starting on 144 of the PDF. Here is a download link: http://soma.larc.nasa.gov/europa/pdf_files/Europa_Study_2012_Report-Final-20120501.pdf
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/15/2015 09:03 PM
I'm fairly certain that the 2012 orbiter study was still assuming 30 days. There is depletion of hot electrons in the corotational plasma wake of Europa. I'm pretty sure that beta radiation is the most hazardous to electronics, so I would think that spending as much time as possible orbiting in the wake would be beneficial.

The 2010 Jupiter Europa orbiter would have lasted a few months as I recall.  That's what ~$2B more buys you.

The Clipper proposal isn't mass starved as I recall.  If more shielding would help, I think they would use it.  The design team has said that if the spacecraft can survive 45 flybys, it can do many more.  Having the instrument sensors that are outside the vault survive is the limiting factor.
Title: Re: Proposed Europa Missions
Post by: baldusi on 01/15/2015 10:23 PM
If I understand it right, some sort of ionizing radiations generate "noise" (as in latch-ups that need a re-cycle), some slowly degrade the materials, and some have a chance of directly permanently disable a part. The last type, as any stochastic process, can be mitigated, but nothing prevents a bad luck day of happening at the beginning of the mission. You just lower your chances.
The worse part, is that to halve the chance of a radiation event, you need twice the amount of mass in front. Thus, if you want to take your reliability from 99% to 99.9% you need 10 more mass. This gets very heavy very fast. And anything outside the vault isn't protected. What's the point of a fully functional bus if you have no instruments (specially if your star/IR/sun trackers and most comm are dead).
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/16/2015 03:33 AM
What's the point of a fully functional bus if you have no instruments (specially if your star/IR/sun trackers and most comm are dead).

Isn't is possible to shield them in some way? Why not feed the image into the sensor via a lens system or fiber optics and keep the sensor inside the vault?
Title: Re: Proposed Europa Missions
Post by: RonM on 01/16/2015 03:43 AM
What's the point of a fully functional bus if you have no instruments (specially if your star/IR/sun trackers and most comm are dead).

Isn't is possible to shield them in some way? Why not feed the image into the sensor via a lens system or fiber optics and keep the sensor inside the vault?

Fiber optics would be good for spectral analysis, but not imaging. Mirrors would work just fine sending the light to a protected sensor. A right angle would do the trick. Don't know what to do with comm systems, unless you can pull the same right angle mirror trick with a comm laser.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/16/2015 04:21 AM
Isn't is possible to shield them in some way? Why not feed the image into the sensor via a lens system or fiber optics and keep the sensor inside the vault?
There appear to be various tricks that can create partial vaults around sensors, but apparently they aren't as effective as a true vault.  The primary reason, as I understand it, that NASA is doing the Clipper instrument selection so early is so they can do a lot of radiation hardening technology development for specific instrument designs.

How ironic is it that the 1st or 2nd most interesting place in the solar system (depending on your preferences, and assuming Enceladus is 3rd) is almost as harsh to explore as Venus?
Title: Re: Proposed Europa Missions
Post by: JH on 01/16/2015 04:57 AM
I tend to think that the space squids don't like company.

On the topic of partial vaults, gyromotion of the incident particles would mean that you can't really avoid exposure, just reduce it proportionally to the shielded angular area. Also, having any opening at all will probably mean a big bump in secondary radiation exposure. Secondary radiation will also be a problem if you add a bend in the opening.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/16/2015 04:55 PM
Yeah, I can guess why a primary camera would be difficult to shield. I was really wondering about star sensors and sun sensors, when I sort of imagine you don't need great resolution, just get the light onto an imager, which might be tucked inside better shielding. But I'm sure that they think of all of these things.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/16/2015 04:59 PM
Yeah, I can guess why a primary camera would be difficult to shield. I was really wondering about star sensors and sun sensors, when I sort of imagine you don't need great resolution, just get the light onto an imager, which might be tucked inside better shielding. But I'm sure that they think of all of these things.
My understanding is that the navigation cameras now are quite respectable cameras in their own right.  Anyone know for sure or not?
Title: Re: Proposed Europa Missions
Post by: JasonAW3 on 01/16/2015 05:21 PM
If radiation is such an issue, why not encase the whole rig in Polyethel Chloride?  It's supposed to be able to reduce the radiation damage astronauts take during a solar storm, it's far lighter than Aluminium, and would actually be able to help insulate some of the more cold ot heat sensitive components.
Title: Re: Proposed Europa Missions
Post by: JH on 01/16/2015 06:29 PM
I know that LRO included a shielding experiment that had to do with RXF1 (the structural shielding that I think you are talking about) and that the results were in line with ground based testing. I have no idea what its TRL is, though.
Title: Re: Proposed Europa Missions
Post by: jongoff on 01/16/2015 06:50 PM
Back on the topic of cubesat parasite payloads as a part of EC, I am familiar with several of the proposals that have been funded as part of the JPL program. There are unquestionably instruments that can significantly increase scientific return and can fit onto a cubesat. To add a few details about the program: 10 studies from various institutions were funded and the proposals are targeting a 3U size with the possibility of expanding to 6U if it can be justified. Depending on the proposal's goals, either a solar powered, long(ish) lived cubesat or a battery powered, short duration cubesat might be acceptable. I can confirm that at least one proposal team is considering solar power; it is not impossible at Jupiter given the low power requirements of some of the instruments in question.

Yeah, we had a solar powered concept we've been studying under an SBIR that was designed with for Titan. It's a 6U though, not a 3U, and we haven't done the thermal analysis yet (we just finished Phase 1) to see if the 3-6W of power we could get at Saturn would actually be enough. Cubesat solar at Jupiter or Saturn is probably feasible, just hard to get enough collecting area.

~Jon
Title: Re: Proposed Europa Missions
Post by: ThereIWas3 on 01/16/2015 06:52 PM
Besides using mass for shielding there are also magnetic methods.  (It works for planet Earth)  There are several engineering problems to be solved though.  Superconducting magnets, power source, and how not to mess with your stuff that is inside the field.
Title: Re: Proposed Europa Missions
Post by: JH on 01/16/2015 07:03 PM
Yeah, we had a solar powered concept we've been studying under an SBIR that was designed with for Titan. It's a 6U though, not a 3U, and we haven't done the thermal analysis yet (we just finished Phase 1) to see if the 3-6W of power we could get at Saturn would actually be enough. Cubesat solar at Jupiter or Saturn is probably feasible, just hard to get enough collecting area.

~Jon

I'm pretty impressed that you were able to squeeze a square meter of high efficiency solar arrays into a 6U cube sat. But, yeah, once you go beyond Jupiter, solar becomes crazy hard.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/29/2015 04:07 PM
This is an interesting article. I haven't read it all the way through, but it has some interesting observations on how Culberson squares his skepticism of climate science with his claim that he is supporting the "scientific consensus" on the need for a Europa mission:

http://news.sciencemag.org/funding/2015/01/money-chase-2016-new-head-key-house-science-spending-panel-likes-limited-government?utm_campaign=email-news-latest&utm_src=email

Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/30/2015 03:46 AM
Some people who want a Europa mission will be happy with the president's proposed budget.
Title: Re: Proposed Europa Missions
Post by: redliox on 01/30/2015 11:24 AM
This is an interesting article. I haven't read it all the way through, but it has some interesting observations on how Culberson squares his skepticism of climate science with his claim that he is supporting the "scientific consensus" on the need for a Europa mission:

http://news.sciencemag.org/funding/2015/01/money-chase-2016-new-head-key-house-science-spending-panel-likes-limited-government?utm_campaign=email-news-latest&utm_src=email

It's encouraging to hear a few in government have genuine science interests.

Definitely would love to hear the budget details as they come, most obviously regarding Europa.
Title: Re: Proposed Europa Missions
Post by: mikelepage on 01/30/2015 03:33 PM
This is an interesting article. I haven't read it all the way through, but it has some interesting observations on how Culberson squares his skepticism of climate science with his claim that he is supporting the "scientific consensus" on the need for a Europa mission:

http://news.sciencemag.org/funding/2015/01/money-chase-2016-new-head-key-house-science-spending-panel-likes-limited-government?utm_campaign=email-news-latest&utm_src=email

It's encouraging to hear a few in government have genuine science interests.

Definitely would love to hear the budget details as they come, most obviously regarding Europa.

Also interesting that he's keen on the idea of a Europa penetrator on the first mission.  I still have trouble picturing how that would actually work though.  I mean, you need something to remain on the surface so it can transmit back anything it finds, so do you then have a tether attaching the transmitter to whatever drills down into the ice?  How long do you make that tether? :)  And how do you make this whole craft as small as it needs to be?

Title: Re: Proposed Europa Missions
Post by: vjkane on 01/30/2015 03:51 PM
Also interesting that he's keen on the idea of a Europa penetrator on the first mission.  I still have trouble picturing how that would actually work though.  I mean, you need something to remain on the surface so it can transmit back anything it finds, so do you then have a tether attaching the transmitter to whatever drills down into the ice?  How long do you make that tether? :)  And how do you make this whole craft as small as it needs to be?
Check out these links on penetrators:

http://futureplanets.blogspot.com/2010/05/europaganymede-penetrator.html

http://futureplanets.blogspot.com/2009/04/europa-hard-landers-and-penetrators.html
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/30/2015 06:18 PM
I can see a penetrator adding a lot of cost to the mission. How does it affect the baseline design? Is there room/mass for a penetrator to be added to Europa Clipper? Do they have to change a lot of the work they have already done? And how do planetary protection requirements affect this, including the cost? Up until now, EC has been designed so that nothing touches the surface ever, but adding a penetrator now means that something does touch the surface.

I'm not saying that it is a bad idea. But it may be a bad idea.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/30/2015 08:03 PM
I can see a penetrator adding a lot of cost to the mission. How does it affect the baseline design? Is there room/mass for a penetrator to be added to Europa Clipper? Do they have to change a lot of the work they have already done? And how do planetary protection requirements affect this, including the cost? Up until now, EC has been designed so that nothing touches the surface ever, but adding a penetrator now means that something does touch the surface.

I'm not saying that it is a bad idea. But it may be a bad idea.
Congressmen don't need to worry about those things.  I cannot imagine that the Clipper will carry any kind of lander.  However, the advanced work on landers that Congress funded this year may advance the data at which a lander will someday fly
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/30/2015 08:21 PM
I can see a penetrator adding a lot of cost to the mission. How does it affect the baseline design? Is there room/mass for a penetrator to be added to Europa Clipper? Do they have to change a lot of the work they have already done? And how do planetary protection requirements affect this, including the cost? Up until now, EC has been designed so that nothing touches the surface ever, but adding a penetrator now means that something does touch the surface.

I'm not saying that it is a bad idea. But it may be a bad idea.
Congressmen don't need to worry about those things.  I cannot imagine that the Clipper will carry any kind of lander.  However, the advanced work on landers that Congress funded this year may advance the data at which a lander will someday fly

I agree with that. I would also add that throwing some technology money at penetrators is not necessarily a bad thing (although throwing too much money at it, when it is not going to fly for decades, is nonsensical). There may be some better ways to spend Europa money, however. For instance, advanced sensors.
Title: Re: Proposed Europa Missions
Post by: redliox on 01/30/2015 08:46 PM
I can see a penetrator adding a lot of cost to the mission. How does it affect the baseline design? Is there room/mass for a penetrator to be added to Europa Clipper? Do they have to change a lot of the work they have already done? And how do planetary protection requirements affect this, including the cost? Up until now, EC has been designed so that nothing touches the surface ever, but adding a penetrator now means that something does touch the surface.

I'm not saying that it is a bad idea. But it may be a bad idea.
Congressmen don't need to worry about those things.  I cannot imagine that the Clipper will carry any kind of lander.  However, the advanced work on landers that Congress funded this year may advance the data at which a lander will someday fly

I agree with that. I would also add that throwing some technology money at penetrators is not necessarily a bad thing (although throwing too much money at it, when it is not going to fly for decades, is nonsensical). There may be some better ways to spend Europa money, however. For instance, advanced sensors.

A penetrator would be awesome, but I have to side with Blackstar in that it's probably impossible for the time being.  It certainly would need a good investment put into it; last thing we want to see is a repeat of Deep Space 2.  Ultimately it would depend on how much money gets thrown Europa's way, and beefing up the orbiter's instruments would be wiser, such as restoring the mass spectrometer to ion-neutral capability or adding a UV spectrometer.
Title: Re: Proposed Europa Missions
Post by: Donosauro on 01/30/2015 09:35 PM
Also interesting that he's keen on the idea of a Europa penetrator on the first mission.  I still have trouble picturing how that would actually work though.  I mean, you need something to remain on the surface so it can transmit back anything it finds, so do you then have a tether attaching the transmitter to whatever drills down into the ice?  How long do you make that tether? :)  And how do you make this whole craft as small as it needs to be?
Check out these links on penetrators:

http://futureplanets.blogspot.com/2010/05/europaganymede-penetrator.html

http://futureplanets.blogspot.com/2009/04/europa-hard-landers-and-penetrators.html

It seems like representative Culberson has in mind some much more capable kind of penetrator than those you wrote about on your blog, since he expects it to penetrate the Europan crust and to reach its ocean: "...I put in the technology money so that NASA could develop the penetrator that we'll need to get below the ice and down into its ocean."
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/31/2015 02:02 AM
It seems like representative Culberson has in mind some much more capable kind of penetrator than those you wrote about on your blog, since he expects it to penetrate the Europan crust and to reach its ocean: "...I put in the technology money so that NASA could develop the penetrator that we'll need to get below the ice and down into its ocean."

Either he misunderstands what is possible, or he is talking about generic technology/study money not intended for a penetrator on the Europa Clipper. Considering how close he is to this subject, I don't think he misunderstands this stuff.

For some of those of us who worked on the Decadal Survey, we always had a worry that Culberson's zeal for Europa was so great that he would essentially unbalance the rest of the planetary science program in order to fund a Europa mission. I remember attending an event after the DS was released where he seemed skeptical/negative about the Mars cacher rover that was at the top of the list of the DS flagship missions. But for a long time his power was limited. Also, for a long time the JPL Europa option was too big to fund and would have wrecked the entire planetary budget, so it was not going to get approval from anybody.

I can say that some of the things I have heard in the past few months, and some of the things Culberson has said, indicate that he will not unbalance the planetary science program in favor of a Europa mission. He has indicated an interest in funding basic technology and in getting planetary a top-line budget equivalent to what it was several years ago before the administration started cutting it.

But this is from the above-linked article:

"Culberson’s stance leaves him open to the charge that he is substituting his judgment for that of scientific experts. That’s especially problematic for a lawmaker who emphasizes that his support for the Europa mission is driven not by his own fascination with its frozen oceans but by his desire to reinforce the consensus of the scientific community.

The consensus Culberson is referring to is a 2011 decadal study for planetary science, written by a panel convened by the U.S. National Academies. He regards such decadal studies, which identify high-priority research areas and often help set agency spending priorities, as “the gold standard” for setting NASA’s direction. And he vows that the CJS bills his panel produces will continue to require NASA “to fund and fly” the survey’s priority missions. (At the top of the report’s list was a trip to collect, and eventually return, samples from Mars, part of a multistep approach to exploring the Red Planet that NASA is pursuing.)"



Now that is written in such a way as to be a bit ambiguous. Does it mean that Culberson is going to fund all of the DS priorities, or the "priority missions"? And does that simply mean that he will make sure it funds Mars 2020 and Europa Clipper, but ignores everything else?

There is an invisible gorilla in the room, which is that the administration has essentially zeroed-out the New Frontiers program line. New Frontiers funds missions to other parts of the solar system. The New Horizons Pluto mission is a New Frontiers mission. If Culberson primarily cares about Europa Clipper and doesn't care about New Frontiers, that could leave NASA with a planetary program that essentially does Mars missions and a Europa mission and nothing else for the next decade plus--no comets, no asteroids, no Moon, no Venus, or any of the other possible missions other than the next Discovery mission selection.

And I would note that that is NOT what the Decadal Survey's priorities were. It did not say "flagships first, then all the other stuff." In fact, it put the flagships after the other stuff.

I actually suspect that Culberson knows this and I would not be surprised to see him put some money into the New Frontiers program. But right now that is uncertain.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/31/2015 03:16 AM
There is an invisible gorilla in the room, which is that the administration has essentially zeroed-out the New Frontiers program line. New Frontiers funds missions to other parts of the solar system. The New Horizons Pluto mission is a New Frontiers mission. If Culberson primarily cares about Europa Clipper and doesn't care about New Frontiers, that could leave NASA with a planetary program that essentially does Mars missions and a Europa mission and nothing else for the next decade plus--no comets, no asteroids, no Moon, no Venus, or any of the other possible missions other than the next Discovery mission selection.

After the decision to do a new start for Clipper, the key question is when is the expected launch.  If it is around 2024, then current funding can support Mars 2020, Discovery missions around every 3.5 years, and Clipper but no new New Frontiers (by my budget analysis).  If Clipper is pushed to 2022 (I don't see anyway to do it before then as still do the missions in the pipeline), then the next Discovery AO would need to be pushed out.  (This is all assuming relatively flat planetary budgets.)

I am a big fan of New Frontiers missions and I am sad to see the program effectively shutting down for the next while.  That said, the planetary science community is just one stake holder in setting planetary priorities.  NASA management is another, and so are the NASA centers, OMB, Congress, and the public.  A program that includes more frequent Discovery missions and the top two priority Flagship missions is much better than I had hoped for just a couple of years ago.

We got MSL in its final form (the 2003 Decadal Survey called for a modest technology demonstration rover), Mars 2020, and now Clipper because of political issues outside the purvey of the Decacal Surveys.  Flagships get a great deal of visibility and therefore political momentum.
Title: Re: Proposed Europa Missions
Post by: baldusi on 01/31/2015 04:27 AM
I was truck with hos comment that he wanted to take some of the OMB power over setting NASA's priorities. Quite interesting to this particular mission (given how they still haven't allowed an ATP).
Title: Re: Proposed Europa Missions
Post by: simonbp on 01/31/2015 05:15 AM
After the decision to do a new start for Clipper, the key question is when is the expected launch.  If it is around 2024, then current funding can support Mars 2020, Discovery missions around every 3.5 years, and Clipper but no new New Frontiers (by my budget analysis).  If Clipper is pushed to 2022 (I don't see anyway to do it before then as still do the missions in the pipeline), then the next Discovery AO would need to be pushed out.  (This is all assuming relatively flat planetary budgets.)

I've heard rumblings that they might select two of the current round of Discovery proposals and then stagger their development. That would give more flexibility in terms of making a Europa mission happen while the political winds are blowing for it, and then once it is entrenched and a separate line item (like JWST), go back to a more regular Discovery schedule. But that might simply be wishful thinking on the part of those people proposing for Discovery.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/31/2015 03:53 PM
I've heard rumblings that they might select two of the current round of Discovery proposals and then stagger their development. That would give more flexibility in terms of making a Europa mission happen while the political winds are blowing for it, and then once it is entrenched and a separate line item (like JWST), go back to a more regular Discovery schedule. But that might simply be wishful thinking on the part of those people proposing for Discovery.

I go with wishful thinking. The problem is that delays don't save money--the proposing team still has to keep their team together during the delay and this costs NASA money. No team can guarantee that the team they said would be available in year 1 will be available in year 3, unless they are paid to be available.

This is what happened with Juno. NASA selected the mission and then immediately delayed it, and I think that increased the cost of the mission by 100 million or so.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/31/2015 03:57 PM
I was struck with his comment that he wanted to take some of the OMB power over setting NASA's priorities. Quite interesting to this particular mission (given how they still haven't allowed an ATP).

That's part of the ongoing struggle regarding NASA funding. There has long been the perception that OMB budget examiners have been setting NASA priorities without executive oversight or direction. I won't say if I believe that is true, but the claim has been that certain projects have been rejected (and others have been pushed) because OMB civil servants have their own priorities aside from the White House's priorities. For example, they have been opposed to both flagships in general and Mars sample return in particular, essentially for the same reason that they will end up costing lots of money.

If you look at what Culberson has done the past few years with Europa, you see that he's been trying to essentially get Congress to set the budget priorities for planetary science, following his interpretation of the Decadal Survey.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/31/2015 03:59 PM
This is what happened with Juno. NASA selected the mission and then immediately delayed it, and I think that increased the cost of the mission by 100 million or so.
I heard in some meeting or other -- I think it was an OPAG meeting -- that the Juno team did a classic job of using the extra time to do early engineering work and reduce risk.  The NASA official said there might be a lesson in the longer development time for all missions.  If there was, it wasn't followed, presumably because it adds costs to every mission.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 01/31/2015 04:01 PM
1-That said, the planetary science community is just one stake holder in setting planetary priorities.  NASA management is another, and so are the NASA centers, OMB, Congress, and the public. 

2-A program that includes more frequent Discovery missions and the top two priority Flagship missions is much better than I had hoped for just a couple of years ago.


1-That is true. I would not dispute it. I would posit the notion that the science community, NASA management (at least part of it), and Congress are all closer in agreement than OMB is.

2-I would agree. I'm not going to whine. I view this political exercise as like pushing spaghetti across a plate: you apply some pressure in one spot, then go on to another. I expect that pressure for New Frontiers will come next, possibly boosted by the fact that New Horizons is going to be an incredibly famous New Frontiers mission.

I would still add a caution/caveat: flagship missions if they go over budget can wreck the rest of the program by sucking all the money away.

And it looks like we are now going to have TWO.
Title: Re: Proposed Europa Missions
Post by: vjkane on 01/31/2015 04:12 PM
There has long been the perception that OMB budget examiners have been setting NASA priorities without executive oversight or direction. I won't say if I believe that is true, but the claim has been that certain projects have been rejected (and others have been pushed) because OMB civil servants have their own priorities aside from the White House's priorities.
I suspect that NASA's planetary program is such a minor detail in the scheme of White House officials that the OMB civil servants may be the responsible officials.  Their mandate, apparently, is to keep the programs within budget boundaries.  If the Decadal Priorities can be followed, too, that's good.  I've also heard that they have many pictures on their office walls from NASA, but that they are from the manned program.  Any thoughts, Blackstar?
Title: Re: Proposed Europa Missions
Post by: zubenelgenubi on 02/01/2015 04:31 PM
-I am sure that the people at OMB see things entirely differently than the people at NASA, or the "informed" public.
Has anyone from OMB, past or present, ever spoken about their participation in setting NASA's budget and/or budget priorities?

This might not be perceived as GLAMOROUS content, but it should be informative.

"I was there at the dawn of NASA's FY 2016 budget."
(For full effect, I suggest reading the above sentence with a Londo Mollari accent.)

Curious,
Zubenelgenubi
Title: Re: Proposed Europa Missions
Post by: zubenelgenubi on 02/02/2015 02:31 AM
-I am sure that the people at OMB see things entirely differently than the people at NASA, or the "informed" public.
Has anyone from OMB, past or present, ever spoken about their participation in setting NASA's budget and/or budget priorities?

This might not be perceived as GLAMOROUS content, but it should be informative.

"I was there at the dawn of NASA's FY 2016 budget."
(For full effect, I suggest reading the above sentence with a Londo Mollari accent.)

Curious,
Zubenelgenubi

They keep a pretty low profile. And you wouldn't get a candid answer out of them anyway. That's now how Washington works.

Copy that.  And I ask pardon if am straying from the topic.

But.

Does this count for retirees?  Not those who have put in their 30 years as civil servants, but still need to watch what they say and do, so as not to wreck their chances at employment as contractors?  Or political appointees who don't want to jeopardize the next political appointment?

I mean those who have retired, and don't much care about negative consequences to telling the (perceived) truth, because they don't have to impress an employer or politicians any more.  However, they do care enough to respond to an interview request and give honest, informative answers.

If one can find them--they are assumed to be keeping a low profile.

Or am I describing a null set?

Zubenelgenubi
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/02/2015 06:01 PM
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/02/2015 06:09 PM
$30 million to start Europa.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/02/2015 06:12 PM
You can also see that there's no money for New Frontiers. I don't know what kind of profile the outer years budget would fund--next selection in 2019?
Title: Re: Proposed Europa Missions
Post by: redliox on 02/02/2015 06:19 PM
So, if I'm reading the various clips correctly, we finally have an official start on EC, but it would be a small flagship and not in the New Frontiers class?  If it's not an official start how is "formulation work" different from all the work done in the past ~5 years? (since they divided things into the orbiter, fly-by, and lander concepts)
Title: Re: Proposed Europa Missions
Post by: redliox on 02/02/2015 06:24 PM
You can also see that there's no money for New Frontiers. I don't know what kind of profile the outer years budget would fund--next selection in 2019?

Between Discovery, flagships, and mega-projects like either Webb or SLS I'm not surprised something gets inevitably neglected.  However I do hope they begin putting renewed emphasis on the outer planets, starting with Europa obviously but hopefully the ice giants next.  Saturn could wait a little...they've had the luck of Cassini for ~15 years now.
Title: Re: Proposed Europa Missions
Post by: vjkane on 02/02/2015 06:51 PM
You can also see that there's no money for New Frontiers. I don't know what kind of profile the outer years budget would fund--next selection in 2019?
The budget text says the next New Frontiers AO would be issued at the end of FY16 (fall 2016).  It typically takes ~2 years to select a mission, so the ramp up would start in FY19, which is what the budget ramp suggests.
Title: Re: Proposed Europa Missions
Post by: vjkane on 02/02/2015 06:54 PM
So, if I'm reading the various clips correctly, we finally have an official start on EC, but it would be a small flagship and not in the New Frontiers class?  If it's not an official start how is "formulation work" different from all the work done in the past ~5 years? (since they divided things into the orbiter, fly-by, and lander concepts)
NASA has a formulation period for all missions (this covers at least Phase A and I think possibly Phase B).  The mission  isn't officially approved until a design review at the end of the formulation period.

I read this budget as drawing out the formulation phase to support a launch in the mid-2020's.  While a somewhat longer formulation phase makes sense for a mission with the radiation challenges and hence design challenges of the Clipper, this long is basically the budget office saying, 'We heard you on Europa, it's an official project, now go away until around 2020 when the real work (and budget ramp up) occurs.'
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/02/2015 07:27 PM
So, if I'm reading the various clips correctly, we finally have an official start on EC, but it would be a small flagship and not in the New Frontiers class?  If it's not an official start how is "formulation work" different from all the work done in the past ~5 years? (since they divided things into the orbiter, fly-by, and lander concepts)

There was never a New Frontiers Europa Clipper. All of the Europa options were flagship class missions. OMB last year wanted to see if it was possible to do a Europa mission for approximately $1 billion, or around the equivalent of a New Frontiers mission. NASA asked for proposals, got six, and determined that none of them would be able to do Decadal level science (in other words, "science that the scientific community considered worthwhile"). So that effort died a quiet death.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/02/2015 07:29 PM
By the way, here is the summary budget briefing.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/02/2015 07:30 PM
Here is the full budget document.
Title: Re: Proposed Europa Missions
Post by: Star One on 02/02/2015 09:37 PM
You can also see that there's no money for New Frontiers. I don't know what kind of profile the outer years budget would fund--next selection in 2019?
The budget text says the next New Frontiers AO would be issued at the end of FY16 (fall 2016).  It typically takes ~2 years to select a mission, so the ramp up would start in FY19, which is what the budget ramp suggests.
I wonder how much consideration a mission to either the ice giants or Titan would get by then.
Title: Re: Proposed Europa Missions
Post by: ccdengr on 02/03/2015 02:27 AM
NASA has a formulation period for all missions (this covers at least Phase A and I think possibly Phase B).
Certainly not Phase B, and I suspect the first FY only covers pre-phase-A activities.  For a mission with competed instruments, Phase A starts after instrument selection.  See http://fpd.gsfc.nasa.gov/NPR71205/NID.pdf
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/03/2015 03:48 AM
You can also see that there's no money for New Frontiers. I don't know what kind of profile the outer years budget would fund--next selection in 2019?
The budget text says the next New Frontiers AO would be issued at the end of FY16 (fall 2016).  It typically takes ~2 years to select a mission, so the ramp up would start in FY19, which is what the budget ramp suggests.
I wonder how much consideration a mission to either the ice giants or Titan would get by then.

None. Those are going to have to wait until the next decadal survey. NASA is going to have a full plate for the next few years. And if the agency is going to take on anything more, it should be adding another Discovery and/or New Frontiers opportunity.
Title: Re: Proposed Europa Missions
Post by: Geron on 02/03/2015 05:10 AM
Couldn't we do more exploration missions by saving money on launchers? If a sls launch is 1 billion, why not do 2 falcon heavies for 260 million? Then we would have an extra 740 million for another science mission!!
Title: Re: Proposed Europa Missions
Post by: vjkane on 02/03/2015 05:26 AM
Couldn't we do more exploration missions by saving money on launchers? If a sls launch is 1 billion, why not do 2 falcon heavies for 260 million? Then we would have an extra 740 million for another science mission!!
Perhaps in a rational world (let me know if you find one :> ) that would make sense.  However, NASA, like many organizations, budgets within categories.  It has been decided that NASA will have an SLS launcher that will cost about $1B per launch.   To make the system viable, they have to launch every so often and the SLS budget will be sized for that rate.  They now need missions to use that launcher.  So, the SLS budget gets hit for a planetary mission (perhaps the planetary program has to transfer the equivalent of a commercial launch cost).

What scares me is that the SLS system may well never fly or only fly once or twice.  Its reason for being is a manned spaceflight mission that isn't funded and to provide jobs in key congressional districts.  I could easily see the program being cancelled before the Europa Clipper flies.  Fortunately, my fears seem to be widely held, and I suspect that a commercial launcher will be held as a backup.  There are complications from that strategy -- a commercial launch may would entail Venus flybys and that would require extra heat protection not needed if the SLS launches the mission.


Title: Re: Proposed Europa Missions
Post by: Proponent on 02/03/2015 01:21 PM
Which gives me nasty flashbacks to the effects of NASA's previous in-house launch system, the Shuttle, and its effect on Galileo.
Title: Re: Proposed Europa Missions
Post by: Blackstar on 02/03/2015 01:43 PM
As I like to say, "it's complicated.&