I'm still trying to pick myself up after the hint hit me on the head
Thanks Blackstar.
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.
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.
JPL has continued to iterate the "clipper" (flyby) mission and the results have been positive, and surprising (to me).
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.
[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 ... 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.
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.
high resolution imaging of the surface is required before you can fly a lander.
I'm guessing that a cut down fly by mission from the ones in the already posted presentations are what is being considered?
It just means the probe doesn't stay at the one moon.
Obviously doing it like this takes a lot longer to image the full surface
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).
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).
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.
With that kind of price tag no one is going to fund this anytime soon are they?
Here is the rest of the presentation.
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.
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.
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.
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 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
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.
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.
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.
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.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.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.
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.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.
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.Quote2-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".
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.
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.
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?
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. >:(
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.
I found a word Americans don't use lolWhy don't you go and read the MSR discussion on the MSL forum? It has answers to what you think.
Here's what wiki saysQuoteRort 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.
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.
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?
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?
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.
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.
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.
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. :-\
"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".
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.
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.
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.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 hope that all that is stopping a mapping mission being funded is the plutonium.
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 hope that all that is stopping a mapping mission being funded is the plutonium.
No. It's money.
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
A little politics but only for reference.QuoteProvided, 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... ???
A little politics but only for reference.QuoteProvided, 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 guess it's just a risk reduction to get prepared for when the stars align and the mission is funded.
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.
Well, uh oh...;D
http://www.bbc.co.uk/news/science-environment-21341176
Ice blades threaten Europa landing
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.
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.
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.
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.
"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".
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.
There is, of course, a lot more that could be said about the whole subject, but I'd have to start writing a textbook.
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.
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."
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.
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."
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.
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
...
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.
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.
It seems that lake Vostok is indeed full of life.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.
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.
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)
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.
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.
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. »
The latest on Europa Clipper. Note the new spacecraft configuration on slide 12 (there is no slide 10).
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?).
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?
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.
Maybe they can test fly the ASRG unit and recover it for refueling with a space capsule.
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.
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.
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.
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.
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.
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.
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
- TiME: Low technical risk (essentially a reflight of Huygens hardware with an added ASRG)
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...
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.
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.
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.
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.
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.
What would be the timeframe for an actual decision on this?
Why was the ASRG taken out of the option space?
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?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?
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?
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?
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.
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.
Europa Clipper | JUICE | ||
Instrument Name | Science Type | Sciente Type | Instrument Name |
Ice Penetrating Radar (IPR) | Radar | Radar | RIME |
Magnetometer (Mag) | Magnetometer | Magnetometer | Magnetometer Magnetometer JMAG |
Reconnaisance Camera (Recon) | Camera | Camera | Camera JANUS |
Langmuir Probes (LP) | Plasma | Plasma & Fields | Radio and Plasma Wave Investigation (RPWI) |
Neutral Mass Spectometer (NMS) | Particles | Particles | Particle Environment Package (PEP) |
Gravity Science Antenna (GS) | Gravity | Gravity | Radio Science 3GM |
Topographical Imager (TI) | Topography | Topography | Laser altimeter Ganymede Laser Altimeter (GALA) |
Shortwave Infrared Spectometer (SWIRS) | SW/FIR Spec | Heterodyne receiver | Submillimeter Wave Instrument (SWI) |
Thermal Imager (Thermal) | IR Image | IR Imaging Spectometer | MAJIS |
UV Spectograph | Ultraviolet Spectograph (UVS) | ||
VLBI | PRIDE |
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.
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
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.
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.
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.
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.
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.
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.
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?
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-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.
Can only hope that next time around in the survey the focus moves away from Mars towards Europa.
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.
how the JPL and Decadal Survey cost models could differ by a factor of 2.
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.
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."
... I don't know if the proposal guidelines specify a certain minimum readiness for all proposed sub-systems...
if you did that, and just allocated this 'uncertainty' money to technology development, would it allow for a greater rate of missions?
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?
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?
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.
... 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.
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.)
... 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.
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.
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.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.
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 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.
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.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.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.
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.
And thanks everyone for the very insightful comments in the latter part of this thread.
Is WFIRST still planning to use the gifted NRO telescope?
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.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.
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.
That reality should hit much sooner and more acutely with flagships.
1-Cubesats cannot do much of jack squat. They're too small. They lack power.
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.
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.
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.
2-Why? What's that going to buy you?
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.
Now you're getting bad mannered.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.
The original point was cubesats to increase technology TRL. You can validate only small components
Cubesats are useful, but you can't compare Skybox, Satellogic and much less Planet-Lab with Landsat 8.
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.
Now you're getting bad mannered.
The fact that they even had to state that should tell you how much they felt they had to justify it.
You're not going to find cubesats prioritized as scientific platforms in any decadal survey.
They're used for minor things,
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?).
I think that CubeSats will play a role, but as deployed auxiliary instruments carried to their destinations by larger craft.
"Toys" can't provide Landsat-class imagery,
I'll take what's written in black-and-white in an NSF presentation over hearsay and innuendo.
This statement is now ignorant in multiple fields.
Proof please and not based on advertisements.
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.
what hearsay and innuendo
And yours are also in overstating the role of cubesats.
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.
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.
If you don't know, Landsat 7/8 images are 15-100m resolution.
I've provided multiple, factual examples of cubesats obtaining remote sensing and space science data on par with larger, modern spacecraft.
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.
Another overstatement. far from "on par. They have a niche role.
I think the Landsat versus Planet Lab comparisons are misleading. Landsat produces highly geometrically precise and spectrally consistent images
Chill. You called me ignorant multiple times
Don't give more people no reason to take you seriously.
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?
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.
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.
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.
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?
B-could SLS make any difference for that mission given its difficult parameters (like delta-vee)?
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'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.
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.
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.
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.
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.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.
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.
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:
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?
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.
... 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).
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.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.
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.
(If you ask me, this was just OMB wasting time.)
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.)
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.
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.
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.”
“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.
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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.
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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.
The MPPG finds that sample return architectures provide a promising intersection of objectives and integrated strategy for long term SMD/HEOMD/STP collaboration
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.
New article from the New Scientist about missions to Europa.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.
http://www.newscientist.com/article/mg22129502.700-water-plumes-spark-a-race-to-jupiter-moon-europa.html
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?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).
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.
For a start how would you even effectively radiation shield a cubesat in that kind of environment.
Do the math, it doesn't work. And i think thats off topic here.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.
Europa Ice Clipper.
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.
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.
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).
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.
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.
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).
I take back what I just wrote. Wait until the budget comes out. You'll be surprised.
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).
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
Here you go.
So how much of a pain would it be to aerocapture a probe at Jupiter?
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.
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.
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.”
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.
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.
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.
The key instrument for the plumes would be a mass spectrometer. That instrument also would be highly desired for measuring surface composition.
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.
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?
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?
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
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
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.
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.
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 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.
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?"
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
[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.
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
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.
Nice article on SpaceflightNow
http://spaceflightnow.com/news/n1403/14europa/#.UySenYX3ip0
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.
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."
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.
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?
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.
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?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)
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
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.
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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).
An interesting idea suggested by Andrew LePage involves a Europa-Io Sample Return by flying through the plumes of each respective moon:
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.
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.
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 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):
So, going by priority, finding the depth and extent of the subsurface ocean comes first followed by chemistry.
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.
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.
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.
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.
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.
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.
Might need to add the last part of the SpaceNews article.QuoteThat 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.
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.
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.
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?
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?
Europa Clipper Would Wash Out Other Nuclear-powered Missions.
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?).
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.
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.
If they go with SLS, RTG also mean nuclear-rating it.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.
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 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.
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.
It will be interesting, once Falcon Heavy gets going, to see what its payload/C3 graph looks like.
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?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.
If they go with SLS, RTG also mean nuclear-rating it.
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?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.
As for the cost of engineering evaluation, it is one of the main reason all these missions cost billions.
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.
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.
But as the departure dates get closer the calculus might change.
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.
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's no internal equivalent to an insurance or warranty?
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.
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?
How often does a window to Jupiter occur?
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.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.
ARC/JPL studied Europa sample return before under the Ice Clipper concept for a ~$250M Discovery proposal back in 1996/7.
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)?
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.
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.
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?
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.
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.
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?
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 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.
Why is the SLS being push as a launch vehicle?Because it needs payloads. There's not much else to it.
Why is the SLS being push as a launch vehicle?Be cause it needs payloads. There's not much else to it.
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.
But they can prepare their input for the *next* Decadal Survey. Starting now is smart.
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.
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?
-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.
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.
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?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?
Hmm. Don't think solar power is variable beyond the orbit of Jupiter.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.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...
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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.
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
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.
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.
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.
Why weren't they launched on Delta or some other medium lift (?) rocket? Why did they get launched on STS?
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?
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....
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.
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.
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.
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.
"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?
"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-238although 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...
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.
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?
...
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.
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.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).
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...
Americium 241 (Am-241) is apparently a fairly virtuous RHU option.QuoteAm-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
Stephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)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?
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
From Stephen Clark Tweeter at IAC2014QuoteStephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)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?
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
From Stephen Clark Tweeter at IAC2014QuoteStephen Clark @StephenClark1 (https://twitter.com/StephenClark1/status/517754605619253248)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?
APL's Thomas Magner: We've selected solar power for the Europa Clipper mission, baselined for launch on SLS in June 2022. #IAC2014
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.
SLS has lower throw weight than Atlas V for this mission.
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?
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?).
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.
I'm disingenuous?
We're in agreement?
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.
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]http://en.wikipedia.org/wiki/Impoundment_of_appropriated_funds
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
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.
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.
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.
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
How did NASA sign a contract with Boeing and SpaceX for crew access to ISS when no funds have been appropriated?
From Stephen Clark Tweeter at IAC2014QuoteStephen 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
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.
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).
http://www.spacenews.com/article/civil-space/42121europa-clipper-opts-for-solar-power-over-nuclearQuoteIn 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).
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,
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.
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.
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.
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.
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.
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.
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.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.
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
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.
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).
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.
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
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
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.
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%.
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.
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".
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.
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.
$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?
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?
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?
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".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.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).
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.
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.
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.
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...
So don't think that "we now can do solar at Jupiter." No, we can do it in some specific mission implementations.
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...
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.
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
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
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?
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?
But yeah, it's a perpetual struggle, and nobody thinks that R&D is winning.
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.
...you have the approach typified by DS-1 (I forget the name of the overall program it was part of).
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.
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.
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.
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.
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.
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.
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?
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.
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.
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.
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.
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.
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.
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?
ATP: Authorization To Proceed, that was what I understand was a new start.Doesn't the F9 160M number for NASA you mentioned include Dragon?
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.
How much does NASA pay for a Falcon 9 and a comparable Atlas?
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.http://www.nasa.gov/home/hqnews/2012/jul/HQ_C12-029_RSLP-20_Launch_Services.html
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.
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.http://www.nasa.gov/home/hqnews/2010/oct/HQ_C10-065_Maven_Services.html
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.
InSight will launch in March 2016 aboard an Atlas V 401 rocket from Space Launch Complex 3E at Vandenberg Air Force Base in California.http://www.nasa.gov/press/2013/december/nasa-awards-launch-services-contract-for-insight-mission/#.VHWzINLF_X4
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.
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.http://www.nasa.gov/press/2014/march/nasa-awards-launch-services-contract-for-solar-orbiter-mission/#.VHWzW9LF_X4
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.
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?
Is it possible to estimate the marginal cost of each additional year of interplanetary cruise?
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.
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.
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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.
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.
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.
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?
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?
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?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?
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.
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-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.
You do realize that this [Europa Clipper] is a solar powered mission.
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.
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?
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).
Is the current estimate really $2.5B? Last I heard, it was hovering around $2B. Is the larger figure with launch vehicle?
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.
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.
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.
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
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.
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.
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.
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.
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.
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).
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.
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.
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.
* 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).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.
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?
Regarding cubesats at Europa, would they be sufficiently large enough to host a short-lived mass spectrometer experiment (ion, neutral, both)?Simple experiment:
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.
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)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.
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.
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.4. Not true at all. There isn't much difference in the trajectories.
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.
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.
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.
A lot of demands for something typically the size of a desktop computer.More like the size of a loaf of bread.
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.
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.4. Not true at all. There isn't much difference in the trajectories.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.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.
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.
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.
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)
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.
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.
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.
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.
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.
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.
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.
There's a meeting for the OPAG in February. That would be the next likely burst of news we hear specifically for Europa Clipper.
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.
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.
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?
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?
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.
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.
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.
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.
The radiation is hell. It just screws you over bad. The only decent way to deal with it is to avoid it.
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.
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).
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?
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.
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?
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
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
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?Check out these links on penetrators:
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.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'm not saying that it is a bad idea. But it may be a bad idea.
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.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'm not saying that it is a bad idea. But it may be a bad idea.
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.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'm not saying that it is a bad idea. But it may be a bad idea.
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.
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."
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'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 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).
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.
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.
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?
-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?
-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.
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?
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.
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.
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)
I wonder how much consideration a mission to either the ice giants or Titan would get by then.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.
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
I wonder how much consideration a mission to either the ice giants or Titan would get by then.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.
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).
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!!
I assume that NASA added this language and that it didn't come from OMB. I wonder if this is wiggle room language, or if they really think there is a possibility that they may have to change the instruments if they get more plume evidence. I just don't get to talk to Europa scientists all that much anymore, so I don't have the chance to ask.We may learn more at next week's OPAG meeting
I assume that NASA added this language and that it didn't come from OMB. I wonder if this is wiggle room language, or if they really think there is a possibility that they may have to change the instruments if they get more plume evidence. I just don't get to talk to Europa scientists all that much anymore, so I don't have the chance to ask.We may learn more at next week's OPAG meeting
Wish I could attend!There is almost always a call in number and a WebEx page for viewing the presentations.
Wish I could attend!There is almost always a call in number and a WebEx page for viewing the presentations.
Does accessing those require conference registration etc? Or are publicly accessible?Publicly accessible without meeting registration
I assume that NASA added this language and that it didn't come from OMB. I wonder if this is wiggle room language, or if they really think there is a possibility that they may have to change the instruments if they get more plume evidence. I just don't get to talk to Europa scientists all that much anymore, so I don't have the chance to ask.We may learn more at next week's OPAG meeting
Reading through their agenda page, http://www.lpi.usra.edu/opag/feb2015/agenda.pdf (http://www.lpi.usra.edu/opag/feb2015/agenda.pdf), missions to Jupiter are going to be a heavy topic. Updates on 'Clipper, JUICE, and Juno are planned, even time is given to the Io Volcano Observer. New Horizons, the Kuiper Belt, and Enceladus are additional topics.
Wish I could attend!
First time I've heard of the Io Volcano Observer, sounds interesting and see it's a Discovery class mission, so wonder how much chance it has in the next choice. It might get overshadowed by the not completely dissimilar but higher profile Europa Clipper which could impact its chances I suppose.McEwan's Io observer has been around for awhile. It was proposed for the last competition with a Sterling RTG. This looks to be the second or perhaps third try, which isn't unusual for Discovery concepts.
First time I've heard of the Io Volcano Observer, sounds interesting and see it's a Discovery class mission, so wonder how much chance it has in the next choice. It might get overshadowed by the not completely dissimilar but higher profile Europa Clipper which could impact its chances I suppose.McEwan's Io observer has been around for awhile. It was proposed for the last competition with a Sterling RTG. This looks to be the second or perhaps third try, which isn't unusual for Discovery concepts.
Any outer planets mission inevitably is more complex than an inner planets mission with a similar science scope. In the last two selections, that risk factor seems to have been a major factor.
First time I've heard of the Io Volcano Observer, sounds interesting and see it's a Discovery class mission, so wonder how much chance it has in the next choice. It might get overshadowed by the not completely dissimilar but higher profile Europa Clipper which could impact its chances I suppose.McEwan's Io observer has been around for awhile. It was proposed for the last competition with a Sterling RTG. This looks to be the second or perhaps third try, which isn't unusual for Discovery concepts.
Any outer planets mission inevitably is more complex than an inner planets mission with a similar science scope. In the last two selections, that risk factor seems to have been a major factor.
One thought is maybe it will be changed to an all solar powered mission if the Sterling RTG has gone away for now.
If they can mitigate the radiation for a dozen orbits I think it would be worth it. Having a trio of Jupiter orbiters investigating the Gaileans would be great!That's my hope for my golden years -- results of three simultaneous Jovian missions.
If they can mitigate the radiation for a dozen orbits I think it would be worth it. Having a trio of Jupiter orbiters investigating the Gaileans would be great!That's my hope for my golden years -- results of three simultaneous Jovian missions.
However, it has yet to be established that a Discovery proposal can convince reviewers that it can be done with the budget cap with acceptable technical and budget risk. My fingers are crossed.
Ditto. At least between 'Clipper and JUICE we can be assured Europa and Ganymede will get a thorough examination. Once their missions are complete the priority should then shift to Enceledus and the Ice Giants.The actuarial tables suggest that I may not be around for that next wave. I hope (perhaps against hope) that one of the Discovery proposals for Enceladus and Titan are actually feasible within the budget cap.
My impression is that there's just no way to do that mission on a Discovery budget.At least five sets of credible scientists and engineers have proposed Discovery missions that they thought were or will be close or within the budget: Journey to Enceladus and Titan, TiME, Enceladus Life, Enceladus sample return, and Io Observer.
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.
I don't recall seeing those numbersThere 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.
VJKane,
Do you have numbers on what the Europa Clipper mass would be for the EELV version, and what the C3 they're assuming is for the SLS version? I'm guessing I can find those by digging back through the thread, but I was wondering if you had them handy. The reason I ask is that I'm curious how much of the benefit of the SLS launch you could get by just refueling the Centaur on the Atlas V 551 before departure (using a depot or a tanker). I know it's a political non-starter at this point, but as a technical point it has me curious, and I wanted to run some numbers.
~Jon
I don't recall seeing those numbersThere 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.
VJKane,
Do you have numbers on what the Europa Clipper mass would be for the EELV version, and what the C3 they're assuming is for the SLS version? I'm guessing I can find those by digging back through the thread, but I was wondering if you had them handy. The reason I ask is that I'm curious how much of the benefit of the SLS launch you could get by just refueling the Centaur on the Atlas V 551 before departure (using a depot or a tanker). I know it's a political non-starter at this point, but as a technical point it has me curious, and I wanted to run some numbers.
~Jon
I don't recall seeing those numbersThere 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.
VJKane,
Do you have numbers on what the Europa Clipper mass would be for the EELV version, and what the C3 they're assuming is for the SLS version? I'm guessing I can find those by digging back through the thread, but I was wondering if you had them handy. The reason I ask is that I'm curious how much of the benefit of the SLS launch you could get by just refueling the Centaur on the Atlas V 551 before departure (using a depot or a tanker). I know it's a political non-starter at this point, but as a technical point it has me curious, and I wanted to run some numbers.
~Jon
After some digging, it looks like the SLS missions were using ~85.4km^2/s^2, and both the Atlas V 551 and SLS Block I concepts had spacecraft masses around 5 metric tonnes. I'm going to run some numbers real quick.
~Jon
At least five sets of credible scientists and engineers have proposed Discovery missions that they thought were or will be close or within the budget: Journey to Enceladus and Titan, TiME, Enceladus Life, Enceladus sample return, and Io Observer.
But you would need a well-stocked propellant depot--<cue vigorous handwaving>.
But you would need a well-stocked propellant depot--<cue vigorous handwaving>.
How many launches would be required to refuel that depot?
When we did the Decadal Survey, it became pretty clear that it was impossible to send even a brick to Saturn for less than a billion dollars. I doubt that Jupiter is much better. Look at how much Juno cost, and things haven't gotten cheaper since then.Hmmm. To get a brick to fly past Saturn, you could get by with a spacecraft that only has a medium gain antenna, no instruments other than a star scanner. So, say a 100 kg spacecraft total, perhaps even including the fuel. Go into deep hibernation for much of the seven year flight (might be much shorter for this small of a spacecraft) x $5M per year for mission ops. Might even be able to use solar panels (a JPL engineer told me that the same low temperature cells that work at Jupiter would also work at Saturn; you just need lots more). That doesn't feel like a $1B mission.
When we did the Decadal Survey, it became pretty clear that it was impossible to send even a brick to Saturn for less than a billion dollars. I doubt that Jupiter is much better. Look at how much Juno cost, and things haven't gotten cheaper since then.Hmmm. To get a brick to fly past Saturn, you could get by with a spacecraft that only has a medium gain antenna, no instruments other than a star scanner. So, say a 100 kg spacecraft total, perhaps even including the fuel. Go into deep hibernation for much of the seven year flight (might be much shorter for this small of a spacecraft) x $5M per year for mission ops. Might even be able to use solar panels (a JPL engineer told me that the same low temperature cells that work at Jupiter would also work at Saturn; you just need lots more). That doesn't feel like a $1B mission.
The $1B box mission studies of circa 2007 assumed that highly capable spacecraft would be needed to justify a mission after Cassini, and they found that such a mission couldn't be done for less than something well over $1B as I recall. They may be right in that base assumption, but the spacecraft they sized isn't the one you would use to take that brick past Saturn.
I worked with a lot of gifted engineers in the high tech industry, and I learned not to bet against good engineers. At some point, advancing technology will enable a Discovery-class mission to the outer solar system. I think that the real challenge will be whether these low-cost outer solar system will have sufficiently compelling science to win selections against inner solar system missions.
The best way to ensure that something isn't possible is for everyone to decide it can't be done and nobody tries. While all evidence to date argues that Blackstar is correct, I'm glad that teams are challenging the assumptions. One of them may find a way to change the paradigm, and if they don't nothing is lost but their time. That's the reason I give up my usual rational conservatism when it comes to engineering and costs, and cheer these guys on.
My problem with wishful thinking is when senior managers get a fancy and mandate that we can fly Battlestar Gallactica to Jupiter (JIMO), do a Europa orbiter for $100M, say that we can push faster-cheaper-better without stop, or haul an asteroid back to the moon for about the cost of the OSIRIS-ReX mission. (I saw plenty of examples in private industry of this, too.)
The Discovery selection process has good checks and balances. Only the credible will get through, and in the meantime, there's a lot of creative analysis looking for new ways to do things.
Here you go. Knock yourselves out.
But you would need a well-stocked propellant depot--<cue vigorous handwaving>.
How many launches would be required to refuel that depot?
Well, you'd need ~27mT of prop, or maybe a little less since you wouldn't use all the DCSS prop getting a measly 4mT payload to the LEO depot--maybe on the order of 22-23mT. That would require either one Delta IV Heavy or two Falcon 9 v1.1s or about half of a Falcon Heavy or a bit more than one Atlas V 552.
In the case of the Falcon options (which would likely be the cheapest), there's the question of how you would get LOX/LH2 into a payload tanker, but my guess is the pad modifications to make that feasible might be cheaper than going the DIVH or AV552 route.
As I said, apply a modest amount of handwaving.
But that's about as far as I probably should take that hypothetical on your thread, unless you're interested. :-)
[I'm actually trying not to be as tedious as some other depot-enthusiasts we could both name.]
When we did the Decadal Survey, it became pretty clear that it was impossible to send even a brick to Saturn for less than a billion dollars. I doubt that Jupiter is much better. Look at how much Juno cost, and things haven't gotten cheaper since then.Hmmm. To get a brick to fly past Saturn, you could get by with a spacecraft that only has a medium gain antenna, no instruments other than a star scanner. So, say a 100 kg spacecraft total, perhaps even including the fuel. Go into deep hibernation for much of the seven year flight (might be much shorter for this small of a spacecraft) x $5M per year for mission ops. Might even be able to use solar panels (a JPL engineer told me that the same low temperature cells that work at Jupiter would also work at Saturn; you just need lots more). That doesn't feel like a $1B mission.
The $1B box mission studies of circa 2007 assumed that highly capable spacecraft would be needed to justify a mission after Cassini, and they found that such a mission couldn't be done for less than something well over $1B as I recall. They may be right in that base assumption, but the spacecraft they sized isn't the one you would use to take that brick past Saturn.
I worked with a lot of gifted engineers in the high tech industry, and I learned not to bet against good engineers. At some point, advancing technology will enable a Discovery-class mission to the outer solar system. I think that the real challenge will be whether these low-cost outer solar system will have sufficiently compelling science to win selections against inner solar system missions.
The best way to ensure that something isn't possible is for everyone to decide it can't be done and nobody tries. While all evidence to date argues that Blackstar is correct, I'm glad that teams are challenging the assumptions. One of them may find a way to change the paradigm, and if they don't nothing is lost but their time. That's the reason I give up my usual rational conservatism when it comes to engineering and costs, and cheer these guys on.
My problem with wishful thinking is when senior managers get a fancy and mandate that we can fly Battlestar Gallactica to Jupiter (JIMO), do a Europa orbiter for $100M, say that we can push faster-cheaper-better without stop, or haul an asteroid back to the moon for about the cost of the OSIRIS-ReX mission. (I saw plenty of examples in private industry of this, too.)
The Discovery selection process has good checks and balances. Only the credible will get through, and in the meantime, there's a lot of creative analysis looking for new ways to do things.
In the last Discovery round TiME made it to the final three. Surely that must mean that at least someone (other than the proposers) thought that a Discovery class outer planet mission is not completely infeasible?I've also met several of the principles in outer planet Discovery proposals, and they were sane, sober, even conservative types who'd been around the block a few times.
So I can't reconcile their willingness to spend their limited time proposing these missions with the fact that actual missions seem to cost 2-3X.You mean the TMCO reviewers think the missions will be more expensive, right? Frankly I think it's the fault of the overconservative cost models that are being used more than what it may actually cost.
So I can't reconcile their willingness to spend their limited time proposing these missions with the fact that actual missions seem to cost 2-3X.You mean the TMCO reviewers think the missions will be more expensive, right? Frankly I think it's the fault of the overconservative cost models that are being used more than what it may actually cost.
We're gonna all end up talking about different things and talking past each other.To put what you said in another perspective, there are risks owned by the PI and risks owned by NASA. In the former are the risks of implementing the spacecraft and instruments, in the latter are the risks of funding flows, overruns in supplied equipment (such as RTGs), and launch vehicle costs.
It may be that tightly focused outer planet missions could be done within the risks managed by the PIs. The NASA-owned risks may push those outside of the acceptable envelope for PI-led missions. (It's also possible that NASA judges the risks to the PI costs to be too high for these proposals, too.)
I hope that the reviewer comments and NASA are giving proposers honest feedback about where their risks appear to be making outer planet missions non-competitive.
I don't know if anybody has ever done a detailed assessment of the causes of cost overruns for space projects. I'm sure that Aerospace has done that internally and may have provided it to USAF and NASA and NRO, but I don't know of anything public. The public things I do know about are rather general, like GAO reports and I think the NRC did one a few years ago.I've been informally told of one analysis that found that missions under $1B rarely seriously bust their budgets while missions >$1B regularly bust their budgets. I suspect that one reason is that for the cheaper missions, the budget cap is the defining requirement, while for the more expensive missions a set of missions goals is the defining requirement. If you read all the new capabilities that had to be developed and tested for MSL to meet the ambitious goals, for example, it's no surprise that the mission went seriously over budget. The mission was defined by capabilities, not budget.
I suspect that good engineering teams can find ways to propose missions within the Discovery program that could fit within the Discovery budget that traditionally have been thought of as too expensive."traditionally thought of as too expensive" means the cost models will say they're too expensive, and so such proposals won't do well in TMCO review.
After some digging, it looks like the SLS missions were using ~85.4km^2/s^2, and both the Atlas V 551 and SLS Block I concepts had spacecraft masses around 5 metric tonnes. I'm going to run some numbers real quick.
Ok, it looks like a refueled Centaur wouldn't cut it--I'm only getting 3600kg to a C3 of ~85-86km^2/s^2. But a refueled DCSS 5m stage looks like it would work--I'm getting ~4800kg to a C3 of 85-86km^2/s^2.
So theoretically, in a magical world where depots exist instead of SLS Block I, you could do the direct to Europa injection using a refueled Delta-IV M+ (5,2) launch, with a lot of mass to spare, you wouldn't need a DIV-H. But you would need a well-stocked propellant depot--<cue vigorous handwaving>.
As I said, it's a political non-starter, but I was morbidly curious from a technical standpoint.
Spreadsheet I used (showing C3 vs payload for a refueled DCSS and a refueled Single-Engine Centaur) attached.
One other thing: Falcon Heavy is not using cross-feed.... So you shouldn't use it in your calculations.
Back in October I had lunch sitting next to a guy from Aerojet who was working on an upper stage for (I think) Falcon Heavy to enable SpaceX to compete for the Solar Probe Plus mission. Dunno if that's gone public anywhere, but it may be mentioned elsewhere on this site. Anyway, they're locked out of a number of missions unless they upgrade their hardware.Solar Probe Plus is an extremely high delta-v mission, so most likely they were just talking to them about a kick stage or something.
...
http://spacenews.com/europa-clipper-team-seeking-earlier-launch/?_wcsid=FBF7A9E96BE3C2239D3BAF4A4638A03433FDA26192541BE07BCB7699D6C55D9A
Europa Clipper Team Seeking Earlier Launch
NASA has announced that they will be accepting instrument proposals.In fact NASA had an AO last year for Europa instruments ( http://www.nasa.gov/press/2014/july/nasa-seeks-proposals-for-europa-mission-science-instruments/ ) and the selections are supposed to be announced in April -- though what the relationship between that AO and an actual flight project was never all that clear.
http://spacenews.com/europa-clipper-team-seeking-earlier-launch/?_wcsid=FBF7A9E96BE3C2239D3BAF4A4638A03433FDA26192541BE07BCB7699D6C55D9A
Europa Clipper Team Seeking Earlier Launch
So I am guessing that the SLS launcher option is iffy for a 2022 launch. What are the alternate launcher options?
By 2022, even only flying a few times per year, falcon heavy will have ~20 flights under its belt. If they add a centaur/rl-10 based upper, the risk is in the integration and ground ops, not the upper stage itself. SLS has its own risk structure as well, and there are some planetary folks still sore about being politically married to a launcher.http://spacenews.com/europa-clipper-team-seeking-earlier-launch/?_wcsid=FBF7A9E96BE3C2239D3BAF4A4638A03433FDA26192541BE07BCB7699D6C55D9A
Europa Clipper Team Seeking Earlier Launch
So I am guessing that the SLS launcher option is iffy for a 2022 launch. What are the alternate launcher options?
I suppose Falcon Heavy might still be too new a launcher to be entrusted with such an important mission, as I get the feeling that the dispensation that SLS gets on this wouldn't be applicable to another newish launcher. Especially as from what I have read on here they need to develop a high energy upper stage for it to be used on missions such as this.
You can't add that. The four options are:By 2022, even only flying a few times per year, falcon heavy will have ~20 flights under its belt. If they add a centaur/rl-10 based upper, the risk is in the integration and ground ops, not the upper stage itself. SLS has its own risk structure as well, and there are some planetary folks still sore about being politically married to a launcher.http://spacenews.com/europa-clipper-team-seeking-earlier-launch/?_wcsid=FBF7A9E96BE3C2239D3BAF4A4638A03433FDA26192541BE07BCB7699D6C55D9A
Europa Clipper Team Seeking Earlier Launch
So I am guessing that the SLS launcher option is iffy for a 2022 launch. What are the alternate launcher options?
I suppose Falcon Heavy might still be too new a launcher to be entrusted with such an important mission, as I get the feeling that the dispensation that SLS gets on this wouldn't be applicable to another newish launcher. Especially as from what I have read on here they need to develop a high energy upper stage for it to be used on missions such as this.
SLS aside would all the others need gravity assists?You can't add that. The four options are:By 2022, even only flying a few times per year, falcon heavy will have ~20 flights under its belt. If they add a centaur/rl-10 based upper, the risk is in the integration and ground ops, not the upper stage itself. SLS has its own risk structure as well, and there are some planetary folks still sore about being politically married to a launcher.http://spacenews.com/europa-clipper-team-seeking-earlier-launch/?_wcsid=FBF7A9E96BE3C2239D3BAF4A4638A03433FDA26192541BE07BCB7699D6C55D9A
Europa Clipper Team Seeking Earlier Launch
So I am guessing that the SLS launcher option is iffy for a 2022 launch. What are the alternate launcher options?
I suppose Falcon Heavy might still be too new a launcher to be entrusted with such an important mission, as I get the feeling that the dispensation that SLS gets on this wouldn't be applicable to another newish launcher. Especially as from what I have read on here they need to develop a high energy upper stage for it to be used on missions such as this.
1) Atlas V 551 (gotta watch for replacement by NGLV)
2) SLS
3) Delta IV Heavy with kick stage (something like OrbitalATK's Star 48GXV)
4) Falcon Heavy (non cross feed) with something like OrbitalATK's Star 48GXV or whatever Aerojet comes up with.
I heard Green say that the Discovery down selection had slipped to September-ish. They received 28 proposals.NASA has announced that they will be accepting instrument proposals.In fact NASA had an AO last year for Europa instruments ( http://www.nasa.gov/press/2014/july/nasa-seeks-proposals-for-europa-mission-science-instruments/ ) and the selections are supposed to be announced in April -- though what the relationship between that AO and an actual flight project was never all that clear.
Actually, now that I think about it, I may have mis-heard Jim Green yesterday. He may have said that the instrument selection is slipping from April to September. (I thought he was discussing the Discovery program, but I might have confused the two.)
Where did you hear 28 Discovery proposals? On Thursday Green said that he did not know how many they received. I heard Alfred McEwen say 28, but 28 was the number last year and I assumed that he made a mistake when he said that was the number for this year.As Green was preparing to talk about the <$1B Europa proposals, he said that there had been an error in his slides the previous day that said the Discovery down selection would be in May when it should have said September. He then said that they received 28 proposals and it would take them some time to get through them.
You can't add that. The four options are:By 2022, even only flying a few times per year, falcon heavy will have ~20 flights under its belt. If they add a centaur/rl-10 based upper, the risk is in the integration and ground ops, not the upper stage itself. SLS has its own risk structure as well, and there are some planetary folks still sore about being politically married to a launcher.http://spacenews.com/europa-clipper-team-seeking-earlier-launch/?_wcsid=FBF7A9E96BE3C2239D3BAF4A4638A03433FDA26192541BE07BCB7699D6C55D9A
Europa Clipper Team Seeking Earlier Launch
So I am guessing that the SLS launcher option is iffy for a 2022 launch. What are the alternate launcher options?
I suppose Falcon Heavy might still be too new a launcher to be entrusted with such an important mission, as I get the feeling that the dispensation that SLS gets on this wouldn't be applicable to another newish launcher. Especially as from what I have read on here they need to develop a high energy upper stage for it to be used on missions such as this.
1) Atlas V 551 (gotta watch for replacement by NGLV)
2) SLS
3) Delta IV Heavy with kick stage (something like OrbitalATK's Star 48GXV)
4) Falcon Heavy (non cross feed) with something like OrbitalATK's Star 48GXV or whatever Aerojet comes up with.
BTW, I wish JUICE would end up orbiting Europa instead of doing multiple flybys. Technically it's possible; it wouldn't be harder IMHO than sending a spacecraft to orbit Mercury.Designing JUICE to take the radiation of Europan orbit would probably add $2-3B to the current ~$1B budget. That's why it makes two quick flybys and then stays away from the intense radiation belts.
From what I understand, AV 551 would need a one pass through Earth and two through Venus.[...]SLS aside would all the others need gravity assists?
The four options are:
1) Atlas V 551 (gotta watch for replacement by NGLV)
2) SLS
3) Delta IV Heavy with kick stage (something like OrbitalATK's Star 48GXV)
4) Falcon Heavy (non cross feed) with something like OrbitalATK's Star 48GXV or whatever Aerojet comes up with.
They clearly put a lot of thought into the solar arrays, and concluded it's worth the effort. I find it ironic that they might actually outlive the MMRTG power supply. I'm honestly surprised they proved lighter and more efficient to use than MMRTGs, but apparently the equipment and shielding for plutonium is heftier than even a large pair of wings. Otherwise the remaining concern is ensuring they don't affect the pointing for optical and infrared imaging.
They clearly put a lot of thought into the solar arrays, and concluded it's worth the effort. I find it ironic that they might actually outlive the MMRTG power supply. I'm honestly surprised they proved lighter and more efficient to use than MMRTGs, but apparently the equipment and shielding for plutonium is heftier than even a large pair of wings. Otherwise the remaining concern is ensuring they don't affect the pointing for optical and infrared imaging.
I believe that one of the issues is that the MMRTGs have a faster power drop off rate than the older RTGs. Not quite sure why, but I can find out. The MMRTG was made to be more robust to survive landing on Mars. My guess would be that this includes more structure that cuts down on the heat transfer and thus the power drops off faster.
During the presentation they said that so far they have been testing spare solar cells from Juno. Those are not the most efficient arrays and the next phase of testing they want to do would be testing higher power arrays to see if they work as well.
MCR Findings (4 of 7)Even a 2.1B Flagship mission is classified as a Class B payload. It might still require a Category 3 certified LV, but still less than A level mission assurance requirements. In my book that means that they are willing to take reasonable risks.
• A Class A risk classification for the mission may be overly constraining the system designs and trades, and not truly being applied consistently across the board, a Class B classification is recommended
Is there any appropriately certified, or even slightly bespoke Atlas V (e.g not a remix of Titan-Centaur),
Apologies, in the sense of tailored; but probably the fact that I could not compose it without bespoke or tailored is telling that any such LV is not really a plausible idea...
This makes me wonder if the Atlas V will also be affected by ULA's desire to phase into a NGLV as well as replacing the Russian engines. If so, this leaves Falcon (Heavy I presume) and SLS as the choice launchers.
This makes me wonder if the Atlas V will also be affected by ULA's desire to phase into a NGLV as well as replacing the Russian engines. If so, this leaves Falcon (Heavy I presume) and SLS as the choice launchers.
It isn't affected, Atlas V is a choice. Anyways, the ban was for military missions.
Would any kind of electric propulsion such as ion propulsion be of any use for a Europa bound craft?
New article on Europa Clipper's progress. Mentions they'll have to make a choice soon on whether to go with the Juno solar panels or if to go with a more advanced design. Sounds also that they are only really considering Atlas V or SLS for the launcher. It sounds like SLS will be the far better choice if the cost can be resolved as well as fitting it into the SLS schedule.
http://spaceflightnow.com/2015/03/10/europa-clipper-concept-team-aims-for-launch-in-2022/
I know how thermal/vac tests work. But how do they actually test for radiation? Do they zap them in a microwave oven or equivalent? And does this have to be done while also in cold vacuum?
While I have no doubt that the scientist working on Europa Clipper would love to see the mission launch in 2022, getting the funding to do so is may be challenging. Currently, Planetary Science gets about $1.35 billion a year. Europa Clipper is expected to cost near $2 billion (plus launch vehicle). So Congress is going to have to either substantially increase Planetary Science funding and/or some other missions will have to be delayed, with the “and” option being the most likely path towards a 2022 Europa Clipper launch.
The Mars orbiter proposal isn't all that definite at the moment to be worrying about its cost.While I have no doubt that the scientist working on Europa Clipper would love to see the mission launch in 2022, getting the funding to do so is may be challenging. Currently, Planetary Science gets about $1.35 billion a year. Europa Clipper is expected to cost near $2 billion (plus launch vehicle). So Congress is going to have to either substantially increase Planetary Science funding and/or some other missions will have to be delayed, with the “and” option being the most likely path towards a 2022 Europa Clipper launch.
It has a reasonable chance to do so; it does have public support behind it or at least that of planetary scientists. The real question is which launch vehicle will be ready by 2022. Still regarding the probe itself, with a decent push it is possible.
2-Agreed. I would think that simply from a programmatic perspective NASA officials, if presented with a viable Venus mission, would recognize that it has been a long time since the last NASA Venus mission and therefore Venus is due. But they have to get a viable mission that they can support.I am thinking that NASA has received viable proposals. Venus missions have been finalists for two New Frontiers competitions and at least one Discovery competition. A number of groups have proposed radar mapping missions (which would address Bob Shaw's points) and various descent probes and balloon missions.
Sounds like poor old Venus is off the register, despite it being the only other genuinely Earth-class planet in our Solar System. If we're looking at the evolution of such planetary objects at all, then it demands much more attention. The USSR dominated past Venus research almost by accident after their early probes did well and drew political support, and since then the dearth of large-scale efforts (notwithstanding NASA's 1970/80s Pioneer and Magellan missions, and ESA's more recent repurposed Mars orbiter) has been pretty obvious. Venus is the Titan of the Inner Solar system, with lessons for all sorts of disciplines, and demands much more attention.
Here's the facts. Earth's land mass is about 30% of the planet; Venus, though smaller, has a surface area 95% of the total of the Earth including the oceans. Unlike the Earth, all of Venus is visible from orbit in exactly the same way (mostly RADAR) - the only Earth-sized planet which may make that claim. The surface of Mars is about equal to the surface area of Earth, and the Moon is about the same size as Africa - and both of these worlds are easily seen optically from orbit, and are reasonably easy to land on.
Venus isn't the low-hanging fruit in terms of planetary science, but certainly is a key aspect of the whole business of the evolution of Earth-class planets, and has been seriously undervalued.
That's not the same as saying that there were no credible Venus proposals.Have you heard that there were technical or budget issues with the numerous Discovery Venus proposals?
Last Discovery round none made it to category 1.
I would argue that Venus has had its fair share of recent missions
Name the recent missions to Venus. With dates.
I would argue that Venus has had its fair share of recent missions
Name the recent missions to Venus. With dates.
Venus Express only just finished. Akatsuki still active & due in orbit this year.
So, two missions in 25 years.And both are focused on the atmosphere and not the surface or interior
If we are going to play this game how many dedicated missions has there ever been to any of the targets I mentioned, none in most cases, which is a heck of a lot less than Venus and that was my point.I would argue that Venus has had its fair share of recent missions
Name the recent missions to Venus. With dates.
Venus Express only just finished. Akatsuki still active & due in orbit this year.
So, "fair share" means one mission, launched in 2005, now dead, and one mission that hasn't actually reached Venus and may not work because the spacecraft is severely damaged. And before that, Magellan, launched in 1989.
So, two missions in 25 years.
If we are going to play this game how many dedicated missions has there ever been to any of the targets I mentioned, none in most cases, which is a heck of a lot less than Venus and that was my point.
The lamentable truth is that, while the outer planets and their moons are A) vastly less well explored (and therefore more worthwhile scientifically, assuming the goal is to understand the solar system as a whole) and B) a much better bet for having currently habitable environments, they are A) a massive pain to get to and operate at and B) not places that people have romantic aspirations of colonizing.
I would argue that Europa has always had extremely good PR, along with good hard science reasons to go (at least with probes - I don't imagine I'm going to live to see astro/cosmo/taiko/whatevernauts touch down on that particular rock. However, most people can at least name the moon, even if they can't name any of the other moons in the same planetary system.
I would argue that Europa has always had extremely good PR, along with good hard science reasons to go (at least with probes - I don't imagine I'm going to live to see astro/cosmo/taiko/whatevernauts touch down on that particular rock. However, most people can at least name the moon, even if they can't name any of the other moons in the same planetary system.
And before someone says that 2020 is in line with the Decadal Survey directive for MSR, with the most recent mission profile revision in which now essentially the rover will drill out material and then leave it in piles on the ground as it goes, it is no longer a valid step in sample return.The 2020 team has reviewed this with NASA HQ and gotten permission to proceed.
I apologize, having looked at Farley's MEPAG presentation again, it is, in fact, in tubes. While that does alleviate my concerns about sample degradation due to exposure, the current plan still kicks a lot of the sample return burden down the road.
NASA invites ESA to build Europa piggyback probe
http://spaceflightnow.com/2015/04/10/nasa-invites-esa-to-build-europa-piggyback-probe/
Assuming that ESA does decide to contribute a probe, I would be surprised if they chose the plume fly-through option mentioned by Jim Green. There has only been the one observation and subsequent Hubble campaigns, intended to demonstrate tidal driving, have so far failed to produce results.And unless I've missed something, the main Europa Clipper spacecraft could do plume flybys.
A key aspect to making this work is keeping the programs as separate as possible, with Huygens as the model. That works much better than intricate cooperation.
I hope so as well. Assuming they go with a full (albeit small i.e. Huygens-size) lander, how much mass might that require to do a Pathfinder-style landing in the airless (not to mention radioactive) environment of Europa.You might want to check out these links:
Something further to consider for Europa Clipper...
...by the time it launches in either the early or mid 2020s the launch vehicle choices may be this trio: SLS, Falcon Heavy, and Vulcan. I'm sure most of you have learned about the last one's recent announcement although exact specs are pending it seems.
If anyone can find out the capacities of the Vulcan and list them alongside SLS and FH it'd be sweet. If SLS proves too heavy I'd hope for a launcher that would only need a single Earth flyby to get something to Jupiter.
Europa Clipper is being designed for Delta IV Heavy or SLS. Vulcan will have more performance than Delta IV Heavy so it won't be an issue.
I wouldn't be surprised if this didn't end up on a Vulcan rather than SLS for a variety of factors.
If completed and if still operational in the mid-2020's, SLS will be an awesome launch vehicle. Note the 'if's', thoughI wouldn't be surprised if this didn't end up on a Vulcan rather than SLS for a variety of factors.
I don't think anybody would be surprised if it ended up on a non-SLS rocket. That said, apparently the latest SLS figures are pretty impressive for this mission. You may hear more about that soon.
If completed and if still operational in the mid-2020's, SLS will be an awesome launch vehicle. Note the 'if's', though
Definitely agreed, just factoring in the alternatives. I'm guessing the new Vulcan initially might perform slightly better than Atlas V. If this becomes the option 'Clipper uses in the near future I just hope it at least mitigates the need for a 'Venus fry-by.'
Definitely agreed, just factoring in the alternatives. I'm guessing the new Vulcan initially might perform slightly better than Atlas V. If this becomes the option 'Clipper uses in the near future I just hope it at least mitigates the need for a 'Venus fry-by.'
No, there will be multiple flybys required for non SLS boosters
If they used SLS and did the flybys anyway, how much could they increase the payload mass?Might not matter. There's a strong correlation between spacecraft mass and cost. There's only so much spacecraft ~$2B can buy.
From what I recall, a SLS launch will allow for a less lengthy trajectory and the exclusion of the flyby(s). However, the flyby(s) option gives the spacecraft more margin for mass changes, since you can modify the flyby trajectory to get more out of it. Can't do that with SLS, since all the velocity goes into the Jupiter transfer orbit (so it's fixed).But you save the mass and thermal requirements for a Venusian GA.
From what I recall, a SLS launch will allow for a less lengthy trajectory and the exclusion of the flyby(s). However, the flyby(s) option gives the spacecraft more margin for mass changes, since you can modify the flyby trajectory to get more out of it. Can't do that with SLS, since all the velocity goes into the Jupiter transfer orbit (so it's fixed).But you save the mass and thermal requirements for a Venusian GA.
This might be interesting to a few people on here.
This might be interesting to a few people on here.
When and why did the interplanetary trajectory for a mission launched on EELV go from VEEGA taking 6 years to EVEEGA taking 7.6 years?
Hope they can come up a way of making any lander last longer on the surface than Huygens did on Titan.
To go further than batteries and slow data needs RTGs, which open up a whole new set of issues.
To go further than batteries and slow data needs RTGs, which open up a whole new set of issues.
Yeah, one of the big issues with RTGs is planetary protection. An RTG is warm and would melt the ice. The concern is that this could then create a water pocket that Earth bacteria could grow in. I don't think anybody has done any serious analysis of this from a planetary protection standpoint. It will likely prove to be a contentious issue.
It might be possible to rig a way for an RTG to dump its heat directionally, away from the surface. Maybe simply thermally isolating it from the body of the lander and putting in reflectors to point waste heat up and out into the vacuum would suffice. But it's sure not a proven technology yet.
I'm more concerned about where the extra billion is going to come from... It would be very bad if EC was axed because it became a Christmas tree.
Poking around on Berger's Twitter feed reminds me how much I hate Twitter.
But I picked up a few things. Apparently JPL is looking at a bunch of different lander iterations (nine?) with a notional cost of $700 million to $1 billion. And they're also considering using SLS with a VEEGA trajectory for a 4.7 year transit time.
Now considering that you can probably take their cost estimates and at least double them, that means an additional $1.4 to $2 billion for the mission. And the transit time goes down as well.
In other words, it starts to look like somebody is contemplating gold-plating the mission.
I'm surprised they're willing to risk losing the mission by trying to add to it. I would have thought they'd have learned a lesson about overly expensive Europa missions in their past decades of attempts.
ESA will allow scientists to propose additions to to the Clipper mission as part of the M5 call
Don't forget that congress added $15m to the planetary budget to study Europa landers. Dad may be encouraging the sports car.
Poking around on Berger's Twitter feed reminds me how much I hate Twitter.
But I picked up a few things. Apparently JPL is looking at a bunch of different lander iterations (nine?) with a notional cost of $700 million to $1 billion. And they're also considering using SLS with a VEEGA trajectory for a 4.7 year transit time.
Now considering that you can probably take their cost estimates and at least double them, that means an additional $1.4 to $2 billion for the mission. And the transit time goes down as well.
In other words, it starts to look like somebody is contemplating gold-plating the mission. Which is not all that surprising considering what I wrote above--it's in JPL's nature to do this. It is also the requirement of NASA HQ to reign them in. But unfortunately, this kind of activity is what makes OMB nervous and could kill the program outright. OMB does not want to approve a program that grows and grows and becomes impossible to cancel.
It's like having your dad offer to buy you a car, but instead of a nice, safe affordable car you start looking at high-end sports cars. The result is you make the old man unsure about the idea and your ability to drive any car responsibly and he rescinds the offer.
And a notional picture of the lander being discussed at JPL:
https://twitter.com/chronsciguy/status/596421392469372928
But I picked up a few things. Apparently JPL is looking at a bunch of different lander iterations (nine?) with a notional cost of $700 million to $1 billion. And they're also considering using SLS with a VEEGA trajectory for a 4.7 year transit time.
In other words, it starts to look like somebody is contemplating gold-plating the mission. Which is not all that surprising considering what I wrote above--it's in JPL's nature to do this. It is also the requirement of NASA HQ to reign them in. But unfortunately, this kind of activity is what makes OMB nervous and could kill the program outright. OMB does not want to approve a program that grows and grows and becomes impossible to cancel.
It's like having your dad offer to buy you a car, but instead of a nice, safe affordable car you start looking at high-end sports cars. The result is you make the old man unsure about the idea and your ability to drive any car responsibly and he rescinds the offer.
And a notional picture of the lander being discussed at JPL:
https://twitter.com/chronsciguy/status/596421392469372928
Several things I notice about that picture:
1) Although just my POV, but it looks like suspiciously round and Huygens-like for a body plan. I suspect ESA.
2) They're discussing a drilling option.
3) They're discussing some kind of spider-like-rover option, possibly in conjunction with drilling.
However, considering we can see "2030" clearly drawn on the board, I think we can safely guess this actually isn't part of the Europa Clipper design. I'm pretty sure a lander (rover?) is being discussed for a separate follow-on mission. Still cool and exciting, and makes me wish I could be in that meeting.
I have my suspicions that nobody has done much thinking about the planetary protection requirements for a Europa lander. That could really trip them up.
Isn't the ice crust like 20km thick (or 1km even over the "lakes" that might be in the crust)?
Sure there may be some surface/ocean interaction but radiation would kill "bugs" quickly so they would pretty much have to drop right into a hole leading into the ocean... seems incredibly implausible.
(leaving out the whole question of whether human-commensal/spacecraft-facility bugs would be well adapted for a hydrothermal vent or quasi Antarctic subglacial lake environment...)
Just a few random thoughts...
I'm fairly sure that ESA remembers the NASA ExoMars episode. Will they be eager to jump in on a lander for Europa?
Just a few random thoughts...One thing is to go as equal partners of an ESA led mission. Another is to be given a hike in a flagship mission. The above mentioned Cassini/Huygens is a good example. But the correct question might be about JUICE mission, and how will this impact. Even if ESA wanted to do the lander, they will already be putting most of their L-Mission money on JUICE. It would seem that the budget would end up too Jovian biased. On the other hand, if NASA were to supply an extra Atlas V 551 (or Falcon Heavy) for JUICE, ESA might do two landers for the price of one. But that's all wishful thinking. Look how many issues were to get Euro 80M for ExoMars. And a lander might well be 20X that.
I'm fairly sure that ESA remembers the NASA ExoMars episode. Will they be eager to jump in on a lander for Europa?
And a notional picture of the lander being discussed at JPL:
https://twitter.com/chronsciguy/status/596421392469372928
You can't really for-sure sterilize stuff anyway and it only takes one bacterium to start a population.
Here's a transformed crop of the flip-chart in the photograph linked to above:
You can't really for-sure sterilize stuff anyway and it only takes one bacterium to start a population.
As I understand it, the planetary protection people accept that there is nothing that can be considered complete sterilization. Nevertheless, there is a big difference between sterilized and not sterilized, which is why you're supposed to wash your hands after using the loo.
1-Yeah. I am just uncertain that the analogy to human sanitation/infection actually holds. Humans are relatively robust since we have an immune system and a certain natural bacterial "population" etc...
2-I still think it's ultimately irrelevant since the surface environment is deadly enough already ...
I'm skeptical about the report. JPL concluded that we needed Clipper to scout for interesting while safe sites for a lander. It would also be hard to define build and test a large walking rover with a heat probe by the mid-2020s.
Jpl/NASA may be considering an enhanced Clipper but I'd be shocked if it is with the rover on the flip chart
I'm reminded of what Alan Stern told the Solar Probe advocates back when he was AA: "do you want 80 percent of something, or 100 percent of nothing?"While I concur, if there's one division that deserves a bit of love is the heliophysics guys. On the other hand, they got a Delta IV Heavy + Star-48B. So, they are getting somethings extra.
I'm skeptical about the report. JPL concluded that we needed Clipper to scout for interesting while safe sites for a lander. It would also be hard to define build and test a large walking rover with a heat probe by the mid-2020s.
Jpl/NASA may be considering an enhanced Clipper but I'd be shocked if it is with the rover on the flip chart
All of this makes me uneasy. At a time when we should see JPL narrowing the design toward something that can be built and be affordable, we see evidence that they are holding a jam session to come up with new and exciting (and expensive) ideas. That may be happening because they think they've got an in now, that because they have a powerful sponsor they can start proposing things regardless of the costs.
I'm reminded of what Alan Stern told the Solar Probe advocates back when he was AA: "do you want 80 percent of something, or 100 percent of nothing?"
1-It's an analogy. It's not meant to be perfect. (And you still wash your hands, right?) My point was that the planetary protection people accept that there is no such thing as completely 100% contamination free. Nevertheless, they believe that there is a big difference between sterilized and unsterilized.
2-Take it up with a planetary protection expert. I'm sure you can convince them.
I wouldn't worry about it until you find evidence that _management_ is actually pushing inclusion of these ideas in the current clipper plans. After all, mission planners' jobs is to come up with creative mission ideas, so they are just doing their job and telling a reporter who fuzzes out a bit on when or even if those ideas might ever be implemented.
[Culberson] supported the soft lander. He went so far as to say, “I will not sign a bill unless it has money for a lander.”
And a notional picture of the lander being discussed at JPL:
https://twitter.com/chronsciguy/status/596421392469372928
Here's a transformed crop of the flip-chart in the photograph linked to above:
ESA will allow scientists to propose additions to to the Clipper mission as part of the M5 callIf ESA goes about it this way then what are the realistic chances that there will be an ESA contribution? Any proposals involving the Europa mission would have to compete against all the other proposals. This potentially includes some pretty attractive runners up to the M4 call. Also the budget limits were pretty brutal for the latest call and eliminated all the beyond Earth missions. A lander even with a free ride is still going to be an expensive proposal.
Anyone know if the Congress mandated the SLS as the EC launch vehicle? :-\
I'm also skeptical that the Planetary Decadal Survey would want to throw out their list of New Frontiers missions and replace them with this, or to add a lander to the Europa mission that they wanted descoped so it would fit in a reasonable budget, or to restrict the destination of some Discovery-class missions to ocean moons.
My plane won't land until 3 hours after the press conference. Does NASA archive these anywhere?NASA TV usually rebroadcasts press conferences in the evening.
My plane won't land until 3 hours after the press conference. Does NASA archive these anywhere?NASA TV usually rebroadcasts press conferences in the evening.
Also the archive will probably be at:
http://www.space-multimedia.nl.eu.org/index.php?option=com_frontpage&Itemid=1
They're still somewhat mass and power limited even with an SLS. But I wonder if it is possible to put some kind of lasercom experiment onboard. Laser pointing from Jupiter is apparently really difficult, and we haven't even done it at Mars yet, but maybe it's possible to take a step toward developing the technology.
Would be worthwhile to test, and if it worked at Jupiter it certainly would be a boon with the heavy amount of data the probe has to deal with.
Would be worthwhile to test, and if it worked at Jupiter it certainly would be a boon with the heavy amount of data the probe has to deal with.
I don't know if there is a realistic test that they could do. It may require a level of effort that is too high for this mission. And Jupiter just may not be doable for lasercom. I'm just thinking out loud that it would be nice to see some kind of effort to develop the technology because missions to the outer planets are so few and far between.
We will see more development of lasercom at Mars. NASA will be looking for every opportunity to get that technology out there.
Maybe as a secondary payload so that there is minimal complication to EC's overall design...ESA is planning to use the deep-space laser communications terminal onboard the proposed AIM mission also for scientific purposes, i.e. as a laser altimeter once in orbit (therefore scrapping the separate laser altimeter once proposed for it).
I've worked with both Phil Christensen and Zibi Turtle and think highly of them.
It has something to do with pointing requirements, I think.
As for "adding... distractions," I wish that was true, but if you've read the recent articles about this mission it is clear that JPL is trying to make it considerably bigger and more expensive. Anybody who thinks that a lander could be added for only a billion dollars has forgotten that this is JPL.
There was a question about lasercom--it won't be carried. NASA needs to demo it at Mars first.
Now the next question I'm curious about is on EIS: are the wide and narrow cameras analogous to the previously imagined topographical and reconnaissance cameras?I think so. The press release states global coverage at 50 m, which I believe was a bit better than the stand in topo imager, and the hi resolution instrument will be able to do up to 500 times better.
Now the next question I'm curious about is on EIS: are the wide and narrow cameras analogous to the previously imagined topographical and reconnaissance cameras?I think so. The press release states global coverage at 50 m, which I believe was a bit better than the stand in topo imager, and the hi resolution instrument will be able to do up to 500 times better.
Makes sense to have these in the same instrument so they can share electronics and software.
Will be interesting to learn things like color bands and whether there's any stereo capability.
What's the technology behind the ice penetrating radar? What's the band, the scanning mode, etc.? I'm asking because the SAOCOM-1B and SAOCOM-CS are going to investigate a very interesting technology that enables direct ice tomography in a single pass.
Very exciting to see the instrument announcement; I do hope there are more details soon from each team, now that the selection has taken place, though it is rather a long time to even the more optimistic launch date.
With the bandwidth constraints, and no feasible option of laser communication, is there anything else on the horizon that might improve the compression beyond ICER-type rates, LDPC coding or similar? It looked like the radar had on-instrument compression, would anything be suitable (mass, power) for the EIS that could not be done by the RAD750? An FPGA or an ASIC with some added flexibility in an FPGA block?
It still looks luxuriant compared to S-Band mission, just tend to get over-enthused when a Europa mission finally start to take some sort of shape.
Wow! I don't have the URL nor link, but I read an article that NASA project developers have suggested that the upcoming heavy-lift SLS meant to send humans back to Lunar-orbit could also carry a future (large) unmanned spacecraft to the surface (and subsurface) of Europa.The SLS system would reduce the travel time from 4+ years (as I recall) to around 2 years. However, this assumes that the SLS system is still viable in the mid-2020s given that the manned missions to justify it before then largely aren't funded.
It's refreshing to read that some NASA can compliment other NASA projects without triggering
a competing struggle for taxpayer money.
Wow! I don't have the URL nor link, but I read an article that NASA project developers have suggested that the upcoming heavy-lift SLS meant to send humans back to Lunar-orbit could also carry a future (large) unmanned spacecraft to the surface (and subsurface) of Europa.The SLS system would reduce the travel time from 4+ years (as I recall) to around 2 years. However, this assumes that the SLS system is still viable in the mid-2020s given that the manned missions to justify it before then largely aren't funded.
It's refreshing to read that some NASA can compliment other NASA projects without triggering
a competing struggle for taxpayer money.
Wow! I don't have the URL nor link, but I read an article that NASA project developers have suggested that the upcoming heavy-lift SLS meant to send humans back to Lunar-orbit could also carry a future (large) unmanned spacecraft to the surface (and subsurface) of Europa.
It's refreshing to read that some NASA projects can compliment other NASA projects without triggering
a competing struggle for taxpayer money.
Although a gravity science instrument wasn't announced, considering there will be a large HGA as part of the spacecraft, any guesses as to whether some gravity data could still be gained from the 'Clipper?I emailed Curt Niebur, NASA outer planets program director (or a similar title), about this. He said that gravity studies will be part of the mission. Since then, I seem to remember that NASA issued a statement about forming a gravity science team for the mission, but I can't find it.
Although a gravity science instrument wasn't announced, considering there will be a large HGA as part of the spacecraft, any guesses as to whether some gravity data could still be gained from the 'Clipper?I emailed Curt Niebur, NASA outer planets program director (or a similar title), about this. He said that gravity studies will be part of the mission. Since then, I seem to remember that NASA issued a statement about forming a gravity science team for the mission, but I can't find it.
During the flybys, the high gain antenna will be pointed away from Earth. In the last detailed briefing about the spacecraft design that I saw, there were 2 or 3, as I recall, medium gain antennas that would be used for these studies.
I also wouldn't be surprised to hear that one or more the Cubesat concept studies for this mission involves gravity studies, either with direct Earth tracking or by spacecraft to spacecraft tracking.
Is there any room on it to carry a laser communication payload. Thought this would be the ideal opportunity to try this out at Jupiter distance.
Came across the link to the gravity science working group (also radiation working group)
http://science.nasa.gov/media/medialibrary/2015/07/07/GandRWGs4EST.pdf
I wrote about Europa Clipper in the Discovery proposals thread, and was asked to move the discussion over here. To recap:
"Europa Clipper could be done more cheaply...
SNIP
I'm not sure what Europa Clipper is supposed to cost...
OK, good catch. Europa Clipper is supposed to cost $2 billion. You can add the cost of nuclear rating SLS to that.
Some folks seem to be worried about a requirement for imaging to support a lander. We successfully landed 3 times on Mars based on Viking imagery that was no better than 8m per pixel. Most was 150-300m per pixel. 8m per pixel needs a low altitude flyby, not an expensive camera. I personally think it is foolish to impose expensive requirements on current missions for future landers that may never fly.Pathfinder and the Vikings main and pretty much only criteria for landing site selection was safety. The Viking orbiter's cameras were not high enough resolution to see hazards which could doom the landers. They could see larger features such as craters, groves, and scarps but a hazard as small as 22 cm could make the Viking landing fail. Earth based radar was used extensively to gauge the smoothness of the terrain for all three landings. The reflected signal would be more diffused if it hit rough ground. The radar trick will not work at Europa due to the distance. Without high resolution imagery not only does the landing risk increase due to hazards but the potential science of a lander mission decreases. Interesting targets can be missed simply because they didn't show up in the imagery. The risk of a boring landing site increases as well.
OK, good catch. Europa Clipper is supposed to cost $2 billion. You can add the cost of nuclear rating SLS to that.
Europa Clipper is going to be solar powered, so no nuclear rating needed.
Pathfinder and the Vikings main and pretty much only criteria for landing site selection was safety. The Viking orbiter's cameras were not high enough resolution to see hazards which could doom the landers. They could see larger features such as craters, groves, and scarps but a hazard as small as 22 cm could make the Viking landing fail. Earth based radar was used extensively to gauge the smoothness of the terrain for all three landings. The reflected signal would be more diffused if it hit rough ground. The radar trick will not work at Europa due to the distance. Without high resolution imagery not only does the landing risk increase due to hazards but the potential science of a lander mission decreases. Interesting targets can be missed simply because they didn't show up in the imagery. The risk of a boring landing site increases as well.
I wrote about Europa Clipper in the Discovery proposals thread, and was asked to move the discussion over here.
"Europa Clipper could be done more cheaply. The current data for Europa is crap. When the antenna on the Galileo orbiter failed, 99% of the data return was lost. Europa today is mapped at 1-2 km/ pixel, which is weather satellite resolution. Studies of the surface of the earth use at least 200 m/pixel. Imaging sensors, particularly in the infrared, have improved enormously since the early 1980s when Galileo was built. Big improvements won't be hard.
The basics are a camera for surface morphology, an imaging infrared spectrometer for a compositional map, and a uv spectrometer to keep an eye on the magnetosphere and look at the composition of plumes from Europa and Io. Instruments similar to the New Horizons Pluto probe should be perfectly adequate. The main thing that needs to be added is radiation shielding, which I am assuming is cheap but heavy. You might opt for a larger antenna. Fill the rest of the mass budget with fuel, which gives you options for an interesting tour. That's it. It might be doable for a little more than the cost of New Horizons, or $900 milllion, which makes it worth two Discovery missions. Given all the interesting things to see in the Jupiter system, it is probably a good option at that price."
Some folks seem to be worried about a requirement for imaging to support a lander. We successfully landed 3 times on Mars based on Viking imagery that was no better than 8m per pixel. Most was 150-300m per pixel. 8m per pixel needs a low altitude flyby, not an expensive camera. I personally think it is foolish to impose expensive requirements on current missions for future landers that may never fly.
Other folks claim that if we are going all the way to Europa, a small mission isn't worth the trouble. I'm sure similar arguments were made against the New Horizons probe to Pluto back in the day. NASA allegedly studied $1 billion missions, and decided they weren't worth the trouble. Isn't it interesting how none of those studies have ever been made public?
I'm not sure what Europa Clipper is supposed to cost, but the current proposal looks awfully similar to the $3.6 billion mission proposed to the decadal survey. Oh sure, it doesn't orbit Europa, but that mostly saves fuel and radiation hardening requirements. Oh yes, they are going to solar power it, but that option was also considered for the decadal survey mission. If they stay nuclear, they only need four RTGs rather then five, which probably implies a cost of around $2.8 billion.
The basics are a camera for surface morphology, an imaging infrared spectrometer for a compositional map, and a uv spectrometer to keep an eye on the magnetosphere and look at the composition of plumes from Europa and Io. Instruments similar to the New Horizons Pluto probe should be perfectly adequate. The main thing that needs to be added is radiation shielding, which I am assuming is cheap but heavy. You might opt for a larger antenna. Fill the rest of the mass budget with fuel, which gives you options for an interesting tour. That's it. It might be doable for a little more than the cost of New Horizons, or $900 milllion, which makes it worth two Discovery missions. Given all the interesting things to see in the Jupiter system, it is probably a good option at that price."
If you could dissect the mission into a specific categories like: imaging, radar, composition, fields & particles, you might be able to make several Discovery-sized missions that focus on each aspect.Some folks seem to be worried about a requirement for imaging to support a lander. We successfully landed 3 times on Mars based on Viking imagery that was no better than 8m per pixel.
OPAG meeting next week:I'm hoping to listen in but there's no information on web access for the meeting.
http://www.lpi.usra.edu/opag/meetings/aug2015/agenda.pdf
The cheaper cameras, like LORRI on New Horizons, have as much resolution as the best cameras on Cassini. On a close pass Cassini recently achieved 2.8m / pixel on one of the Saturn moons. The best camera, Hirise, is somewhere between two and a half to five times better than that. At Jupiter, all the imagers will be limited by the ability of the telecommunications system to transmit data.The sensor called Europa Imaging System has been selected for the Europa mission. Details are tricky to come by since it is still very early in development. However based on the abstract submitted to the AGU's 2015 fall meeting its Narrow Angle Camera will have a spatial resolution of 0.5m at 50km. You have mentioned LORRI. How does it compare? Fortunately it is pretty easy to figure out the spatial resolution of a sensor if you know the altitude and angular resolution. LORRI's IFOV is 5 μrad so we can compare New Horizon's LORRI's spatial resolution in the same scenario to EIS. The result is pretty interesting. LORRI would have a spatial resolution of 0.25 meters at 50km. If EIS is more expensive than LORRI it is not because of a superior spatial resolution. Therefore downgrading the resolution is unlikely to be a significant savings as other things than spatial resolution are driving the cost. Especially when the loss in science and utility for future missions are factored in.
If they are not willing to give anything up then they will blow out way over $3 billion. I did a bit of digging into the archives and it seems like Cassini came in at three times the initial cost, so the history with large outer planets probes is not good.What's your source for the $3B claim? NASA's mission cost has been estimated using multiple methods.
As for Cassini's costs, have you adjusted for inflation? There's been a bit over the last 25 years.
I just double checked it and think I am still correct. Lorri's Angular Resolution = 5 μrad = 0.000286 degrees. The equation is 2(TAN(1/2 Angular Resolution) * Altitude) = Spatial Resolution. So 2(TAN(0.000143o) * 50,000m) = 0.25 meters. To double check that I ran through the numbers on HiRISE because I know what the answer is. Its Angular Resolution is 1 μrad or 5.729E-5 o, orbital height 300km, and Spatial Resolution 30cm. Which is exactly what I get from that equation.
As for Cassini's costs, have you adjusted for inflation? There's been a bit over the last 25 years.
So, adjusting to 2015 $.
Cassini was initially promised at $1.55 billion as part of a two spacecraft deal. The other spacecraft, called CRAF, was canceled. If they had just ordered one it would have been priced at $2billion. It was finally delivered at $5.1 billion, which is about 3 times the initial cost.
Galileo was initially promised for a 1982 launch at $1.5 billion, and was delivered at $2.5 billion and launched in 1989. That project was very messed up by the space shuttle problems.
Voyager cost $2 billion for two spacecraft.
@notsorandom... I think you have misplaced the decimal point. LORRI's resolution would come out to 2.5m, not .25. My point in comparing the cameras is that the economical instruments aren't bad. Going for the very best can really drive up the cost, which I think is what happened on Cassini and in the Jupiter Europa orbiter design study. There isn't much information on what has been chosen for Europa Clipper, but the camera selection could give a hint as to the way things are going.
Cassini was initially promised at $1.55 billion as part of a two spacecraft deal. It was finally delivered at $5.1 billion, which is about 3 times the initial cost.You need to be very careful about what is included in those initial costs. Were operations included? At ~$70M per year for almost 18 years that adds up. Instruments? Launch? NASA overhead? Did that cost cover the European contribution?
To give an example. The InSight mission's quoted cost is ~$425M. But that doesn't include NASA's general overhead costs, the launch, or the cost of the contributed instruments.
Generally, the Cassini mission costs out there today bundle all those costs and then inflates them to current dollars. A dollar spent at the beginning of the project inflates to almost 2X today at 3% annual inflation.
Cassini was initially promised at $1.55 billion as part of a two spacecraft deal. It was finally delivered at $5.1 billion, which is about 3 times the initial cost.You need to be very careful about what is included in those initial costs. Were operations included? At ~$70M per year for almost 18 years that adds up. Instruments? Launch? NASA overhead? Did that cost cover the European contribution?
To give an example. The InSight mission's quoted cost is ~$425M. But that doesn't include NASA's general overhead costs, the launch, or the cost of the contributed instruments.
Generally, the Cassini mission costs out there today bundle all those costs and then inflates them to current dollars. A dollar spent at the beginning of the project inflates to almost 2X today at 3% annual inflation.
And I would argue science wise they've more than got their money's worth out of Cassini.
You need to be very careful about what is included in those initial costs. Were operations included? At ~$70M per year for almost 18 years that adds up. Instruments? Launch? NASA overhead? Did that cost cover the European contribution?
To give an example. The InSight mission's quoted cost is ~$425M. But that doesn't include NASA's general overhead costs, the launch, or the cost of the contributed instruments.
Generally, the Cassini mission costs out there today bundle all those costs and then inflates them to current dollars. A dollar spent at the beginning of the project inflates to almost 2X today at 3% annual inflation.
Also, when you look back to Galileo, it was granted two extended missions and returned decent science (with what the antenna limitations could allow). Furthermore, it did all that with early '80s technology including primitive CCDs coupled to a Voyager cam and a VHS-esque magnetic tape for memory (which got partly crippled en route to Jupiter, becoming the second Achilles' heel for the mission). Between what Galileo managed and what the Cassini continues to reward us with, I have high hopes for what a genuinely 21st century machine could achieve even against the poisonous radiation of Jupiter.
A flyby/orbiter like 'Clipper could easily get at least one mission extension. If designed properly, I'd even willingly bet the first Pathfinder-class lander could likewise last an extra few months (though I wouldn't go so far to wager a full [Earth] year for its longevity). Indeed, the real trick would be making a machine that can endure Jupiter's radiation for months-on-end much like a Venus lander needs to endure that planet's extreme heat; an orbiter around either planet is relatively easy.
But doesn't the electronics on space missions always lag at least ten years behind that on Earth because
I know that there are efforts to design more radiation hardened electronics, but I think they lag behind the latest electronics in size and speed. Anyone here have more solid information?
The presentations from the recent OPAG meeting are on their website now. A lot about the Europa mission (obviously) but a fair amount of other interesting information as well (RPS anyone? :D ). Very handy for those of us who couldn't quite make the times for the real thing.
http://www.lpi.usra.edu/opag/meetings/aug2015/presentations/
http://www.scientificamerican.com/article/within-nasa-a-plutonium-power-struggle/
New article on the subject. I have only read a few paragraphs, but I disagree with the premise. Things are looking better on the Pu-238 production issue than they have in a long time. DoE needs some more time (and possibly a bit more money), but stuff is finally working and the logjam is broken. And citing the Ohio politicians is an indication that the reporter may not understand what is really going on (they were making a political claim, not one based in reality).
http://www.scientificamerican.com/article/within-nasa-a-plutonium-power-struggle/
New article on the subject. I have only read a few paragraphs, but I disagree with the premise. Things are looking better on the Pu-238 production issue than they have in a long time. DoE needs some more time (and possibly a bit more money), but stuff is finally working and the logjam is broken. And citing the Ohio politicians is an indication that the reporter may not understand what is really going on (they were making a political claim, not one based in reality).
Not surprised it's a slow process, but encouraging to hear your own news about production Blackstar.
Juno obviously demonstrates that we're at the point of solar power being useful at Jupiter, and that seems a reasonable benchmark. Considering the heavy amount of science Saturn, the Ice Giants, and Kuiper Belt will demand, giving them the plutonium seems fair to properly fulfill missions. I'd hate to see the size a solar array at Pluto would require (or better yet Eris and Sedna). I wager your counterargument, Blackstar, would be that scientists interested in the solar system depths need convincing arguments to warrant the limited plutonium, which is limited by current technology to put payloads into orbit (especially at Neptune and beyond).
Hopefully they set guidelines. Letting Mars hog everything is a bit of a travesty with a resource so scarce.
I wager your counterargument, Blackstar, would be that scientists interested in the solar system depths need convincing arguments to warrant the limited plutonium, which is limited by current technology to put payloads into orbit (especially at Neptune and beyond).
Looking to the 2020s, Pu-238 will be available but it looks like it may be constrained if I read slides right. We are unlikely to see flagship missions each with 3-4 MMRTGs as has been proposed in the past. Further out than Jupiter, we may see small spacecraft with constrained data rates that have just a single or perhaps two MMRTGs. New Horizons-class instead of Cassini- or Europa Clipper-class.
There is a current problem with manufacturing useful pellets. Because of this, there wasn't the opportunity to offer an MMRTG for the current Discovery competition. I know of one mission that wasn't proposed because of this, and there are probably more.
Looking to the 2020s, Pu-238 will be available but it looks like it may be constrained if I read slides right. We are unlikely to see flagship missions each with 3-4 MMRTGs as has been proposed in the past. Further out than Jupiter, we may see small spacecraft with constrained data rates that have just a single or perhaps two MMRTGs. New Horizons-class instead of Cassini- or Europa Clipper-class.
re: NASA Struggles over Deep-Space Plutonium Power
http://www.scientificamerican.com/article/within-nasa-a-plutonium-power-struggle/ (http://www.scientificamerican.com/article/within-nasa-a-plutonium-power-struggle/)
by Lee Billings and the commentary here in this thread, particularly Blackstar's:
Does the article author read NSF?
If he did, then he would know that his article premise is wrong! :)
Seriously, I've learned a great deal from the NSF articles and the forum here. The level of knowledge and thought-through analysis based on that collective knowledge here is astounding.
But even I could be full of $hit, right?
But even I could be full of $hit, right?
If this is the case, then you are in good company these days and we are lessened thereby. I value your comments here, as they have increased my knowledge exponentially over the years.
Keep up the good etc...
(Threadjack complete, returning you to your regularly scheduled discussion.)
ESA is going to use Americium because they have it available, but based upon long American experience, I think they will find it a lot more expensive and difficult to develop than they expect. That has always been the case with these materials.Actually, the program is moving at a somewhat faster pace than the original planning, and yes a lot of material available.
Actually, the program is moving at a somewhat faster pace than the original planning,
The longer half life of Am-241 may not matter too much in thermocouple based RTGs. Those break down faster than the Pu-238 does.ESA is going to use Americium because they have it available, but based upon long American experience, I think they will find it a lot more expensive and difficult to develop than they expect. That has always been the case with these materials.Actually, the program is moving at a somewhat faster pace than the original planning, and yes a lot of material available.
Someone at Quora had put this together :
http://www.quora.com/How-does-ESA-plan-to-power-its-future-space-missions-if-they-dont-want-to-use-RTGs
Polonium-210 ? Russians did that a long time ago. They also operated remote lighthouses (http://englishrussia.com/2009/01/06/abandoned-russian-polar-nuclear-lighthouses/) on Strontium-90 powered RTGs
The longer half life of Am-241 may not matter too much in thermocouple based RTGs. Those break down faster than the Pu-238 does.Yep - but if you look at the details of the program, you'll find stirlings and something novel : thermo-acoustic generators (http://pamir.sal.lv/2014/cd/container/B.7.02=DidierA_Pamir14.pdf) being worked on too.
I don't doubt that as with every engineering project, things will be harder and more difficult. I just pointed out though that so far the program has been going smoother than expected, and Europe has its own indigenous nuclear industry expertise, that in some respects is ahead of US - for terrestrial applications. Not to mention, Russian experts with as long experience are sometimes available for cheap ..
As for the Russians, well, that's an interesting issue. The Russians provided Pu-238 heat sources to China for their CE-3 mission. And they are planning to use them for their Luna-25 mission (although I am not sure if they are simply going to use them as heaters, or if they are going to generate electricity and then run heaters from them). I cannot remember if they had anything on their Phobos-Grunt spacecraft. But this implies that Russia is back doing Pu-238 RTG work (although they may not be making Pu-238).
On the other hand, I disagree with your contention that the shortage of plutonium had nothing to do with NASA passing over concepts like the Jupiter Europa Orbiter. You say the issue was a shortage of another scarce resource -- money. Well, yes. As everyone reading this probably knows, a shortage of money tends to be the explanation for almost every inadequacy in spaceflight. But let's not act as if the shortages of money and shortages of plutonium have no relation. Producing and using plutonium for a space mission is monetarily very expensive, for a host of complicated and multidimensional reasons. So, was there enough plutonium available for something like JEO? It seems the answer is yes, just barely. But if such a mission is going to wipe out essentially your whole stockpile, you're certainly going to factor in the cost of obtaining more into your decision-making about whether to pursue that mission or not, right? These are not unrelated issues kept entirely separate from each other in watertight compartments, and anyone telling you otherwise is trying to sell you something. I think Van covered this pretty well in his earlier comment, and he's spot on about why Casey has some crucial quotes in the piece -- Casey can say things that others within or closely affiliated with NASA cannot. He can speak plainly with much less risk of reprisal.
The less-than-ideal relative quality of Russian Pu-238 was something two separate sources independently alluded to. I didn't follow up for much more detail but figured it was worth mentioning. Maybe that was a mistake.
Wasn't there also a Europa "billion dollar box" study too?I thought so, too, but haven't found it.
I'm still trying to figure out if there was a 2007 Europa "billion dollar box" study. I went through some old files and found this presentation. Some of the latter slides refer to a 2007 Europa study following a 2006 study. But I don't know if I have the 2007 study anywhere.
I'll have to keep looking.
I'm still trying to figure out if there was a 2007 Europa "billion dollar box" study. I went through some old files and found this presentation. Some of the latter slides refer to a 2007 Europa study following a 2006 study. But I don't know if I have the 2007 study anywhere.
I'll have to keep looking.
Circa 2007, Laplace was also in early concept phase, and initially they pegged some costs pretty low too, like around $1BThe last budget quote I heard for JUICE was around 1B Euros, so that's still in line. Under ESA accounting practices, that includes the launch but not the instrument costs or the cost of the science teams for the instruments. (NASA does it the other way around.) My guess is that the instruments cost more than the launch. NASA is contributing $100M to pay for the UV spectrometer and parts of two other instruments.
Indubitably, a bunch of optimists
Now I have heard some criticism of the studies because of that. I believe the gist of the criticism was that the studies said "you have to do X, Y, and Z and figure out if you can do it for $1 billion." Instead, they think that the studies should have started from a different premise, "What can you do for $1 billion?" That would provide different options.Since I think that I'm the unnamed somebody, I'll reply. As way of background, I ran product and product line definition teams for a prominent high tech company. The highest development cost for one of the products was ~$800M, but most were much cheaper. Revenue impacts for our decisions were in the $10Bs.
The point isn't simply to go somewhere and say that you've gone there, it is to go there and do something useful.
Since I think that I'm the unnamed somebody, I'll reply.
To take another case, I look at the Saturn probe mission that was proposed in the Decadal Survey. To fit within the cost cap, the proposed mission appears to be the bare minimum that can be justified as scientifically credible. The instrument suite on the probe is bare bones -- compare it to what the Pioneer Venus and Galileo probes carried or what has previously been proposed in studies of Saturn atmospheric probes. There is no microwave radiometer instrument on the back shell for deep atmosphere composition and structure measurements (this has been proposed in previous studies). The carrier has no instruments to characterize the state of the atmosphere or the entry site.
I'm not arguing that this wouldn't be a good expenditure of $1B -- it did make the Decadal New Frontiers list. But this was a case where the proposal team appears to have looked to see what could be done in within a fixed cost cap and didn't look for the scientific sweet spot.
I'm hoping that the next Decadal will again return to the question of whether there is a credible New Frontiers class Enceladus and/or Titan mission. Three Discovery proposal teams (JET, TiME, ELF) have argued that there are credible missions for half the cost. Perhaps they are optimistic, but would doubling the budget make them credible?
The science teams proposing the Saturn-system Discovery missions have solid credentials. And all three had either APL or JPL as their implementation partners. As you pointed out in a previous post, these proposals are too expensive to prepare to back one that obviously won't fit in a Discovery box. Perhaps the proposers were off by 50% in their cost estimates. That would still put them in a New Frontiers box.
And credible to whom?
But part of the problem was that they could not limit their science requirements for Titan or Enceladus, and so they ended up with bigger missions than they could afford. The Io mission had much more limited science objectives and could fit in a NF box. So it was not simply a matter of having good studies going into the DS, I don't think they could agree on an affordable minimum set of requirements for Titan or Enceladus. If they had, they might have picked that instead of the Io mission. But I think they just spread themselves too thin.
As we all know, science and technology march on. We know a lot more about Enceladus today than in 2010, so it should be easier to define science requirements for a future Enceladus NF mission. But that community will also need to focus and prioritize ahead of time. They cannot chase all the balls.
The science teams proposing the Saturn-system Discovery missions have solid credentials.
Another article this time from Space News on Pu-238 supply and future missions. http://spacenews.us10.list-manage.com/track/click?u=75806695e6f086874391c9624&id=93974ecb96&e=fa0fd80c45
The problem for the satellites panel is that they have a bunch of really interesting places to go to, and they cannot get all of them because that wouldn't be fair to the other panels. So they had to pick.
Is that good for planetary science as a whole? If there is more interesting stuff in the satellites it seems to me they should get more missions...
That's kind of an odd way to put it. The missions under consideration, TiME and CHOPPER, would have used ASRGs. We don't know why NASA selected InSight instead of one of those missions (my guess is a-cost, and b-NASA wanted to do a Mars mission), but if they had selected one of them, NASA would have had to continue funding the ASRG.If I remember correctly, the ASRG program was facing some serious development problems, something like a year or two behind and $100M over budget. (Anyone have a better memory or old article filing system?) Selecting either of those two missions might well have meant a serious increase in mission cost to cover the ASRG and a slip in the mission launch date. NASA has said that the ASRG problems was not a factor in deciding to select InSight; maybe there were issues such as seriously greater development risk with TiME and CHopper. We'll never know.
job of the Decadal Survey is to recommend a balanced portfolio of missions. Thus, no matter how many compelling missions any one panel can come up with, they only get to recommend one or two to the final list(s). It enforces some discipline on the panelists - pick the very best.GClark got it exactly right. The outer planets panel got the Saturn probe, small bodies got a comet sample return and a Trojan asteroid review, and inner planets got a lunar sample return and Venus lander. Since it appears there will be only one selection during the period of the current Decadal, adding more candidates doesn't really help. If there had been two selections then an Io mission and a lunar network mission would have been added to the list.
The problem for the satellites panel is that they have a bunch of really interesting places to go to, and they cannot get all of them because that wouldn't be fair to the other panels. So they had to pick.
Is that good for planetary science as a whole? If there is more interesting stuff in the satellites it seems to me they should get more missions...
The outer planets panel got the Saturn probe, small bodies got a comet sample return and a Trojan asteroid review, and inner planets got a lunar sample return and Venus lander. Since it appears there will be only one selection during the period of the current Decadal, adding more candidates doesn't really help. If there had been two selections then an Io mission and a lunar network mission would have been added to the list.
If I remember correctly, the ASRG program was facing some serious development problems, something like a year or two behind and $100M over budget. (Anyone have a better memory or old article filing system?) Selecting either of those two missions might well have meant a serious increase in mission cost to cover the ASRG and a slip in the mission launch date. NASA has said that the ASRG problems was not a factor in deciding to select InSight; maybe there were issues such as seriously greater development risk with TiME and CHopper. We'll never know.
A question for anyone knowledgeable about the ESA M5 call. As I recall, the M5 mission is expected to launch in the late 2020s (M4 in the mid-2020s, I believe). This is several years later than the most pessimistic NASA Europa mission launch that I've seen. How are these two schedules reconciled?
A question for anyone knowledgeable about the ESA M5 call. As I recall, the M5 mission is expected to launch in the late 2020s (M4 in the mid-2020s, I believe). This is several years later than the most pessimistic NASA Europa mission launch that I've seen. How are these two schedules reconciled?
The planned launch date for the M5 mission is 2029-2030. The actual launch date of the mission is likely to be driven by the mission's complexity and development schedule, rather than by the budget profile. In particular, missions of lower complexity (and thus likely of lower cost) might have a faster development schedule and thus an earlier launch date. The actual launch date for missions with enabling international participation (i.e., missions for which the implementation schedule depends on significant contributions from a partner) or for contributions to partner-led missions is likely to be driven in large part by the partner's technical schedule, and not necessarily by the ESA budget profile.
A question for anyone knowledgeable about the ESA M5 call. As I recall, the M5 mission is expected to launch in the late 2020s (M4 in the mid-2020s, I believe). This is several years later than the most pessimistic NASA Europa mission launch that I've seen. How are these two schedules reconciled?
M missions are scheduled for relatively long development phases and some technology development. The launch dates are indicative of this, but are not set in stone. If a mission is proposed requiring little development and can be built on a shorter schedule then the launch can be earlier.
That said, it just occurred to me that these concept missions seem scaled smaller than a typical M mission. And of course no launch cost, which normally comes from the mission budget. I wonder if they may be looking to run them on an S class mission with significant national instrument contributions? Note the blurb doesn't actually state it's for M-class CV. S3 should launch far sooner than M5.
I think you are right, the target mass is 250kg which makes it similar size than CHEOPS (S1) and much smaller than other M-class missions (1.5 to 2 tons).
The website says "... in defining a potential mission of opportunity...". Missions of opportunity are missions that do not necessarily fall in the predefined schedule of S/M/L missions of the science program (the only part of ESA that is compulsory to member states). So if there is a good concept with enough interest of some member states who are willing to finance it, the mission could be adopted without taking on of the existing S slots (or a new S slot could be added).
I definitely like how ESA's offered some great options to the Europa mission.Just to be clear, these are proof of concept studies, not "offers"
In the same sentence it also says "... in the frame of future Cosmic Vision calls." Huygens wasn't much larger (318 kg), and it was the first medium-size mission in Horizon 2000.
Arstechnica has a somewhat fluffy piece on the efforts of Rep. Culburtson to get a soft lander added to the Europa mission. http://arstechnica.com/science/2015/11/attempt-no-landing-there-yeah-right-were-going-to-europa/ (http://arstechnica.com/science/2015/11/attempt-no-landing-there-yeah-right-were-going-to-europa/)
Oy vey. Mission goals have the potential to explode until the whole thing gets killed.
Much better to set up a program of missions like was done at Mars.
And I'm not surprised about the skycrane. Mars is just pesky with that atmosphere requiring a heat shield. Terminal terrain navigation could search for relatively small spots of smoothness. I would be surprised if the lander didn't end up something like Mars Pathfinder, with petals for self righting (the interesting places appear to have really rough surfaces). Petals could also have solar cells.
Hmmm, how about a small rover.
20-30 kg of instruments would allow a really rich scientific payload, although its not clear if that's just instruments or all the equipment needed to power, operate, and return data from the instruments. If the latter, then it's really tight.
At that time, the massive Space Launch System rocket NASA is developing could deliver it to Jupiter in 4.6 years. Once there, the lander would separate from the Clipper, parking in a low-radiation orbit.
From the article:They would probably do gravity assists for changing the orbit, but only the minimum number needed. Clipper will do many more to find the right landing site.QuoteAt that time, the massive Space Launch System rocket NASA is developing could deliver it to Jupiter in 4.6 years. Once there, the lander would separate from the Clipper, parking in a low-radiation orbit.
Any guesses as to how much delta-v it would take to take the lander from a relatively high, but low-radiation Jupiter orbit to a soft landing on Europa? And what kind of propulsion system would that take? Hydrazine? A Star-xx solid?
Europa orbiter/lander mission design question:
Europa orbits within the co-rotating inner section of Jupiter's magnetosphere.
The magnetospheric plasma, sweeping around Jupiter at approximately once/10 hours, would constantly "lap" Europa, which completes one orbit in approximately 3.5 days.
Europa is a synchronous rotator ("day" = "year").
Could a Europan orbiter use a Molniya or Tundra type orbit, with "apo-Europa" above the leading Europan hemisphere?
The orbiter would stay in the "shadow" of the Jovian magnetosphere (relatively speaking--I'm sure it will still be exposed to some radiation inside any magnetic "shadow") as much as possible. And, the orbiter would return to "hover" at apo-Europa over the same region repetitively--perhaps over a lander's latitude/longitude?
The lander would not have continuous communication with the orbiter, but it would have regular, predictable communications windows. And there would be more windows, as the orbiter would survive longer than otherwise.
...Given this architecture, the lander is a full spacecraft in its own right and could launch later.The lander would need to loiter for a while while a good landing site was found. That implies a power system which can keep it going while in orbit around Jupiter. I wonder if they would try to use that same system on the surface or jettison it like the cruise stage of the Mars lander.
...Given this architecture, the lander is a full spacecraft in its own right and could launch later.The lander would need to loiter for a while while a good landing site was found. That implies a power system which can keep it going while in orbit around Jupiter. I wonder if they would try to use that same system on the surface or jettison it like the cruise stage of the Mars lander.
As VJKane said the lander would essentially be a separate spacecraft. Either launched together with the Europa Mission or not. I'm wondering how it would be powered. The Europa Mission will be solar. That solution seems to be harder to pull off for a lander. The arrays might be big and bulky and less tolerant to gee forces from the landing engines. I reread the presentations you suggested. They discuss either RTG power or batteries. That study also assumed that the orbiter would carry the lander until shortly before the landing. With the lander loitering separately waiting for a good landing site to be found that would seem to make batteries alone a much less favorable trade. If they use an RTG then the power issues become much less of a concern yet the orbiter itself is using solar....Given this architecture, the lander is a full spacecraft in its own right and could launch later.The lander would need to loiter for a while while a good landing site was found. That implies a power system which can keep it going while in orbit around Jupiter. I wonder if they would try to use that same system on the surface or jettison it like the cruise stage of the Mars lander.
Go back and look at the JPL study of a Europa lander around 2012 or so. I probably posted it up-thread.
As VJKane said the lander would essentially be a separate spacecraft. Either launched together with the Europa Mission or not. I'm wondering how it would be powered. The Europa Mission will be solar. That solution seems to be harder to pull off for a lander. The arrays might be big and bulky and less tolerant to gee forces from the landing engines. I reread the presentations you suggested. They discuss either RTG power or batteries. That study also assumed that the orbiter would carry the lander until shortly before the landing. With the lander loitering separately waiting for a good landing site to be found that would seem to make batteries alone a much less favorable trade. If they use an RTG then the power issues become much less of a concern yet the orbiter itself is using solar.
Europa orbiter/lander mission design question:
Europa orbits within the co-rotating inner section of Jupiter's magnetosphere.
The magnetospheric plasma, sweeping around Jupiter at approximately once/10 hours, would constantly "lap" Europa, which completes one orbit in approximately 3.5 days.
Europa is a synchronous rotator ("day" = "year").
Could a Europan orbiter use a Molniya or Tundra type orbit, with "apo-Europa" above the leading Europan hemisphere?
The orbiter would stay in the "shadow" of the Jovian magnetosphere (relatively speaking--I'm sure it will still be exposed to some radiation inside any magnetic "shadow") as much as possible. And, the orbiter would return to "hover" at apo-Europa over the same region repetitively--perhaps over a lander's latitude/longitude?
The lander would not have continuous communication with the orbiter, but it would have regular, predictable communications windows. And there would be more windows, as the orbiter would survive longer than otherwise.
As your question/analysis implies, the leading hemisphere receives much less radiation than the trailing. Analyses of orbiter lifetimes always take this into account.
My guess is that any lander would have direct to Earth communications for a critical subset of the data. Galileo managed 10 bps with a low gain antenna. An antenna such as Curiosity carries (or as it may be substantially enhanced for the 2020 rover, would do much better). Spectroscopy experiments produce relatively low data rates. Its the imaging and seismography that kills you.
Europa orbiter/lander mission design question:
Europa orbits within the co-rotating inner section of Jupiter's magnetosphere.
The magnetospheric plasma, sweeping around Jupiter at approximately once/10 hours, would constantly "lap" Europa, which completes one orbit in approximately 3.5 days.
Europa is a synchronous rotator ("day" = "year").
Could a Europan orbiter use a Molniya or Tundra type orbit, with "apo-Europa" above the leading Europan hemisphere?
The orbiter would stay in the "shadow" of the Jovian magnetosphere (relatively speaking--I'm sure it will still be exposed to some radiation inside any magnetic "shadow") as much as possible. And, the orbiter would return to "hover" at apo-Europa over the same region repetitively--perhaps over a lander's latitude/longitude?
The lander would not have continuous communication with the orbiter, but it would have regular, predictable communications windows. And there would be more windows, as the orbiter would survive longer than otherwise.
As your question/analysis implies, the leading hemisphere receives much less radiation than the trailing. Analyses of orbiter lifetimes always take this into account.
My guess is that any lander would have direct to Earth communications for a critical subset of the data. Galileo managed 10 bps with a low gain antenna. An antenna such as Curiosity carries (or as it may be substantially enhanced for the 2020 rover, would do much better). Spectroscopy experiments produce relatively low data rates. Its the imaging and seismography that kills you.
Thanks for the information. I guessed, but did not KNOW, such details of mission planning.
Also, I didn't know that seismography data is high data-rate. If it's not too off-topic, how so?
Elsewhere I read that the ICPS of Block 1 was scheduled for only one or at most two of the initial missions. I know the EUS of Block 1B isn't a sure thing yet, but it seems more likely it will be available by the time the Europa mission can be launched, and the ICPS would be retired by then. Won't that make a difference in the possible payload and mission choices?Arstechnica has a somewhat fluffy piece on the efforts of Rep. Culburtson to get a soft lander added to the Europa mission. http://arstechnica.com/science/2015/11/attempt-no-landing-there-yeah-right-were-going-to-europa/ (http://arstechnica.com/science/2015/11/attempt-no-landing-there-yeah-right-were-going-to-europa/)
"The JPL engineers have concluded the best way to deliver the lander to Europa’s jagged surface is by way of a sky crane mechanism, like the one successfully used in the last stage of Curiosity’s descent to the surface of Mars. With four steerable engines and an autonomous system to avoid hazards, the lander would be lowered to the moon’s surface by an umbilical cord.
Although the SLS rocket has been designed to lift as much as 70 tons into low-Earth orbit, it can only propel a small fraction of that across the 800 million kilometers of space to Jupiter, and fuel and the Clipper will consume most of that mass. The engineers have calculated they can spare a total of about 510 kg for the sky crane and lander, and of the 230 kg lander, about 20 to 30 kg can be given over to scientific instruments. That may seem slight, but it’s equivalent to what the Spirit and Opportunity rovers had to work with on Mars.
That payload would contain a mass spectrometer to identify any complex biological molecules. The engineers are also trying to add a second type of spectrometer, based on Raman scattering, to provide independent confirmation of any significant findings. “Honestly,” Culberson said, “if you’re going to go all that way to determine if there’s life on another world, why wouldn’t you double-check it?”
To gather samples for the spectrometers, the lander will have a scooper and sampling arm with at least one set of counter-rotating saw blades that could penetrate to a depth of about 10 cm. At Europa’s low surface temperatures, its ice is harder than steel."
And
"Scientists will attempt to find this hardware a landing site near an active crevasse. If the Hubble telescope data is correct, this would offer a potential opening to the ocean far below. Ideally, if the lander can be placed near a vent, it might sample spouts from the ocean below. The engineers are also working through the feasibility of more exotic options, such as bots that might detach from the lander and examine the crevasses.
On Europa’s harsh surface, the battery-powered lander would have about a 10-day lifespan, although solar cells might extend that further. But with dim sunlight and continual radiation, the lander’s functional time would necessarily be short.
Finally, the JPL engineers are working on a “plume probe,” not as part of the lander but which would detach from the Clipper and fly close to the moon’s surface, perhaps 2 km or lower, to obtain samples and relay that data back to the Clipper."
Elsewhere I read that the ICPS of Block 1 was scheduled for only one or at most two of the initial missions. I know the EUS of Block 1B isn't a sure thing yet, but it seems more likely it will be available by the time the Europa mission can be launched, and the ICPS would be retired by then. Won't that make a difference in the possible payload and mission choices?
If Europa exploration will be a continuing pursuit by NASA (Europa Clipper, followed by proposed Europa orbiter and proposed Europa lander), then, at some point in time, should a separate Europa exploration line item in the NASA budget be initiated?
Running the concept up the flagpole; will anyone salute?
Or might I as well ask for a rainbow-maned astronaut pegasus-pony?
JPL trying to worm its fingers into the fiscal cookie jar for more eh? Where's the Congressional nun with a ruler when you need her? :P
heard from several people that what Culberson really wants is to drill through the ice and send down a sub. Asking for only a soft lander is him showing restraint.
re: Ocean Worlds program--that's a great idea! Thank you for the information.
If Europa exploration will be a continuing pursuit by NASA (Europa Clipper, followed by proposed Europa orbiter and proposed Europa lander), then, at some point in time, should a separate Europa exploration line item in the NASA budget be initiated?
The article suggests that the deliver spacecraft/lander would be around $500M, so that could fit within a continuing program.
May I ask if there's any chance that a new budget line comes with a new budget addition?You can't go on average funding needed because the bulk of the money is spent in 18 to 24ish (depending on mission size). Probably the reasonable funding level would be $500M/year. Take that out of the existing budget and blows out the ability to do much of anything else except perhaps the Discovery program.
I'm asking because even a 2.5B mission per decade is 250M per year. And the travel time alone to the Water Worlds is around that. In the overall budget 250M seems quite possible. In fact, pork and lobbied lines usually have higher swings.
May I ask if there's any chance that a new budget line comes with a new budget addition?
May I ask if there's any chance that a new budget line comes with a new budget addition?
There is a chance that a new budget line can come with a new budget addition. But who is going to provide that bump up? The White House? Or Congress?
One thing I would note is that the ocean worlds line that has been proposed was not mentioned in the last decadal survey. So there is no scientific consensus that says it should be done. It has become rather common in the past decade or so to not approve a mission (or a funding line) unless there is clear scientific consensus for it. So you can expect political opposition to such a proposal as well.
Based on mission options for the outer planet moons, there are a couple of ways that an Ocean Worlds program could be funded (assuming that the planetary program's budget is significantly increased).
Because Europa sits in the midst of an intense radiation belt, almost any mission that will significantly enhance our understanding of this moon will require missions >$1.5B. The only exception I see would be if predictable plumes are discovered by the Europa clipper, in which case a dedicated follow on plume fly-through or sample return mission could be cheaper. Short of that, furthering the exploration of Europa would likely require dedicating the next 2-3 Flagship mission slots to Europa. The cost would be no sample return from Mars and probably no Uranus or Neptune mission.
Flagship missions tend to be chosen through political decisions. What became the Curiousity mission was approved by the first planetary Decadal Survey as only a modest technology demonstration mission. The 2020 rover mission was approved through a political decision driven by OMB. It would not surprise me if the Flagships for the 2020s and 2030s are also chosen through the political process.
It appears that *modest* Titan and/or Enceladus missions might be done within the New Frontiers budget cap. If so, then a new mission program could be inserted by stretching out the time between Flagship missions and probably the current New Frontiers program. It is unclear whether such missions would have the scientific return within this cost cap to win the backing of the next Decadal Survey given other candidate ~$1B missions. (I suspect such missions would be competitive, but my opinion is just that.)
The core problem for the planetary program is an embarrassment of riches. Mars becomes only more interesting the more we explore it in depth, and a sample return mission is the next obvious goal. Europa, Enceladus, and Titan are, in my opinion, equally important targets. The ice giants cry out for an orbital mission with an atmospheric probe.
Simply put, short of a big increase in the budget for the planetary program, there will be big losers once the winner(s) of the 'what do we focus on' is/are chosen.
Perhaps the Ocean Worlds program, if it becomes reality, might be the Europa Clipper mission (plus a small lander?) and a New Frontiers class mission to Titan and/or Enceladus for the 2020s. (There are opportunities for international collaboration in the latter.) That would be the least disruptive option I see to the overall planetary program.
Based on mission options for the outer planet moons, there are a couple of ways that an Ocean Worlds program could be funded (assuming that the planetary program's budget is significantly increased).
Because Europa sits in the midst of an intense radiation belt, almost any mission that will significantly enhance our understanding of this moon will require missions >$1.5B. The only exception I see would be if predictable plumes are discovered by the Europa clipper, in which case a dedicated follow on plume fly-through or sample return mission could be cheaper. Short of that, furthering the exploration of Europa would likely require dedicating the next 2-3 Flagship mission slots to Europa. The cost would be no sample return from Mars and probably no Uranus or Neptune mission.
Flagship missions tend to be chosen through political decisions. What became the Curiousity mission was approved by the first planetary Decadal Survey as only a modest technology demonstration mission. The 2020 rover mission was approved through a political decision driven by OMB. It would not surprise me if the Flagships for the 2020s and 2030s are also chosen through the political process.
It appears that *modest* Titan and/or Enceladus missions might be done within the New Frontiers budget cap. If so, then a new mission program could be inserted by stretching out the time between Flagship missions and probably the current New Frontiers program. It is unclear whether such missions would have the scientific return within this cost cap to win the backing of the next Decadal Survey given other candidate ~$1B missions. (I suspect such missions would be competitive, but my opinion is just that.)
The core problem for the planetary program is an embarrassment of riches. Mars becomes only more interesting the more we explore it in depth, and a sample return mission is the next obvious goal. Europa, Enceladus, and Titan are, in my opinion, equally important targets. The ice giants cry out for an orbital mission with an atmospheric probe.
Simply put, short of a big increase in the budget for the planetary program, there will be big losers once the winner(s) of the 'what do we focus on' is/are chosen.
Perhaps the Ocean Worlds program, if it becomes reality, might be the Europa Clipper mission (plus a small lander?) and a New Frontiers class mission to Titan and/or Enceladus for the 2020s. (There are opportunities for international collaboration in the latter.) That would be the least disruptive option I see to the overall planetary program.
You didn't even mention Pluto which to my mind has certainly put itself on the scientific map this year.
May I ask if there's any chance that a new budget line comes with a new budget addition?
There is a chance that a new budget line can come with a new budget addition. But who is going to provide that bump up? The White House? Or Congress?
One thing I would note is that the ocean worlds line that has been proposed was not mentioned in the last decadal survey. So there is no scientific consensus that says it should be done. It has become rather common in the past decade or so to not approve a mission (or a funding line) unless there is clear scientific consensus for it. So you can expect political opposition to such a proposal as well.
And there is the downside of doing a review of such things every ten years that scientific priorities can shift considerably within that period.
Flagship missions tend to be chosen through political decisions. What became the Curiousity mission was approved by the first planetary Decadal Survey as only a modest technology demonstration mission. The 2020 rover mission was approved through a political decision driven by OMB. It would not surprise me if the Flagships for the 2020s and 2030s are also chosen through the political process.
Based on mission options for the outer planet moons, there are a couple of ways that an Ocean Worlds program could be funded (assuming that the planetary program's budget is significantly increased).
Because Europa sits in the midst of an intense radiation belt, almost any mission that will significantly enhance our understanding of this moon will require missions >$1.5B. The only exception I see would be if predictable plumes are discovered by the Europa clipper, in which case a dedicated follow on plume fly-through or sample return mission could be cheaper. Short of that, furthering the exploration of Europa would likely require dedicating the next 2-3 Flagship mission slots to Europa. The cost would be no sample return from Mars and probably no Uranus or Neptune mission.
Flagship missions tend to be chosen through political decisions. What became the Curiousity mission was approved by the first planetary Decadal Survey as only a modest technology demonstration mission. The 2020 rover mission was approved through a political decision driven by OMB. It would not surprise me if the Flagships for the 2020s and 2030s are also chosen through the political process.
It appears that *modest* Titan and/or Enceladus missions might be done within the New Frontiers budget cap. If so, then a new mission program could be inserted by stretching out the time between Flagship missions and probably the current New Frontiers program. It is unclear whether such missions would have the scientific return within this cost cap to win the backing of the next Decadal Survey given other candidate ~$1B missions. (I suspect such missions would be competitive, but my opinion is just that.)
The core problem for the planetary program is an embarrassment of riches. Mars becomes only more interesting the more we explore it in depth, and a sample return mission is the next obvious goal. Europa, Enceladus, and Titan are, in my opinion, equally important targets. The ice giants cry out for an orbital mission with an atmospheric probe.
Simply put, short of a big increase in the budget for the planetary program, there will be big losers once the winner(s) of the 'what do we focus on' is/are chosen.
Perhaps the Ocean Worlds program, if it becomes reality, might be the Europa Clipper mission (plus a small lander?) and a New Frontiers class mission to Titan and/or Enceladus for the 2020s. (There are opportunities for international collaboration in the latter.) That would be the least disruptive option I see to the overall planetary program.
You didn't even mention Pluto which to my mind has certainly put itself on the scientific map this year.
I'd suggest one addendum that'd be a convergence of the topics of Pluto, Ice Giants, and Ocean Worlds: Triton.
Triton's the most remote, positively confirmed geologically active world (Pluto's ice volcanoes are still under debate) with a variety of quirks that make it kin to the other 3 ocean worlds (Europa, Titan, Enceladus) with Pluto as a close cousin. It may itself have some liquid like Titan and Ganymede in its structure, albeit to a lesser extent since it is rockier like Europa. Although it would be difficult to reach, it should be added to the targets in fairness. Instead of radiation at Europa we'd have to deal with time and decelerating first around Neptune and possibly again around Triton itself.
Might be wise to direct this Ocean Worlds talk to a different thread although Europa technically is one of them. Europa just has the luck of being the closest of the lot. :)
I'll re-enforce Blackstar's point. Consensus on missions to fly build slowly and are relatively stable. For the major missions (New Frontiers and Flagship), the only serious addition to that list I can think of is Enceladus based on Cassini's findings. The last Decadal Survey looked at a number of flavors of Enceladus missions. It concluded that the options were too expensive and that for the $s, Europa was a higher priority. I also suspect they concluded that the community should let Cassini complete its studies first, and since the last Decadal, our understanding of Enceladus has greatly deepened.
In one of the astronomy magazines I was reading recently they were making a argument that a strong case should be put forward for the prioritisation of Pluto in the next decadal survey on geology alone let alone other factors such as any internal ocean.
We'll see. I love the Pluto data. But there are also a lot of other fascinating subjects to go after. The ice giants of course are still almost unexplored. And doing a major next step at Pluto is going to be much more expensive than New Horizons. If you had $2 billion to spend going back to Pluto to do more detailed study, or spending $2 billion to orbit Uranus or Neptune, which mission do you think would return more data for that expenditure?
Okay, that's not even a tough question: that money spent on an ice giant mission is going to return far more data.
Long lineage is what makes stuff happen. That's just how it works. Planetary scientists don't, and should not, go chasing after each new shiny object.The Discovery program is the one place where individual science teams get to propose to chase after their preferred shiny object. But even then, any proposal that doesn't tie the proposed mission back to key and long standing questions posed by the planetary community and codified into the Decadal Survey isn't going to get funded. The creativity comes in finding small highly focused missions that can tackle bits and pieces of the big questions.
Now I'll agree that there is more politics involved in the big mission selections. But that does not mean that there is no logic to what happens and how it happens. There is a process that provides input to the political decisions that get made.Green has said in meetings that OMB told NASA that they could take a Curiosity class rover as the Flagship for this decade or have no Flagship. A Mars rover fit with NASA's overall focus on Mars, and it was believed that the cost would be constrained because we'd already flown this design. There were politics, as there always is for big money projects. (The latest cost estimates put the 2020 rover within 75% of the cost of Curiosity adjusted for inflation.)
In one of the astronomy magazines I was reading recently they were making a argument that a strong case should be put forward for the prioritisation of Pluto in the next decadal survey on geology alone let alone other factors such as any internal ocean.
We'll see. I love the Pluto data. But there are also a lot of other fascinating subjects to go after. The ice giants of course are still almost unexplored. And doing a major next step at Pluto is going to be much more expensive than New Horizons. If you had $2 billion to spend going back to Pluto to do more detailed study, or spending $2 billion to orbit Uranus or Neptune, which mission do you think would return more data for that expenditure?
Okay, that's not even a tough question: that money spent on an ice giant mission is going to return far more data.
Green has said in meetings that OMB told NASA that they could take a Curiosity class rover as the Flagship for this decade or have no Flagship. A Mars rover fit with NASA's overall focus on Mars, and it was believed that the cost would be constrained because we'd already flown this design.
Really I would say that's debatable. Pluto is proving to be such a unique object, I mean it's geology alone is an incredibly mishmash of types. We have also only seen properly one side of it, plus there is the totality of its unusual moon system. The problem with Triton is it isn't a pristine KBO it has no doubt been altered by its position as a moon of Neptune. The processes on Pluto are separated from any influence of a giant planet.
Really I would say that's debatable. Pluto is proving to be such a unique object, I mean it's geology alone is an incredibly mishmash of types. We have also only seen properly one side of it, plus there is the totality of its unusual moon system. The problem with Triton is it isn't a pristine KBO it has no doubt been altered by its position as a moon of Neptune. The processes on Pluto are separated from any influence of a giant planet.
It isn't really. The ice giants were prioritized in the last decadal survey, Pluto was not. That gives them heritage (meaning that scientists can say "We said this was important before and we are saying that it is still important," which is a much more powerful political argument than "Hey! Something new and cool!"). Plus, we're comparing planetary systems consisting of icy planets with large atmospheres and multiple moons, as well as magnetic fields, etc., with a relatively small rock. Pluto is interesting, but it does not have the scientific constituency or the breadth that the ice giants do. It is a far harder argument to spend significantly more money on Pluto than on an ice giant mission.
But if some of the Pluto pictures come back and reveal a monument, then all bets are off.
Second, unless the planetary program gets a budget boost of perhaps $500M a year, do we want to make the program an Ocean Worlds program plus perhaps Discovery missions? Good arguments could be made either way.
But is that a fair comparison as at the time of the last survey we only had limited knowledge about Pluto compared to what we know now, so no wonder there wasn't the constituency behind it, especially as a lot of people just expected it to be a boring planetary body?
re: Ocean Worlds program--that's a great idea! Thank you for the information.
Based on the assumption that the satellites are differentiated and using an equilibrium condition between the heat production rate in the rocky cores and the heat loss through the ice shell, we find that subsurface oceans are possible on Rhea, Titania, Oberon, Triton, and Pluto and on the largest TNO's 2003 UB313, Sedna, and 2004 DW.
As I recall, the case for Titan as an ocean world is quite strong. I have the vague memory that the ocean may be neither in contact with the surface nor with the silicate core.What - no Titan? It definitely has seas (although of methane/ethane rather than water).
At the workshop last month they considered Titan to be an ocean world.
Wait - Titan would thus have two oceans - a methane ocean on the surface, and a water ocean under the surface ? :oYes. Check out:
Before the encounter many expected a boring ice ball and therefore dismissed the possibility of follow-up missions being justified.IMHO, anyone expressing this sentiment was being foolish. If there's one consistent lesson to take away from our exploration of the outer solar system, right since the 1970s, it's that there are no boring worlds. Io and Europa were supposed to be dead chunks of rock. Triton was a frozen hunk of ice. And Enceladus was surely boring. Wrong, wrong, wrong. Always bet on interesting.
Before the encounter many expected a boring ice ball and therefore dismissed the possibility of follow-up missions being justified.IMHO, anyone expressing this sentiment was being foolish. If there's one consistent lesson to take away from our exploration of the outer solar system, right since the 1970s, it's that there are no boring worlds. Io and Europa were supposed to be dead chunks of rock. Triton was a frozen hunk of ice. And Enceladus was surely boring. Wrong, wrong, wrong. Always bet on interesting.
Before the encounter many expected a boring ice ball and therefore dismissed the possibility of follow-up missions being justified.IMHO, anyone expressing this sentiment was being foolish. If there's one consistent lesson to take away from our exploration of the outer solar system, right since the 1970s, it's that there are no boring worlds. Io and Europa were supposed to be dead chunks of rock. Triton was a frozen hunk of ice. And Enceladus was surely boring. Wrong, wrong, wrong. Always bet on interesting.
Airbus Defence & Space SAS in France was announced as the prime contractor in July when ESA approved the €350 million contract.
The contract covers the design, development, integration, test, launch campaign and in-space commissioning of the spacecraft. The Ariane 5 launch is not included and will be procured later from Arianespace.
The 10 state-of-the-art instruments were approved by ESA in February 2013 and are being developed by teams spanning 16 European countries, the USA and Japan, under national funding.
The spacecraft will be assembled at Airbus Defence and Space GmbH in Friedrichshafen, Germany.
...on a side note, it will be interesting to see which of the two will reach Jupiter first!
That is assuming that SLS completes development. At least one new president and a couple of new Congresses. If it doesn't, Europa Clipper launches later and takes the same slow route as JUICE.
...on a side note, it will be interesting to see which of the two will reach Jupiter first!
Europa Clipper. JUICE has a convoluted orbit picking up energy in the inner solar system before getting to Jupiter. Europa Clipper will be on a direct ascent orbit to Jupiter, just like the Pioneers and the Voyagers before it
That is assuming that SLS completes development. At least one new president and a couple of new Congresses. If it doesn't, Europa Clipper launches later and takes the same slow route as JUICE.
...on a side note, it will be interesting to see which of the two will reach Jupiter first!
Europa Clipper. JUICE has a convoluted orbit picking up energy in the inner solar system before getting to Jupiter. Europa Clipper will be on a direct ascent orbit to Jupiter, just like the Pioneers and the Voyagers before it
That is assuming that SLS completes development. At least one new president and a couple of new Congresses. If it doesn't, Europa Clipper launches later and takes the same slow route as JUICE.
...on a side note, it will be interesting to see which of the two will reach Jupiter first!
Europa Clipper. JUICE has a convoluted orbit picking up energy in the inner solar system before getting to Jupiter. Europa Clipper will be on a direct ascent orbit to Jupiter, just like the Pioneers and the Voyagers before it
I'd a thought SLS is too far along for easy cancellation.
Will the Congressional critters fund the EUS upper stage? Otherwise you are struck with the iCPS upper stage on top of the SLS. Which is only a little better than a Delta IV Heavy with a solid kick stage.
Jeff Foust
@jeff_foust
That planetary figure includes $175M for a Europa mission that “shall include an orbiter with a lander” with a 2022 target launch date.
QuoteJeff Foust
@jeff_foust
That planetary figure includes $175M for a Europa mission that “shall include an orbiter with a lander” with a 2022 target launch date.
https://twitter.com/jeff_foust/status/677031184128438272
Huh.
Is the $175M funding for 1 year only, or for the entire project?
Is the $175M funding for 1 year only, or for the entire project?
It's for the next year.
QuoteJeff Foust
@jeff_foust
That planetary figure includes $175M for a Europa mission that “shall include an orbiter with a lander” with a 2022 target launch date.
https://twitter.com/jeff_foust/status/677031184128438272
Huh.
That seems to be setting quite a high bar on capabilities and the timescale to deliver them?
What you have to understand is that this is a form of budgetary chicken--Congress is going to keep adding the money in for Europa in order to force the President to fund the Europa mission, and the President (OMB) is going to keep dragging its feet. The threat inherent (implicit) in the congressional move is that if the President keeps dragging his feet, then the money is going to be wasted--it is not enough to actually build a spacecraft, but it is way more than is required for studies and basic hardware development. It is a really inefficient way to do things.
I worked on the planetary decadal survey and I don't remember a Europa lander being recommended there...
I don't know enough about US politics on this matter but I thought missions such as this were always funded via Congress?
Well, yeah, but it's complex and full of subtleties. Most times a new project has to be initiated in the president's budget request. Congress then appropriates the money. If the administration does not really want a project to happen, they can drag their heels on the implementation and the money gets spent very inefficiently. Essentially, it's like the administration telling all the workers to sit around on their hands and not do anything useful.
In order for a project to properly work, the administration has to plan out a multi-year budget profile--year 1, 2, 3, 4 and so on. That indicates a commitment by them to not only spend the money in the coming year, but to ask for money in following years and keep working toward the goal. To date the administration has really dragged its heels on this. They only agreed to a "new start" on the Europa mission because Congress (Culberson) kept appropriating the money. The money kept piling up there and getting spent inefficiently, because the administration did not want to commit to a big expensive Europa mission. Eventually they gave in, but they did so reluctantly.
In addition, Culberson is writing things into law (like the lander and the SLS launch) that very few people have actually asked for. The science community outlines its priorities in the decadal survey. You might look at the decadal survey and see what it says about the requirement for a Europa lander...
I doubt the decadal survey or any science really will be all that relevant if this just turns into yet another political football between a Democratic White House & Republican Congress, which from the sound of it is exactly what it is in danger of becoming.
I'm moderately optimistic on this one. But I want to see an affordable Europa mission, not something that is going to be ridiculously expensive. There is some reason to be concerned.
I doubt the decadal survey or any science really will be all that relevant if this just turns into yet another political football between a Democratic White House & Republican Congress, which from the sound of it is exactly what it is in danger of becoming.
Here's a question though, maybe I've missed something - do they mean a Jupiter orbiter and Europa lander or a Europa orbiter and Europa lander?
The first one I could see being done more (very relatively speaking) easily, with a separate launch for the lander. The second possibility is what worries me more given it would need a massive redesign.
Jupiter orbiter with multiple Europa flybys, deploying a Europa lander.
This would have to be a small lander. I have a hard time figuring out how they get to that point. One of the big challenges for a lander is the requirement for good landing site photography. So they somehow have to do that with the orbiter before deploying the lander. And how do they define "good" photography?
I'd also ask about science-per-dollar for the lander. Can a lander that is small enough to fit on this mission, and will only last a short time on the Europa surface, do anything useful for the high cost? JPL has estimated this as $700 million to $1 billion.* What will we get for that amount of money? That is the equivalent of another New Frontiers mission. Will it provide a New Frontiers mission's worth of data?
The joys of putting a price on science, eh Blackstar? ;)
Surprised a lander is mentioned...but then again, maybe it is implied as a future mission, not necessarily glued directly to 'Clipper (until they come up with a better acronym or name I'm gonna stick with 'Clipper). After all, if 'Clipper is successful the successor is guaranteed to be a lander. Blackstar is right about Culberson pushing his influence, but NASA might be able to interpret it several ways: small piggy-back, ESA partnership, or large future mission. We'll have to see...
My personal opinion: I'd hope for the ESA-option.
My understanding is that ESA is adding the option to piggyback on the Europa Mission in the M5 opportunity. A proposal can be made which involves partnering with NASA on the Europa Mission but that proposal is not guaranteed to win the M5 competition. ESA has made no firm commitment, just that they will allow a Europa Mission add-on to compete against all the other proposals. Is that still the case?
The joys of putting a price on science, eh Blackstar? ;)
Surprised a lander is mentioned...but then again, maybe it is implied as a future mission, not necessarily glued directly to 'Clipper (until they come up with a better acronym or name I'm gonna stick with 'Clipper). After all, if 'Clipper is successful the successor is guaranteed to be a lander. Blackstar is right about Culberson pushing his influence, but NASA might be able to interpret it several ways: small piggy-back, ESA partnership, or large future mission. We'll have to see...
My personal opinion: I'd hope for the ESA-option.
ESA seems to be willing to do a joint mission, such options are specifically mentioned in M5 plans. But I don't believe ESA plans are compatible with launch in early 2020s.
The joys of putting a price on science, eh Blackstar? ;)
Blackstar is right about Culberson pushing his influence, but NASA might be able to interpret it several ways: small piggy-back, ESA partnership, or large future mission. We'll have to see...
My personal opinion: I'd hope for the ESA-option.
It's pretty clear: Congress doesn't fund science missions for the same reasons scientists seek funding from Congress. So it's nice when things happen to align. But its not something we should expect on a regular basis!
Setting science return aside entirely, isn't it obvious why Congress wants a lander as part of a Europa mission? I think I can summarize the concept in one word: "Philae."
The most recent decadal survey does not call for a Europa lander. Such a thing is obviously potentially very interesting, but the scientists whose jobs are to determine the best use of the available resources do not believe it's the right way to go. If the politicians were to boost funding for planetary science so that the lander did not squeeze the rest of the planetary program, it would still be a win from the planetary scientits' point of view. But such a funding boost is unlikely, especially when you consider that even a Europa orbiter was recommended by the decadal survey only given a robust planetary-science budget (otherwise the survey recommends a Uranus orbiter and probe instead).
But perhaps I should just be impressed that America is blessed with brilliant scientist-politicians like Rep. Culberson who know better than all of those stupid PhD scientists! :)
It's pretty clear: Congress doesn't fund science missions for the same reasons scientists seek funding from Congress.
You extrapolate from this one example to a sweeping generalization like that?
The most recent decadal survey does not call for a Europa lander. Such a thing is obviously potentially very interesting, but the scientists whose jobs are to determine the best use of the available resources do not believe it's the right way to go.
The secondary issue is cost-vs-benefit. If this lander costs $1 billion and operates for a few days, is it worth skipping an entire New Frontiers mission for that?
Don't know if you can do it in a few days, but the best way to discover whether there's life in Europa's oceans is via paleontology. If there are any visible areas of ice that are the remnants of liquid plumes ejected from Europa's interior, those plumes would probably have carried any organisms living in that water, and then entombed them in ice when it froze onto the surface. There may be fossil remnants of those organisms that can be detected.The most recent decadal survey does not call for a Europa lander. Such a thing is obviously potentially very interesting, but the scientists whose jobs are to determine the best use of the available resources do not believe it's the right way to go.The secondary issue is cost-vs-benefit. If this lander costs $1 billion and operates for a few days, is it worth skipping an entire New Frontiers mission for that?
In general I have to say, given choice, waiting for a larger, full-fledged lander is the wiser option. Still, while pricey, a billion dollars to solve a few essential questions about the outer solar system's most habitable world (Enceladus would be 2nd) might be worthwhile. Naturally, it'd depend on if a piggyback-lander, ESA or NASA-built, could be properly managed...which is obviously tricky with only a billion for an ambitious quest.
I'd suggest two avenues a small, short-lived lander might pursue: seismology and chemistry. While the 'Clipper's radar will offer very strong evidence, a seismometer would be even better confirmation an ocean exists under Europa. Secondly, drilling into the ice even by a few centimeters should tell if there's unique chemistry happening both from below and through radiation-alternation; the chemistry results would be affected by where it lands, but I'd say odds are most regions of Europa should have some chemical traces of churning with the subsurface, just some are more pristine than others.
Going with seismology and chemistry as the priorities, a small lander needs three primary instruments: a seismometer, a wet-chemistry lab, and a camera. The instruments themselves could be derived from Phoenix and InSight, which themselves were fairly cheap landers (compared to monstrous programs like JWST or Curiosity at least), perhaps with a drill system borrowed from Philae (ESA anyone?). If there were to be a 4th instrument, I'd suggest a microscope; while unlikely on the irradiated surface, nothing would justify a billion well-spent than seeing a microbe or worm wiggling under a lens.
Just my thoughts, but I'm still two-parts favoring a large, separate lander with one-part favoring a potential piggyback lander.
While I do agree with the sentiment here that a lander might make the mission too expensive, the recent budget deal congress passed is a pretty clear signal that congress is willing to give NASA the money. The increase for both SLS (including ordering NASA to bypass ICPS) and for Planetary Science is making me cautiously optimistic that a flagship, orbiter + lander mission might not break the bank.
What's the total cost of the Europa mission including SLS?
While I do agree with the sentiment here that a lander might make the mission too expensive, the recent budget deal congress passed is a pretty clear signal that congress is willing to give NASA the money. The increase for both SLS (including ordering NASA to bypass ICPS) and for Planetary Science is making me cautiously optimistic that a flagship, orbiter + lander mission might not break the bank.
What's the total cost of the Europa mission including SLS?
That should be the next billion dollar question: will the SLS be part of the mission cost or will it be treated separately? I can only assume separately, and previously in the Discovery program the launcher was treated as a "freebie" as long as the probe wouldn't overload it. If 'Clipper is given a free ride, I'd wager a handful of mini-missions would ride along too; as in cube-sats like for EM-1. Perhaps a new premise could be set that for every large mission (flagship or frontier), a half-dozen tiny ones accompany it aboard an SLS launch. If it is to be used for probes (as it should be), it would be only fair to include smaller packages to make the most out of a gigantic rocket.
IMO, Blackstar has nailed it. The spacecraft plus lander will cost $3Bish and the SLS launch will be $1Bish (from memory; the heaviest lift standard launchers are, again from old memories) around $500Mish.
Thought I'd post this here,
https://www.ucl.ac.uk/mssl/planetary-science/EuropaPenetratorWorkshop
Gives the timescale for when we might find out more about the proposed ESA contributions that will be put forward for M5.
And the penetrator is dubbed 'Akon'
Edit: also here's a recent update on development of the penetrator, they're currently testing impact resistant batteries and are preparing to design the comms.
http://congrexprojects.com/docs/default-source/15c17_-proocedings/s2-6---chruch_uk_space_pen_presentation_to_esa_conf_nov15_1.pdf?sfvrsn=2
I've published a blog post on the Europa lander for anyone interested in (hopefully) informed speculation given how little is known.
http://futureplanets.blogspot.com/2015/12/a-lander-for-nasas-europa-mission.html
...To the point, a seismometer would verify the ocean on Europa with verifying any potential tectonic/volcanic activity a bonus. I'd even vote to sacrifice an imager if it meant a working seismometer...A very basic imager would be needed to deploy a seismometer. A seismometer needs to go on the surface to get away from the vibration of the lander. To do that an imager and robotic arm are needed. InSight has an imager but it is a panchromatic sensor which isn't suitable for much beyond placing the instruments. That mission had to make the choice for a minimal camera system due to cost. Since no imager has ever been taken to the surface of Europa funding should be easier to find compared to a flat boring area on Mars.
There's something that kind of sounds strange to me. Why send the lander on the same flight to then wait two years or so in a parking orbit. Wouldn't it make much more sense to make a minimal lander later and send it four years later? A Delta IV Heavy can do 2 tonnes to C3=82km²/s². That should be plenty. And you get four extra years to spread the budget expenditure and you can squeeze all the Clipper information.I agree that this does sound strange. Assuming that Berger got it straight (and his reporting his good on other topics) then I can only imagine that this is being done to (1) fly it on the same mission per Culberson's directive (2) buy time to build up high resolution imaging of potential landing sites (3) its lighter/cheaper/smaller to detach early rather than to carry the extra shielding to stay with the main spacecraft during all its forays into the high radiation belts.
It would preclude the option of data relay. But it would seem risky to me to depend on a single pass to actually get your data back.
I've published a blog post on the Europa lander for anyone interested in (hopefully) informed speculation given how little is known.
http://futureplanets.blogspot.com/2015/12/a-lander-for-nasas-europa-mission.html
Is a RTG being considered for the lander?
RHU?Is a RTG being considered for the lander?
No.
RHU?Is a RTG being considered for the lander?
No.
RHU?Is a RTG being considered for the lander?
No.
NASA asked the European Space Agency last year whether it was interested in contributing to the Europa mission, and Gimenez said in an interview with Spaceflight Now that the answer is yes.
“We will participate with no cost to NASA by us contributing something equivalent to a half-billion euros in cost to ESA,” Gimenez said. “Now, where it goes depends on the cooperation.
“This is a NASA mission, and we are happy to be a junior partner with NASA,” Gimenez told Spaceflight Now in December. “It’s our natural partnership with the U.S., and we will be very happy to do it. Now, they have to tell us the profile of the mission, what they want to do, and where do we have a role. But certainly we would appreciate the opportunity.”
“We are ready and interested,” Gimenez said. “As I said to my colleague in the U.S., we cannot allow Americans to go to Europa without Europeans. We have to be part of it. We think that it is natural, but certainly we will not lead, so we have to wait.”
Gimenez said ESA is taking its cues from NASA on Europa, so Europe will wait for a formal invitation before making the next move, which could come as soon as this year in the form of a request for mission proposals from the European science community.
“In all the discussions we have had, NASA is very open to our cooperation, but again, they have to define it,” Gimenez said. “It is a complicated mission. For Europa, in particular, we need a lot of mass. This is a very harsh environment (due to high radiation doses at Jupiter).”
ESA wants to be a part of NASA’s mission to EuropaQuoteNASA asked the European Space Agency last year whether it was interested in contributing to the Europa mission, and Gimenez said in an interview with Spaceflight Now that the answer is yes.
“We will participate with no cost to NASA by us contributing something equivalent to a half-billion euros in cost to ESA,” Gimenez said. “Now, where it goes depends on the cooperation.
“This is a NASA mission, and we are happy to be a junior partner with NASA,” Gimenez told Spaceflight Now in December. “It’s our natural partnership with the U.S., and we will be very happy to do it. Now, they have to tell us the profile of the mission, what they want to do, and where do we have a role. But certainly we would appreciate the opportunity.”
http://spaceflightnow.com/2016/01/05/esa-wants-to-be-a-part-of-nasas-mission-to-europa/
The call would have a special emphasis on Europa, but any space science mission could be proposed and be eligible for the competition, according to Favata.
QuoteThe call would have a special emphasis on Europa, but any space science mission could be proposed and be eligible for the competition, according to Favata.
Because the top guys essentially prejudging the outcome is not gonna go down like a cold cup of sick with the rest of the science community...
As far as I'm aware pretty much most past proposals, plus a whole lot more, are planning to respond to the M5 call. It's the first real opportunity since M3 and lots of cool ideas are being floated which I'm not sure a Europa contribution could beat in a fair fight.
QuoteThe call would have a special emphasis on Europa, but any space science mission could be proposed and be eligible for the competition, according to Favata.
Because the top guys essentially prejudging the outcome is not gonna go down like a cold cup of sick with the rest of the science community...
As far as I'm aware pretty much most past proposals, plus a whole lot more, are planning to respond to the M5 call. It's the first real opportunity since M3 and lots of cool ideas are being floated which I'm not sure a Europa contribution could beat in a fair fight.
I also wonder about using M5 as the funding mechanism. $550M for a 250 kg probe and NASA provides the launch seems like vast overkill. Thoughts anyone?
I also wonder about using M5 as the funding mechanism. $550M for a 250 kg probe and NASA provides the launch seems like vast overkill. Thoughts anyone?
I think it might fit like a glove, although of course ESA would have its members do a vote as they always do for their various missions. In a way the setup would be parallel to what Cassini-Huygens went through: a NASA-supplied flyby-orbiter delivering a ESA lander to the moon of a giant planet; the main difference lays with the moon's environment: irradiated and no atmosphere.
I also wonder about using M5 as the funding mechanism. $550M for a 250 kg probe and NASA provides the launch seems like vast overkill. Thoughts anyone?
But I would doubt that any of those would be going to high value target like Europa. I don't blame ESA wanting to have a piece of the action.
I also wonder about using M5 as the funding mechanism. $550M for a 250 kg probe and NASA provides the launch seems like vast overkill. Thoughts anyone?
Indeed I mentioned this previously, it seems overkill especially if they go with the penetrator as plenty of development work has already been funded and instrumentation will be naturally limited. But they do seem to be taking the M5 route. All I'm thinking is perhaps they are expecting extra expense in fast-tracking this, since M5 launch is nominally right at end of the 2020s.But I would doubt that any of those would be going to high value target like Europa. I don't blame ESA wanting to have a piece of the action.
Really? Since I heard there might be an Enceladus plume-sniffing orbiter with a proposed piggybacked American Titan boat for instance...
I also wonder about using M5 as the funding mechanism. $550M for a 250 kg probe and NASA provides the launch seems like vast overkill. Thoughts anyone?
Indeed I mentioned this previously, it seems overkill especially if they go with the penetrator as plenty of development work has already been funded and instrumentation will be naturally limited. But they do seem to be taking the M5 route. All I'm thinking is perhaps they are expecting extra expense in fast-tracking this, since M5 launch is nominally right at end of the 2020s.
Huygens was "about" 460 million Euro including the instruments, in 2012 EUR - with inflation that's 480 million EUR to today.The 550M Euro figure comes from the standard cost for ESA Medium class missions (the M4 call was less because the M3 mission is over budget). By ESA budgeting rules, this amount covers launch (paid for by NASA if the selected mission is a piggyback on NASA's mission), spacecraft, and operations. Instruments are paid for by the member nations separately.
See https://www.esa.int/esaSC/SEM77EUZJND_0_spk.html
ESA basically just picked the same ballpark number again, especially given that design, size and scope would likely be similar as for Huygens.
Splitting the mission into two launches could allow the clipper spacecraft to remain on a fast track. Niebur said that, given current funding trends where Congress has allocated significantly more for the mission than NASA has requested, a clipper spacecraft alone could be technically ready for launch as soon as 2022.
“If you put a very capable lander on there, I think that’s going to slow things down a bit,” he added. “Do you put them all on the same spacecraft and launch them on the same rocket, or do you split them onto separate rockets? That’s also an option we could consider.”
Niebur said that, separate from the discussion about a lander, NASA was examining several smaller “augmentations” to the clipper spacecraft. One example he mentioned is a cubesat-sized spacecraft that would fly through plumes of water ice ejected by Europa. Other additions to the clipper spacecraft could address studies of Europa’s gravitational field.
The current spacecraft design has about 250 kilograms of spare mass to support those or other additions to the clipper spacecraft separate from the lander. Those augmentations, he said, would not affect the primary science mission of the main spacecraft and its suite of 10 instruments NASA announced last year.
Is there any word regarding how the Outer Planet Assessment Group meeting went on the 1st and the 2nd? Talk on the Europa (Clipper) was supposed to be prominent according to their online schedule, seconded with talks on New Horizons, Cassini, and brief discussion on the Ice Giants. I was hoping by new some news leaked if nothing else.
I was hoping by new some news leaked if nothing else.
Usually the presentations are put up here http://www.lpi.usra.edu/opag/ after a couple of days.
OPAG can be up to a couple of weeks or more before the presentations are posted (VEXAG a month or two; MEPAG and SBAG the next day, often).Usually the presentations are put up here http://www.lpi.usra.edu/opag/ after a couple of days.
It's like the anxiety of Christmas all over again...
I listened to much of the meeting and a friend sent me notes on what I missed. The Space News article covered the big news -- including the lander would add more mass to the mission than the orbiter spacecraft.
There was a lot of talk about how to develop a plan for the Ocean Worlds missions. Since there isn't a program with a separate budget, it looks like it will be more identifying science goals and mission chunks (Discovery, New Frontiers, Flagship) that would address compelling portions of those goals. The Venus community has dome the equivalent in the last year or so (and two of those chunks are now Discovery finalists). There is a good sized chunk of funding for Ocean Worlds tech development that may address much of the cost problem.
So, don't expect anything that will be terribly exciting. Almost all the good stuff was said in the discussion and therefore wasn't captured in the presentations. One tidbit -- NASA will be pushing to do concept studies for the next Decadal Survey well before the start of the survey. Doing 38(?) of them in parallel for the last Survey nearly broke the system. Specific comments were that the cost estimates often were not seen as credible, and there was no time to study a range of concepts with different price points.
For example, the Enceladus studies were conceived of as a Flagship class mission and there wasn't time to study cheaper options. Someone who was on the Titan lake lander concept said that he tried to get cheaper options examined but there wasn't time and a mindset of what the scale of the mission should have been; having TiME come in at approximately half the estimated cost, was he said, an embarrassment. (Peace, Blackstar, I'm only reported what was said.)
I want to emphasize that I am NOT criticizing either the Decadal Survey team or NASA on the concept studies. The first planetary Decadal did not, if I remember correctly, do systematic mission studies or cost studies. The second did, and a learning was that doing a few dozen at once and quickly was much better than none, but starting early would be a good thing to do the next time, and NASA is. Fortunately, the priorities for planetary science evolve slowly, so there's a good idea of which missions to prioritize for study.So, don't expect anything that will be terribly exciting. Almost all the good stuff was said in the discussion and therefore wasn't captured in the presentations. One tidbit -- NASA will be pushing to do concept studies for the next Decadal Survey well before the start of the survey. Doing 38(?) of them in parallel for the last Survey nearly broke the system. Specific comments were that the cost estimates often were not seen as credible, and there was no time to study a range of concepts with different price points.
This is generally true--not enough mission concept studies had been done before the Decadal Survey. But the people who complain about this often fail to give NASA credit for stepping up and funding a lot of mission concept studies during the DS. NASA spent a LOT of money on the Decadal Survey. Funding the survey itself cost a bit, but the mission concept studies probably cost NASA over $5 million to do (I've got numbers written down somewhere in my notes). It's not fair to simply complain and whine and not give credit where it is due.
As for the "cost estimates were not seen as credible" issue, there is validity to that claim, but it's a complex discussion. And keep in mind that there is a tendency for the people who are advocating something to argue that it will be cheap, but nobody on the outside believes that. Have we all forgotten that from 2005-2009 there was a constant drumbeat about NASA missions blowing past their cost estimates? It was not just JWST and MSL, but there were problems with other missions like Dawn and Kepler. Remember that Alan Stern, when he was Associate Administrator for the Science Mission Directorate, made cost discipline a major issue. The reason that the CATE process was imposed (it was required by Congress) was because too many science programs were blowing past their budgets. Now that NASA has had 5+ years of pretty good cost discipline on their science projects, a bunch of scientists are now taking advantage of short memories and complaining about cost estimates imposed upon them from outside.
As I said, there is validity to the argument, but it's not a complaint that will win much sympathy with outsiders and budgeteers at OMB and Congress.
As for the range of concepts with various price points, that's a valid issue. But even when that is done, somebody is going to complain that their specific option did not get a fair hearing. You'll always find somebody to complain about something.
Blackstar can probably comment on this more, but at the time, there appeared to be an assumption that orbiters were needed to advance Enceladus and Titan studies meaningfully. Now we have the Europa multiflyby design to show another way (biggest change -- power and comms requirements drop dramatically with time between encounters to return data between encounters). There are also new trajectory designs that provide very low flyby speeds at Enceladus. There also have been three teams that have put extensive time into defining three Discovery-class missions. I see this as a case of the community internalizing the results of the Decadal concept studies and looking for less expensive alternatives. Exactly how things should work.For example, the Enceladus studies were conceived of as a Flagship class mission and there wasn't time to study cheaper options. Someone who was on the Titan lake lander concept said that he tried to get cheaper options examined but there wasn't time and a mindset of what the scale of the mission should have been; having TiME come in at approximately half the estimated cost, was he said, an embarrassment. (Peace, Blackstar, I'm only reported what was said.)I don't remember the details on the Enceladus studies. But one problem with hindsight is that it tends to compress the past and it is difficult to remember what was happening and when it was happening. We know a lot more about Enceladus today than we did in 2009 when the Decadal Survey was kicking off, or a few years earlier when people would have conducted more mission studies. Even if NASA had performed an Enceladus mission study in 2007 would they have had enough information about it to do "the range of studies with different price points" that people are talking about today?
One of the problems with Ocean Worlds is that it was created by a politician, and not by the scientists. For all the other topics the science community has been developing these science requirements for decades. They've been doing it a long time. Ocean Worlds has just popped up, and it has very little pedigree. If somebody comes along and asks "What are the requirements for Ocean Worlds science? What are the objectives?" they will not get a single succinct and coherent answer. They'll get a lot of mumbling and differing opinions. That is a problem. (It's actually a much bigger problem than those of us outside of all of this can comprehend.)Curt Niebur, outer planets program director, said that the Ocean Worlds proposers would be at disadvantage compared to the other New Frontiers because the goals and design concepts would be less mature. He also said, that based on the three Discovery proposals, Ocean Worlds proposals should be able to rise to the top of the competition. On the other hand, it wasn't clear from the meeting how much money NASA is putting into defining the science goals and funding mission concept studies. The SAG team was practically begging Niebur for admin support for their effort and Niebur seemed to be elusive. Perhaps this will be clearer by the next meeting. All of this is new to NASA and the community. At one point in the meeting, someone from NASA (Niebur?) said that the decision to include Ocean Worlds in New Frontiers was made in a two week period, presumably following the approval of the FY16 NASA budget directing NASA to pursue an Ocean Worlds program.
He also said, that based on the three Discovery proposals, Ocean Worlds proposals should be able to rise to the top of the competition.
One of the problems with Ocean Worlds is that it was created by a politician, and not by the scientists. For all the other topics the science community has been developing these science requirements for decades. They've been doing it a long time. Ocean Worlds has just popped up, and it has very little pedigree. If somebody comes along and asks "What are the requirements for Ocean Worlds science? What are the objectives?" they will not get a single succinct and coherent answer. They'll get a lot of mumbling and differing opinions. That is a problem. (It's actually a much bigger problem than those of us outside of all of this can comprehend.)Which leads to the question, how might the community go about establishing science requirements for Ocean Worlds and how much time does that need; initially and then refined?
Which leads to the question, how might the community go about establishing science requirements for Ocean Worlds and how much time does that need; initially and then refined?
From following Alan Stern's tweets it looks like there might be a follow up Pluto mission that will go into the mix for the next Decadal survey.There will probably be 20-50 missions proposed in the white papers submitted to the process. A smaller number will be considered in more depth.
If you can only do a flyby, I think it will be hard for a follow up mission to compete with the existing and possible new candidate missions for New Frontiers and Flagship. How do you fundamentally enhance our understanding of Pluto or the solar system with another flyby. If you see anything from Stern addressing this, please post a link.
If you can only do a flyby, I think it will be hard for a follow up mission to compete with the existing and possible new candidate missions for New Frontiers and Flagship. How do you fundamentally enhance our understanding of Pluto or the solar system with another flyby. If you see anything from Stern addressing this, please post a link.
Yeah, I agree. Pluto was a scientifically fascinating target the first time because a) we knew nothing about it, and b) we knew nothing about the class of objects that it represents. So a flyby provided a huge increase in data. But what could a second flyby reveal that would be that big a step? My guess is that they'll have a penetrator or something like that to add on, but even then that's not much.
NASA has a general philosophy of "flyby, orbit, land, rove" that makes a lot of sense.
If you can only do a flyby, I think it will be hard for a follow up mission to compete with the existing and possible new candidate missions for New Frontiers and Flagship. How do you fundamentally enhance our understanding of Pluto or the solar system with another flyby. If you see anything from Stern addressing this, please post a link.
Yeah, I agree. Pluto was a scientifically fascinating target the first time because a) we knew nothing about it, and b) we knew nothing about the class of objects that it represents. So a flyby provided a huge increase in data. But what could a second flyby reveal that would be that big a step? My guess is that they'll have a penetrator or something like that to add on, but even then that's not much.
NASA has a general philosophy of "flyby, orbit, land, rove" that makes a lot of sense.
A Pluto orbiter would be a heck of a technical challenge to resolve.
I'm sure SpaceX could do it. They can do anything.Now that is funny! ;) ;D :o
Which leads to the question, how might the community go about establishing science requirements for Ocean Worlds and how much time does that need; initially and then refined?
As I said, normally this is a process that is underway for years, and constantly being updated.
I'm sure that somebody could establish science requirements in a couple of minutes, a couple of hours, a day, or a week. The question then is how credible are they? And does the community as a whole agree with those requirements?
Given a need/desire to move quickly and a 'can do' attitude, what might be a reasonable minimum time to establish credible science requirements that have community agreement?
As for how long to reach consensus, that depends on the question and the class of mission.
I suspect that nearly everyone would agree that improving the chemical analyses of Enceladus' plumes with modern mass spectrometers (which the proposed ELF mission would have done) is a top priority.
Go one level below that, and it gets much, much harder. Is it more important to study the size and salinity of Enceladus' interior ocean (a top priority for Europa), map the surface geology of Titan using the spectral windows (a top priority for Europa; was included in the JET proposal), analyze the chemistry of Titan's lakes (the TiME proposal), or fly a balloon in Titan's atmosphere? Each represents different scientific questions, so which questions are most important.
Getting back to Europa...
Reading through the presentations, I get a strong vibe that preserving the flyby orbiter (whether you call it 'Clipper or otherwise) is foremost, which is both wise and something I agree with.
Getting back to Europa...
Reading through the presentations, I get a strong vibe that preserving the flyby orbiter (whether you call it 'Clipper or otherwise) is foremost, which is both wise and something I agree with.
To expand upon this a bit, as I noted earlier, JPL has been working on the design now for about four years. It's still in Phase A (or maybe pre-Phase A?) status, but it's actually quite mature for that stage. (That's something that we could certainly dive into much deeper. From what I understand, the longer missions stay in this stage, the less likely they are to encounter problems when they go into hardware development. Push them out of Phase A early and chaos and budget overruns ensue.)
And that's where NASA is in a bit of a bind, because they have been given a set of somewhat contradictory requirements. If they really are going to try and make the 2022 launch date, then they need to preserve as much of the design work as they can and not change too much. But if they add in a lander, or a bunch of new instruments, or whatever, that can create all kinds of shifts in the design and that can create big problems. This is the challenge of systems engineering: you reach a point in the design where every new change affects EVERYTHING ELSE.
Go back and read that Space News article linked above and you'll understand why they're talking this way now. It's crunch time, do we want a Europa spacecraft that can probably be launched in six years, or do we want to keep mucking around with the design for a few more years and maybe launch it in seven, nine, ten years?
From my limited understanding of how this is done and how the community approaches it, generally the most important science is the stuff that is considered "fundamental," meaning that it answers a major question about the solar system as a whole, or a whole class of objects in the solar system. If you look at the science goals for a number of the New Frontiers missions like South Pole-Aitken Basin Sample Return, you will see that the science goals are often to answer things like "how did the solar system form?" or "where did the Moon come from?" or "what role did the late heavy bombardment play in key processes on Earth?" (I'm paraphrasing these things, probably badly.)
Put another way, "when did life form on planet Earth?" is a much bigger and more important question than "when did giraffes get their long necks?" Applying that to this subject, if they can identify science questions where answering it for one body like Enceladus provides lots of insight into other bodies, like Europa, Ganymede, even Earth, then that science will be considered more valuable and more scientists will say "Yeah, that's important to know and we support missions that will answer that."
As an analogy, for Mars there has been a focus on finding locations with a history of prolonged surface water. That isn't a set of goals transferable to any other world in our solar system.
No arguments here; I was just glad when the instrument selections came through and adding in the UV spectrograph was enough of a bonus to hear; a UV imager tended to be a less demanding device whereas optical/thermal imagers and mass spectrometers were data/power munchers.
Looks like there won't be an SLS configuration for Europa Clipper since ICPS is only flying once.
Is there no chance of it using an EUS then?
Is there no chance of it using an EUS then?
Considering the EUS would need a flight test I mainly presumed that the Europa mission would be the guinea pig in exchange for using the vehicle "free of charge." Frankly though I'd like to hear actual news confirming what vehicle it will fly on, not just 'either the SLS or Altas V' retort.
Considering the EUS would need a flight test I mainly presumed that the Europa mission would be the guinea pig in exchange for using the vehicle "free of charge." Frankly though I'd like to hear actual news confirming what vehicle it will fly on, not just 'either the SLS or Altas V' retort.
EM-2 is EUS with Orion
the question is...especially with any delays to EM-2, whether Europa's flight could still get squeezed in beforehand on the first EUS.
That's been known for a little while, the question is...especially with any delays to EM-2, whether Europa's flight could still get squeezed in beforehand on the first EUS.
That's been known for a little while, the question is...especially with any delays to EM-2, whether Europa's flight could still get squeezed in beforehand on the first EUS.
What delays? If there are any delays, they will be EUS driven and not Orion driven. The push is going to be on EM-2. Plus Europa is not going on SLS with an EUS.
So nominally the Europa mission is being budgeted for Atlas V partially because they can predict that expense better? I would hope somewhere someone is attempting to account for SLS' expense, but I understand the precaution since the vehicle still has yet to be flight tested (not to mention being just-plain-huge). The only other thought on launcher is, going the SLS route, was it planned for Europa to fly Block I or Block Ib originally? Odds seem to imply a EUS route unless NASA decides to use the spare for Europa.
Assuming the Atlas V route, how extensive was the 'long-route' to Jupiter?
So nominally the Europa mission is being budgeted for Atlas V partially because they can predict that expense better?
So nominally the Europa mission is being budgeted for Atlas V partially because they can predict that expense better?
I'm not sure that is the only reason. Keep in mind that NASA has a list of approved launch vehicles and their characteristics (these are all covered under a launch services contract that the agency has with its providers). Thus choosing Atlas is relatively easy to do for planning purposes because they know exactly how long it takes to build, what it can do, and what it costs for a given configuration. SLS is still much more of a moving target. It's sort of the difference between buying off the shelf and buying custom made.
And also keep in mind that SMD (Planetary Sciences Division) will only pay the cost of an Atlas to HEOMD for an SLS. In other words, if the SLS is going to cost the science division more than an Atlas, they don't want it. But that still requires HEOMD to pay the full cost of the SLS. And that still requires the overall NASA budget to account for it. So adding an SLS launch to NASA's manifest also requires more money in the budget to pay for it.
I am still doubtful that they'll ever fly the Europa mission on an SLS, but it remains a viable option. But it is also problematic for budgeting purposes.
I am assuming if they do end up using Atlas it will be in the most powerful 551 configuration for this mission? Would they need to use an additional third stage as featured on New Horizons?
I was under the impression Atlas on a VEEGA could throw more too. I went looking for the exact figures. I found this document which I am attaching that states that SLS can throw more on a direct trajectory than an Atlas V 551 can on a VEEGA trajectory. It is the table on page 6:
Atlas V 551 (VEEGA) = 3,582kg, SLS Block 1 = 4,380kg, and SLS Block 1b = 8,920kg.
Are there better figures out there which show Atlas as being able to get more mass on a VEEGA trajectory or SLS with less on a direct trajectory?
So it will be double Galileo's mass and possess a HGA that's side-mounted instead of axial-mounted? Are there any further details available beyond the instrument listing?
They mentioned considering the Falcon Heavy as a launch vehicle choice. Do we know how much oomph it could provide a Jovian mission? Offhand I know it's supposed to do better than an Atlas V but I assume at least 1 gravity assist would be required to get it all the way there.
They mentioned considering the Falcon Heavy as a launch vehicle choice. Do we know how much oomph it could provide a Jovian mission? Offhand I know it's supposed to do better than an Atlas V but I assume at least 1 gravity assist would be required to get it all the way there.
Yes, all hype and claimed numbers aside, I'm skeptical FH would be near the capability of launching it on a direct trajectory. It probably could, however, haul quite a bit of mass onto a gravity assist trajectory where the C3 requirement isn't as high and so its lower Isp doesn't hurt as much.
Rocket Falcon Heavy
PLF Mass 4,000 kg
PLF separation 231 seconds
Payload to LEO (185 km x 185 km x 28 deg) 60,539 kg
Payload to GTO (-1800 m/s (18 degrees)) 24,236 kg
Payload to GTO (-1500 m/s (18 degrees)) 21,141 kg
Payload to GSO 10,968 kg
Payload to Moon (TLI) 17,692 kg
Payload to Mars 14,419 kg
Payload to Venus 15,135 kg
Payload to Jupiter (direct) 3,090 kg
Payload to Mercury 5,353 kg
I did some digging around in the SpaceX forums and found some figures Hyperion5 quoted on back in May:
http://forum.nasaspaceflight.com/index.php?topic=35419.1320QuoteRocketFalcon Heavy
PLF Mass4,000 kg
PLF separation231 seconds
Payload to LEO (185 km x 185 km x 28 deg)60,539 kg
Payload to GTO (-1800 m/s (18 degrees))24,236 kg
Payload to GTO (-1500 m/s (18 degrees))21,141 kg
Payload to GSO10,968 kg
Payload to Moon (TLI)17,692 kg
Payload to Mars14,419 kg
Payload to Venus15,135 kg
Payload to Jupiter (direct)3,090 kg
Payload to Mercury5,353 kg
So while no SLS or Saturn V, the FH would be able to put ~2/3 of the Europa mission's mass onto a direct flight. or presumably 2/3 of the required velocity for a ~5000 kg vehicle. Even factoring in an additional 300 kg (the budgeted mass for a small lander), this still equates to better than half. So at least 1 Earth flyby would be required, or possibly a double Earth flyby with no Venus fry-bys required.
That's a better performance than I was expecting. So once it is qualified by NASA for their payloads it might be the best alternative to SLS for this mission.
Is that with total performance dedicated to the mission and no fly back of the first stages?
I did some digging around in the SpaceX forums and found some figures Hyperion5 quoted on back in May:
http://forum.nasaspaceflight.com/index.php?topic=35419.1320QuoteRocketFalcon Heavy
PLF Mass4,000 kg
PLF separation231 seconds
Payload to LEO (185 km x 185 km x 28 deg)60,539 kg
Payload to GTO (-1800 m/s (18 degrees))24,236 kg
Payload to GTO (-1500 m/s (18 degrees))21,141 kg
Payload to GSO10,968 kg
Payload to Moon (TLI)17,692 kg
Payload to Mars14,419 kg
Payload to Venus15,135 kg
Payload to Jupiter (direct)3,090 kg
Payload to Mercury5,353 kg
So while no SLS or Saturn V, the FH would be able to put ~2/3 of the Europa mission's mass onto a direct flight. or presumably 2/3 of the required velocity for a ~5000 kg vehicle. Even factoring in an additional 300 kg (the budgeted mass for a small lander), this still equates to better than half. So at least 1 Earth flyby would be required, or possibly a double Earth flyby with no Venus fry-bys required.
That's a better performance than I was expecting. So once it is qualified by NASA for their payloads it might be the best alternative to SLS for this mission. Is that with total performance dedicated to the mission and no fly back of the first stages?
I was curious about the Cubesat studies JPL issued last(ish) year, and scraped together a bit of information from various sources which might be of interest to people.
The two concepts I personally found the most interesting are the APEX with its super cool trajectory (Io flyby!) and massive MS instrument, and the Imaging Cubesat from ASU with its plan of doing targeted, 3D imaging for 400km down the length of a ridge on Europa.
The Europa Imaging System will be able to return targeted imagery up to about 1 meter in resolution. AUS's cubesat proposal will do 0.2 to 0.3 meters. Interestingly this is about the same difference between the Mars Global Surveyor and its successor Mars Reconnaissance Orbiter. MRO discovered that the initial prime landing site for Mars Phoenix had too many rocks and boulders. Phoenix couldn't land on any rocks bigger than 0.35 to 0.45 meters. I don't know if the imagery before that was taken at MGS's highest resolution. If it was it would be a good argument for getting that higher resolution imagery.The two concepts I personally found the most interesting are the APEX with its super cool trajectory (Io flyby!) and massive MS instrument, and the Imaging Cubesat from ASU with its plan of doing targeted, 3D imaging for 400km down the length of a ridge on Europa.
Those two also stood out the most to me. APEX's visit to Io would make a great finale to their mission not to mention possibly finding more details on Europa's atmosphere and plumes than 'Clipper itself might. ASU's idea is ambitious for a cubesat, although I'm unsure one ridge would be enough of an advantage versus 'Clipper's complete mapping of Europa.
The Europa Imaging System will be able to return targeted imagery up to about 1 meter in resolution. AUS's cubesat proposal will do 0.2 to 0.3 meters. Interestingly this is about the same difference between the Mars Global Surveyor and its successor Mars Reconnaissance Orbiter. MRO discovered that the initial prime landing site for Mars Phoenix had too many rocks and boulders. Phoenix couldn't land on any rocks bigger than 0.35 to 0.45 meters. I don't know if the imagery before that was taken at MGS's highest resolution. If it was it would be a good argument for getting that higher resolution imagery.The two concepts I personally found the most interesting are the APEX with its super cool trajectory (Io flyby!) and massive MS instrument, and the Imaging Cubesat from ASU with its plan of doing targeted, 3D imaging for 400km down the length of a ridge on Europa.
Those two also stood out the most to me. APEX's visit to Io would make a great finale to their mission not to mention possibly finding more details on Europa's atmosphere and plumes than 'Clipper itself might. ASU's idea is ambitious for a cubesat, although I'm unsure one ridge would be enough of an advantage versus 'Clipper's complete mapping of Europa.
Jeff Foust @jeff_foust
Elachi: Europa orbiter and lander will be two separate spacecraft, not attached to each other.
Elachi: Europa orbiter and lander will be two separate spacecraft, not attached to each other.
Elachi: if you launch Europa orbiter and lander together on 1 SLS, still need to do flybys to get there. Faster if launched on separate SLSs
Hrg is on "ocean worlds" and JPL Dir Elachi incl Mars in that bin because it USED to have oceans.
QuoteElachi: if you launch Europa orbiter and lander together on 1 SLS, still need to do flybys to get there. Faster if launched on separate SLSs
Two SLS launches has me a little worried... Then again, we've been complaining about a lack of missions for SLS for a long time, so hey.
QuoteElachi: if you launch Europa orbiter and lander together on 1 SLS, still need to do flybys to get there. Faster if launched on separate SLSs
Two SLS launches has me a little worried... Then again, we've been complaining about a lack of missions for SLS for a long time, so hey.
2 SLS seems a bit much, even for the sake of giving the SLS an itinerary list. Personally, I'd suggest either one SLS for both spacecraft, an SLS for orbiter with Falcon Heavy for lander, or two FHs. Optimally I'd suggest the middle setup to get the orbiter there fast while giving the lander a cheaper-yet-efficient ride.
The orbiter could take the quick trip to gather info about potential landing sites while the lander takes the slow way round.The orbiter is four years into its definition. The lander is barely a few months into its development. Unless you delay the orbiter, the lander should launch later.
QuoteElachi: if you launch Europa orbiter and lander together on 1 SLS, still need to do flybys to get there. Faster if launched on separate SLSs
Two SLS launches has me a little worried... Then again, we've been complaining about a lack of missions for SLS for a long time, so hey.
A question about using the Falcon Heavy for the Europa mission. Will the transit time to Europa be less than the baseline EELV?
Rocket Falcon Heavy
PLF Mass 4,000 kg
PLF separation 231 seconds
Payload to LEO (185 km x 185 km x 28 deg) 60,539 kg
Payload to GTO (-1800 m/s (18 degrees)) 24,236 kg
Payload to GTO (-1500 m/s (18 degrees)) 21,141 kg
Payload to GSO 10,968 kg
Payload to Moon (TLI) 17,692 kg
Payload to Mars 14,419 kg
Payload to Venus 15,135 kg
Payload to Jupiter (direct) 3,090 kg
Payload to Mercury 5,353 kg
Elachi: SLS will get spacecraft to Jupiter in 2-2.5 yrs instead of 6-7. If lander is really heavy cld do 1 Earth flyby & get there in 4 yrs
A question about using the Falcon Heavy for the Europa mission. Will the transit time to Europa be less than the baseline EELV?
I pondered about the same thing too. I actually dug into the Falcon Heavy threads and found this (not to mention posted it within this thread too), courtesy of Hyperion5:QuoteRocketFalcon Heavy
PLF Mass4,000 kg
PLF separation231 seconds
Payload to LEO (185 km x 185 km x 28 deg)60,539 kg
Payload to GTO (-1800 m/s (18 degrees))24,236 kg
Payload to GTO (-1500 m/s (18 degrees))21,141 kg
Payload to GSO10,968 kg
Payload to Moon (TLI)17,692 kg
Payload to Mars14,419 kg
Payload to Venus15,135 kg
Payload to Jupiter (direct)3,090 kg
Payload to Mercury5,353 kg
Considering the Europa mission is going to weigh ~5,000 kg that means the FH can deliver 2/3 of the mass directly to Jupiter. It is only going to need a modest push to get it finally to Jupiter, so most likely 1 Earth flyby just like Juno. As for timeline, vjkane mentioned Elachi here:Elachi: SLS will get spacecraft to Jupiter in 2-2.5 yrs instead of 6-7. If lander is really heavy cld do 1 Earth flyby & get there in 4 yrs
The FH specs Hyperion5 mentioned are just under a year old, more than likely still relevant. The FH would make a fine alternative to SLS. But, to answer your question, YES. ;)
I want them to hold out for a lander. Congress is interested in this, c'mon people, get the money for a drill or a boat.
I should mention that the "thin shell" theory (the one in which Europa's ice shell is only a few km thick) is all but dead. There are very few people in the community who don't think that the ice shell is closer to 30 km thick.
I want them to hold out for a lander. Congress is interested in this, c'mon people, get the money for a drill or a boat.
Or why not a submarine? Or a manned mission to Europa?
I want 80% of something instead of 100% of nothing.
But I think it's important to recognize that even if we could do a very ambitious mission now it is probably not the best way to do it. A series of missions over a longer period of time allows for people to spend more time analyzing the data and formulating better questions. Science takes time. Things have to be learned and discussed and distributed.
Re: Landers of the further future reaching liquid water on EuropaI should mention that the "thin shell" theory (the one in which Europa's ice shell is only a few km thick) is all but dead. There are very few people in the community who don't think that the ice shell is closer to 30 km thick.
I wouldn't be surprised if the ice shell on Europa varies just like crustal thickness varies on Earth; oceanic and continental crusts have distinct differences and considering water ice is "just another rock" out in the outer solar system, it's not unreasonable to think it would behave any differently (in an overall sense, of course the chemistry differs). The only way to settle and confirm which hypothesis is right is with more data - radar from the orbiter and seismic readings from a lander.
What about "perched lakes," as mentioned in this November 2011 on-line article in Sky & Telescope, Europa’s Subsurface Lakes (http://www.skyandtelescope.com/astronomy-news/europas-subsurface-lakes/)? They might be only 2 kilometers under the surface. Autonomous drilling to 2 km depth is preferable to drilling 30 km.The ice penetrating radar on the orbiter will look for both differences in ice shell thickness and perched lakes.
Well, Europa has some special situation that could make drilling feasible. Namely, the ice is in vacuum. If you used and RTG to sublimate the ice very slowly, it should just evaporate. Main issue (besides comm) should be vapor deposition on the tunnel walls.that depends on the speed of the melting as you suggest. clearly when water seeps up from below the ice (either shell fracturing or impact) not all of the exposed water sublimates. most apparently freezes
What about "perched lakes," as mentioned in this November 2011 on-line article in Sky & Telescope, Europa’s Subsurface Lakes (http://www.skyandtelescope.com/astronomy-news/europas-subsurface-lakes/)? They might be only 2 kilometers under the surface. Autonomous drilling to 2 km depth is preferable to drilling 30 km.The ice penetrating radar on the orbiter will look for both differences in ice shell thickness and perched lakes.
However, deep drilling in ice (even 2 km) is hard on Earth, and we lack the technology to do it on an icy moon, especially one in an intense radiation field.
Another goal for the orbiter will be to find a landing site where there is a good chance that nature has recently delivered subsurface water to the surface. The ideal site would have:
1. An active plume (or several). Nothing like real time delivery. Failing that:
2. Surface composition that includes organics and salts. I believe that spectral measurements can suggest how recently the material was delivered.
3. Fractured surface suggesting that the ice shell was broken to allow water on to the surface
This in spades. If a recent impact or hydro-volcanism has brought water up from deeper layers, and if life exists on Europa, then the equivalent of fossils should be embedded within that ice. I don't think deep drilling is necessary at all. We just need a way to establish stratigraphic sequences.Ice turns out to be a great shield against radiation effects. So if the lander can get down a meter or two, the material may be pretty pristine
This in spades. If a recent impact or hydro-volcanism has brought water up from deeper layers, and if life exists on Europa, then the equivalent of fossils should be embedded within that ice. I don't think deep drilling is necessary at all. We just need a way to establish stratigraphic sequences.Ice turns out to be a great shield against radiation effects. So if the lander can get down a meter or two, the material may be pretty pristine
However, deep drilling in ice (even 2 km) is hard on Earth, and we lack the technology to do it on an icy moon, especially one in an intense radiation field.
Eric Berger – Verified account @SciGuySpace
No free rides on SLS for science payloads, NASA's Bolden says. "The science community is going to have to pay for launch vehicles."
https://mobile.twitter.com/SciGuySpace/status/715541138145325056
Eric Berger – Verified account @SciGuySpace
No free rides on SLS for science payloads, NASA's Bolden says. "The science community is going to have to pay for launch vehicles."
https://mobile.twitter.com/SciGuySpace/status/715541138145325056
Well, what the science leadership at NASA has been saying for awhile now is that they'll pay the cost of an EELV (essentially a top line Atlas V) and no more. They don't want to get stuck with the full cost of an SLS. If they do, they won't buy it. I don't think this statement from Bolden is inconsistent with that.
I suppose you're not going to see rovers on places like Europa until autonomous technology is far more advanced because of the communication delays.I don't think so, a daily cycle as used for Mars rovers should work fine. The reason you won't see a Europa rover any time soon is money.
On the lander, I would have thought that even a few days of seismic data would be extremely valuable in characterizing the thickness of the ice crust. With Jovian tides, I imagine there would be a lot of seismic activity going on in the crust.I watched the Europa presentation at the meeting. Another slide showed a geophone as part of the baseline (desired, attempt to include) rather than the threshold (don't fly without these) instrument suites.
Is it just a difficulty in getting a long enough surface lifetime for meaningful data, or more of a deployment issue?
As to the inclusion of a seismic element to a Europa Lander I couldn't agree more. The only problem is the instrument itself. It was the SEIS seismic tool leakage that delayed the Mars Insight mission . It's obviously a difficult piece of technology .The SEIS instrument apparently worked fine. It would the containing vessel that has vacuum leaks. This isn't likely to be a problem at Europa since its surface has a high grade vacuum.
Thanks everyone for the insights into interplanetary mission planning and costs. I'm a huge fan of the Falcon Heavy and in sure one day it will pay a big role , thought not till SpaceX use their ISS and commercial crew public money to first get the launcher as expendable and heap as possible to consolidate their core business of LEO comes satellites and GEO DoD whatevers. Whilst avoiding any confrontation with principal paymasters Nasa over SLS for as long as possible , though that will come.At the meeting, the Europa project manager said that they expect to evaluate the Falcon Heavy, but can't do so until the design and the resulting specifications are complete. He said that the performance would be similar to that of a Delta IV heavy.
Is there high politics at play here? Delay till new more mission friendly President gets in and assists at last , unencumbered as much over the critical mission years by JWST overspend. Is there a Flyby only compromise or does there need to be cuts and if so what ? If so what ? Neither NASA or ESA can really afford their proposed Mars Rovers so is the reach out to the ESA over a lander a suggestion for a Mars Rover merger ? The U.S. One is proven through Curiosity so a less risky choice , especially with sky crane landing heritage . Two landers there too whose cash could be redirected ( as from same fund ) to offset SLS, assuming cancellation of expensive "Insight" and use of its launcher for a combined Mars mission . May be too advanced for that , but it illustrates the sort of drastic things that would need to be done unless the President comes to rescue . "Tactical" mission cuts at least rather than much more damaging " strategic" programme cuts .OMB clearly doesn't want to see the Europa mission fly. Stating in the most recent proposed budget that the mission may fly as early as the late 2020s is the same as saying never. That's at least two Presidents and several Congresses from now, and you could never keep a design team together for that long.
The new slides are impressive to look at.I would still like to see cubesats as an option, but they haven't been mentioned in awhile.
So the lander will be separate and a plume probe is nixed; I suspect daughter craft with the 'Clipper will be out of the question in general; had some hopes for the Io mini-flyer but then again Europa is the priority so you have to admire the tenacity and focus the team is keeping toward that end.
So if anything else is added, a laser altimeter? Most if its benefits were tied to the orbiter concept as opposed to fly-by; how useful could it be during flybys?
Thanks everyone for the insights into interplanetary mission planning and costs. I'm a huge fan of the Falcon Heavy and in sure one day it will pay a big role
A question about using the Falcon Heavy for the Europa mission. Will the transit time to Europa be less than the baseline EELV?
I pondered about the same thing too. I actually dug into the Falcon Heavy threads and found this (not to mention posted it within this thread too), courtesy of Hyperion5:QuoteRocket Falcon Heavy
PLF Mass 4,000 kg
PLF separation 231 seconds
Payload to LEO (185 km x 185 km x 28 deg) 60,539 kg
Payload to GTO (-1800 m/s (18 degrees)) 24,236 kg
Payload to GTO (-1500 m/s (18 degrees)) 21,141 kg
Payload to GSO 10,968 kg
Payload to Moon (TLI) 17,692 kg
Payload to Mars 14,419 kg
Payload to Venus 15,135 kg
Payload to Jupiter (direct) 3,090 kg
Payload to Mercury 5,353 kg
Considering the Europa mission is going to weigh ~5,000 kg that means the FH can deliver 2/3 of the mass directly to Jupiter. It is only going to need a modest push to get it finally to Jupiter, so most likely 1 Earth flyby just like Juno. As for timeline, vjkane mentioned Elachi here:Elachi: SLS will get spacecraft to Jupiter in 2-2.5 yrs instead of 6-7. If lander is really heavy cld do 1 Earth flyby & get there in 4 yrs
The FH specs Hyperion5 mentioned are just under a year old, more than likely still relevant. The FH would make a fine alternative to SLS. But, to answer your question, YES. ;)
More than that. Rovers take a lot of power, and a lot of bandwidth, just to move around safely. That+actual science, at Europa, would get very big very fast. Money solves most mass problems but that's a big one.I suppose you're not going to see rovers on places like Europa until autonomous technology is far more advanced because of the communication delays.I don't think so, a daily cycle as used for Mars rovers should work fine. The reason you won't see a Europa rover any time soon is money.
Based on our current understanding of interesting places on Europa scientifically, they are chaotic regions full of large ice blocks and cliffs. A spider walker would be more useful than a rover.More than that. Rovers take a lot of power, and a lot of bandwidth, just to move around safely. That+actual science, at Europa, would get very big very fast. Money solves most mass problems but that's a big one.I suppose you're not going to see rovers on places like Europa until autonomous technology is far more advanced because of the communication delays.I don't think so, a daily cycle as used for Mars rovers should work fine. The reason you won't see a Europa rover any time soon is money.
Based on our current understanding of interesting places on Europa scientifically, they are chaotic regions full of large ice blocks and cliffs. A spider walker would be more useful than a rover.Which actually raises a bigger issue: To know what instruments make sense and what capabilities are required, you really want much better data than we have now. Trying to design a rover (or walker) mission now would be very expensive and high risk. Imagine trying to design MSL based on Mariner data.
Imagine trying to design MSL based on Mariner data.Anything beyond Huygens-level capabilities would be stretching it.
A very basic lander on the first mission may make sense
I don't see why people are discussing a rover that would be dead from radiation damage before it ever got off the lander.
I also don't think that NASA should be talking about the lander doing 'astrobiology' . Europa has an ice shell 1-30 km thick, the surface may be covered with sulfuric acid and is subject to intense radiation. None of that is promising for biology. What a lander can realistically do is to measure surface chemistry and isotope ratios. Isotope ratios could tell you something about the formation history of the moon. It should also have a small drill experiment to measure the mechanical properties of the ice so that future drilling schemes can be constrained by data.
Of course NASA doesn't have the money for a lander. If NASA did have the money they would probably spend it on something else, and the science-political support isn't there because the decadal survey didn't mention a lander mission.
Is the shell around the lander an actual structure or some bounding box sort of thing? It's a little hard to tell, it looks like the lander stack slots into the doughnut-shaped carrier and pops out the top before dumping the shell?
There are similar issues with Mars sample return. Every time I see somebody suggest that they should add ISRU to the Mars sample return architecture I cringe. That's adding unproven and complicated technology to something that is already difficult to do, and it does not actually improve the result, it only adds risk (a good rule of thumb is that if you are going to add risk, you should also have a good benefit to the mission for doing so).
OT comment by me, but adding operational ISRU allows increasing the returned sample mass by about an order of magnitude. Despite the advances in analytical techniques, sample size and diversity is still very important. I quite agree with the point of added complexity but I'll match your cringe with my eye roll over the greatly reduced return any day. OK, back to the scheduled program. :)
–Lander
•Science!!!
OT comment by me, but adding operational ISRU allows increasing the returned sample mass by about an order of magnitude. Despite the advances in analytical techniques, sample size and diversity is still very important. I quite agree with the point of added complexity but I'll match your cringe with my eye roll over the greatly reduced return any day. OK, back to the scheduled program. :)
I fully agree with you that untested, unproven, theoretical technologies that are high risk have far greater performance than tested, proven, existing technologies. Absolutely true. On Mars. On Europa. Everywhere.
I believe that you have to read again the very definition of TRL.OT comment by me, but adding operational ISRU allows increasing the returned sample mass by about an order of magnitude. Despite the advances in analytical techniques, sample size and diversity is still very important. I quite agree with the point of added complexity but I'll match your cringe with my eye roll over the greatly reduced return any day. OK, back to the scheduled program. :)
I fully agree with you that untested, unproven, theoretical technologies that are high risk have far greater performance than tested, proven, existing technologies. Absolutely true. On Mars. On Europa. Everywhere.
Nothing theoretical, untested, or unproven about ISRU. TRL varies between 3 and 6 depending on type under discussion.
Nothing theoretical, untested, or unproven about ISRU. TRL varies between 3 and 6 depending on type under discussion.Not to sidetrack, but i'm aware of multiple projects that have gone to TRL 4/5, but not legitimately at 6 - i.e. mostly flight weight/volume prototype that meets the performance goals, tested in analog environment.
The House bill also specified that, of the $5.6 billion allocated for NASA’s science programs, $260 million go towards a mission to Europa. NASA requested less than $50 million for the Europa mission, while the Senate’s bill did not specify an amount for that proposed mission.
The additional Europa funding is not surprising, as Rep. John Culberson (R-Texas), chairman of the CJS subcommittee, has been a leading advocate for a Europa mission for several years, adding funding well above any NASA request for a spacecraft to help determine if the icy moon can support life.
Looks like the politicians are trying to force NASA's hand this.QuoteThe House bill also specified that, of the $5.6 billion allocated for NASA’s science programs, $260 million go towards a mission to Europa. NASA requested less than $50 million for the Europa mission, while the Senate’s bill did not specify an amount for that proposed mission.
The additional Europa funding is not surprising, as Rep. John Culberson (R-Texas), chairman of the CJS subcommittee, has been a leading advocate for a Europa mission for several years, adding funding well above any NASA request for a spacecraft to help determine if the icy moon can support life.
http://spacenews.com/house-bill-offers-19-5-billion-for-nasa-in-2017/
It's not forcing NASA's hand. It's forcing the OMB/Obama administration's hand. And this has been going on for a number of years now. There are people at NASA who would love if the administration asked for sufficient money to fund a Europa mission. But the administration is not doing that, so Congressman Culberson is forcing it on them.
Obama's administration definitely had zero interest in NASA, that's proven obvious by now; even (Bill) Clinton and George (W) Bush before him showed at least slightly more interest. Not terribly surprised NASA's the Cinderella of the situation, although at least the Planetary Science program is fairing vastly better than it was in the 1980s.
Steering back to the proper topic though, it is still heartwarming to know Europa hasn't been forgotten. Clearly it will be funded and become the next flagship after Mars 2020. The real fun part will be seeing IF it flies aboard SLS or not, which is also part of the funding fun.
Will it be able to reach completion as a project if there is a repeated stance of indifference by the next adminstration?
And yes, you are right about Europa. It will indeed be interesting to see what happens.
The people who run it (HQ, JPL) have to know how much money they will have for the next several years so that they can start buying stuff. ..
Wishes. Horses. Unicorns.
I think Clipper will happen (although not by that name). I knew about the plan to separate the lander from the Clipper mission. NASA was telegraphing that many months ago and the question was if they would convince Culberson it was the way to go (and it really is a very bad idea to put the flyby mission and the lander on the same launch, for lots and lots of reasons). A few months back I heard that some wise people had convinced Culberson of the wisdom of separating them. So it was only a question of when that became public.
Now the lander... That's going to slip. It will be an expensive spacecraft to design and it will take some time. You really want to do it right, not half-assed. So 2 years after the flyby mission is not a good phasing for that. But baby steps. Baby steps.
As for the SLS, it's a complex budget issue and I don't understand it (well, I just haven't asked the right people to explain it to me). But an extra SLS will cost more money to NASA, no matter whether it comes out of the SMD budget or the HEOMD budget. It will probably be added on top of the NASA budget, and book-kept in HEOMD or SMD or somewhere. But the key thing is that it's going to cost more money.
And the example proposed above, launching propellant into orbit with nothing for it to do based upon the idea that eventually you might build a payload that could use it, is an imaginary idea. It's a really nonsensical way to do something, like going out and buying 200 gallons of gas and storing it in your garage in case someday you may buy a car. Nobody does that.
I think that if Congress is going to mandate that NASA fly robotic payloads on SLS, then Congress (or a new White House) is going to have to add in more money for the additional SLS rockets.
And you were proposing launching propellant into space long before there is a spacecraft built that can use it. That's nonsensical.About as nonsensical as collecting samples on Mars before there is even a token plan of getting these back home
And you were proposing launching propellant into space long before there is a spacecraft built that can use it. That's nonsensical.About as nonsensical as collecting samples on Mars before there is even a token plan of getting these back home
It is a helluva way to run a railroad.
Gosh, I had missed the two SLS news. So the deal is now, one SLS for the orbiter, one other SLS for the lander ?With the way the senate has been throwing money at SLS, I doubt we'll have trouble funding it. We managed to launch the shuttle multiple times a year, and this is basically the same.QuoteIt is a helluva way to run a railroad.
Sure it is. Who gonna pay for the uber-expensive twin SLS flights ?
"We have increased funding for planetary programs and made sure we are going to complete the incredibly important mission to Europa that the planetary decadal survey mapped out because of the very high likelihood that life will be discovered in those oceans," Culberson said during a hearing Tuesday. "This will be a transformative moment in the history of humanity and the country."
In its documents about the Europa mission, NASA has not formally approved a lander, and it says only that the flyby mission will launch "sometime in the 2020s." The House bill is much more specific, calling for an orbiter launch no later than 2022 and a lander launch no later than 2024. Senior officials at the Jet Propulsion Laboratory have told Culberson that those dates are attainable. Additionally, the bill specifies that NASA's next budget, for fiscal year 2018, includes a five-year funding profile to support those two launches.
This looks like it is growing into a $6bn megaproject. To my eye, the orbiter and its instruments looks more like a $4bn mission than a $2bn mission. As for the lander, who knows? I'll open the bidding at $3bn. The use of the skycrane landing system suggests a large and complex mission like Curiosity, which cost $2.4bn To drive the cost up, there is the fact that the surface of Europa requires a large delta-v, and the radiation environment is much more demanding than at Mars. The thermal environment will be distinctly chilly during the Europan night, which will probably require an RTG unless the surface mission is very short.
Then there is the cost of the SLS launches. The real cost of an SLS launch at a flight rate of 1/year could easily be over $1bn when all the overheads are included. Charging those costs to the science budget gives SLS an opportunity to loot science in order to pay their own bills.
I think there is a way for everybody to agree on a Europa orbiter if everyone agrees to keep the costs down to $2bn or so. That means no lander of course. If Congress wants to add money to the planetary science budget they need to show where it will come from. More money for planetary would be very welcome, but realistic cost estimates for the lander and a fixed price for the SLS launches are still needed.
However much money is on offer, NASA should not promise an astrobiology lander. There isn't enough data on the surface of Europa to design such a beast, and what little is known is not at all promising for the survival of surface organics. All that can be done is a basic exploration of the surface chemistry and composition, and the collection of engineering data needed to design something more ambitious.
How good are relations between Culbertson (Mr Europa) ....
Not quite sure why you're assuming the lander is just going to examine the surface alone. Such a project would be rather limited unless it was put down somewhere where it could also access one of the numerous cracks on Europa's surface and therefore conduct some subsurface science as well.Without data from the orbiter, that's very speculative. We know the cracks are young (in geological terms) and somehow relate to interior activity, but that doesn't necessarily mean landing in these areas would tell us much about the interior.
Not quite sure why you're assuming the lander is just going to examine the surface alone. Such a project would be rather limited unless it was put down somewhere where it could also access one of the numerous cracks on Europa's surface and therefore conduct some subsurface science as well.Without data from the orbiter, that's very speculative. We know the cracks are young (in geological terms) and somehow relate to interior activity, but that doesn't necessarily mean landing in these areas would tell us much about the interior.
We also don't know what capabilities are required to land there. Without better data, the lander either has to be designed for worst case scenarios (very expensive), or run a high risk of not being able to land safely in those regions.
Similar issues apply to the science payload.
A lander designed after the data from the first orbiter have been analyzed will be much lower risk, more cost effective and have better science return.
Maybe a topic for another thread if the answer gets too long, but how were interplanetary payloads for the Shuttle handled from a funding standpoint? Is there any similarity with that and how things are proceeding with Clipper on SLS?
Cost is probably the true issue for flying via SLS. For the Europa mission (either the orbiter or lander), it would be wonderful to get directly to Jupiter; bad news is it may cost a lot, which coupled with safety was also a reason satellite providers rapidly abandoned the space shuttle. I'd like to see the flyby-orbiter fly with it, but I wouldn't want to do that with the lander since developing that will be enough of a future expense as is.I've worked with enough finance people to know that there is a lot of leeway on how costs are accounted for. NASA will have large fixed costs for maintaining the capability of launching SLS missions. Then there will be the marginal costs associated with building an individual booster, transporting it, fueling it, launching it, etc. The key will be whether the science division (I suspect there are some great telescope observatories that SLS could launch in addition to planetary missions) is charged only the marginal cost or a substantial portion of the fixed costs.
While the SLS is unflown for now...And that's the crazy part .. This will predictably become a multi-billion dollar mission. It will be trusted to a launcher that will have scored one or two flights maybe ? Whatever happened to launcher certification and all that.
While the SLS is unflown for now...And that's the crazy part .. This will predictably become a multi-billion dollar mission. It will be trusted to a launcher that will have scored one or two flights maybe ? Whatever happened to launcher certification and all that.
Well, wasn't Cassini launched on only the 2nd Titan IVB vehicle flown? Yeah, it wasn't a completely new vehicle, but still it puts things into some context.
But how similar will the configuration be. Isn't there a chance the Europa mission could be the first to use EUS.Well, wasn't Cassini launched on only the 2nd Titan IVB vehicle flown? Yeah, it wasn't a completely new vehicle, but still it puts things into some context.
Right. The SLS will certainly fly at least once with Orion aboard before a chance comes up before Europa's turn.
Well, wasn't Cassini launched on only the 2nd Titan IVB vehicle flown? Yeah, it wasn't a completely new vehicle, but still it puts things into some context.
In the case of the Europa multiflyby mission, a key decision will be whether to expand the fuel tanks or not and/or design the spacecraft for the heat of Venus gravity assists. The former would allow a deep space maneuver that would shorten the flight to 4.7 years with a Delta IV Heavy. The latter would allow an EVEEGA trajectory and a 7.4 year flight. How much insurance will NASA buy?
I heard someone say that they're designing it for the thermal effects of a Venus flyby no matter what. I don't know why, but myabe the margins opened up and they figured it is better to just plan for that no matter what.The lowest launch energy solutions for getting to Jupiter, as I understand it, require Venus gravity assists. Designing for Venus is insurance against either increases in spacecraft mass or the eventual need to use a smaller launch vehicle.
New paper by Ralph Lorenz just published showing that the retropropulsion on a Europa Lander will likely alter a region about 10m in radius; if using conventional hydrazine, the ammonia-rich exhaust will likely frustrate assays of nitrogen-bearing compounds which would be very important for any Europan life.
New paper by Ralph Lorenz just published showing that the retropropulsion on a Europa Lander will likely alter a region about 10m in radius; if using conventional hydrazine, the ammonia-rich exhaust will likely frustrate assays of nitrogen-bearing compounds which would be very important for any Europan life.
Could a Europa lander use airbags? Or is the retrofire still too close to the surface for that to matter?
New paper by Ralph Lorenz just published showing that the retropropulsion on a Europa Lander will likely alter a region about 10m in radius; if using conventional hydrazine, the ammonia-rich exhaust will likely frustrate assays of nitrogen-bearing compounds which would be very important for any Europan life.
Could a Europa lander use airbags? Or is the retrofire still too close to the surface for that to matter?
New paper by Ralph Lorenz just published showing that the retropropulsion on a Europa Lander will likely alter a region about 10m in radius; if using conventional hydrazine, the ammonia-rich exhaust will likely frustrate assays of nitrogen-bearing compounds which would be very important for any Europan life.
Could a Europa lander use airbags? Or is the retrofire still too close to the surface for that to matter?
skycrane strikes back!
Jeff Foust – @jeff_foust
NASA’s Curt Niebur, at OPAG meeting, on Europa Clipper: strong support for mission from Congress now shared by administration and NASA.
Jeff Foust – @jeff_foust
Niebur: studied several “enhancements” to Clipper, like probes for plumes, add’l astrobiology payloads; decided to pursue them.
Jeff Foust – @jeff_foust
Niebur: for lander, definition of mission success is that, at end of 23-day mission, hold a press conference to announce finding life.
Jeff Foust – @jeff_foust
Niebur: for lander, definition of mission success is that, at end of 23-day mission, hold a press conference to announce finding life.
Julie Rathbun – @lokivolcano
Hand: Europa Lander SDT has planetary scientists, microbiologists, and geochemists, some folks not part of outer planets community
Hand: SDT science goals: search biomarkers & life, assess habitability via in situ techniques, characterize surface properties
Hand: lander separate launch, target 2024, carries own communication, battery powered, 20-day life, 35 kg science payload
Hand: draft science trace matrix: search for evidence of life: detect organic, morphological, & inorganic indicators
Determine where sample came from, determine if living organisms persist in sample (not threshold)
Hand: 2. Assess Habitability of Europa: composition, proximity to liquid water, activity
Hand: 3. characterize surface properties at lander scale: biosignature preservation potential, surface dynamics, material properties
Joking scientists are always dangerous... No matter how obvious a joke may seem to them, it still often is reported as a serious comment in the media.
Joking scientists are always dangerous... No matter how obvious a joke may seem to them, it still often is reported as a serious comment in the media.
Especially when jokes don't always translate well in Tweeted reporting.
There was a serious intent behind his statement (I was listening). He wants instruments that can determine if life is present (or more likely on the surface, unequivocally detect dead microbes).
I believe that the assumption is that they will find a landing site with material recently delivered from the subsurface ocean. So the equivalent of finding the remains of microbes from a platform on the top of the arctic ice sheet.There was a serious intent behind his statement (I was listening). He wants instruments that can determine if life is present (or more likely on the surface, unequivocally detect dead microbes).
What kind of instrumentation will have for assessing beneath the surface of Europa. I know the orbiter will have ice penetrating radar.
I believe that the assumption is that they will find a landing site with material recently delivered from the subsurface ocean. So the equivalent of finding the remains of microbes from a platform on the top of the arctic ice sheet.There was a serious intent behind his statement (I was listening). He wants instruments that can determine if life is present (or more likely on the surface, unequivocally detect dead microbes).
What kind of instrumentation will have for assessing beneath the surface of Europa. I know the orbiter will have ice penetrating radar.
Seems to suggest that a staggered launch of orbiter and lander would be the best solution rather launching them together.That is now assumed. Both a funding stream and a mass driven split (as well as it is good to complete the orbital reconnaissance first).
Is there any idea on the weight of the lander, are we talking about something in the Curiosity class if they are intending to use Sky Crane technology?Check out http://futureplanets.blogspot.com/2016/04/defining-missions-for-ocean-worlds.html
Two missions will result in two launches for SLS. That should help the SLS program. NASA needs to launch one SLS per year and they need payloads for that.
Two missions will result in two launches for SLS. That should help the SLS program. NASA needs to launch one SLS per year and they need payloads for that.
Not necessarily. If it is going to take time to sort through the orbiter's maps you may as well slow-boat the lander. Put it on maybe a FH at most and put it on a flyby route. The SLS is good but expensive, so I think use it for the orbiter once since it is needed more heavily than the lander. It's naive to expect 2 freebie SLSs when 1 is enough of a miracle.
He was joking. Scientists don't define mission success as "finding life." There are just too many problems with that (starting with how do you define "life"?).
Two missions will result in two launches for SLS. That should help the SLS program. NASA needs to launch one SLS per year and they need payloads for that.
Not necessarily. If it is going to take time to sort through the orbiter's maps you may as well slow-boat the lander. Put it on maybe a FH at most and put it on a flyby route. The SLS is good but expensive, so I think use it for the orbiter once since it is needed more heavily than the lander. It's naive to expect 2 freebie SLSs when 1 is enough of a miracle.
The thing about SLS freebies is that NASA needs to maintain the SLS production line with one flight per year and currently doesn't have enough payloads. Now if more payloads for manned flights are selected, then there wouldn't be SLS launches available for planetary sciences.
If SpaceX can get the MCT flying, then SLS could be cancelled. Too many variables at the moment to say what is going to happen. The Europa missions might never fly.
Updates are starting to come in from the OPAG meeting. Their page now includes a posters section here:
http://www.lpi.usra.edu/opag/meetings/aug2016/posters/index.shtml (http://www.lpi.usra.edu/opag/meetings/aug2016/posters/index.shtml)
It looks like a mix of good and bad news for 'Clipper (or whatever it should be called).
Good news: Sources from spacenews.com state the choice of launcher still has SLS as first choice, but second choices include both the Delta 4 and Falcon Heavy; the 'standard' for probes of late,Atlas V, isn't on their list anymore. So, obviously, they're trying to favor launchers than can shorten the trip as much as possible.
Bad news: Congress, while still supportive of the mission, can't collectively decide how much to fund the mission at steadily. The 'Clipper team says they expect a funding crunch during '17 and are trying to plan around it as best as possible. Another problem relates to power; they're debating on whether to have each of the 2 solar arrays to have 4 or 5 panels, with a push toward 4 if possible. Between these 2 factors, this may force a descope to prevent options like a laser altimeter from being added.
As for the lander, not much is mentioned aside from making surviving 23 days a priority. One of the posters mentions an idea to use a form of chemical(?) energy at Europa as an alternative power source, which might be interesting to pursue: http://www.lpi.usra.edu/opag/meetings/aug2016/posters/A-Fire-On-Europa.jpg (http://www.lpi.usra.edu/opag/meetings/aug2016/posters/A-Fire-On-Europa.jpg)
So Congress were the ones throwing money at NASA in the first place for Clipper to get started ASAP and now when NASA decides to push forward with it seriously the money starts becoming uncertain. Typical politicians.
As for the lander, not much is mentioned aside from making surviving 23 days a priority. One of the posters mentions an idea to use a form of chemical(?) energy at Europa as an alternative power source, which might be interesting to pursue: http://www.lpi.usra.edu/opag/meetings/aug2016/posters/A-Fire-On-Europa.jpg (http://www.lpi.usra.edu/opag/meetings/aug2016/posters/A-Fire-On-Europa.jpg)
As for the lander, not much is mentioned aside from making surviving 23 days a priority. One of the posters mentions an idea to use a form of chemical(?) energy at Europa as an alternative power source, which might be interesting to pursue: http://www.lpi.usra.edu/opag/meetings/aug2016/posters/A-Fire-On-Europa.jpg (http://www.lpi.usra.edu/opag/meetings/aug2016/posters/A-Fire-On-Europa.jpg)
The 'heat battery' idea is very interesting, and not just for power and not just for Europa.
On Europa, it might be used as part of a drill system using hot water to melt down to non-irradiated ice in search of biochemical traces.
Ditto on Mars, and in the permanently shadowed Lunar polar craters.
On the manned front, this technology might keep a Lunar outpost ticking over during the night, or act as a 'get-me-home' emergency power source.
I wonder whether the battery can be recharged like crystallisation types of hand warmer? They generate heat through the exothermic crystallisation of supersaturated solution of food-grade sodium acetate.
So Congress were the ones throwing money at NASA in the first place for Clipper to get started ASAP and now when NASA decides to push forward with it seriously the money starts becoming uncertain. Typical politicians.
So Congress were the ones throwing money at NASA in the first place for Clipper to get started ASAP and now when NASA decides to push forward with it seriously the money starts becoming uncertain. Typical politicians.
You misunderstand. This is a complex and subtle issue, but it goes to the core of how the government works and how projects get funded. The ideal way for things to work is for the president to request money to start a program and issue a proposed budget outline for the program, and then for Congress to fund that program at the requested level over all those years.
That never happens.
Instead, what usually happens is that the president requests money to start a program and proposes a budget outline for the program, and then Congress provides most, but not all of the money over the course of the program. This requires the agency (in this case NASA) to defer some things each year because there is not enough money in the budget to fund them. That stretches out a program and ultimately leads to higher costs overall (but lower annual costs).
That's not what is happening here.
Instead, what is happening here is that the president (and actually, we're talking about the appointed and career civil servant people at the Office of Management and Budget) never wanted to fund a Europa mission. So they never put in a request or developed a budget profile. Then Congress--really congressman Culberson--said "Well, this is an important mission, and if you are not going to request the money, I'm going to put it in the budget anyway." Culberson was powerful enough to do that. And he kept doing that despite the fact that OMB/White House opposed the mission. With no overall spending profile for the Europa mission, it was not possible to develop a good cost estimate for the entire thing, or a good budget profile.
Eventually, OMB got the message and realized that unless they started requesting the money themselves, and unless they produced their own budget profile, Culberson was going to keep doing that. And OMB was going to be stuck behind the cart getting dragged instead of being out in front of the cart, pulling it (reluctantly).
But, guess what? We're going into an election. Elections are somewhat like event horizons and nobody can see beyond them. NASA is not really allowed to make budget predictions beyond elections unless they're very sure that a project is going to continue (for instance, if development is nearly complete). So they cannot predict with any certainty if the money is going to be there for the Europa mission in two years. What happens if the Republicans lose the Senate? Or the House? If they lose the House, Culberson loses his chairmanship and he can no longer stuff money into the NASA budget for Europa, and presumably people at OMB would open up the champagne.
You can assign blame if you want, but it's not very useful to do so. If you're in favor of a Europa mission, you might assign most of the blame to faceless people in OMB. If you are neutral about it, you might just shrug your shoulders and accept that government policy making in a democracy is complicated and messy.
I will stick to blaming the OMB then as from my interpretation of what you and others have posted over time on here really don't have a clue here. The fact that they are still effectively passively resisting this says a lot about their shortsightness or intransigence take your pick.
A space policy guru who has substantial NASA experience explained the basic operating rules for OMB to me. If I remember correctly it goes like this:
-oppose big programs
-oppose multi-part programs (meaning ones where the first step commits you to a second step, and so on)
-oppose international cooperative programs
OMB wants flexibility in budgeting, meaning the ability to shift money around from project to project to cover shortfalls. Any of those things above, and particularly when they are in combination, restrict their freedom of movement. A really big multi-billion dollar project, like an international Mars sample return mission, ties them up for a long time and they cannot shift money out of it. So they don't want those kinds of things to start.
And right now they have both a Mars 2020 rover and a Europa mission starting, and they look at the out-year expenditures and they shudder, because they imagine lots of cash getting stuck in those programs and they cannot shift them out of those budgets to cover shortfalls elsewhere.
It's logical from their point of view.
And that's where leadership is required. "Leadership" gets bandied around a lot, but here I use it to refer to a senior official who provides clear direction (i.e. "do this, by this timetable") and who also follows up and makes sure things happen (as opposed to giving an order and then walking away, which is very common in Washington). Right now there is no advocate within the executive branch for a Europa mission. There's nobody in the White House who really wants it to happen and who has the clout to tell people to make it happen. Absent that advocate, asserting leadership, the people at OMB revert to their internal guidelines that I listed above. And so they're bucking up against a member of Congress who has some power to make things happen, but can only do so much without similar advocates in the executive branch.
So does that mean that the Europa mission is doomed to go nowhere and the money already spent on it wasted if there is determination amongst the OMB to kill it.
No.
And I'll add an aside: when you go to school they teach you about the three branches of government. If you go to college, you may learn a bit more about government, like the bureaucracy and the budgeting process. But the actual implementation of laws and policies is really hard to discover and understand. A lot of government activity involves the little everyday decisions and interactions between the various branches and bureaucrats and individuals. I still find it really difficult to figure out what is going on.If I remember correctly, Blackstar, you have a PhD in public policy. So if you have problems understanding the system, then the rest of us are screwed... :)
And I'll add an aside: when you go to school they teach you about the three branches of government. If you go to college, you may learn a bit more about government, like the bureaucracy and the budgeting process. But the actual implementation of laws and policies is really hard to discover and understand. A lot of government activity involves the little everyday decisions and interactions between the various branches and bureaucrats and individuals. I still find it really difficult to figure out what is going on.If I remember correctly, Blackstar, you have a PhD in public policy. So if you have problems understanding the system, then the rest of us are screwed... :)
Yeah, Ph.D. in political science, focusing on space policy and national security policy. But here's the thing: a lot of this stuff is not in textbooks or academic journals. You really have to see it in action in order to understand how it works. I think that part of that is that there is a blurry line between the rules and regulations and the tactics that people and institutions use to get what they want.
So, we all know the saying that the president proposes and the Congress disposes. Officially, Congress produces the budget and the president signs it. But we also know that in practice, the starting point is the president's budget. If a new project is not in the president's budget, it is really hard for Congress to initiate that project on their own, and it is very very hard for them to sustain it (except when we're talking about simply buying more of something that is already in production, like tanks or airplanes). And because the agencies like NASA are all in the executive branch, they take their marching orders from the White House, even if Congress is putting money into a project that the people in that agency support.
Getting back to the Europa mission, in the past few years what was happening was that Congress (Culberson) was pushing money into the budget, but NASA did not have an approved blueprint from OMB on how to spend it, even though they were required to spend it. Now NASA got lucky because there was a way for them to spend a big chunk of that money: they could buy instruments for the spacecraft. That would spend up a lot of the cash sitting around. But of course Culberson was going to shove more money into the budget after NASA spent the initial batch on the instruments, trying to force OMB to approve a formal development plan for the Europa mission. Everybody knew this. This was a tactic.
I mentioned earlier the analogy of putting the horse before the cart and it really works fairly well as an analogy. OMB--and really, the White House--wants to be leading the decisions and the program development. They want to be steering. But they were like a horse that wanted to go in a different direction (i.e. not a Europa mission), and the cart was pulling them in a direction for several years. Finally, OMB approved the Europa "new start," but at a lower level of funding. Think of it like the horse trying to keep the cart from moving too fast.
And where is NASA in all of this? NASA is an executive branch agency, so of course it has to abide by what the White House says NASA should do. Certainly there are people at NASA (and definitely at JPL!) who want a Europa mission. But they also want full funding for such a mission, and a clear budget outline. They're not getting that, and so they're stuck in the middle of this clash between the White House and Congress. And all that uncertainty gets magnified when there's an election coming up. They literally cannot plan for future budgets for a Europa mission. They can sketch the outlines (meaning penciling-in procuring item X in 2018 and item Y in 2019 and so on), but the uncertainty factor is very high.
But like I've said, this kind of stuff happens all the time. Pick a non-space subject and you can find similar fights.
We also need to remember that we are talking about total dollar amounts that are a gnat upon a gnat in terms of the federal budget. If the peak funding for Clipper turns out to be $500M in a given year, that is equivalent to an expense of $12.66 to a family that spends $100K a year. How hard to you try to optimize spending for that small of an amount? Most spending is done on autopilot -- this year's spending looks much like last year's spending and next year's spending.
One thing that I see in the lander presentation that I don't think was there earlier was a communications relay orbiter. They cannot plan for having Clipper still be alive to serve as a relay.
One thing that I see in the lander presentation that I don't think was there earlier was a communications relay orbiter. They cannot plan for having Clipper still be alive to serve as a relay.The relay, as I recall, was previously included but not emphasized. There's a European discussion that ESA might provide the relay, which would later orbit Europa to provide high fidelity gravity and magnetic studies. Such a craft could essentially be all vault with solar panels, a radio antenna, and a magnetometer sticking out. I don't think it would have to last long in orbit to significantly improve on the Europa Clipper measurements, but don't know that for sure.
One thing that I see in the lander presentation that I don't think was there earlier was a communications relay orbiter. They cannot plan for having Clipper still be alive to serve as a relay.
Would it be right to characterize that as being a direct consequence of launching independently? Also is there a chance the lander's relay orbiter could provide a redundant relay channel for Clipper data transmission back to Earth?
Claudio Flores Martinez has just finished an MSc at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany and is now enroute to a PhD in theoretical biology. He currently serves as a research assistant at the Developmental Biology Unit of EMBL and the University of Heidelberg’s Centre for Organismal Studies. With three papers in Acta Astronautica under his belt, Claudio is already deep into theoretical evolutionary biology, and in particular the contingency vs. convergence debate. In the paper below, he discusses how these issues couple with the possible emergence and development of life on Europa and the potential biosignatures by which we might find it, a journey that takes us deep into the nature of living systems. Just what might we encounter under that Europan ice?
50 tons payload to Europa orbit and surface! 2x25 tons with two SLS.Because NASA has nowhere near the funding needed to build 50 tons of planetary spacecraft. There's a rough linear relationship between spacecraft cost and its mass. If you want 50 tons of operating spacecraft at Jupiter, you need to come up with billions more in funding.
Why is this not reflected in the spacecraft design now under consideration?
But one could build a spacecraft cheaper if one doesn't have to care so much about the mass of the components. You could use off the shelf stuff and redundancy to compensate for their quality. Kind of the Russian philosophy.50 tons payload to Europa orbit and surface! 2x25 tons with two SLS.Because NASA has nowhere near the funding needed to build 50 tons of planetary spacecraft. There's a rough linear relationship between spacecraft cost and its mass. If you want 50 tons of operating spacecraft at Jupiter, you need to come up with billions more in funding.
Why is this not reflected in the spacecraft design now under consideration?
But one could build a spacecraft cheaper if one doesn't have to care so much about the mass of the components. You could use off the shelf stuff and redundancy to compensate for their quality. Kind of the Russian philosophy.
OMB goes along with that.
Yeah, up to a point. In fact, the cost of Juno and the cost of Clipper is lower because they use commercial grade chips, not rad-hardened. Juno relies upon a vault to protect the electronics.No, Juno in general uses standard rad-hard components that are good to something like 50 to 100 krads. It needs the vault because the environment would be much higher than that otherwise.
Don2, you may want to go re-read the Decadal Survey. It makes clear that both a Mars caching rover and a Europa mission were nearly equally ranked priority Flagship missions. Congress has decided to increase the funding for the planetary science budget to fly both of the missions that were top ranked by the scientific community.
Given how few Discovery and New Frontiers missions have been flown recently, it seems to me that restoring those programs should be given a higher priority.Congressional action has led to the Discovery and New Frontiers getting back on track. Green says he expects to select 5 Discovery missions and two New Frontiers missions a decade going forward, which is the Decadal recommended pace.
Don2, you may want to go re-read the Decadal Survey. It makes clear that both a Mars caching rover and a Europa mission were nearly equally ranked priority Flagship missions. Congress has decided to increase the funding for the planetary science budget to fly both of the missions that were top ranked by the scientific community.
There is no mention of a Europa lander in the Decadal Survey. In fact it says:
"the costs of the recommended Flagship missions must not be allowed to grow above the values quoted in this report. Central to accomplishing this is avoiding “requirements creep.” The CATE process does not account for a lack of discipline that allows a mission to become too ambitious. In order to preserve programmatic balance, then, the scope of each of the recommended Flagship missions cannot be permitted to increase significantly beyond what was assumed during the committee’s cost estimation process."
The Recommended Program was:
"• Discovery program funded at the current level adjusted for inflation;
• Mars Trace Gas Orbiter conducted jointly with ESA;
• New Frontiers Missions 4 and 5;
• MAX-C (descoped to $2.5 billion);
•Jupiter Europa Orbiter (descoped);
•Uranus Orbiter and Probe "
The Cost Constrained Program was:
"• Discovery program funded at the current level adjusted for inflation;
• Mars Trace Gas Orbiter conducted jointly with ESA;
• New Frontiers Mission 4 and 5;
• MAX-C (descoped to $2.5 billion);
• Uranus Orbiter and Probe "
Note that a Europa mission does not appear on the Cost Constrained list, so arguably it is the fifth or sixth priority. You can make a case that the Decadal viewed a $4.7 billion Europa mission as too expensive, but would have ranked a $2 billion mission much higher. However, the survey clearly comes out against the kind of requirements creep represented by the lander.
It also explicitly states that :
"If cuts to the program are necessary, the first approach should be descoping or delaying Flagship missions. Changes to the New Frontiers or Discovery programs should be considered only if adjustments to Flagship missions cannot solve the problem."
Given how few Discovery and New Frontiers missions have been flown recently, it seems to me that restoring those programs should be given a higher priority.
@vjkane:I think there is a reasonable amount of political maneuvering going on. Culberson, under House Repbulican rules, must give us his chairmanship somewhere around 2022. So he is trying to push a the program forward while he still has the political power.
I agree there would be solid support for a $2 billion class Europa multi-flyby mission. However, that is not where things are going right now. The lander is a symptom of out of control requirements growth, which is probably also affecting the orbiter.
The lander now requires a communications relay orbiter, a 23 day surface life, and is thinking seriously about astrobiology. They mention 3 samples from a depth of 10cm, so there is some sort of a drilling requirement. 4.4t of dry mass is not going to be cheap.
JPL doesn't seem to be worried that there is no guarantee that a lander will be able to access material from the underlying ocean. People seem to have forgotten what high radiation does to organics, not to mention the sulfuric acid and peroxides which are also mentioned as possible surface materials. We know very little about the chemical environments on Europa, and can only speculate about how that might interact with potential instruments.
This is rapidly heading in the direction of a $6 billion class program like Cassini. Culberson has stated in the past that a Europa mission should be the biggest and best outer planets mission ever flown, and JPL seems happy to oblige.
@vjkane:
I agree there would be solid support for a $2 billion class Europa multi-flyby mission. However, that is not where things are going right now. The lander is a symptom of out of control requirements growth, which is probably also affecting the orbiter.
The lander now requires a communications relay orbiter, a 23 day surface life, and is thinking seriously about astrobiology. They mention 3 samples from a depth of 10cm, so there is some sort of a drilling requirement. 4.4t of dry mass is not going to be cheap.
JPL doesn't seem to be worried that there is no guarantee that a lander will be able to access material from the underlying ocean. People seem to have forgotten what high radiation does to organics, not to mention the sulfuric acid and peroxides which are also mentioned as possible surface materials. We know very little about the chemical environments on Europa, and can only speculate about how that might interact with potential instruments.
This is rapidly heading in the direction of a $6 billion class program like Cassini. Culberson has stated in the past that a Europa mission should be the biggest and best outer planets mission ever flown, and JPL seems happy to oblige.
@Star One
If by bias you mean that I think that Discovery and New Horizons produce better returns on investment than flagships then you would be right. Or if you mean that I don't think the surface of Europa is a very promising environment for life then you would be also be right. We know very little, but what we do know isn't very promising.
If you compare Mars and Jupiter missions it is apparent that everything in the outer solar system costs more. A basic , stripped down orbiter like Mars Odyssey cost $300 million. A basic Jupiter orbiter like Juno cost $1 billion. So Jupiter is around 3 times as much. If you remember that Phoenix at Mars cost $750 million, then something over $2 billion is a sensible guess for a simple Europa lander. Of course it could be more.Probably a fairer comparison in terms of spacecraft capability and instrument complexity is the Mars Reconnaissance Orbiter, which cost $720M in 2005 and inflated to today (3% inflation per year) is $996M. Juno has an advanced set of instruments; it's hard to find anything that lists their final total mass, but one paper I saw from pre launch listed their mass as 174 kg.. (If anyone reading this knows the answer to this, I'd appreciate hearing the actual number.) MRO's instruments are 139 kg.
Well surely that's what they are proposing effectively two flagship missions.If you compare Mars and Jupiter missions it is apparent that everything in the outer solar system costs more. A basic , stripped down orbiter like Mars Odyssey cost $300 million. A basic Jupiter orbiter like Juno cost $1 billion. So Jupiter is around 3 times as much. If you remember that Phoenix at Mars cost $750 million, then something over $2 billion is a sensible guess for a simple Europa lander. Of course it could be more.Probably a fairer comparison in terms of spacecraft capability and instrument complexity is the Mars Reconnaissance Orbiter, which cost $720M in 2005 and inflated to today (3% inflation per year) is $996M. Juno has an advanced set of instruments; it's hard to find anything that lists their final total mass, but one paper I saw from pre launch listed their mass as 174 kg.. (If anyone reading this knows the answer to this, I'd appreciate hearing the actual number.) MRO's instruments are 139 kg.
But I agree with you that a Europa lander that is more than a penetrator or simple hard lander is going to get into Flagship mission costs.
,,,I'd think (Europa) is one of the easiest objects in the Solar System to orbit or land on. Also given its low surface gravity and lack of atmosphere and the huge gravity well of Jupiter. If it is difficult anyway, compared to for example Mars, I'd like to learn what makes it so difficult.
And the lander is even more of a challenge, since from the moment it starts operating on the Europan surface, it's being irradiated at a very high rate. Electronics and sensors will either need to be able to sink under the ice via melting down a few meters, or likely result in a short lifetime for such a lander. Note, current concepts call for a lander lifetime of around 21 days -- that's not because they're cheaping out on the power source for the lander, it's because it's hard to design something to operate in that radiation environment for much longer than that.One "trick" to extending the life of any lander is to land on the leading hemisphere of the moon. Since the radiation particles slam into the trailing hemisphere, the body of the moon acts as a very large radiation shield. There's a map of radiation levels contrasting the two hemispheres around half way down on this blog post (double click for an enlarged image). The contrast is very dramatic.
Any lander that is tasked with actually drilling or melting a hole down into the liquid ocean below (assuming its presence is confirmed, since as of now it is inferred, albeit strongly, from things like magnetic field responses) is likely going to need to bury most of itself under a few meters of ice to provide the radiation shielding required for any kind of long-life operations. It will have to leave enough of an antenna structure above the ice to retain contact with a relay spacecraft, but most of the thing will likely need to pull up a bit of the ice shell over itself, like a rabbit shivering in its warren during the winter...
If you compare Mars and Jupiter missions it is apparent that everything in the outer solar system costs more. A basic , stripped down orbiter like Mars Odyssey cost $300 million. A basic Jupiter orbiter like Juno cost $1 billion. So Jupiter is around 3 times as much. If you remember that Phoenix at Mars cost $750 million, then something over $2 billion is a sensible guess for a simple Europa lander. Of course it could be more.Probably a fairer comparison in terms of spacecraft capability and instrument complexity is the Mars Reconnaissance Orbiter, which cost $720M in 2005 and inflated to today (3% inflation per year) is $996M. Juno has an advanced set of instruments; it's hard to find anything that lists their final total mass, but one paper I saw from pre launch listed their mass as 174 kg.. (If anyone reading this knows the answer to this, I'd appreciate hearing the actual number.) MRO's instruments are 139 kg.
... but most of the thing will likely need to pull up a bit of the ice shell over itself, like a rabbit shivering in its warren during the winter...
... but most of the thing will likely need to pull up a bit of the ice shell over itself, like a rabbit shivering in its warren during the winter...
You make it all sound so cozy. It might work too, if the ice was very pure. You could heat the ice under the lander, and encourage the vapor that sublimes to condense on top, giving a nice layer of radiation shielding.
Of course, if there is a little silicate dust or elemental sulfur mixed into the ice, that won't sublime. It will collect under the lander until there is enough to block further progress.
What other impurities might there be in the ice? The scientists are talking about sulfuric acid and hydrogen peroxide. Sulfuric acid ices will tend to collect underneath the lander, while the hydrogen peroxide will tend to go with the water. It goes without saying that a mix like that will destroy any organics, but it also has a good chance of dissolving the lander. Aerospace projects are not usually built out of highly corrosion resistant materials.
One thing's for sure. The creature from Alien will be right at home in that highly acidic environment. Your lander, not so much.
A couple of things I don't understand here.
1) Difficulty of reaching
Europa has an orbital speed of 13.7 km/s. That's alot. Add Jupiter's orbital speed of 13 km/s to that and you have a great speed range, relative to Earth, to choose from. This should allow for matching an arriving spacecraft's speed with its speed much better than for example a mission from Earth to the Moon. I'd think it is one of the easiest objects in the Solar System to orbit or land on. Also given its low surface gravity and lack of atmosphere and the huge gravity well of Jupiter. If it is difficult anyway, compared to for example Mars, I'd like to learn what makes it so difficult.
2) SLS for free
Why would it be more expensive to use the SLS to send probes to Europa, than to use them to something else?
3. Such as a non-scientific asteroid boulder technology demonstration mission. If Congress gives away two SLS to the planetary science program, why not accept the gift most graciously? SLS obviously has a huge political support and will fly a few times at any cost to save face. Otherwise this poorly designed but potent thing wouldn't have gotten this far.
4. And it's built on proven legacy technology so it should be quite reliable.
MRO is vastly more capable than Juno. For instance, MRO has 2kW of power, Juno has 400W. That is a factor of 5 difference. MRO can achieve a data rate to earth of 6Mb/s, Juno can achieve no more than 18kb/s. That is a factor of 333 difference. Juno is spin stabilized which is much less convenient for cameras that the 3-axis stabilized MRO. Juno is built around one heavy, expensive instrument, the microwave radiometer, with a bunch of small add-ons. MRO has multiple heavy, expensive, data intensive instruments.Don2, you clearly know much more about this than I do, so could I pick your brains a bit since this is a question I've wondered about?
If you think about the physics it is easy to understand why Jupiter is much more expensive. The energy needed to send a bit of data will increase with the square of the distance from earth. Sunlight decreases with the square of the distance from the sun, so the cost of energy will increase with the square of the distance, until you switch over to RTGs. So you need more energy to send data home and that energy gets more costly. Things get worse if you need to divert energy to thermal control as sunlight gets weaker.
The cost of electricity for the instruments also goes up steeply until you switch to RTGs. Even after that point, you need more delta-v to go farther out, so the cost of the RTG mass and energy will increase with distance.
For Juno we should also add the 200kg of radiation vault to the discussion. That adds 12.5% to the dry mass of the probe.
I think there's a lot of misunderstanding of the political maneuvering here. The only mission that is being actively developed is the Clipper. The lander mission is still in the early study phase. And it is likely to stay in that stage for several years. As long as the money spent on studying the lander is not huge, what's the harm in studying it? In fact, studying lander concepts helps refine the Clipper, because it enables the people working on the Clipper to think about the best science and operations to support a future lander mission, whether it happens in 22, 26, or 30.
@vjkane...I'm not sure I do know more about this than you, and I'm sure I know less than some of the other posters here, but I will have a go at the problem.I am increasingly of the view that you have some kind of political axe to grind regarding this whole Europa project, if this is the case I wish you would just come out and say it.
As you go further out the cost of power and data rate explodes. The other thing to mention is that mission operations costs go up because the missions become longer.
So at Mars perihelion MRO will generate 2000W of power. At Jupiter at perihelion the same spacecraft will generate 155W. At apihelion that goes down to 128W. The big problem here is that you need a certain amount of overhead just to run computers, attitude and thermal control, and a radio receiver. The Decadal Survey did a number of design studies and from those you can figure out that the minimum survival power is about 100-200W for a probe. So MRO would be using all its power just to survive at Callisto and would have almost nothing for instruments or data return.
You can't just hang an extra solar panel on the spacecraft without triggering a whole cascade of other design changes. An extra panel means more weight, so you need bigger reaction wheels and rocket engines. To preserve the same delta-v capability you need larger fuel tanks and more fuel. All that extra mass needs a larger structure. Pretty soon you are talking about a substantially bigger and more expensive spacecraft.
How much does the cost of a spacecraft influence the cost of a project? Again, I use the Decadal survey studies to get a sense of how the costs stack up. Simplifying and combining some of the NASA items I end up with this breakdown for the Jupiter Europa orbiter:
Instruments 27%, Spacecraft 41%, Launch 9%, Operations 22%
For the Trojan Tour I get:
Instruments 20%, Spacecraft 39%, Launch 29%, Operations 12%
I think there's a lot of misunderstanding of the political maneuvering here. The only mission that is being actively developed is the Clipper. The lander mission is still in the early study phase. And it is likely to stay in that stage for several years. As long as the money spent on studying the lander is not huge, what's the harm in studying it? In fact, studying lander concepts helps refine the Clipper, because it enables the people working on the Clipper to think about the best science and operations to support a future lander mission, whether it happens in 22, 26, or 30.
Some posters appear to be deliberately kicking up a lot of fuss about the lander, even though as you say it's actually at a very early stage, just in an effort to discredit the whole Europa enterprise because it doesn't suit how they think things should be done.
MRO can achieve a data rate to earth of 6Mb/s, Juno can achieve no more than 18kb/s.Actually Juno can do 120 kb/s to a 70m antenna and 22 kb/s to a 34m antenna.
The decadel survey only looks at the goals of one interest group (the planetary science community). NASA programs usually aren't justified by these measures alone. Economic growth, technology spin-offs, national soft power,national prestige, employment, and even national defense are all factors used to justify the expense. If astrobiology didn't have any ramifications for those factors I just listed, there probably wouldn't be a Europa mission funded by a national government. Of course, scientists and people that are curious about what is out there could fund their own mission. Try looking at a lander through those prisms as well as the pure science and maybe the logic will be more apparent. Just as an example: the technology that allows a robotic lander to work on the surface of Europa could potentially be used for disaster relief (i.e. the robots Japan has sent in to the Fukushima Daichi nuclear plant have been killed by the radiation).
I am increasingly of the view that you have some kind of political axe to grind regarding this whole Europa project, if this is the case I wish you would just come out and say it.
I am increasingly of the view that you have some kind of political axe to grind regarding this whole Europa project, if this is the case I wish you would just come out and say it.
I have no problem with the orbiter if it stays under $2.5bn. Europa is like nowhere else in the Solar System, and the orbiter will address questions that have been out there for nearly 20 years. The Galileo mission was partly a failure, and a return to the moons of Jupiter with a fully functioning spacecraft is long overdue. The Jupiter system has a very rich set of scientific phenomena, and there are plenty of other things to see besides Europa.
I am increasingly of the view that you have some kind of political axe to grind regarding this whole Europa project, if this is the case I wish you would just come out and say it.
I have no problem with the orbiter if it stays under $2.5bn. Europa is like nowhere else in the Solar System, and the orbiter will address questions that have been out there for nearly 20 years. The Galileo mission was partly a failure, and a return to the moons of Jupiter with a fully functioning spacecraft is long overdue. The Jupiter system has a very rich set of scientific phenomena, and there are plenty of other things to see besides Europa.
@vjkane....Europa may be driving the design, and that's OK, but I have a feeling the science team will find excuses to point the probe at other targets.At the talk by the project manager, it was clear from his language that they expect to look at other targets (and certainly will keep the field and particles instruments collecting data throughout the orbits); they just hadn't put time into considering what yet.
@vjkane....Europa may be driving the design, and that's OK, but I have a feeling the science team will find excuses to point the probe at other targets.
If they use the Hirise camera that will get them no better than 250m/pixel on Io from Europa orbit. However, an extended mission to Io is a very obvious possibility, and HiRise can collect data very quickly during a flyby. The limitation would be on returning it back to earth. For the disk of Io you could get 50m2/px in color back in 28 days at 40kb/s. You need a 12 GB data store for that.
What you really want for Io is a very long orbit so you have plenty of time to transmit the flyby data back to Earth. 3 flybys would give good coverage of the equatorial regions. I can see that happening at the end of the mission with a little luck.
@Star One...You're welcome!
ESA's JUICE will spend a lot of its time looking at all the other wonders of the Jupiter system. Per the Europa mission's project manager, they haven't spent any time looking at studies of additional bodies. I did see one orbital study for the mission that included several flybys of Ganymede and Callisto. Right now the plan to dispose of Clipper is to crash it on Ganymede; the project manager says his dream is to see it do a couple of flybys of Io first before crashing it on that moon.
But JUICE has instruments better suited to studying Jupiter and the magnetosphere than the Clipper.
Together the two missions will do an awesome job, especially if they operate at the same time.
In my fantasy world, a Discovery Io flyby mission would also operate at the same time, but it would have to be selected in the next competition for that to happen.
Unlike JUICE, the (formerly known as) 'Clipper has superior radiation protection, so between the 2 it has the best potential for examining Io. Also unlike JUICE, 'Clipper isn't planned to end up bound to one satellite; it can visit the others readily with a gravitational assist and approval from management. Galileo, despite its poor state (largely the antenna among other factors), was granted 2 mission extensions that added 6 years onto the primary's 2; I'd confidently bet 'Clipper could endure into at least 1 extension.
I hope the project manager sees his dream with Io fulfilled. Considering it is, aside from Europa, the most scientifically intriguing satellite of Jupiter, any visit to it is worthwhile; more so, Galileo's visits proved that since Voyager's the moon significantly changed...meaning every visit will surely reveal surprises. Also, considering it's a volcanic, fiery, and radioactive rock that only Venus and the Sun exceed in inhospitality, good place to dispose a used spacecraft if you fear contaminating its neighbors.
I think that one thing that could affect extended mission planning for Clipper is the desire to keep it around to support a lander mission.
As for Io, I'd love to see more study of Io. But my understanding is that its surface is not exactly "fiery"--despite all the volcanic activity, the surface is actually rather cold. (There was a recent published paper on this, I believe.) I wonder if anybody has tried to model a heat map? I imagine that anything coming out of a volcano hot is going to cool very quickly.
I think that one thing that could affect extended mission planning for Clipper is the desire to keep it around to support a lander mission.
True, barring the next Congress being stingier but we'll see. In any case, if it's still functional with or without a lander its use ought to be continued, just like with Cassini, LRO, Opportunity...which collectively are another example of why an extension could be favored. If it still has fuel and the electronics haven't been fried, keep it going a lil longer.
I think that one thing that could affect extended mission planning for Clipper is the desire to keep it around to support a lander mission.
True, barring the next Congress being stingier but we'll see. In any case, if it's still functional with or without a lander its use ought to be continued, just like with Cassini, LRO, Opportunity...which collectively are another example of why an extension could be favored. If it still has fuel and the electronics haven't been fried, keep it going a lil longer.
There is one difference for missions around Jupiter--they have to "fail safe" from a planetary protection standpoint. That means that the policy is not to simply run them until they fail and die. Instead, when it becomes highly likely that they will die, they have to be crashed into a safe body, like Jupiter or a dead moon.
If we were all going to bet on this, the safe money is that Clipper gets delayed a bit, but still flies, and the lander gets delayed a lot, or canceled. That could mean that any lander would arrive many years after Clipper. So the odds of Clipper still being alive to support a lander are slim.
I think that one thing that could affect extended mission planning for Clipper is the desire to keep it around to support a lander mission.
True, barring the next Congress being stingier but we'll see. In any case, if it's still functional with or without a lander its use ought to be continued, just like with Cassini, LRO, Opportunity...which collectively are another example of why an extension could be favored. If it still has fuel and the electronics haven't been fried, keep it going a lil longer.
There is one difference for missions around Jupiter--they have to "fail safe" from a planetary protection standpoint. That means that the policy is not to simply run them until they fail and die. Instead, when it becomes highly likely that they will die, they have to be crashed into a safe body, like Jupiter or a dead moon.
If we were all going to bet on this, the safe money is that Clipper gets delayed a bit, but still flies, and the lander gets delayed a lot, or canceled. That could mean that any lander would arrive many years after Clipper. So the odds of Clipper still being alive to support a lander are slim.
In that case would there be any possibility to move it to Saturn after it has finished at Jupiter, surly Enceladus would be ideal for study with the exact same set of instruments?
I think that one thing that could affect extended mission planning for Clipper is the desire to keep it around to support a lander mission.
True, barring the next Congress being stingier but we'll see. In any case, if it's still functional with or without a lander its use ought to be continued, just like with Cassini, LRO, Opportunity...which collectively are another example of why an extension could be favored. If it still has fuel and the electronics haven't been fried, keep it going a lil longer.
There is one difference for missions around Jupiter--they have to "fail safe" from a planetary protection standpoint. That means that the policy is not to simply run them until they fail and die. Instead, when it becomes highly likely that they will die, they have to be crashed into a safe body, like Jupiter or a dead moon.
If we were all going to bet on this, the safe money is that Clipper gets delayed a bit, but still flies, and the lander gets delayed a lot, or canceled. That could mean that any lander would arrive many years after Clipper. So the odds of Clipper still being alive to support a lander are slim.
In that case would there be any possibility to move it to Saturn after it has finished at Jupiter, surly Enceladus would be ideal for study with the exact same set of instruments?
No, too much delta V would be required
Many additional potential spacecraft disposalhttp://www.lpi.usra.edu/opag/europa2012/ES%202012%20Report%20C%20Flyby%20-%20Final%20-%2020120501.pdf
options exist that avoid collision with Europa,
including (but not limited to) the following:
Jovian system impacting trajectories:
– Jupiter (via short- or long-period
orbits, the latter using solar perturbations)
– Io, Ganymede, or Callisto
Long-term Jupiter-centered orbits:
– Circular orbit between Ganymede
and Callisto
– Eccentric orbit outside of Callisto
Jupiter system escape:
– Heliocentric orbit
– Saturn flyby, impactor, or potentially
even capture
– Icy-giant flyby or impactor
– Trojan asteroid flyby or impactor
In that case would there be any possibility to move it to Saturn after it has finished at Jupiter, surly Enceladus would be ideal for study with the exact same set of instruments?Maybe just build two copies from the get go, like MER
In that case would there be any possibility to move it to Saturn after it has finished at Jupiter, surly Enceladus would be ideal for study with the exact same set of instruments?Maybe just build two copies from the get go, like MER
I doubt solar power would work at Saturn (at least without huge changes), and getting good enough data rates would probably need some changes to communications. And if you're going to change all that, you'll probably also want to rethink the instrument set...
No, too much delta V would be required
This study seems to think capture into Saturn orbit could be possible. Europa Clipper can always add mass by doing one earth gravity assist instead of doing a direct flight that adds a year or 2. The real problem is power, not Delta-V. The study below assumes Radio-isotope and so wouldn't be affected as much by distance from the Sun.QuoteMany additional potential spacecraft disposalhttp://www.lpi.usra.edu/opag/europa2012/ES%202012%20Report%20C%20Flyby%20-%20Final%20-%2020120501.pdf
options exist that avoid collision with Europa,
including (but not limited to) the following:
Jovian system impacting trajectories:
– Jupiter (via short- or long-period
orbits, the latter using solar perturbations)
– Io, Ganymede, or Callisto
Long-term Jupiter-centered orbits:
– Circular orbit between Ganymede
and Callisto
– Eccentric orbit outside of Callisto
Jupiter system escape:
– Heliocentric orbit
– Saturn flyby, impactor, or potentially
even capture
– Icy-giant flyby or impactor
– Trojan asteroid flyby or impactor
I think that one thing that could affect extended mission planning for Clipper is the desire to keep it around to support a lander mission.
True, barring the next Congress being stingier but we'll see. In any case, if it's still functional with or without a lander its use ought to be continued, just like with Cassini, LRO, Opportunity...which collectively are another example of why an extension could be favored. If it still has fuel and the electronics haven't been fried, keep it going a lil longer.
There is one difference for missions around Jupiter--they have to "fail safe" from a planetary protection standpoint. That means that the policy is not to simply run them until they fail and die. Instead, when it becomes highly likely that they will die, they have to be crashed into a safe body, like Jupiter or a dead moon.
If we were all going to bet on this, the safe money is that Clipper gets delayed a bit, but still flies, and the lander gets delayed a lot, or canceled. That could mean that any lander would arrive many years after Clipper. So the odds of Clipper still being alive to support a lander are slim.
In that case would there be any possibility to move it to Saturn after it has finished at Jupiter, surly Enceladus would be ideal for study with the exact same set of instruments?
No, too much delta V would be required
This study seems to think capture into Saturn orbit could be possible. Europa Clipper can always add mass by doing one earth gravity assist instead of doing a direct flight that adds a year or 2. The real problem is power, not Delta-V. The study below assumes Radio-isotope and so wouldn't be affected as much by distance from the Sun.QuoteMany additional potential spacecraft disposalhttp://www.lpi.usra.edu/opag/europa2012/ES%202012%20Report%20C%20Flyby%20-%20Final%20-%2020120501.pdf
options exist that avoid collision with Europa,
including (but not limited to) the following:
Jovian system impacting trajectories:
– Jupiter (via short- or long-period
orbits, the latter using solar perturbations)
– Io, Ganymede, or Callisto
Long-term Jupiter-centered orbits:
– Circular orbit between Ganymede
and Callisto
– Eccentric orbit outside of Callisto
Jupiter system escape:
– Heliocentric orbit
– Saturn flyby, impactor, or potentially
even capture
– Icy-giant flyby or impactor
– Trojan asteroid flyby or impactor
Here's a proposal for a daughter craft I hadn't heard of before: http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf (http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf)I believe that NASA is no longer considering this.
Biosignature Explorer for Europa (BEE)
Anybody heard about this BEE buzzing?
Here's a proposal for a daughter craft I hadn't heard of before: http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf (http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf)I believe that NASA is no longer considering this.
Biosignature Explorer for Europa (BEE)
Anybody heard about this BEE buzzing?
My understanding is that this was proposed by a team led by APL. NASA management decided against daughter craft for cost, mass, and complexity reasons. I have heard of one other daughter craft, much smaller, that may still be under consideration. Will check it out.Here's a proposal for a daughter craft I hadn't heard of before: http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf (http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf)I believe that NASA is no longer considering this.
Biosignature Explorer for Europa (BEE)
Anybody heard about this BEE buzzing?
I wanted to confirm that; I heard of a few daughter craft incarnations but never saw one in detail like this. I'm pretty sure the lander inclusion killed their chances. All the same was curious who heard of this. Blackstar would be perfect, although I suspect he'll just verify what you said.
In a separate, earlier project, the team experimented with which kind of drills or cutters might work best to bore through Europa’s ice, even tooling around with some of the standard drills you can find in your local hardware store. That research led to a prototype that’s now informing the development of future robotic arms at JPL.
“Those kinds of higher-end experiments would never be possible without first doing the kind of scientific and engineering rapid prototyping to answer the basic question first,” Hand says.
In answering these basic questions, they get closer to their ultimate goal. “The big-picture motivation [of this lab] is to advance our capability to seek out and understand signs of life on ocean worlds beyond Earth,” says Hand.
Scientists are hoping to gather clues about whether or not Europa could support life in the upcoming fly-by NASA mission. The spacecraft (it has no official name yet) is slated to launch as soon as 2022, and could potentially arrive at the satellite as early as 2026.
The spacecraft will be equipped with nine main instruments, including spectrometers, magnetometers, cameras, and a radar. The plan is for the spacecraft to orbit Jupiter and use its gravity, and that of the Galilean moons, to do multiple fly-bys of Europa, all in about 3.5 years.
Mission scientists are also preparing for the possibility of launching some kind of lander soon after sending off the probe, so that researchers can more quickly apply the information being projected back.
If the spacecraft were to detect a hotspot of geological activity, for instance, or a region with evidence of organic materials, “then that might be the place that we want to send a future lander,” says Pappalardo. “But we’ll see how that plays out.”
The design surprises me a little, although still overall practical. Instead of a pyramid it looks like they're sending a box with legs, eyes, and a robot arm.
It seems strange that the carrier/relay would have no science payload. You'd think even the ability to record detailed surface changes over time would be major. Maybe they just aren't at that point in the design yet?
Note that this is still "pre-Phase A." That's a very preliminary design. The actual hardware could change quite a bit.
I've heard that from an engineering standpoint, the margins on this vehicle are really huge. They don't know much about the surface of Europa, so how can you accurately design a vehicle that will land there? How would the lander look if the surface were rolling smooth ice mounds as opposed to 1-meter tall ice spikes? So I suspect that one of the next steps would be to model several widely different types of surfaces and then drop a model vehicle on them and see what happens (this could all happen as a computer simulation, but some physical modeling might be necessary).
I think that there's a lot of uncertainty about this program overall. From a normal program management sense, it is better to wait for good data on Europa before trying to design a lander. But they have somebody who wants to fund it right now, so it's not like the cart is in front of the horse, the horse is on top of the cart...
It seems strange that the carrier/relay would have no science payload. You'd think even the ability to record detailed surface changes over time would be major. Maybe they just aren't at that point in the design yet?I think that they are simply so early in the process that they haven't thought about an orbiter. Similarly, the Europa multiple-flyby mission team hasn't spent time thinking about all the great science they could do for the rest of the Jovian system with the flybys of Callisto and Ganymede, for Jupiter, and for the magnetosphere.
I think that they are simply so early in the process that they haven't thought about an orbiter.
The two highest priority measurements for an orbiter vs a flyby mission, as I understand it, is the gravity measurements that require just an ultra stable oscillator for the radio system, and the magnetic field measurements that require a magnetometer and a simple plasma instrument. I have hope that these could be included.I think that they are simply so early in the process that they haven't thought about an orbiter.
Yes, but I think there might be another thing going on as well. I got info from another channel that implies that the mission is only possible with an SLS, and even then, it's marginal. I think that they may have ended up a bit surprised that there wasn't a lot of room to do other stuff on this mission.
In 2015, NASA revealed its plans to send a spacecraft to conduct several close flybys of Europa sometime in the 2020s. Now, the space agency has detailed — in a Science Definition Team (SDT) report — a mission to send a lander to the icy moon.
The 264-page report, which can be accessed here, lists out three key science goals for a future lander mission — searching for life on the moon, assessing its habitability by analyzing material from the surface, and characterizing Europa’s surface and subsurface to support future robotic missions.
The Europa mission went through some kind of confirmation review on Wednesday. I forget the details. I'll have to check. I was also told that its official name is now "Europa Clipper," but I won't believe that until I see it officially confirmed.
The Europa mission went through some kind of confirmation review on Wednesday. I forget the details. I'll have to check. I was also told that its official name is now "Europa Clipper," but I won't believe that until I see it officially confirmed.
I just heard it will be called Clipper from Jim Green.
OPAG is meeting Wednesday. You can get an update on Europa there. Also, MEPAG is meeting Wednesday as well. I included that agenda for comparison.I'm on a plane during the Europa Clipper session, and so would appreciate anyone who can grab some screen shots. Appreciate slides from the other sessions, too; darn that day job! Thanks.
OPAG is meeting Wednesday. You can get an update on Europa there. Also, MEPAG is meeting Wednesday as well. I included that agenda for comparison.
OPAG is meeting Wednesday. You can get an update on Europa there. Also, MEPAG is meeting Wednesday as well. I included that agenda for comparison.I'm on a plane during the Europa Clipper session, and so would appreciate anyone who can grab some screen shots. Appreciate slides from the other sessions, too; darn that day job! Thanks.
OPAG is meeting Wednesday. You can get an update on Europa there. Also, MEPAG is meeting Wednesday as well. I included that agenda for comparison.I'm on a plane during the Europa Clipper session, and so would appreciate anyone who can grab some screen shots. Appreciate slides from the other sessions, too; darn that day job! Thanks.
Hope it doesn't get completely buried under the TRAPPIST-1 announcement.
It's an AG meeting, not a public announcement. People continue to do their jobs despite press announcements.
Hope it doesn't get completely buried under the TRAPPIST-1 announcement.
It's an AG meeting, not a public announcement. People continue to do their jobs despite press announcements.
Won't there be any public information release afterwards?
From an AG meeting? No. It's a workshop meeting of scientists to share information. You can listen in over the web. But it's a meeting, not a press announcement.
NASA officials say the Clipper mission is still on track for a mid-2022 launch.
Using a powerful boost from NASA's new heavy lift rocket, the Space Launch System, the Clipper would fly directly to Jupiter and arrive in 2025. Without SLS, the journey would take five years longer, and require flybys of Venus and Earth to reach the right trajectory.
Flying past Venus means flying closer to the Sun. Flying closer to the Sun means extra heat shielding. And extra heat shielding means a heavier spacecraft. Though Congress has ordered NASA to use SLS for both the Clipper and lander missions, the agency is still keeping the extra heat shielding in the Clipper's design for now—just in case anything derails development of the yet-to-be-flown rocket.
Without SLS, the lander as currently designed might not be able to fly at all, according to the SDT report. That's because the spacecraft will be heavy. In addition to the lander itself, there are three other components: a carrier and relay stage, a de-orbit stage, and a descent stage. Officials aren't publicly saying how heavy the entire package might be, but it would currently require a deep space thruster burn and Earth gravity assist to put it on the correct path to Jupiter—even with the added boost from SLS. The earliest the lander would launch is 2024 or 2025, putting it at Jupiter around 2030.
Once in orbit around Jupiter, the lander spacecraft would spend 18 months slowly spiraling inward to Europa, swinging past Callisto and Ganymede on the way. At Europa, the carrier and relay orbiter would separate and act as a data relay satellite. The Clipper, ideally still operating in an extended mission, would be used as a backup relay. The lander would not have the capability to talk to Earth on its own.
Remember the Curiosity spacecraft's seven minutes of terror, during which it plunged to the Martian surface in a harrowing process known as entry, descent and landing, or EDL? Since Europa has no atmosphere, and the descent begins in orbit, a new acronym is in play: DDL, which stands for de-orbit, descent and landing.
First, the de-orbit stage will pull the descent stage and lander out of orbit. As the thruster-powered descent stage approaches the surface, it will perform the same skycrane maneuver that deposited Curiosity onto Mars, where a tether lowers the lander. The descent stage then cuts loose and flys away for an intentional crash-landing.
Once the lander is safely on the surface, scientists will have to work fast to gather their data. The spacecraft is powered only by a 45-kilowatt-hour battery designed to last between 20 to 40 days. Why not find a way to stay longer? Because the carrier relay orbiter, which will be bathed in Jupiter's radiation, is expected to fail in just a single a month.
I'm on a plane during the Europa Clipper session, and so would appreciate anyone who can grab some screen shots. Appreciate slides from the other sessions, too; darn that day job! Thanks.
Is there any official cost estimate for Europa Clipper? Isn't some sort of estimate usually given by the time a mission goes to phase B?
Is there any official cost estimate for Europa Clipper? Isn't some sort of estimate usually given by the time a mission goes to phase B?They are reportedly still managing the project to target ~$2B. Not clear if that includes launch; I suspect not. See Blackstar's other post on when official cost estimate is set.
They are reportedly still managing the project to target ~$2B. Not clear if that includes launch; I suspect not. See Blackstar's other post on when official cost estimate is set.
verified NASA Europa Mission account
@NASAEuropa
It's official! @NASA's mission to explore an ocean world orbiting Jupiter will be called #Europa Clipper. https://www.nasa.gov/europa
I was talking to some people attached to the mission at JPL recently and the consensus was that Pappalardo thought of the separate names as a sort of version control. In his mind, Europa Clipper is the 2013 concept and the current mission has evolved away from it enough (moving to solar, for one thing) that a new name was needed in order to distinguish it. I think you're right as far as OMB's reasoning, though.
There might have been a logic that they used at JPL. But the pressure to not use "Clipper" came from OMB.
Yeah... Culberson is probably going to be Chairman of the House Appropriations CJS Subcommittee for another 4 years. I think he is more likely to shiv Trump than let him can the Europa lander.
I'm not sure what re-instatement would mean at this point. As I understand it, a relatively small team is conducting concept studies. So far as we know there is no official estimate of what the mission would cost (but I'm betting it will be substantially more than Clipper, whose last cost estimate I saw from Eric Berger was $2.7B, although I don't know if that includes the launch vehicle).Yeah... Culberson is probably going to be Chairman of the House Appropriations CJS Subcommittee for another 4 years. I think he is more likely to shiv Trump than let him can the Europa lander.
The lander I expect will be reinstated by Culberson.
I'm not sure what re-instatement would mean at this point. As I understand it, a relatively small team is conducting concept studies. So far as we know there is no official estimate of what the mission would cost (but I'm betting it will be substantially more than Clipper, whose last cost estimate I saw from Eric Berger was $2.7B, although I don't know if that includes the launch vehicle).Yeah... Culberson is probably going to be Chairman of the House Appropriations CJS Subcommittee for another 4 years. I think he is more likely to shiv Trump than let him can the Europa lander.
The lander I expect will be reinstated by Culberson.
I believe that OMB is telling Culberson that it won't support the ramp up in spending that would come in a couple to a few years if the mission were to be approved to enter Phase A.
Mars 2020 is a very important mission so I'm not really shocked to see the uber-expensive Europe lander pushed after it. It makes some sense.
Mars 2020 is a very important mission so I'm not really shocked to see the uber-expensive Europe lander pushed after it. It makes some sense.The two missions may end up having costs within a few hundred million of each other; but caveat, I don't know if the budget numbers I'm hearing include any launch costs. The Clipper costs certainly don't include the full cost of an SLS launch, but it's uncertain how much of an SLS cost will be charged to SMD
Yeah, both vjkane and Star One are right, but...I believe, but haven't looked at the spreadsheets for months, that 2018 is the peak year of funding for Mars 2020
It is very hard to see how both projects could be afforded simultaneously. There's not enough budget to pay for them. I don't know when Mars 2020 finally starts ramping down, but that has to get out of the way before Europa Clipper can really ramp up, and even if EC and the lander cost the same amount, there's not enough in the budget--and my rough guestimate is that the lander is going to cost twice what Europa Clipper costs, if not more.
A good argument could be made for delaying the lander until surface conditions are understood. Having the lander die by being impaled on ice spikes during terminal descent would be double-plus ungood. But if delaying the lander, hopefully there'd be funding for instrument development and landing strategy studies, so some some of that risk can be bought down in the early, less expensive stages of such an ambitious project.
- lander mission total mass 16 metric tons (Clipper is 6 tons). There are also pictures; the lander itself is a lot bigger than I had thought
Quote- lander mission total mass 16 metric tons (Clipper is 6 tons). There are also pictures; the lander itself is a lot bigger than I had thought
Well, that's the mass of a Lunar Module. Then again, landing on Europa probably takes a helluva lots of propellants.
Must be hypergolic.
One question I am having about Europa Clipper: As far I know the heaviest mission launched to date (or I should say that made it to the launchpad) is Mars 96, which is still slightly heavier than Cassini.
One question I am having about Europa Clipper: As far I know the heaviest mission launched to date (or I should say that made it to the launchpad) is Mars 96, which is still slightly heavier than Cassini.
Fobos Grunt was reported at 13,535 kg at launch, as it had to carry the engine for escaping Earth and for orbit insertion, Chinese probe and adapter. hard to beat that
I'm almost tempted to wonder how well SEP would function at braking into Jupiter's orbit although I suspect 'not well' as a default answer due to weak sunlight and power-hungry systems.
NASA Watch @NASAWatch
Watch @NewsHour tonight for a story on #Europa and #NASA space policy with @milesobrien @Alienoceans
@CongCulberson & Robert Walker
Interesting post on Mike Brown's blog regarding verifying if the proposed hotspot is real, looks like it might be;
http://www.mikebrownsplanets.com/2017/04/europa-is-hot.html
I'd imagine the lander would land in the safest place possible, the Europan surface can be very rough.
Interesting post on Mike Brown's blog regarding verifying if the proposed hotspot is real, looks like it might be;
http://www.mikebrownsplanets.com/2017/04/europa-is-hot.html
I'd imagine the lander would land in the safest place possible, the Europan surface can be very rough.
I am sure I read today that once the lander has finished its mission it will incinerate itself?
Finally, an incendiary device design option is being explored for the vault. This device would potentially be triggered just prior to the end of the lander surface phase so as to further sterilize the space craft.https://solarsystem.nasa.gov/docs/Europa_Lander_SDT_Report_2016.pdf
I'd imagine the lander would land in the safest place possible, the Europan surface can be very rough.
I am sure I read today that once the lander has finished its mission it will incinerate itself?
Yes, from Section 10.5.2 of the Science Definition Team report:QuoteFinally, an incendiary device design option is being explored for the vault. This device would potentially be triggered just prior to the end of the lander surface phase so as to further sterilize the space craft.https://solarsystem.nasa.gov/docs/Europa_Lander_SDT_Report_2016.pdf
Archived video of the press conference:
https://www.youtube.com/watch?v=3n-0CSCcJuQ
I'd imagine the lander would land in the safest place possible, the Europan surface can be very rough.
I am sure I read today that once the lander has finished its mission it will incinerate itself?
Yes, from Section 10.5.2 of the Science Definition Team report:QuoteFinally, an incendiary device design option is being explored for the vault. This device would potentially be triggered just prior to the end of the lander surface phase so as to further sterilize the space craft.https://solarsystem.nasa.gov/docs/Europa_Lander_SDT_Report_2016.pdf
Thanks. Sounds a sensible precaution.
NASA and ESA join forces to build life-seeking Europa lander
https://www.newscientist.com/article/2128751-nasa-and-esa-join-forces-to-build-life-seeking-europa-lander/
They seem to be discussing JEM, one of the M5 proposals. I don't know in what sense the plan was unveiled now; there are already some links to JEM presentations and meeting abstracts in the ESA M5 call thread: http://forum.nasaspaceflight.com/index.php?topic=41991.0
Maybe this confirms that JEM passed the technical downselection?
According to a colleague, this JEM mission proposal has been around awhile and is not going anywhere. See the attached abstract that describes it.
According to a colleague, this JEM mission proposal has been around awhile and is not going anywhere. See the attached abstract that describes it.
All the same hopefully it can happen. Hard to predict the president but Congress seems to be supportive of Europa and NASA as a positive.
This idea came out of a set of studies of possible ESA contributions to NASA's Clipper mission when it appeared that the latter could carry a European sub-satellite. I suspect that it's still being promoted to keep the idea of a joint ESA/NASA mission to Europa alive should NASA go ahead with a lander mission. At this point, all Europa missions past the Clipper mission are concept studies. There's some good ideas in the JEM proposal. Should the ESA and NASA funding streams and interest align in time, I'd like to see them pursued. But there's a lot of ifs in that stream.
I think you're misunderstanding. This is a specific proposal that is going nowhere. It has apparently been kicking around awhile and has gained no traction.
If a joint Europa mission is to occur, it has to come from a different vector than this.
NASA and ESA join forces to build life-seeking Europa lander
https://www.newscientist.com/article/2128751-nasa-and-esa-join-forces-to-build-life-seeking-europa-lander/
The headline is misleading. It states that NASA and ESA have already done this. But the article indicates that this was a proposal at a science meeting.
NASA and ESA join forces to build life-seeking Europa lander
https://www.newscientist.com/article/2128751-nasa-and-esa-join-forces-to-build-life-seeking-europa-lander/
The headline is misleading. It states that NASA and ESA have already done this. But the article indicates that this was a proposal at a science meeting.
Why don't you take that up with SN as they are the people linking to the article where I got it from.
http://spacenews.com/scientists-want-nasa-and-esa-to-work-together-on-a-europa-lander-mission/
NASA and ESA join forces to build life-seeking Europa lander
https://www.newscientist.com/article/2128751-nasa-and-esa-join-forces-to-build-life-seeking-europa-lander/
The headline is misleading. It states that NASA and ESA have already done this. But the article indicates that this was a proposal at a science meeting.
Why don't you take that up with SN as they are the people linking to the article where I got it from.
http://spacenews.com/scientists-want-nasa-and-esa-to-work-together-on-a-europa-lander-mission/
Space News has a correct headline: "Scientists want NASA and ESA to work together on a Europa lander mission." That is accurate.
This New Scientist headline is inaccurate: "NASA and ESA join forces to build life-seeking Europa lander."
This Futurism headline is truly horrible: "It’s Official. In 2025, NASA and the ESA Will Land on Europa to Look For Alien Life"
The Space News short blurb is by Jeff Foust. I've known Jeff for about 15 years now. Jeff has a Ph.D. in planetary sciences from MIT. His writing is almost always very accurate. And he is very careful with interpreting his sources.
This Futurism headline is truly horrible: "It’s Official. In 2025, NASA and the ESA Will Land on Europa to Look For Alien Life"
It's almost like the job of the media is to sell, not be truthful or accurate.
In my experience, New Scientist generally is pretty solid although they tend towards solid coverage of somewhat more sensational stories. In some cases the reporting is sloppy. My guess is that someone with no understanding of how missions actually get approved was handed a press release or the equivalent.It's almost like the job of the media is to sell, not be truthful or accurate.
Well, we expect greater accuracy from the trade press. Why is New Scientist so sloppy?
In my experience, New Scientist generally is pretty solid although they tend towards solid coverage of somewhat more sensational stories. In some cases the reporting is sloppy. My guess is that someone with no understanding of how missions actually get approved was handed a press release or the equivalent.It's almost like the job of the media is to sell, not be truthful or accurate.
Well, we expect greater accuracy from the trade press. Why is New Scientist so sloppy?
In my experience, New Scientist generally is pretty solid although they tend towards solid coverage of somewhat more sensational stories. In some cases the reporting is sloppy. My guess is that someone with no understanding of how missions actually get approved was handed a press release or the equivalent.It's almost like the job of the media is to sell, not be truthful or accurate.
Well, we expect greater accuracy from the trade press. Why is New Scientist so sloppy?
New Scientist is fond of stories about very speculative theories. To their credit, they usually at least include a sceptical comment from some expert who is not directly involved in the work. Even in their news article they like to emphasise the sensational part (there's always a miracle cure found or some impeding catastrophe is threatening), though they don't usually get things as clearly wrong as in this case.
New Scientist was really bad a few years ago, but they've maybe toned down their sensationalism a bit lately.
Another example of a clickbait headline. You can read it in the url:
http://www.independent.co.uk/news/science/cassini-spacecraft-nasa-loses-contact-dive-through-saturns-rings-grand-finale-a7703616.html
That planetary science funding also includes $275 million for Europa missions, both the Europa Clipper multiple flyby spacecraft and a proposed lander. Language in the bill requires NASA to launch Europa Clipper no later than 2022 and the lander no later than 2024, although NASA officials have recently said they don’t expect the lander mission to be ready for launch until at least 2025. The Trump administration’s 2018 budget blueprint supported Europa Clipper but included no funding for a Europa lander.
Although there are no plans at present to send a lander to Europa, we continue to work on the prospects, asking what kind of operations would be possible there. NASA is, for example, now funding a miniature seismometer no more than 10 centimeters to the side, working with the University of Arizona on a project called Seismometers for Exploring the Subsurface of Europa (SESE). Is it possible our first task on Europa’s surface will just be to listen?
The prospect is exciting because what we’d like to do is find a way to penetrate the surface ice to reach the deep saltwater ocean beneath or, barring that, any lakes that may occur within the upper regions of the ice shell. The ASU seismometer would give us considerable insights by using the movements of the ice crust to tell us how thick it is, and whether and where ocean water that rises to the surface can be sampled by future landers.
Seismometers would help us detect ongoing activity in the shell. ASU envisions a seismometer mounted on each leg of a lander — four to six seismometers in all, depending on lander design. These would be driven deep into the ground, avoiding the kind of loose surface materials that would isolate the instruments from seismic waves passing through the shell. And that calls for the kind of rugged instrument ASU is building. Able to operate at any angle, the prototype can survive landings hard enough to ensure deep penetration for each seismometer.
Mike Brown @plutokiller
LOOK! fresh-from-the-satellite-link HST spectral slices of Europa. Mmmmmm. Time to get to work!
You can find the Europa program in the NASA budget proposal. Somebody with more energy than I can cut it down to only the relevant parts and post them here.
The bit about the lander is likely to be over-ridden by the politicians that's pretty clear by now.The politicians may make noise, but unless they increase the planetary budget by something on the order of $200M/year to keep the Clipper on a 2022 launch and then by several hundred million more a year for the lander, it is all noise.
The bit about the lander is likely to be over-ridden by the politicians that's pretty clear by now.The politicians may make noise, but unless they increase the planetary budget by something on the order of $200M/year to keep the Clipper on a 2022 launch and then by several hundred million more a year for the lander, it is all noise.
http://www.leonarddavid.com/a-human-touch-on-the-icy-moons-of-jupiter-saturn/
Does anyone know what propellant will be used for Europa Clipper's thrusters? Is it ion, mono, or biprop?
Does anyone know what propellant will be used for Europa Clipper's thrusters? Is it ion, mono, or biprop?
Pretty sure it's bipropellant; NTO/MMT combo with the later doing double-duty for small maneuvers and attitude. Pretty much similar to what Cassini or MRO used. NASA may debate on which fuel to use for a human mission, but with probes they stick with known mono propellants or a bi-setup when big orbit insertions unavoidable.
Does anyone know what propellant will be used for Europa Clipper's thrusters? Is it ion, mono, or biprop?
Pretty sure it's bipropellant; NTO/MMT combo with the later doing double-duty for small maneuvers and attitude. Pretty much similar to what Cassini or MRO used. NASA may debate on which fuel to use for a human mission, but with probes they stick with known mono propellants or a bi-setup when big orbit insertions unavoidable.
Does anyone know what propellant will be used for Europa Clipper's thrusters? Is it ion, mono, or biprop?
Pretty sure it's bipropellant; NTO/MMT combo with the later doing double-duty for small maneuvers and attitude. Pretty much similar to what Cassini or MRO used. NASA may debate on which fuel to use for a human mission, but with probes they stick with known mono propellants or a bi-setup when big orbit insertions unavoidable.
FYI. MRO was monoprop.
Europa Clipper Update Planned for 2017 Mars Society Convention
The Mars Society is pleased to announce that Dr. Robert Pappalardo, a Project Scientist in JPL’s Planetary Science Division, will provide an update about NASA’s Europa Clipper mission during the 20th Annual International Mars Society Convention, scheduled for September 7-10, 2017 at the University of California Irvine.
Due for launch in the 2020’s, the Europa Clipper mission will place a spacecraft in orbit around Jupiter in order to perform a detailed investigation of the giant planet's moon Europa - a world that shows strong evidence for an ocean of liquid water beneath its icy crust and which could host conditions favorable for life.
Dr. Pappalardo’s research focuses on processes that have shaped the icy satellite moons of the outer solar system, especially Europa, the nature, origin and evolution of bright grooved terrain on Jupiter’s moon Ganymede and the geological implications of geyser-like activity on Saturn’s moon Enceladus. Prior to joining JPL in 2006, Dr. Pappalardo served as an Assistant Professor of Planetary Science at the University of Colorado Boulder’s Astrophysical & Planetary Science Department.
For more details about the 2017 Mars Society Convention, including registration information for the four-day convention and evening banquet, please visit our web site (www.marssociety.org). The full 2017 speaker schedule will be posted online in the near future.
Witnesses
Dr. Jim Green
Director, Planetary Science Division, Science Mission Directorate, NASA
Dr. Kenneth Farley
Mars Rover 2020 Project Scientist; Professor of Geochemistry, California Institute of Technology
Dr. Robert Pappalardo
Europa Clipper Project Scientist, Jet Propulsion Laboratory, California Institute of Technology
Dr. Linda T. Elkins-Tanton
Director and Foundation Professor, School of Earth and Space Exploration, Arizona State University; Principal Investigator, NASA Psyche Mission
Dr. William B. McKinnon
Co-Chair, National Academy of Sciences, Committee on Astrobiology and Planetary Science; Professor of Earth and Planetary Sciences, Washington University in St. Louis
Space Subcommittee Hearing- Planetary Flagship Missions: Mars Rover 2020 and Europa ClipperQuoteWitnesses
Dr. Jim Green
Director, Planetary Science Division, Science Mission Directorate, NASA
Dr. Kenneth Farley
Mars Rover 2020 Project Scientist; Professor of Geochemistry, California Institute of Technology
Dr. Robert Pappalardo
Europa Clipper Project Scientist, Jet Propulsion Laboratory, California Institute of Technology
Dr. Linda T. Elkins-Tanton
Director and Foundation Professor, School of Earth and Space Exploration, Arizona State University; Principal Investigator, NASA Psyche Mission
Dr. William B. McKinnon
Co-Chair, National Academy of Sciences, Committee on Astrobiology and Planetary Science; Professor of Earth and Planetary Sciences, Washington University in St. Louis
https://science.house.gov/legislation/hearings/space-subcommittee-hearing-planetary-flagship-missions-mars-rover-2020-and
We present a daytime thermal image of Europa taken with the Atacama Large Millimeter Array. The imaged region includes the area northwest of Pwyll Crater, which is associated with a nighttime thermal excess seen by the Galileo Photopolarimeter Radiometer and with two potential plume detections. We develop a global thermal model of Europa and simulate both the daytime and nighttime thermal emission to determine if the nighttime thermal anomaly is caused by excess endogenic heat flow, as might be expected from a plume source region. We find that the nighttime and daytime brightness temperatures near Pwyll Crater cannot be matched by including excess heat flow at that location. Rather, we can successfully model both measurements by increasing the local thermal inertia of the surface.
Proceeding with development of a Mars Ascent Vehicle and fetch rover for a launch in 2026 will strain NASA’s planetary science budget.
The multibillion-dollar Europa Clipper mission is scheduled for launch in the early 2020s to make dozens of low-altitude flybys of Jupiter’s ice-covered moon, and NASA is also studying a Europa lander that could launch later in the decade. Europa Clipper is an approved mission, while the lander is still awaiting a go-ahead from NASA Headquarters.
Jeff Foust @jeff_foust
Niebur: concerned about growth in resources for payloads on Europa Clipper. Reporting plan in place to monitor instruments in development.
Jeff Foust @jeff_foust
Niebur: Europa Lander had mission concept review in June; still evaluating different options for mission, so premature for instrument AO.
Jeff Foust @jeff_foust
Bob Pappalardo, JPL, at OPAG meeting: Europa Clipper spacecraft now up to 4.5 solar panels per wing for add’l power for instruments.
Jeff Foust @jeff_foust
Pappalardo: already started preliminary design reviews for subsystems of Europa Clipper. Full project PDR in August 2018.
Jeff Foust @jeff_foust
Niebur reiterates that NASA is “reconsidering the trade space” for Europa Lander, which take some time. “Science is on the table.”
7:59 pm · 6 Sep 2017
Jeff Foust @jeff_foust
Q: cost estimate for Europa Lander?
Niebur: estimates in progress, not yet briefed to HQ. Prefer they hear it from us first, not Twitter.
8:03 pm · 6 Sep 2017
Jeff Foust @jeff_foust
Replying to @jabe8
SLS is currently the only launch vehicle under consideration for launching Europa Lander.
WASHINGTON — NASA is continuing to examine various, potentially less expensive options for a mission to land on Jupiter’s moon Europa even after completing a recent review, postponing a call for instruments for the spacecraft.
At a meeting of the Outer Planets Assessment Group (OPAG) Sept. 6 in La Jolla, California, Curt Niebur, a program scientist in the planetary science division at NASA Headquarters, said mission planners are continuing to examine several factors, including mission cost and science return, as they evaluate the design of the mission.
The lander mission, he said, successfully passed an early-stage review called a mission concept review in June. However, he said the agency had not settled on a specific, single concept for the mission.
“As a result of that mission concept review, what we want to do is essentially continue exploring the different options we have for a Europa lander mission,” he said. “We want to continue balancing the trade amongst risk, cost and science return.”
Progress is going well on Europa Clipper, Niebur and others said at the OPAG meeting. The mission passed a major project milestone called Key Decision Point B in February, allowing it to enter a preliminary design phase. Robert Pappalardo, project scientist for the mission, said at the OPAG meeting that the mission is on schedule to complete a series of preliminary design reviews by next August.
One issue with Europa Clipper that Niebur raised is the growth in resources in the spacecraft’s instrument payload. “It wasn’t so much that the resources grew, but it was the amount that they grew,” he said. The mission, he said, has put into place a “resource monitoring plan” to track that growth, and understand what instruments are having issues as early as possible.
Power demands from those instruments, though, have led to a design change in the spacecraft. The spacecraft’s two solar arrays now consist of four and a half panels each, up from four panels from earlier designs. “We needed to increase the total size of the arrays slightly in order to accommodate the energy demands of the payload,” Pappalardo said.
Further to the above here is the related article.
NASA studying less expensive options for Europa lander mission
Hill, discussing SLS use for Europa Clipper: launch date drifting later into the 2020s, but Congress could add $ to move it up. #VonBraun
QuoteHill, discussing SLS use for Europa Clipper: launch date drifting later into the 2020s, but Congress could add $ to move it up. #VonBraun
https://mobile.twitter.com/jeff_foust/status/923202544100413441
I knew this woman who wanted to have aQuoteHill, discussing SLS use for Europa Clipper: launch date drifting later into the 2020s, but Congress could add $ to move it up. #VonBraun
https://mobile.twitter.com/jeff_foust/status/923202544100413441
I knew this woman who wanted a baby, but didn't want to wait 9 months for it to arrive, so she got eight of her friends together and the nine women were able to have a baby in one month...
I do however see you point about doing a "rush job" on a mission as important as Europa Clipper. I would think being given full funding between now and its earliest tentative launch date of 2022 could get things done in the ~5 year space, emphasis on "if" being key. My concerns are less with the probe itself and more with SLS, especially since it will be the first mission to ride a EUS (and I imagine JPL is less-than-happy about playing Guinea Pig).
In your professional opinion Blackstar, how much time would be best to spend maturing a flagship mission once it's into Phase B onward?
EC has some issues that they are working through. At least one of them could be a major problem, or it could go away suddenly (because it's based upon a model, not actual data, and the model is currently showing something rather bad).
One of the things that has been plaguing them for a while now has been that they committed to a set of instruments rather early, and now they're trying to fit them to a spacecraft. Usually that is more of an iterative process, but because they had the money early, they settled on the instruments early, and it's proving hard to design a spacecraft that can accommodate all of them.
The decision point for SLS happens in 2018. That's when they have to have a vehicle approved.
The lander is a different issue entirely. We'll see what happens there (cue mysterious, slightly ominous music...)
Mass has been another problem because the project wants to keep non-SLS launch options available. If the project goes with SLS, I believe that the mass problems go away, but we are likely looking at a mid-2020s launch based on that vehicle's progress or lack thereof.
........
Thus far, it'll look like 'Clipper could launch somewhere between '22 and '25 with emphasis on the later date?
If the 'Clipper is launched beyond 2023. Then there will be more launch vehicle options available if the various development programs have flying hardware in the next few years. IMO no decision regarding the launch vehicle selection for the 'Clipper should be make until after the next US Presidential election. Funding & launcher availability should be more clear.I believe that the mission has to settle on a launch vehicle soon so they can design the spacecraft to the specific requirements of the vehicle and resulting flight plan (for example, does the spacecraft have to be designed for the heat environment of a Venus flyby?).
If the 'Clipper is launched beyond 2023. Then there will be more launch vehicle options available if the various development programs have flying hardware in the next few years. IMO no decision regarding the launch vehicle selection for the 'Clipper should be make until after the next US Presidential election. Funding & launcher availability should be more clear.I believe that the mission has to settle on a launch vehicle soon so they can design the spacecraft to the specific requirements of the vehicle and resulting flight plan (for example, does the spacecraft have to be designed for the heat environment of a Venus flyby?).
If the 'Clipper is launched beyond 2023. Then there will be more launch vehicle options available if the various development programs have flying hardware in the next few years. IMO no decision regarding the launch vehicle selection for the 'Clipper should be make until after the next US Presidential election. Funding & launcher availability should be more clear.I believe that the mission has to settle on a launch vehicle soon so they can design the spacecraft to the specific requirements of the vehicle and resulting flight plan (for example, does the spacecraft have to be designed for the heat environment of a Venus flyby?).
From what has been publicly said, a key issue has been power. In many missions, the key power driver is the communications system. Ralph Lorenz published a paper showing the power needed to push the data back to Earth is the largest consumer of power on many planetary spacecraft.
Subduction--the sliding of one tectonic plate beneath another--is possible on the ice shell of Jupiter's moon Europa, a new study shows. The process could supply chemical food for life to a subsurface ocean.
Rep. Culberson’s Seat in Jeopardy?
One of the Republican seats that may be in jeopardy according to the Times belongs to Rep. John Culberson, chairman of the House Appropriations Subcommittee on Commerce-Justice-Science (CJS) that funds NASA and NOAA...
Using the power of his chairmanship, he has compelled NASA to build and launch a probe to Jupiter’s moon Europa because he is convinced life exists in the ocean that some scientists believe exists under its icy shell...
Might be more difficult than I thought. F9H fairing is 43 feet tall. Both Centaur and DCSS would both occupy most of that length leaving little room for spacecraft. Extended fairing or placing the 3rd cryo stage between stage 2 and fairing would probably cause more engineering work than SpaceX cares to expend on the F9 at this point.
Might be more difficult than I thought. F9H fairing is 43 feet tall. Both Centaur and DCSS would both occupy most of that length leaving little room for spacecraft. Extended fairing or placing the 3rd cryo stage between stage 2 and fairing would probably cause more engineering work than SpaceX cares to expend on the F9 at this point.
In the afterglow of yesterday's F9H flight I think it is worth spending some time on launch options again. From a taxpayer's standpoint I am not sure I want to keep SLS going just for this mission. I have a much higher degree of confidence that BFR will obviate the rationale by 2030. We have waited half a century for sustainable interplanetary transport I have no problem cancelling SLS and waiting at most an extra 5 years to get into cis lunar space.
Realize F9H stage 2 not optimized for beyond GTO but can F9H do this mission with only Earth flybys?
....
A Europa mission will be able to chose from a variety of rockets, and any (especially new) rocket won't initially be trusted with a payload like a flagship right away.
....
A Europa mission will be able to chose from a variety of rockets, and any (especially new) rocket won't initially be trusted with a payload like a flagship right away.
So sending the Europa Clipper with the first SLS Block 1B is a good idea? ::)
....
A Europa mission will be able to chose from a variety of rockets, and any (especially new) rocket won't initially be trusted with a payload like a flagship right away.
So sending the Europa Clipper with the first SLS Block 1B is a good idea? ::)
Don't be a SpaceX troll ;)
Also, if you invoke the name of either FH or SLS too much the 'Clipper might be jinxed to fly on Atlas V so watch yourself!
Seriously though guys, YES, Falcon Heavy could be an option. Even a good option. However don't turn this into a SpaceX fandom. Besides, wait for the Outer Planet Assessment Group meeting due this month; perhaps in light of the launch the 'Clipper team might give a public update on their options. Let them speak about the matter themselves.
Only pointing out the obvious fallacy in your argument in your previous post. ;)
This budget enables a Europa Clipper launch readiness date in 2025. The Administration proposes to
launch the Clipper on a commercial launch vehicle, which would be several hundreds of millions of
dollars cheaper than an SLS flight and would not impact the availability of SLS rockets to support human
exploration. The Administration recognizes the benefits of using an SLS vehicle, including a shorter
cruise to Europa and a more direct trajectory (enabling a simpler thermal design and earlier science return
to inform future outer planet missions), but makes this proposal primarily due to budget considerations.
Consistent with Public Law 115-31, NASA is currently maintaining the capability to launch the Clipper on an SLS rocket.
The profile assumes $432 million for a commercial launch vehicle, which may be reduced as commercial
offerings and pricing continue to evolve. It is not possible to launch the Clipper on an SLS earlier than
2024 without disrupting current NASA human exploration plans.
If the Congress were to support the Administration’s position, NASA could move forward this year with securing a commercial launch vehicle.
In the FY 2019 PBR details released sometime in the last 12 hours or so:QuoteThis budget enables a Europa Clipper launch readiness date in 2025. The Administration proposes to
launch the Clipper on a commercial launch vehicle, which would be several hundreds of millions of
dollars cheaper than an SLS flight and would not impact the availability of SLS rockets to support human
exploration. The Administration recognizes the benefits of using an SLS vehicle, including a shorter
cruise to Europa and a more direct trajectory (enabling a simpler thermal design and earlier science return
to inform future outer planet missions), but makes this proposal primarily due to budget considerations.
Reference:
https://www.nasa.gov/sites/default/files/atoms/files/fy19_nasa_budget_estimates.pdf
(PS-77, page 433 of the PDF)
Which commercial vehicles/variants would be capable of launching Europa Clipper?
-which versions of Atlas?
-would Vulcan be considered?
-Delta 4 Heavy?
- New Glenn?
- F9/FH?
-NGLV/Antares?
-Ariane 5/6?
Pappalardo said the mission is continuing to study the use of Delta 4 Heavy and Falcon Heavy as alternatives, but those would require the use of gravity assists that increase the mission’s flight time. The use of the Atlas 5 has been “closed off,” he said.http://spacenews.com/europa-mission-planning-for-possible-budget-cuts-in-2017/
QuotePappalardo said the mission is continuing to study the use of Delta 4 Heavy and Falcon Heavy as alternatives, but those would require the use of gravity assists that increase the mission’s flight time. The use of the Atlas 5 has been “closed off,” he said.http://spacenews.com/europa-mission-planning-for-possible-budget-cuts-in-2017/
I am surprised that this article has not been shared yet:
http://spacenews.com/nasa-budget-proposal-continues-debate-on-when-and-how-to-launch-europa-clipper/
Per the article they do not consider Falcon Heavy because they doubt that it will be certified for Class A missions at launch time.
I am surprised that this article has not been shared yet:
http://spacenews.com/nasa-budget-proposal-continues-debate-on-when-and-how-to-launch-europa-clipper/
Per the article they do not consider Falcon Heavy because they doubt that it will be certified for Class A missions at launch time.
One wonders how SLS is supposed to be certified by then.
I am surprised that this article has not been shared yet:
http://spacenews.com/nasa-budget-proposal-continues-debate-on-when-and-how-to-launch-europa-clipper/
Per the article they do not consider Falcon Heavy because they doubt that it will be certified for Class A missions at launch time.
I am surprised that this article has not been shared yet:
http://spacenews.com/nasa-budget-proposal-continues-debate-on-when-and-how-to-launch-europa-clipper/
Per the article they do not consider Falcon Heavy because they doubt that it will be certified for Class A missions at launch time.
I do not see the words 'Class A' in the article, and am I missing this, or has it changed.
QuotePappalardo said the mission is continuing to study the use of Delta 4 Heavy and Falcon Heavy as alternatives, but those would require the use of gravity assists that increase the mission’s flight time. The use of the Atlas 5 has been “closed off,” he said.http://spacenews.com/europa-mission-planning-for-possible-budget-cuts-in-2017/
Article was dated August 17, 2016. A door closed 1.5 years ago or more could be re-opened?
Also, this article quote doesn't appear to preclude use of Vulcan/Centaur.
NASA has studied launching Europa Clipper on both SLS and on the most powerful variant of the United Launch Alliance Atlas 5. SLS offers the ability to fly a fast, direct route to Jupiter, with the spacecraft arriving at the planet less than three years after launch. The Atlas 5 would take more than six years to get Europa Clipper to Jupiter, and require flybys of both Venus and Earth to do so.
Isn’t there some odd situation where Europa Clipper is classed as a class b mission at the moment?
The independent review also raised questions about the risk classification of the mission. WFIRST is considered a “Class B” risk mission by NASA, which means it is high priority but only medium to high cost and with a medium mission lifetime. That is less stringent than the Class A assignments usually given to “strategically important missions with comparable levels of investment and risks,” Zurbuchen wrote.
The review, the memo noted, suggested NASA add more engineering development and spare hardware, as well as additional analysis, “to provide a more robust program” than its existing Class B risk classification.
Isn’t there some odd situation where Europa Clipper is classed as a class b mission at the moment?
You're thinking of the controversial Class B designation for WFIRST:QuoteThe independent review also raised questions about the risk classification of the mission. WFIRST is considered a “Class B” risk mission by NASA, which means it is high priority but only medium to high cost and with a medium mission lifetime. That is less stringent than the Class A assignments usually given to “strategically important missions with comparable levels of investment and risks,” Zurbuchen wrote.
The review, the memo noted, suggested NASA add more engineering development and spare hardware, as well as additional analysis, “to provide a more robust program” than its existing Class B risk classification.
http://spacenews.com/nasa-seeks-cost-cutting-changes-in-design-of-wfirst-mission/ (http://spacenews.com/nasa-seeks-cost-cutting-changes-in-design-of-wfirst-mission/)
It would be nice to get to Jupiter faster, but the problem I can see is that Clipper will never be a priority for SLS and it may get kicked off the launcher if it gets in the way of the manned missions. The other issue is that the reliability of SLS is questionable given the low flight rate. The current schedule has Clipper flying 2 and a half years after the first SLS, which is too long a gap between flights IMO.
In the end, I think Clipper rides another vehicle.
It would be nice to get to Jupiter faster, but the problem I can see is that Clipper will never be a priority for SLS and it may get kicked off the launcher if it gets in the way of the manned missions. The other issue is that the reliability of SLS is questionable given the low flight rate. The current schedule has Clipper flying 2 and a half years after the first SLS, which is too long a gap between flights IMO.
In the end, I think Clipper rides another vehicle.
The sooner that decision is made the better.
One wonders how SLS is supposed to be certified by then.
From another topic:
MATTBLACK:
Yes - things would certainly look good for lunar missions, doing 'distributed launch' of the spacecraft and the Earth Departure Stage (EDS). A Falcon 9 could place a 20 ton Lander or Command Module type vehicle into orbit first. A Falcon Heavy places it's upper stage as an EDS into orbit next, where it's only payload is propellant (65-70 tons?) and a docking mechanism. The spacecraft docks with this and the EDS burns for TLI.
Why not use the scheme for Europa Clipper?
Can Atlas 401/F9 and F9H provide direct flight to Jupiter?
In a presentation at a meeting of the Committee on Astrobiology and Planetary Science of the National Academies March 28, Kevin Hand of the Jet Propulsion Laboratory said that feedback from a mission concept review for the proposed lander last June led to changes in the design to reduce its cost.
“The technology and science were well received. The marching orders that we got out of that review were to see if we could simplify the architecture to reduce complexity and cost,” he said. While there’s been little discussion of the lander’s cost, Hand said there was a “desire” to reduce its cost to below $3 billion.
The concept for the mission presented at that review involved the launch of the lander on a Space Launch System rocket no earlier than late 2025. The spacecraft would enter orbit around Jupiter in 2030 with a landing on Europa to follow no earlier than December 2031. The battery-powered lander would operate on the surface for at least 20 days, relying on a communications relay spacecraft in orbit to return data to Earth.
Twenty days on the surface doesn’t seem all that much for the time and money invested.
Another factor that enables the change in design, he said, is a shift in the science requirements for the lander. A report by a science definition team last year had included, as one of the mission’s priorities, the ability of the lander’s instruments to directly detect any life that might exist in the moon’s icy surface.
“That’s a very high bar,” Hand said. “That bar runs the risk of setting expectations too high, perhaps, and also potentially cannibalizing some of the other science that the community sees as very valuable.”
Instead, the mission team looked at what the “sweet spot” for science from the lander mission might be. Hand said that looking for biosignatures of past or present life would simplify the science requirements for the mission, including reducing the amount of data needed to be transmitted back to Earth.
So is the main part of the redesign to ditch the orbiting relay setup, leaving basically the descent module and the lander?
So is the main part of the redesign to ditch the orbiting relay setup, leaving basically the descent module and the lander?
The briefing was at one of our meetings that just ended today. The Europa lander is going through a lot of redesign. The big change was to get rid of the orbiter, but they've also changed the science focus a lot. The goal is to both get the cost down and to broaden the mission because the focus on finding life was considered too narrow. There are some interesting animations as well. The lack of data about the surface makes landing really challenging, so one of their goals is to develop a very smart landing system that can choose the best landing site in real time.
Impactors have been crashed into asteroids to create a temporary plume of material from just under the surface. A, plume the composition of which could be identified by spectroscopy. Could this also be done on the largest airless bodies, like Europa, or is the surface gravity too strong? (I suppose collecting orbiting ejecta for sample return is way too acrobatic).
OIG announces an audit to assess NASA’s management of its mission to Europa, a moon of Jupiter.
It would be nice to get to Jupiter faster, but the problem I can see is that Clipper will never be a priority for SLS and it may get kicked off the launcher if it gets in the way of the manned missions. The other issue is that the reliability of SLS is questionable given the low flight rate. The current schedule has Clipper flying 2 and a half years after the first SLS, which is too long a gap between flights IMO.
In the end, I think Clipper rides another vehicle.
The sooner that decision is made the better.
One of the biggest impediments to the program moving forward at the moment is SLS. Once they can move it elsewhere the better.
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.
Cost is probably the true issue for flying via SLS. For the Europa mission (either the orbiter or lander), it would be wonderful to get directly to Jupiter; bad news is it may cost a lot, which coupled with safety was also a reason satellite providers rapidly abandoned the space shuttle. I'd like to see the flyby-orbiter fly with it, but I wouldn't want to do that with the lander since developing that will be enough of a future expense as is.I've worked with enough finance people to know that there is a lot of leeway on how costs are accounted for. NASA will have large fixed costs for maintaining the capability of launching SLS missions. Then there will be the marginal costs associated with building an individual booster, transporting it, fueling it, launching it, etc. The key will be whether the science division (I suspect there are some great telescope observatories that SLS could launch in addition to planetary missions) is charged only the marginal cost or a substantial portion of the fixed costs.
I strongly suspect that NASA will design planetary missions so they can also be launched on commercial systems. SLS may not work. Political support may dry up (when will Shelby retire?). There could be a launch failure and the whole system stands down for a couple of years. Backups are good.
In the case of the Europa multiflyby mission, a key decision will be whether to expand the fuel tanks or not and/or design the spacecraft for the heat of Venus gravity assists. The former would allow a deep space maneuver that would shorten the flight to 4.7 years with a Delta IV Heavy. The latter would allow an EVEEGA trajectory and a 7.4 year flight. How much insurance will NASA buy?
I heard someone say that they're designing it for the thermal effects of a Venus flyby no matter what. I don't know why, but myabe the margins opened up and they figured it is better to just plan for that no matter what.
For anyone who's interested in digging a little deeper into this:https://spacepolicyonline.com/news/today-tidbits-december-21-2017/ (https://spacepolicyonline.com/news/today-tidbits-december-21-2017/)QuoteRep. Culberson’s Seat in Jeopardy?
One of the Republican seats that may be in jeopardy according to the Times belongs to Rep. John Culberson, chairman of the House Appropriations Subcommittee on Commerce-Justice-Science (CJS) that funds NASA and NOAA...
Using the power of his chairmanship, he has compelled NASA to build and launch a probe to Jupiter’s moon Europa because he is convinced life exists in the ocean that some scientists believe exists under its icy shell...
Direct link: http://www.rollcall.com/news/gonzales/ratings-change-culbersons-texas-seat-creeps-closer-toss
http://www.planetary.org/blogs/casey-dreier/2013/20130515-nasa-steals-back-money-from-planetary-science.htmlQuoteDespite 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.
... [snip]
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.
Why is it that the Europa spacecraft's electronics vault is made of aluminum rather than some other material?Low atomic weight and won't release volatiles.
The orbits were carefully planned in order to minimize contact with Jupiter's dense radiation belts, which can damage spacecraft electronics and solar panels, by exploiting a gap in the radiation envelope near the planet, passing through a region of minimal radiation. The "Juno Radiation Vault", with 1-centimeter-thick titanium walls, also aids in protecting Juno's electronics. Despite the intense radiation, JunoCam and the Jovian Infrared Auroral Mapper (JIRAM) are expected to endure at least eight orbits, while the Microwave Radiometer (MWR) should endure at least eleven orbits. Juno will receive much lower levels of radiation in its polar orbit than the Galileo orbiter received in its equatorial orbit. Galileo's subsystems were damaged by radiation during its mission, including an LED in its data recording system.
...Europa is like nowhere else in the Solar System, and the orbiter will address questions that have been out there for nearly 20 years. The Galileo mission was partly a failure, and a return to the moons of Jupiter with a fully functioning spacecraft is long overdue. The Jupiter system has a very rich set of scientific phenomena, and there are plenty of other things to see besides Europa.
ESA's JUICE will spend a lot of its time looking at all the other wonders of the Jupiter system. Per the Europa mission's project manager, they haven't spent any time looking at studies of additional bodies. I did see one orbital study for the mission that included several flybys of Ganymede and Callisto. Right now the plan to dispose of Clipper is to crash it on Ganymede; the project manager says his dream is to see it do a couple of flybys of Io first before crashing it on that moon.
But JUICE has instruments better suited to studying Jupiter and the magnetosphere than the Clipper.
Together the two missions will do an awesome job, especially if they operate at the same time.
In my fantasy world, a Discovery Io flyby mission would also operate at the same time, but it would have to be selected in the next competition for that to happen.
For anyone who's interested in digging a little deeper into this:https://spacepolicyonline.com/news/today-tidbits-december-21-2017/ (https://spacepolicyonline.com/news/today-tidbits-december-21-2017/)QuoteRep. Culberson’s Seat in Jeopardy?
One of the Republican seats that may be in jeopardy according to the Times belongs to Rep. John Culberson, chairman of the House Appropriations Subcommittee on Commerce-Justice-Science (CJS) that funds NASA and NOAA...
Using the power of his chairmanship, he has compelled NASA to build and launch a probe to Jupiter’s moon Europa because he is convinced life exists in the ocean that some scientists believe exists under its icy shell...
Direct link: http://www.rollcall.com/news/gonzales/ratings-change-culbersons-texas-seat-creeps-closer-toss
I'm a huge political junkie and my favorite site for this kind of stuff is FiveThirtyEight. They just opened a feature projecting a statistical model giving the odds of which party will win each seat in the House:
https://projects.fivethirtyeight.com/2018-midterm-election-forecast/house/
They have three different models "Lite", which appears identical to the "polls-only" model they had for 2016, "Classic" - the default option, which appears identical to the "polls-plus" model they had for 2016, and "Deluxe" which is completely new. Polls-plus is polls only, but with certain "fundamentals" - such as demographic data - worked in. Polls-Plus was more accurate in previous elections, but in 2016 polls-only was more accurate. "Deluxe" is polls-plus but also with "expert opinions baked in.
They have a cartogram-map of the whole country where each hexagon represents one district. On the default "Classic" map, Rep. Culberson's 7th District is the Pale Blue Dot in the middle of the fourth row from the bottom of what is obviously Texas (even with the distortion) the "Lite" setting turns his hex dark pink.
"Lite" gives him a 75.7% chance of winning, and he's forecast to win 53.5% of the vote (plus or minus ~6.5%)
"Classic" gives him a 51.5% chance of winning, and he's forecast to win 50.2% (+ or - 5.2%)
"Deluxe" gives him a 50.7% chance, and he's forecast to carry 50.1% (+ or - 5.1%)
In short, Rep. Culberson has a slightly better chance of winning than losing, but his seat is nowhere near "safe". If he wins then he'll stay "Chairman" under a GOP majority or he'll probably be "Ranking Member" (if I'm not mistaken) under the Dems. Either way, he'll have more than enough power to push Europa Clipper (if not also the Lander) through and possibly even under his aggressive time-scale.
Not that I would be too worried that Europa Clipper would be in trouble, even if he loses. Planetary Science in general and JPL in particular have strong defenders on the Left:http://www.planetary.org/blogs/casey-dreier/2013/20130515-nasa-steals-back-money-from-planetary-science.htmlQuoteDespite 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.
... [snip]
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.
(Rep. Schiff, for anyone who doesn't know represents the district containing JPL. As a Democrat representing an urban/suburban district in California and further as a known Trump-critic, his seat is probably very safe. 538 gives him ">99%" chance of winning under all models.
nice comments. I was suprised to see when I read that article on 538 that TX 22 was moved from safe.
1) More Europa flybys - Someone posted here on one of the earlier threads that the Solar wings can handle more than 200 flybys, whereas the primary mission only involves 45. How many can the other components handle? Is there fuel enough to match?In presentations, the mission team has said that the spacecraft and instruments likely could survive many more encounters with Europa than the planned 45.
2) Callisto flybys - If 'Clipper can use a gravity assist to circularize it's orbit at apojove, then it could put itself in a less radioactive environment to investigate Ganymede and Callisto. Callisto is more important because she receives less attention from JUICE (that and the radiation is tolerable for humans over there)
3) The Io flybys are most exciting to me. IIRC, Io Observer baselines 6 flybys. How many could ol' 'Clipper handle after its primary mission at Europa?
4) Could some mix of the 3 be at all possible? (I was thinking extra Europa flybys, followed by a few years of Callisto flybys as a second extended mission to take a break from all that radiation and lastly a "grand finale" mission for Io, kinda like Cassini got multiple extended missions)
Also: Why does it need to crash into Ganymede or Io? Why can't they send it hurtling through Jupiter's atmosphere like Cassini?
SLS is the baseline, but it looks like EC is already designed to be launcher-agnostic:Looking at recent NASA launch vehicle specs for high energy trajectories (https://forum.nasaspaceflight.com/index.php?topic=43025.msg1849465#msg1849465), and assuming Europa Clipper stays at 6000 kg, it would appear that Delta-4 Heavy would still require a Venus assist, but Falcon Heavy could do it with a deep space maneuver, saving several years and the need for thermal shielding. Here is the thinking:
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.
I strongly suspect that NASA will design planetary missions so they can also be launched on commercial systems. SLS may not work. Political support may dry up (when will Shelby retire?). There could be a launch failure and the whole system stands down for a couple of years. Backups are good.
In the case of the Europa multiflyby mission, a key decision will be whether to expand the fuel tanks or not and/or design the spacecraft for the heat of Venus gravity assists. The former would allow a deep space maneuver that would shorten the flight to 4.7 years with a Delta IV Heavy. The latter would allow an EVEEGA trajectory and a 7.4 year flight. How much insurance will NASA buy?
I heard someone say that they're designing it for the thermal effects of a Venus flyby no matter what. I don't know why, but myabe the margins opened up and they figured it is better to just plan for that no matter what.
It makes perfect sense to have a backup plan in the design of the spacecraft itself (to avoid the cost of duplicity of design), but much has changed since 2016, so I must ask: Are they still designing with TPS for the EVEEGA trajectory?
It would seem to make more sense to me remove the TPS from the design and plan on expanding the fuel tanks with the idea of using the Heavy EELV-launched EGA trajectory for the following reasons:
nice comments. I was surprised to see when I read that article on 538 that TX 22 was moved from safe.
In presentations, the mission team has said that the spacecraft and instruments likely could survive many more encounters with Europa than the planned 45.
As for studying Ganymede and Callisto, there will be several early flybys used as gravity assists to pump down the orbit for the final Europa-focused orbits. In addition, ESA's JUICE spacecraft will orbit Ganymede and perform a number of Callisto flybys (along with a couple of Europa flybys). There's probably not a whole lot more science that EC could do at those moons that isn't already planned. On the other hand, more flybys of Europa will provide more high resolution imaging coverage and improve the models of the gravity field and the interaction of the magnetosphere with the interior ocean. The greater the number of Europa flybys, the more the coverage comes to become equivalent to that from a spacecraft orbiting that moon.
Looking at recent NASA launch vehicle specs for high energy trajectories (https://forum.nasaspaceflight.com/index.php?topic=43025.msg1849465#msg1849465), and assuming Europa Clipper stays at 6000 kg, it would appear that Delta-4 Heavy would still require a Venus assist, but Falcon Heavy could do it with a deep space maneuver, saving several years and the need for thermal shielding. Here is the thinking:
Juno, for example, had a C3 of about 30 km^2/sec^2, then used about 775 m/s of deep space maneuver followed by one Earth assist. Assuming an ISP of 320 for the DSM engine, that implies a mass ratio of about 1.28, or an initial mass of 7800 kg if the Jupiter arrival mass is to be kept at 6000 kg. The Falcon Heavy can put about 8000 kg to a C3 of 30, so this works.
Delta-4 heavy looks like it can put about 6000 kg to a C3 of 30. This is more than enough to send EC to Venus (which requires only a C3 of 15, even in the worst windows), and hence to Jupiter. But it's not enough to do this with a single deep space maneuver, as Juno did. So you would still need the high-temp shielding.
I'm wondering what the comparative advantages between Ti and Al are. I assume they both do the job of radiation shielding (without radiation spalling) quite well. However, I assume that titanium is more mass-efficient and volume-efficient, but Al is much cheaper. I further assume that, for Juno, which didn't need as much, Ti was more cost-effective, but for 'Clipper - which needs much more - Al will be better because you can just keep piling more of it on, more cheaply.
Looking at recent NASA launch vehicle specs for high energy trajectories (https://forum.nasaspaceflight.com/index.php?topic=43025.msg1849465#msg1849465), and assuming Europa Clipper stays at 6000 kg, it would appear that Delta-4 Heavy would still require a Venus assist, but Falcon Heavy could do it with a deep space maneuver, saving several years and the need for thermal shielding. Here is the thinking:
Juno, for example, had a C3 of about 30 km^2/sec^2, then used about 775 m/s of deep space maneuver followed by one Earth assist. Assuming an ISP of 320 for the DSM engine, that implies a mass ratio of about 1.28, or an initial mass of 7800 kg if the Jupiter arrival mass is to be kept at 6000 kg. The Falcon Heavy can put about 8000 kg to a C3 of 30, so this works.
Delta-4 heavy looks like it can put about 6000 kg to a C3 of 30. This is more than enough to send EC to Venus (which requires only a C3 of 15, even in the worst windows), and hence to Jupiter. But it's not enough to do this with a single deep space maneuver, as Juno did. So you would still need the high-temp shielding.
Huh, weird...
They've been saying for years that the Delta IV trajectory would be 4.7 years and with no Venus flybys. I guess that was the whole point of the extra propellant. Clipper would have to be its own kick stage! There's really no point in spending the extra money for Delta Heavy if it can't skip the Venus flyby. Delta IV is over-kill for that. At that point you may as well go for the exspendable Falcon Heavy, save some money and do the same mission slightly better, i.e. with margin.
It's too bad that the chart you linked didn't have a trajectory for the Falcon 9 Block 5. I wanted to see if it could match the performance of Atlas V 551.
(Wait, I answer my own question: It looks like re-used Falcon Heavy matches the performance of an Atlas V 551 for this mission; therefore it stands to reason that the single-core Falcon 9 Block 5 would perform worse for this mission)
Huh, weird...
They've been saying for years that the Delta IV trajectory would be 4.7 years and with no Venus flybys. I guess that was the whole point of the extra propellant. Clipper would have to be its own kick stage! There's really no point in spending the extra money for Delta Heavy if it can't skip the Venus flyby. Delta IV is over-kill for that. At that point you may as well go for the exspendable Falcon Heavy, save some money and do the same mission slightly better, i.e. with margin.
It's too bad that the chart you linked didn't have a trajectory for the Falcon 9 Block 5. I wanted to see if it could match the performance of Atlas V 551.
(Wait, I answer my own question: It looks like re-used Falcon Heavy matches the performance of an Atlas V 551 for this mission; therefore it stands to reason that the single-core Falcon 9 Block 5 would perform worse for this mission)
Even improving FH's Earth Escape capability by 3 or 4 metric tons - or more - would be a big win.
Anyone who suggests that a flagship planetary mission should plan on using a non-qualified launcher should review the search for a launch vehicle for the Galileo mission and review the length of time it took/will take for FH/SLS to reach its first launch much less its still to come qualification for launching key missions. Rocket development is hard, takes a long time, and almost always takes much longer than planned.Even improving FH's Earth Escape capability by 3 or 4 metric tons - or more - would be a big win.
What would be the business case for that? A heavy interplanetary mission that happens *maybe* once in a decade and you'd do that significant upgrade and lose all flight reliability history of the base vehicle, all the while FH is slated to be retired in favor of BFR anyway.
I don't see it ever happening.
nice comments. I was surprised to see when I read that article on 538 that TX 22 was moved from safe.
I just checked their map. TX 22 is listed as "solid R" under their polls-only model, and as "likely R" under their other two models. Just to bring Culberson back into focus, another one of their articles was pointing out a few places where one of their models disagreed with other expert analyses, and they compared the 7th district (Culberson's) with the 25th. They said that their "Lite" and "Classic" model considered the 25th to be much safer R than the experts' who considered it just as worrisome (for the Republicans) as the 7th. I find it kind of interesting that these ballot-watchers (who aren't necessarily space geeks) consider Culberson a go-to "generic Republican who should be more worried than usual".
(Another interesting note, though was the campaign finance site they had linked: One of the things that people have been saying about Culberson is that he hasn't been fundraising enough, and it is true that he has raised less funds than his opponent, but she has spent just enough the he now has more "cash-on-hand" than she does. I'm not sure if he can or will use that to his advantage, but I mention it because it is interesting.)
I honestly don't know much about this guy outside of his work with NASA, but I really like how has been pushing to make this mission happen, and has also been able to increase NASA's top line budget to make it happen. Other programs have been on 'Clipper's "coattails" to use the political term. I'm not sure how I feel about the lander; it seems too early, and it may get in the way of sample return. In any case, whether he wins or loses, I hope he or his successor as chairperson of CJS' Space Subcommittee will make 'Clipper launches and be mindful of NASA's other priorities.
Would Falcon Heavy be certified to fly this kind of mission as so far it seems to have a relatively low flight rate.If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.
Would Falcon Heavy be certified to fly this kind of mission as so far it seems to have a relatively low flight rate.If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.
If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.*IF*. Do you want to bet your $3B flagship mission on there being no development hiccups (first flight went great; will the second and third?) or SpaceX deciding it really doesn't need the FH with the BFH coming on line or there just turning out not to be enough customers to make it viable?
Anyone who suggests that a flagship planetary mission should plan on using a non-qualified launcher should review the search for a launch vehicle for the Galileo mission and review the length of time it took/will take for FH/SLS to reach its first launch much less its still to come qualification for launching key missions. Rocket development is hard, takes a long time, and almost always takes much longer than planned.
Shhhh!!! Don't interrupt the kids while they're role-playing...
If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.*IF*. Do you want to bet your $3B flagship mission on there being no development hiccups (first flight went great; will the second and third?) or SpaceX deciding it really doesn't need the FH with the BFH coming on line or there just turning out not to be enough customers to make it viable?
I lived through the Galileo search for a launch. You don't want your booster development to be in your critical path. I think it is idiocy to tie Clipper to the SLS for this reason.
Can the heavy do the launch without modifications?
Would Falcon Heavy be certified to fly this kind of mission as so far it seems to have a relatively low flight rate.If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.
That’s might come true but at the moment the first flight wouldn’t count for NASA as that wasn’t using the block 5 configuration and the first flight with this appears to be drifting out of 2018.
Can the heavy do the launch without modifications?
IMHO if Clipper doesn't go up on SLS, the only launch provider that'll launch it is ULA, whether it being Vulcan or D-IVH. It's just too valuable of a payload to risk anything, especially Musk's whims and changes of plans.
Can the heavy do the launch without modifications?
IMHO if Clipper doesn't go up on SLS, the only launch provider that'll launch it is ULA, whether it being Vulcan or D-IVH. It's just too valuable of a payload to risk anything, especially Musk's whims and changes of plans.
Would Vulcan be certified by the point that they have to make a decision on the launcher?
It's just too valuable of a payload to risk anything, especially Musk's whims and changes of plans.
Well, the military has already made this bet: (https://www.forbes.com/sites/bridaineparnell/2018/06/22/spacex-bags-130m-military-contract-after-just-one-falcon-heavy-test-flight/#5599ae9d1e37) So the main risk is technical, not supply and demand. And on the technical side, the FH cores have several technical advantages over Delta-IV cores - (a) more flight experience, (b) teardown and examination of flown cores, (c) human-rating, which implies very extensive analysis. Plus the FH has more margin to cover any performance shortfall. It's still a risk, but I'm not sure the risk is greater than relying on the Delta-IV.If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.*IF*. Do you want to bet your $3B flagship mission on there being no development hiccups (first flight went great; will the second and third?) or SpaceX deciding it really doesn't need the FH with the BFH coming on line or there just turning out not to be enough customers to make it viable?
I lived through the Galileo search for a launch.Galileo was particularly bad because of the RTGs. There is a big difference (in public perception, and in the paperwork required) between risking a $3B mission on a rocket otherwise certified only for lesser missions, and OMG, you want launch a DEADLY, NUCLEAR POWERED mission on an UNQUALIFIED ROCKET, where an accident might KILL US ALL!!!
You don't want your booster development to be in your critical path. I think it is idiocy to tie Clipper to the SLS for this reason.This I agree with 100%. But the FH,though new, seems a much safer bet. It has flown successfully, has both commercial and military contracts, is expected to be certified, and is built from parts with an extensive and current technology base. I'd be willing to bet my career that FH will be around and available in 2022. That's a bet I would not take for SLS.
Okay, can we now end the never-ending which rocket is bestest debate that belongs on another thread and get back to the actual subject of this thread?
Okay, can we now end the never-ending which rocket is bestest debate that belongs on another thread and get back to the actual subject of this thread?
Okay, can we now end the never-ending which rocket is bestest debate that belongs on another thread and get back to the actual subject of this thread?
Aye, Aye, Captain.
The May 2018 issue of the Europa Clipper newsletter had this to chart:
Okay, can we now end the never-ending which rocket is bestest debate that belongs on another thread and get back to the actual subject of this thread?
So Clipper's moving from Preliminary to Critical, at least by November if not the original October goal.
Can the heavy do the launch without modifications?
I'd like to see a breakdown or even a good paper on the various other launcher options (not SLS) for Europa Clipper and how it might effect the size, capability and trajectory of the probe.
Juno, for example, had a C3 of about 30 km^2/sec^2, then used about 775 m/s of deep space maneuver followed by one Earth assist. Assuming an ISP of 320 for the DSM engine, that implies a mass ratio of about 1.28, or an initial mass of 7800 kg if the Jupiter arrival mass is to be kept at 6000 kg. The Falcon Heavy can put about 8000 kg to a C3 of 30, so this works.
Delta-4 heavy looks like it can put about 6000 kg to a C3 of 30. This is more than enough to send EC to Venus (which requires only a C3 of 15, even in the worst windows), and hence to Jupiter. But it's not enough to do this with a single deep space maneuver, as Juno did. So you would still need the high-temp shielding.
...it was debated and sorted way back in the thread with a conclusion like this:
-SLS can do direct to Jupiter (for Clipper, Lander not so much)
-Delta 4 or Falcon Heavy could do a single EGA route
-Atlas 5 would require the multiple GA route
End of line
Huh, weird...
They've been saying for years that the Delta IV trajectory would be 4.7 years and with no Venus flybys. I guess that was the whole point of the extra propellant. Clipper would have to be its own kick stage! There's really no point in spending the extra money for Delta Heavy if it can't skip the Venus flyby. Delta IV is over-kill for that. At that point you may as well go for the expendable Falcon Heavy, save some money and do the same mission slightly better, i.e. with margin.
Perhaps the 6000 kg launch mass already includes the extra fuel for the Deep Space Maneuver , so the Jupiter arrival mass is about 4600 kg? Since the Delta IV can place 6000 kg to a C3 of 30, that would allow D4H with no Venus flyby. FH can do this trajectory as well, with somewhat better margins.
In this case both the D4H and FH could do the mission with the deep space maneuver. But neither of them can put 4600 kg to a C3 of 80, which would be needed for a direct course to Jupiter.
An Atlas 551 can put about 4600 kg to Venus, so that could be the backup-backup-backup plan with a still longer trajectory (if the SLS, D4H, and FH plans fall through).
If only one Earth gravity assist is required to get a good-sized probe to Jupiter when launched on a Delta IV-Heavy or Falcon Heavy; I think that's a tolerable requirement.Apparently, the Clipper team don't consider this as a requirement as they originally baselined Atlas V 551 to do the mission. Cassini-Huygens did the long EVEEGA cruise, JUICE is doing the full ~7 years, this isn't uncommon. I however would like to see the mission happen with the shorter cruise (however the more overlap there is between Clipper's stay at Jupiter and JUICE at Jupiter, the more collaborative science they could do together)
I've been wondering what kind of Europa mission Falcon Heavy could do with 'simple' upper stage upgrades done - I'm not talking about a Raptor-powered upper stage. But an upper stage widened to match the 5.2 meter payload fairing, to give increased propellant loads and a further upgraded Merlin 1D Vacuum? Or if the stage widening is too difficult/costly: keeping the same 3.7 meter diameter but stretching it's tankage another couple meters?
Would Falcon Heavy be certified to fly this kind of mission as so far it seems to have a relatively low flight rate.If the FH can launch twice a year, by 2022 it will have as many launches as Delta-4 Heavy does now - Parker Solar Probe was the 10th mission of the D4H. All of these bigger rockets have quite low flight rates - there are not many payloads that need their services.
Okay, can we now end the never-ending which rocket is bestest debate that belongs on another thread and get back to the actual subject of this thread?
IMO, the safest bet would be to have both the TPS and the extra fuel, if that fits within SLS' mass margin. The best bet however, again IMO - I could be wrong - would be to have the extra fuel, but not the TPS. Of the five rockets considered (Atlas, Delta, Falcon, Vulcan, and SLS) ...
...
I agree with ya, not to mention it was debated and sorted way back in the thread with a conclusion like this:
-SLS can do direct to Jupiter (for Clipper, Lander not so much)
-Delta 4 or Falcon Heavy could do a single EGA route
-Atlas 5 would require the multiple GA route
End of line
...
I agree with ya, not to mention it was debated and sorted way back in the thread with a conclusion like this:
-SLS can do direct to Jupiter (for Clipper, Lander not so much)
-Delta 4 or Falcon Heavy could do a single EGA route
-Atlas 5 would require the multiple GA route
End of line
Which variant of the SLS? Did't they planned for the Clipper to be the Guinea Pig to ushered into service the SLS Block-1B?
Well, the military has already made this bet: (https://www.forbes.com/sites/bridaineparnell/2018/06/22/spacex-bags-130m-military-contract-after-just-one-falcon-heavy-test-flight/#5599ae9d1e37)
And on the technical side, the FH cores have several technical advantages over Delta-IV cores - (a) more flight experience, (b) teardown and examination of flown cores,
And on the technical side, the FH cores have several technical advantages over Delta-IV cores - (a) more flight experience, (b) teardown and examination of flown cores,
Not really. New center core and second stage.
Can you guys all go make your endless back and forth arguments about rockets on some other thread? Seriously, that's all you guys do on this forum and you don't need to pollute this thread with it here too.
The current disposal plan is to dump the spacecraft into Jupiter, although crashing the craft onto Ganymede or Callisto remains a possibility. (From a previous public lecture, another Clipper manager said his favorite idea was to crash into Io, collecting data on the way in. Don't know if that remains a feasible option.)
You may be right about several passes. That was awhile ago.The current disposal plan is to dump the spacecraft into Jupiter, although crashing the craft onto Ganymede or Callisto remains a possibility. (From a previous public lecture, another Clipper manager said his favorite idea was to crash into Io, collecting data on the way in. Don't know if that remains a feasible option.)
I remember you saying that. IIRC, it would have been two or three passes by Io before the crash. How would the science of EC performing such an end of mission maneuver compare to the ~ 6 passes of the proposed, dedicated Io Observer mission?
IIRC, it would have been two or three passes by Io before the crash. How would the science of EC performing such an end of mission maneuver compare to the ~ 6 passes of the proposed, dedicated Io Observer mission?You may be right about several passes. That was awhile ago.
It's hard to compare science with a speculative mission, but here goes:
1) Clipper may well have a much higher data rate than a cheaper Io Discovery or New Frontiers mission, but if the solar panels are seriously degraded, there may not be the power to send back data at the highest rate.
2) Clipper will not have been designed to operate at Io-level of radiation, so there could be faults and noise in the instruments
3) The visual-IR spectrometer will not have been optimized for silicate studies; the same would be true of the dust mass spectrometer. This may not matter; the Clipper instruments might do well at Io. I just haven't looked into this.
4) Clipper will carry more instruments than I've seen planned for Io missions such as the radars. These could provide additional science, but prior Io mission designs have not prioritized these instruments.
IIRC, it would have been two or three passes by Io before the crash. How would the science of EC performing such an end of mission maneuver compare to the ~ 6 passes of the proposed, dedicated Io Observer mission?You may be right about several passes. That was awhile ago.
It's hard to compare science with a speculative mission, but here goes:
1) Clipper may well have a much higher data rate than a cheaper Io Discovery or New Frontiers mission, but if the solar panels are seriously degraded, there may not be the power to send back data at the highest rate.
2) Clipper will not have been designed to operate at Io-level of radiation, so there could be faults and noise in the instruments
3) The visual-IR spectrometer will not have been optimized for silicate studies; the same would be true of the dust mass spectrometer. This may not matter; the Clipper instruments might do well at Io. I just haven't looked into this.
4) Clipper will carry more instruments than I've seen planned for Io missions such as the radars. These could provide additional science, but prior Io mission designs have not prioritized these instruments.
Although obviously not 'Clipper's primary mission, I too am curious what it could do with Io, including a spectacular end crashing on that moon. I'd be thrilled to see an Io Observer, but that sadly remains stuck on paper while 'Clipper has finally reached the assembly process. In short, it's going to be our best shot at examining Io even at a glance...
ESA's JUICE will spend a lot of its time looking at all the other wonders of the Jupiter system. Per the Europa mission's project manager, they haven't spent any time looking at studies of additional bodies. I did see one orbital study for the mission that included several flybys of Ganymede and Callisto. Right now the plan to dispose of Clipper is to crash it on Ganymede; the project manager says his dream is to see it do a couple of flybys of Io first before crashing it on that moon.
Part of the excitement of a possible Io mission extension is the crash: could get a nice close-up picture like the one that NEAR-Shoemaker took of Eros...
On the other hand, it feels more proper to me to send Clipper into the Jovian atmosphere, much like Galileo and Cassini.
I was just reading through the Planet 9/Giant Planet 5 thread and there was some discussion about using data on Cassini's calculations of Saturn's orbit to see if there were perturbations that could be used to narrow down Planet X's location.
Some people sifted through the data and noticed some things, but the folks at JPL said that there was too much "noise" from all of Cassini's orbital changes and thruster firings to know for sure. Any changes were too minute to be statistically significant. Some seemed to be thinking that if Cassini's mission could be extended to 2020, then that would somehow be helpful.
So I got curious:
Could Europa Clipper or JUICE be used in much the same way? Keeping track of Jupiter's orbit and making note of any minute changes that could be evidence of the missing planet? Has the Galileo probe already done this? What about Juno?
I'm assuming that the answer would be no, or that it would be quite challenging because Jupiter is so much bigger and closer to the Sun than Saturn, and because the two probe's science mission is more focused on the satellites, but I figured I'd ask anyways.
If Cassini could do it 'Clipper probably could. If anything limits it maybe bandwidth availability and power if the arrays degrade any later in the mission.
If Cassini could do it 'Clipper probably could. If anything limits it maybe bandwidth availability and power if the arrays degrade any later in the mission.
Clipper, however, will have a huge solar panel surface and experience 3x the solar radiation pressure per unit area than Cassini did so those perturbations will be much more significant. Maybe that can be modeled out leaving sufficiently low residuals, I don't know.
I would also think that Mike Brown hopes to find P9 (if it's there) by the time Clipper has spent several years at Jupiter...
Currently in Phase B.
Europa Clipper was in the decadal survey as a recommended mission (as Jupiter Europa Orbiter). There was no lander as a recommended mission. It only exists because a congressman wants it. That's also why it is controversial.
The article is a pretty accurate reflection of that particular discussion, although the writer took Louise Prockter's comment out of context. She was saying that without a broad constituency (i.e. being recommended by the scientific community), the lander is politically vulnerable. That's totally true.
I thought the thing was to be battery-powered, what need does it have of an RTG?Maybe this is not politically viable, but it didn't keep NASA from issuing an AO for instruments for it, and it didn't keep people from busting their a*es proposing for it. https://nspires.nasaprs.com/external/solicitations/summary!init.do?solId=%7b17B73E96-6B65-FE78-5B63-84C804831035%7d&path=open
We could very well end up with a lander that is not properly designed to do the mission, in part because you really want to design the lander AFTER you gather good data on Europa from Clipper.
We could very well end up with a lander that is not properly designed to do the mission, in part because you really want to design the lander AFTER you gather good data on Europa from Clipper.
Huygens was designed after flybys of Saturn, not after the Cassini Orbiter and worked out just fine. And we are already past the Cassini stage for the Jupiter system, having already operated Galileo there for 8 years (and Juno after that). We know far more about the Jupiter system and the hazards there, including the radiation, than we did about the Saturnian system when Huygens was designed and operated successfully.
We could very well end up with a lander that is not properly designed to do the mission, in part because you really want to design the lander AFTER you gather good data on Europa from Clipper.
Huygens was designed after flybys of Saturn, not after the Cassini Orbiter and worked out just fine. And we are already past the Cassini stage for the Jupiter system, having already operated Galileo there for 8 years (and Juno after that). We know far more about the Jupiter system and the hazards there, including the radiation, than we did about the Saturnian system when Huygens was designed and operated successfully.
Apples and oranges. Voyager 1 flyby of Titan gave us an accurate atmospheric profile to be able to design an *atmospheric* probe, which is what Huygens really was. When it comes to science that a Europa lander would like to do, we don't even know what kind of environment we're looking at down there. Surface roughness, what kind of trace materials, etc.
Note that this was only a call for instrument concepts, not actual instruments.It was an AO for instrument development to the tune of millions of dollars per selection. Word on the street was that, like Clipper where an analogous process was followed, if the actual mission goes forward, selections will be made from the winners of this AO.
Simply because Congress controls the purse. When they feel like doing something, they have the power regardless of what is logical or follows normal protocol. If people don't like what their member of Congress is doing, vote them out. It may happen to the member who pushed this.See, that is the problem with "what ifs".
And you cannot look at this in isolation from the rest of the planetary budget and the planetary program. The decadal survey is where priorities get set. At the last decadal survey they did not even consider a Europa lander. It was only mentioned as a "far term" mission. Why should Europa get a ~$3+ billion orbiter and a ~$2.7 billion (WAG) lander in this decade? Why should other scientists and other parts of the solar system get locked out?
Simply because Congress controls the purse. When they feel like doing something, they have the power regardless of what is logical or follows normal protocol. If people don't like what their member of Congress is doing, vote them out. It may happen to the member who pushed this.The people of his district are not going to consider this issue in decided how to cast their votes. Any representative from this district will be a friend of NASA -- the Houston flight center is either in or adjacent to this district. Like the rest of this fall's election, the votes will largely be a referendum on the occupant of the White House.
But that's the scientific community shooting itself in the foot by taking itself out of the decision making process and devolving into Mad Max chaos. If the outer planets community is going to do that, why shouldn't MEPAG, SBAG and the others all just start buttering up their own preferred congresspeople to get what they want? Just give up on the decadal process completely.
If the outer planets community is going to do that, why shouldn't MEPAG, SBAG and the others all just start buttering up their own preferred congresspeople to get what they want? Just give up on the decadal process completely.
The decadal survey is where priorities get set.
Why should Europa get a ~$3+ billion orbiter and a ~$2.7 billion (WAG) lander in this decade? Why should other scientists and other parts of the solar system get locked out?
But that's the scientific community shooting itself in the foot by taking itself out of the decision making process and devolving into Mad Max chaos.
Relying on a congressman to stay in office, maintain a committee position, and reach handshake agreements with competing congressional interests for their multi-hundred million dollar (and increasing) earmark to go through year after year is a much less viable path.
Cassini, adjusted for inflation, was a similar amount to both of those numbers combined. Why did that happen? Should that have not happened? Was the rest of the solar system locked out during the period of its development?
You know, I could write 2000 words here explaining how space science priorities are established, what a decadal survey is, how space science policy has evolved over the past several decades, what a CATE is, and why all of this is important. But I'd be explaining it to somebody who probably wouldn't listen anyway and would just reply with a snarky remark. i won't bother. Feel free to think you understand how all of this works. Ignorance is blissful.
If the outer planets community is going to do that, why shouldn't MEPAG, SBAG and the others all just start buttering up their own preferred congresspeople to get what they want? Just give up on the decadal process completely.
Culberson is an odd duck. If there were others like him, I'm pretty confident that some members of the planetary science community would opt for Mad Max. Fortunately, he appears to stand alone.
Yeah, yeah, Mob rule/democracy is "Mad Max" chaos. The best form of government is a technocracy ran by technocrats, not the unwashed masses.
Some congressman stay around a lot longer than presidents.
And we should also appreciate that the decadal recommendation of a Europa orbiter wouldn't have happened without him...
For instance, the decadal process doesn't seem too interested in the threat from NEOs,
Congress has much more of a focus on national security objectives.
Scientists are more interested in stuff that happened billions of years ago.
If, in some alternate reality, Culberson actually influenced the flagship priorities in the last planetary science decadal survey, then something is seriously wrong with that reality. Heads should roll...
Flagship missions—The planned continuation of the Cassini mission through 2017 is the most cost-effective and highest-priority way to advance understanding of planetary satellites in the near term. The highest-priority satellite-focused missions to be considered for new starts in the coming decade are, in priority order: (1) Jupiter Europa Orbiter component of EJSM as described in the Jupiter Europa Orbiter Mission Study 2008: Final Report97 and refined subsequently (including several Io science flybys);
We could very well end up with a lander that is not properly designed to do the mission, in part because you really want to design the lander AFTER you gather good data on Europa from Clipper.
Huygens was designed after flybys of Saturn, not after the Cassini Orbiter and worked out just fine. And we are already past the Cassini stage for the Jupiter system, having already operated Galileo there for 8 years (and Juno after that). We know far more about the Jupiter system and the hazards there, including the radiation, than we did about the Saturnian system when Huygens was designed and operated successfully.
Apples and oranges. Voyager 1 flyby of Titan gave us an accurate atmospheric profile to be able to design an *atmospheric* probe, which is what Huygens really was. When it comes to science that a Europa lander would like to do, we don't even know what kind of environment we're looking at down there. Surface roughness, what kind of trace materials, etc.
On the flip side, because of plumes, tectonics due to the liquid subsurface, tidal flexing, a ferocious energetic particle environment, debris impacts, cratering, etc, you probably want the most up to date maps possible. You would likely want to target an area that has had recent plume activity but not current plume activity and an orbiter in the same time frame would be extremely helpful. The plan is I think Europa ~2022 with arrival 2024-2025, with the lander launching in 2026 and arriving in 2033. If you do it sequentially after arrival in 2025, you are probably looking at 2040, in which case your maps are over a decade old, you lose potential orbiter relay options (without sending up another orbiter), etc.
The scientific justification for targeting a geologically active region that is still safe practically requires close orbiter/lander time frames.
They can just as easily smack themselves when they get there and are going to need an orbiter for the landing, and Europa clipper will likely be 90% toast by then. BTW, Juice would be arriving around 2030, which would line up with 2033 a lot better than 2040. Besides, there would probably be a 1 year gap + with Europa doing mapping and the lander on the ground. You could change the landing gear if that unlikely scenario ever happened.
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:QuoteI 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:QuoteYes, 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.
In presentations, the mission team has said that the spacecraft and instruments likely could survive many more encounters with Europa than the planned 45.
He also stated that the likely limiting factor for the mission would be the decay of power from the solar cells as they are degraded by the radiation. (Which brings up the idea to me that at some point they could raise the periapsis of the orbit out of the intense radiation field and become a Jovian system observatory for some period. ESA's JUICE mission will orbit Ganymede and do a number of Callisto flybys. Don't know the science return for additional flybys of these moons by the Clipper spacecraft late in its mission.)
We could very well end up with a lander that is not properly designed to do the mission, in part because you really want to design the lander AFTER you gather good data on Europa from Clipper.
Huygens was designed after flybys of Saturn, not after the Cassini Orbiter and worked out just fine. And we are already past the Cassini stage for the Jupiter system, having already operated Galileo there for 8 years (and Juno after that). We know far more about the Jupiter system and the hazards there, including the radiation, than we did about the Saturnian system when Huygens was designed and operated successfully.
It should be noted that NASA hasn't soft landed on any solar system surface other than Mars since 1972. They need to branch out.
Apples and oranges. Voyager 1 flyby of Titan gave us an accurate atmospheric profile to be able to design an *atmospheric* probe, which is what Huygens really was. When it comes to science that a Europa lander would like to do, we don't even know what kind of environment we're looking at down there. Surface roughness, what kind of trace materials, etc.
edit:
cubesat lander - https://space.skyrocket.de/doc_sdat/omotenashi.htm
Why should Europa get a ~$3+ billion orbiter and a ~$2.7 billion (WAG) lander in this decade? Why should other scientists and other parts of the solar system get locked out?
Yeah, yeah, Mob rule/democracy is "Mad Max" chaos. The best form of government is a technocracy ran by technocrats, not the unwashed masses.
It's not about mobocracy versus technocracy. It's about a coherent technocracy versus an incoherent technocracy. Honestly, it's about herding cats.
Some congressman stay around a lot longer than presidents.
OMB staff are civil servants. They provide budget continuity between administrations that is usually lacking on congressional appropriations.
My statement can be parsed more than one way. It wasn't that he influenced the decadal, the decadal recommendation of an orbiter for Europa wouldn't have happened (as in, wouldn't be being built, not wouldn't be recommended). Bolden was talking in 2013 about no more Flagships and it wasn't showing up in their funding requests until that specific decadal recommendation was inserted by Congress.
And it wasn't just the lander that they were trying to kill, it was the Decadal Survey's Europa orbiter.
You know, I could write 2000 words here explaining how space science priorities are established, what a decadal survey is, how space science policy has evolved over the past several decades, what a CATE is, and why all of this is important. But I'd be explaining it to somebody who probably wouldn't listen anyway and would just reply with a snarky remark. i won't bother. Feel free to think you understand how all of this works. Ignorance is blissful.
One other thing. There were a range of proposals for the instrument list and spacecraft capabilities when what became Clipper was still a concept. Some of those likely would have come in around $2B for the spacecraft and instruments. NASA decided, and as long as Congress was willing to foot the bill I think this was the right decision, to go with a rich instrument set and a highly capable spacecraft. This way, we won't be in the position of needing to send a second remote sensing spacecraft to fill in the holes left by the first.Could someone remind me how the $2 billion Clipper concept became the $3 billion Clipper reality? It's more than just inflation, that much is clear. I think it's something like that they started to develop the instruments, but the instrument payload grew too big and power-hungry for the spacecraft they originally designed. The mid-decadal report says that Clipper will be "~$3.1 billion - ~$4 billion, depending on the launch vehicle." Thanks :)
But I'll correct you and note that Europa Clipper was never really a $2 billion concept. All early cost estimates are blurry, not only because some things are not known, but because some things are not decided. If you go back to the 2011 decadal survey, you'll see (I think--too lazy to check right now) that the DS never recommended a specific cost for a Europa orbiter mission. It only stated that the $4.7 billion CATE estimate for the Jupiter Europa Orbiter was too much, and NASA needed to descope the mission to come up with something more affordable--for various definitions of "affordable."
About a year or so ago this seemed to be in danger of biting them on the butt. The issue, as I remember it, was that they had approved (and started building) more instruments than the spacecraft could actually accommodate. So they ran the risk that they would then have to pull one of the instruments off because they could not provide enough power, mass, whatever for all of them. I don't know if they have solved that problem, but I have not heard any more kvetching about it, so maybe they have (or maybe I just have not asked the right people--there's too much to keep track of).
In my experience, solving dicey engineering problems almost always drives up cost. We are getting the Rolls Royce of Europa missions. Thank you Culberson.
I've been hearing more reassuring noises from people on different instrument teams in the last few months. It was looking dicey for a little while there, though.
How did this topic morph into a discussion of the Federalist Papers? With a side order of snark in both directions?
I am glad it morphed back. Let's try to keep it that way, thanks.
How did this topic morph into a discussion of the Federalist Papers? With a side order of snark in both directions?A number of posts have disappeared. ???
I am glad it morphed back. Let's try to keep it that way, thanks.
How did this topic morph into a discussion of the Federalist Papers? With a side order of snark in both directions?A number of posts have disappeared. ???
I am glad it morphed back. Let's try to keep it that way, thanks.
Exploring the tropics of Jupiter’s ocean moon Europa would be no walk on the beach.
Equatorial regions of the potentially life-supporting Europa, which harbors a huge ocean of salty liquid water beneath its icy shell, are probably studded with blades of ice up to 50 feet (15 meters) tall, a new study suggests.
This finding should be of interest to NASA, which is developing a lander mission that will hunt for signs of life on the 1,900-mile-wide (3,100 kilometers) satellite.
Well this could make life more difficult for any lander.It would also greatly reduce the radiation dose if you can find a nice crevice, so it's not wholly bad.Quoteare probably studded with blades of ice up to 50 feet (15 meters) tall, a new study suggests.
Well this could make life more difficult for any lander.
Europa’s Equator May Be Covered in Perilous Ice Towers (https://www.scientificamerican.com/article/europas-equator-may-be-covered-in-perilous-ice-towers/)QuoteExploring the tropics of Jupiter’s ocean moon Europa would be no walk on the beach.
Equatorial regions of the potentially life-supporting Europa, which harbors a huge ocean of salty liquid water beneath its icy shell, are probably studded with blades of ice up to 50 feet (15 meters) tall, a new study suggests.
This finding should be of interest to NASA, which is developing a lander mission that will hunt for signs of life on the 1,900-mile-wide (3,100 kilometers) satellite.
Ha... I thought of the same thing.Well this could make life more difficult for any lander.
Europa’s Equator May Be Covered in Perilous Ice Towers (https://www.scientificamerican.com/article/europas-equator-may-be-covered-in-perilous-ice-towers/)QuoteExploring the tropics of Jupiter’s ocean moon Europa would be no walk on the beach.
Equatorial regions of the potentially life-supporting Europa, which harbors a huge ocean of salty liquid water beneath its icy shell, are probably studded with blades of ice up to 50 feet (15 meters) tall, a new study suggests.
This finding should be of interest to NASA, which is developing a lander mission that will hunt for signs of life on the 1,900-mile-wide (3,100 kilometers) satellite.
You just have to use the traditional US Army method of clearing landing zone obstacles by blasting them away, Instead of Daisy Cutters use "Rods from God". Using a bunch kinetic impacter rods should do the job.
Only semi kidding. :)
With both Bill Nelson and John Culberson leaving Congress after electoral defeats. Will the Europa mission get de-scoped and/or delay?
I would not be surprised to see the target launch date slip to the mid 2020s from the Culberson target of 2022. The launch vehicle may also switch to a commercial launcher from the SLS, although Shelby is still in the Senate. If both happen, Clipper is likely to arrive in the early 2030s.
I expect that a Europa lander that was so strongly supported by Culberson will disappear for a least another decade.
We do not know what the new House majority wants, but I do not see the SLS going away.I also don't see it going away (from the launch pad).
Dems will want to cut planetary and put the funding into Earth science. Repubs in the Senate will want to do the opposite. They will compromise on doing nothing.
Now that Culberson is about to leave public office, the Europa lander will no longer have its champion, making its future at NASA uncertain. NASA never formally requested a lander for Europa, and the president’s latest budget request noted that the administration had no intention of funding such a program. No other lawmaker seems to be as passionate about the project, nor in the same position to keep the program alive.
The Europa lander, on the other hand, was not included as a top priority in the decadal survey. “That’s why the lander is in a much more uncertain position when Culberson leaves Congress,” says Dreier. “Because you don’t have any sort of institutionalized support for the concept.” And while most scientists agree that sending a lander to touch down on Europa’s surface is crucially important, some think that it’s too soon to start designing such a vehicle now. Even though we’ve sent a few spacecraft near the vicinity of Europa, we still don’t have detailed high-resolution imagery of the surface nor do we have much data from the space environment around the Moon. And it’s hard to design a lander for a terrain and environment you don’t know that well. “I actually put in a proposal for a potential instrument to be on the lander, and I struggled with writing a proposal because we have so many unknowns,” says Yingst.
Still, 2018 isn’t over yet. Culberson is still in office and it’s possible he could negotiate some last-ditch funding for the Europa projects before the end of the year. NASA is being funded through a continuing resolution that lasts until December 7th. It all depends if lawmakers can come to an agreement in the next few months on how funds should be appropriated for fiscal year 2019. But once Culberson leaves, it seems likely the funding for the Europa lander will dry up — and that could mean more waiting before we ever touch down on the mysterious moon’s icy exterior. “This is part of the deal of doing science in a democracy,” says Yingst.
Looks like certain posters on here were spot on about the Europa lander now it has lost its champion.QuoteThe Europa lander, on the other hand, was not included as a top priority in the decadal survey. “That’s why the lander is in a much more uncertain position when Culberson leaves Congress,” says Dreier. “Because you don’t have any sort of institutionalized support for the concept.”...
Looks like certain posters on here were spot on about the Europa lander now it has lost its champion.QuoteThe Europa lander, on the other hand, was not included as a top priority in the decadal survey. “That’s why the lander is in a much more uncertain position when Culberson leaves Congress,” says Dreier. “Because you don’t have any sort of institutionalized support for the concept.”...
When you have projects or programs that require "swimming against the current", you need to be able to exert constant pressure. I see that dissipating with the departure of Rep. Culberson.
However, as the article states, a probe to Europa has had a high priority for a quite a while, so it's still possible that something will be sent to Europa in the next decade - depending on which way the current is flowing... ;)
So is the Europa Clipper staying the way it is now. Or will will there be some de-scoping to make it less costly and quicker to launched?The only descoping that I've heard about is to use a much cheaper commercial launch vehicle instead of the SLS. OMB proposed it, and we'll see what the final budget passed by Congress says.
IMO the Europa lander might get fast tracked or delay further depending on what the Clipper finds. So decision on a lander mission will be a couple of years after the Clipper gets to Europa.
So is the Europa Clipper staying the way it is now. Or will will there be some de-scoping to make it less costly and quicker to launched?The only descoping that I've heard about is to use a much cheaper commercial launch vehicle instead of the SLS. OMB proposed it, and we'll see what the final budget passed by Congress says.
IMO the Europa lander might get fast tracked or delay further depending on what the Clipper finds. So decision on a lander mission will be a couple of years after the Clipper gets to Europa.
A lander that builds on the discoveries of an orbiter is likely to follow by a decade or more. So, say Clipper launches in 2025, arrives in 2031, does its first couple of years of science. Then a lander is designed to take advantage of those findings (5-7 years) and then flies to Europa (another 5-7 years).
Culberson was trying to circumvent that long delay. That plan depended on the lander being designed prior to the Clipper launch still being the right lander after the first couple of years of the Clipper's findings (like whether there are fields of ice blades covering much of the moon).
The only alternative launcher I’ve seen mentioned is the Atlas 551, and that would involve adding a Venus flyby and slower journey. Is this the only viable other choice to SLS?
The only descoping that I've heard about
The only descoping that I've heard about
No, there's other stuff going on.
The only alternative launcher I’ve seen mentioned is the Atlas 551, and that would involve adding a Venus flyby and slower journey. Is this the only viable other choice to SLS?
Elaborate. What do you mean by "people"?The only alternative launcher I’ve seen mentioned is the Atlas 551, and that would involve adding a Venus flyby and slower journey. Is this the only viable other choice to SLS?
People are starting to warm to the idea of a Falcon Heavy because it would eliminate the Venus flyby.
The only alternative launcher I’ve seen mentioned is the Atlas 551, and that would involve adding a Venus flyby and slower journey. Is this the only viable other choice to SLS?
People are starting to warm to the idea of a Falcon Heavy because it would eliminate the Venus flyby.
The only alternative launcher I’ve seen mentioned is the Atlas 551, and that would involve adding a Venus flyby and slower journey. Is this the only viable other choice to SLS?
People are starting to warm to the idea of a Falcon Heavy because it would eliminate the Venus flyby.
To others vehicles, not just FH.
A congressman’s loss clouds the future of two demanding missions to Europa
During a recent update, Clipper planners revealed they are looking at Falcon Heavy.
by Eric Berger - Dec 3, 2018 1:00pm GMT
Eric Berger’s take on impact of mid-terms on Europa missions:QuoteA congressman’s loss clouds the future of two demanding missions to Europa
During a recent update, Clipper planners revealed they are looking at Falcon Heavy.
by Eric Berger - Dec 3, 2018 1:00pm GMT
https://arstechnica.com/science/2018/12/will-the-europa-missions-be-iced-after-congressmans-defeat-not-right-now/
The breakthrough referenced by Goldstein involved the addition of a Star 48 "kick stage" to the Falcon Heavy rocket, which would provide an extra boost of energy after the rocket's upper stage had fired. With this solid rocket motor kick stage, Goldstein said Clipper would need just a single Earth gravity assist and would not have to go into the inner Solar System for a Venus flyby.
"Nobody is saying we're not going on the SLS," Goldstein said. "But if by chance we don't, we don't have the challenge of the inner Solar System. This was a major development. This was a big deal for us."
1) One could argue that JIMO actually got in the way of NASA developing a realistic Europa mission for many years.1) I would argue that the real purpose of JIMO was to delay or cancel any consideration of a real mission. It was a complete fantasy from the start.
2) and it is not really a case of dueling landers, it's more a case of the Europa lander vs. the rest of the scientific community, which would rather see that money spent on a bunch of other priorities.
This was really a no-brainer: the cost estimates on that mission were over $20 billion (yes, you read that right), and nobody expected it to ever progress very far in development. He did everybody a favor before even more money was thrown down that bottomless pit.
1) One could argue that JIMO actually got in the way of NASA developing a realistic Europa mission for many years.1) I would argue that the real purpose of JIMO was to delay or cancel any consideration of a real mission. It was a complete fantasy from the start.
2) and it is not really a case of dueling landers, it's more a case of the Europa lander vs. the rest of the scientific community, which would rather see that money spent on a bunch of other priorities.
This was really a no-brainer: the cost estimates on that mission were over $20 billion (yes, you read that right), and nobody expected it to ever progress very far in development. He did everybody a favor before even more money was thrown down that bottomless pit.
I always suspected that you were a traitor to the Galactic Empire, Blackstar.
2) In addition to the question of scientific balance, there's a question of whether or not we know enough about Europa to design a mission that will cost at least $2.5B (I doubt that includes the SLS launch, either). Where should we land, what are the conditions, what are the right instruments to carry? Remember that Galileo returned only a trickle of information. The current lander proposal is a credit to JPL's engineers, but it makes a lot of assumptions that may prove wrong.
There is a very good argument to be made to do all of these things in steps, with pauses to collect and analyze the data before taking the next step. The typical complaint is that nobody really wants to wait 20-30 years to land on Europa. But is the goal to do it now so that we can see it, or do it right?Europa landers will suffer from the same problem as Venus landers -- it's a damn hostile environment and any lander is going to be bloody expensive and short lived. (While landers can survive days or even weeks at Europa, unlike Venus with present technology, Europa sits deep in a gigantic gravity well and lacks an atmosphere to provide braking.) Imagine the pain of your Europa lander sitting down and the camera shows that the spot you really, really want to sample is 20 m away. To avoid that, you need to find locations that have that condition across a landing eclipse, and then you want to make sure you design the lander for the conditions in that area.
Europa landers will suffer from the same problem as Venus landers -- it's a damn hostile environment and any lander is going to be bloody expensive and short lived. (While landers can survive days or even weeks at Europa, unlike Venus with present technology, Europa sits deep in a gigantic gravity well and lacks an atmosphere to provide braking.) Imagine the pain of your Europa lander sitting down and the camera shows that the spot you really, really want to sample is 20 m away. To avoid that, you need to find locations that have that condition across a landing eclipse, and then you want to make sure you design the lander for the conditions in that area.
What are the arguments for Europa rather than Enceladus?
What are the arguments for Europa rather than Enceladus?
Because the message from 2001 A Space Odyssey was that we are not allowed to go to Europa. That, of course, is why we have to go there. Did you learn nothing as a child? When mother told you not to do something, it was because she was hiding something from you and therefore that's exactly what you did.
Because the message from(note correction above).2001 A Space Odyssey2010: Odyssey Two was that we are not allowed to go to Europa. That, of course, is why we have to go there. Did you learn nothing as a child? When mother told you not to do something, it was because she was hiding something from you and therefore that's exactly what you did.
Now, researchers at with NASA’s Glenn Research COMPASS team have devised an idea for a probe that could access that ocean: a nuclear-powered tunneling bot that could burrow through the moon’s icy shell to probe its composition and, potentially, access the watery darkness under it.
The researchers dreamed up two versions of the “tunnelbot,” one of which would use a small nuclear reactor and the other of which would use a “radioactive heat source module.” In both cases, the tunnelbot would use excess heat from its reactors to melt the ice as it traveled down.
As it went, the tunnelbot would analyze the ice and search it for signs of current or extinct life, reporting back to Earth with a fiber optic cable connected to communication equipment at Europa’s surface. It would even be equipped to explore lakes buried in the ice before it reached Europa’s oceanic depths.
The interiors of Europa and other watery moons in the outer solar system might be too geologically inactive to support life
Sounds like it is possible that if you’re visiting Europa just hoping to find life then you are wasting your time.
Ocean Moons, Promising Targets in Search for Alien Life, Could Be Dead Inside (https://www.scientificamerican.com/article/ocean-moons-promising-targets-in-search-for-alien-life-could-be-dead-inside/)QuoteThe interiors of Europa and other watery moons in the outer solar system might be too geologically inactive to support life
This was really a no-brainer: the cost estimates on that mission were over $20 billion (yes, you read that right), and nobody expected it to ever progress very far in development. He did everybody a favor before even more money was thrown down that bottomless pit.
I always suspected that you were a traitor to the Galactic Empire, Blackstar.
Europa Clipper will launch as soon as 2023, then trek out to the Jupiter system for about 40 close passes over the mysterious icy moon. Once it arrives, the spacecraft will gather vital information about the moon’s geology, composition and hidden interior ocean. But before the team can get to work building the spacecraft, it has one final review to pass.
But there are new challenges to tackle as well, like selecting a path for the spacecraft to follow around the Jupiter system, in a process called trajectory planning, which Senske jokingly refers to as “black magic.” (The spacecraft won’t orbit Europa directly, because it would receive too much radiation if it did. But that restriction offers benefits as well—like catching a peek at other moons. “Io happens to be right there,” Richey said. “Who doesn’t want to look at the planetary body that looks like a pox-ridden abyss?”)
While they’re waiting on a decision, the team is focused on the current hurdle: addressing questions raised on reviews of individual components of the project and how they interact. Once those are addressed, the project will enter what mission designers call phase C, which includes setting the final budget for the project and beginning to build the real spacecraft. “That’s when the fun starts,” Richey said.
Is the Europa Clipper coming up on Critical Design Review at last? Space.com posted a story alluding to it. With the government shutdown I had presumed most programs were on momentary pause.
In addition, my sense is that NASA selected instruments promising cutting edge measurements. It's the 5-star compliment. If this is correct, one downside is that this may have meant a fair amount of development was needed to meet all those goals. So I wouldn't be surprised to learn that some of the instruments are having problems fitting (literally it sounds) into their design boxes.Is the Europa Clipper coming up on Critical Design Review at last? Space.com posted a story alluding to it. With the government shutdown I had presumed most programs were on momentary pause.As I think I posted here late last fall, Europa Clipper had run into problems. The science instruments were all growing out of their boxes and had to be shoved back into them. That is why KDP-C kept getting delayed. You can go back and look to see when KDP-C was originally supposed to happen. We're still waiting. It will happen eventually.
In addition, my sense is that NASA selected instruments promising cutting edge measurements.
Please note that a Europa Clipper mission thread has started, also in the Space Science sub-forum, here: https://forum.nasaspaceflight.com/index.php?topic=47579.0
I found this in a presentation from a few months ago from JPL...It's an aspirational vision for the next 30 years, part of building support for an ambitious set of missions. That doesn't make it controversial.
I imagine this will be quite controversial.
Looks like an orbiter, lander, rover, a drilling rig, a stationary sub-surface platform, an ocean ice rover and two submarines designed for different depths.
The campaign would be similar in scope to the mars exploration program from Mariner 8 in 1971 through to Mars Sample Return in the mid 2020s (~50 years).