Author Topic: DIRECT v3.0 - Thread 1  (Read 1312284 times)

Offline MP99

Re: DIRECT v3.0 - Thread 1
« Reply #3260 on: 07/25/2009 06:25 am »
Quote
But how can NASA come up with its own number without review... seems a bit shady. No oversight at all.

YES!!!

This is another of the major questions we have.   Where is the guy looking over their shoulder?   Where is the guy who they HAVE to satisfy in order to be allowed to proceed?   Shouldn't everyone involved in the development always know that someone INDEPENDENT is above them and has the ability to say they are wrong, in order to keep them honest?   Isn't having that extra layer of checks & balances not a fundamental requirement of any good design process?


Hmm, I thought that the OMB was supposed to fulfil that function?

But I'm very hazy on this aspect of things.

cheers, Martin

Offline MP99

Re: DIRECT v3.0 - Thread 1
« Reply #3261 on: 07/25/2009 07:47 am »


Direct from the get go, has been building in margins of excess capacity, whether it has been in financial accounting, LV ability, etc... so that their LV description will not be seen as 'over' zealously efficient or cost effective... they used the NASA methodology in principal only... ie took the book keeping protocols and used them...

Ares / Constellation, instead of building in margins for potential problems, over exaggerated their potential and under accounted for their costing of the development of the LV... this has now left them in the position of having a weak bird and an inflated budget requirements...
they used the same book keeping methodology as Direct, but applied different parameters to their numbers...

The problem as I see it is that nobody outside the forum knows this. IMHO this is the most important part of the cost argument for Direct, besides the fact that there will only be one LV designed. I don't think it's been emphasized enough.

In fact I'm extremely hopeful for direct thanks to the margins, I think it will just as likely be underbudget to develop assuming people get out of the way.


I think that the ability to deliver the J-130 config with SSME's & 4-segs and without an upper stage (as can SD-HLV) is a great way to take a lot of the pressure off the overall development programme, and the built-in margins hopefully mean the speeded-up core development programme won't be a mad stretch. With avionics & Orion as the long-pole items, other programme elements have some natural give in their schedules, too.

Not having to rebuild the infrastructure and stretching or extending shuttle also helps a lot.

Even if J-130 doesn't achieve it's performance targets it can lose a huge percentage of it's payload and still be a useful vehicle. There's the option of a block II core developed alongside the upper stage, guided using real J-130 flight data.

Obviously, this would impact the Lunar mission, but adding 5-seg SRB's adds over 12mT - 15-17% to the thru-TLI performance. Also useful if Altair needs more L2/L3-type margins.

Whilst no-one would like to see those sorts of issues crop up, I absolutely love that the J-130 has so much performance margin in hand, and that there are obvious workarounds if J-2X performance also falls again or there are RL-10 HR issues (say can only fit a max of 5 "A"-spec engines).


I'm not suggesting that Jupiter has been over-optimistically estimated, but it's always great to have easy growth options in your pocket if you need them. Of course, these would increase costs, but not as much as where the development team need to find extra performance but none is easily available.

cheers, Martin

Offline MP99

Re: DIRECT v3.0 - Thread 1
« Reply #3262 on: 07/25/2009 08:15 am »
A thought on stretching the Shuttle programme to close the gap with J-130.

Jupiter is founded on the idea of retaining the expertise on the ground necessary to fly reliably. This is stuff that's locked away in people's heads, and once they're gone, that knowledge is gone with them. How many of these are the famous grey-beards that won't be around forever anyway?

If the remaining Shuttle flights are stretched out, does that mean that the staff on the ground would be less busy day-to-day - at least until they start planning ops processes for Jupiter?

Would this give NASA the time to start a documentation programme - get a lot of that knowledge written down?

* The ops unique to Shuttle would be nice to have for historical purposes, but not critical.

* Document the Jupiter-relevant stuff as it exists now, and keep it updated as part of the development process for the new Jupiter ops.

The fixed costs for stretching the Shuttle programme are high. Would this be a way to demonstrate getting extra value out of those costs?

cheers, Martin

Offline Nathan

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Re: DIRECT v3.0 - Thread 1
« Reply #3263 on: 07/25/2009 09:53 am »
The main reason why Zubrin's In-Line launcher, also called "Ares", was not considered is because it has a few technical concerns.

Firstly, it uses the more powerful 4-segment ASRM Boosters -- which were canceled for Shuttle after their costs went out of control.   They were replaced by the SLWT, which produced a similar performance improvement.

Second, the Upper Stage has an engine in the SSME thrust class, but which also needs to produce 465s vac Isp -- which is approximately 13s better than SSME, yet needs to be air-startable and then re-startable too.

Both of these elements are pretty costly items which most people don't realize were included.   You're talking about a similar cost ($1.8bn+) to the 5-segs in order to get the ASRM's and you're talking about a really serious development program ($2bn anyone?) to get that combined-higher-efficiency-SSME-air-start/re-start engine qualified for human use.

But if you swap those for existing systems (or J-2X in the case of the US engine), the performance for the vehicle drops significantly.   But if it drops, it can no longer support the size of mission Zubrin was hoping for -- and that short-circuits the plan :(


Also, since that study was conducted its concepts have been refined a lot by Zubrin and the Mars Society.   The "Mars Society Mission" seems to be the most recent iteration from that quarter and the mission size for MSM has grown since "Mars Direct" was first proposed.   It wouldn't fit on two of Zubrin's Ares vehicles now anyway.

Ross.

Still, the concept of the side mounted Engines could assist NASA if they  Choose Direct V2 and need to avoid the base heating problem... :)
Given finite cash, if we want to go to Mars then we should go to Mars.

Offline Analyst

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Re: DIRECT v3.0 - Thread 1
« Reply #3264 on: 07/25/2009 10:55 am »
And this reactor comes from where?

Analyst

Offline simon-th

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Re: DIRECT v3.0 - Thread 1
« Reply #3265 on: 07/25/2009 11:59 am »
And this reactor comes from where?

Los Alamos has a one megawatt Heat Pipe reactor which has a mass of 493 kilograms. Two hundred reactors like this would have a mass of 98.6 metric tons.

Why would you go through the trouble to bundle 200 reactors when you can just develop a single one sized to your payload capacity?
« Last Edit: 07/25/2009 12:47 pm by simon-th »

Offline wannamoonbase

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Re: DIRECT v3.0 - Thread 1
« Reply #3266 on: 07/25/2009 01:17 pm »
Ross or anyone else in the know:

If the Augustine commission picks Direct and General Bolden Obama, and Congress agree,  who should run the Direct development so it gets done right?  Does NASA have anyone that should be moved into the position that won't screw it up?

That's the $64,000.00 question.

I think they need someone from outside NASA.  Give that person deputies that know NASA and rockets. 

NASA's leadership and culture need new ideas and people after the failed development programs in the last 2 decades, shuttle accidents and cost over runs. 

There are people across the US that are use to running huge development programs for naval ships, helicopters, planes, submarines etc.  The skills needed to manage multi billion dollar technical programs exist.  Bolden being a Marine General can find those people and have the Pres. assign them to NASA. 
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Offline SoFDMC

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Re: DIRECT v3.0 - Thread 1
« Reply #3267 on: 07/25/2009 04:26 pm »
And this reactor comes from where?

Los Alamos has a one megawatt Heat Pipe reactor which has a mass of 493 kilograms. Two hundred reactors like this would have a mass of 98.6 metric tons.
Isn't the Heat Pipe Reactor still at the theoretical stage?

http://www.google.com.sg/search?hl=en&q=heat+pipe+reactor&btnG=Google+Search&meta=&aq=f&oq=

Offline kkattula

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Re: DIRECT v3.0 - Thread 1
« Reply #3268 on: 07/25/2009 04:27 pm »
And this reactor comes from where?

Los Alamos has a one megawatt Heat Pipe reactor which has a mass of 493 kilograms. Two hundred reactors like this would have a mass of 98.6 metric tons.

That's 1 MW Thermal.

Doesn't include the electrical generation equipment or the huge radiators needed.  Not to mention the inefficiency of conversion. 
« Last Edit: 07/25/2009 04:29 pm by kkattula »

Offline Ben the Space Brit

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Re: DIRECT v3.0 - Thread 1
« Reply #3269 on: 07/25/2009 05:03 pm »
And this reactor comes from where?

Los Alamos has a one megawatt Heat Pipe reactor which has a mass of 493 kilograms. Two hundred reactors like this would have a mass of 98.6 metric tons.

That's 1 MW Thermal.

Doesn't include the electrical generation equipment or the huge radiators needed.  Not to mention the inefficiency of conversion. 

True, but the point is that there is enough spare weight capacity to add those necessary features.  Either (or more likely both) NTP or NEP are necessary innovations if beyond-LEO flight is going to be more than occasional excursions to Mars and NEOs.  Such a lightweight reactor is a good starting place.
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Offline alexw

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Re: DIRECT v3.0 - Thread 1
« Reply #3270 on: 07/25/2009 10:16 pm »
Ross, I understand you are pushing your booster, but there are serveral problems with your post:

Quote
The scale of *some* (certainly not all) of the missions which SMD wants to do today is pushing the limits of current ELV/EELV launch assets to their breaking point -- or at the very least to the point where it results in significantly higher overall costs in order to squeeze a payload into a vehicle which just isn't the right size.

If this were true, at least some projects would be using Delta IVH, the current maximum. Only they don't, not even missions in their planning stage (Outer planet flagship). SMD can't afford these. Both Atlas 551 launches are high energy (NH in 2006 and Juno in 2011, look how rare they are).
(...)
We had no flagship since Cassini in 1997. MSL may be one (kinda), but it is far from the EELV limit. This leaves JWST, 24 years after HST.
(...)
This is the timescale we are talking: Less than once per decade. As I said, even the rare expensive missions avoid Delta IVH. And you won't be cheaper than Delta IVH, considering you need an upper stage. I don't believe in your cost numbers, sorry.

   Analyst, I think your points are well taken; the fact is that nearly all science missions were flown on smaller boosters, essentially because that's all that science could afford. The obvious exceptions were the great flagships of Voyager and Viking on Titan IIIE (a time when NASA had no flying HSF), and Cassini on Titan IV, and what else? But as I understand it, this is not only a matter of cost, but of *historical accident*, pretty much caused by STS:

1) Titan IIIE (/w Centaur) was the key new platform enabling the big new science missions, but it was only flown 7 times because we were getting rid of expendables, replacing it with...

2) Shuttle + Centaur-G. IIRC, I've read that the USAF was mostly content with  flying the Transtage and IUS from the orbiter, and it was NASA that really pushed Centaur. This was supposed to be the launcher for Galileo, and also Cassini and Ulysses I assume, and would it have been the launcher for Mars Observer and other missions in the 1990s and even now that both happend and could-have-been? But like SLC-6, it was close to ready before 51-L changed everything.

3) Titan IV (/w Centaur) was, as I understand it, an emergency backup plan by the USAF to replace the extra-heavy GTO weight of Shuttle/Centaur-G and the quick-responsive launch of Shuttle/IUS. Since the missions were all classified anyways, who cares what it cost -- what, $400 million each?

  It's very notable that Titan IV was only used once by NASA (Cassini, presumably because they had no other choice), and not even for Galileo or Ulysses, which were saved only by inventive orbital mechanics. NASA had lots of other heavy stuff (like the TDRS satellites), which they could have launched that way. The average per-launch cost of shuttle is I guess similar to Titan IV, but -- and this is the key of course -- the fixed costs of STS were borne by HSF, and the *incremental* costs of flying an orbiter (/w Centaur-G, or IUS) were minimal.

4) Delta-IVH and Atlas VH -- there's a lot of talk about these, but as I understand it, they were both intended as a back-up replacement for Titan IV +IUS/Centaur for those same rare, extra-heavy, who-knows-or-cares-about-the-cost, classified GTO DOD missions. It's a kludge. Only the DOD could use them -- and rarely at that -- not science, not industry.

  So, from the perspective of deep-space science, STS has been horrible. We built Titan IIIE, then threw it away; built Centaur-G, and never flew it; built Titan IV, which finally regained the throw-weight ability lost 15 years earlier, but it was a kludge affordable only by the DOD; and replaced that with DIVH, another kludge only affordable by DOD.   Atlas V, either 551 or lesser varients, finally gives science a decent, semi-affordable high-energy launcher, 30 years later. Yes, it's still very expensive because a science mission has to go out and *buy it*, commercially, but of course It Wasn't Supposed To Be This Way (51-L).

But instead of harping on the past, what about the future of deep-space? We've done multiple Venus orbiters, the Jupiter orbiter, the Saturn orbiter, even a Mercury orbiter, and the Pluto Express. We're flying one more Jupiter orbiter (JUNO). But apart from Mars, what would planetary science really like to do?

   * Jovian *lunar* orbiters: Europa, Ganymede.
   * Saturnian *lunar* orbiter: Titan
   * Neptune orbiter
   * Europa lander. Europa *submarine*!
   * Titan lander

   These are all really high energy, high weight, because the basic task is to throw a giant mass of hydrazine out there, with some instrumentation going along for the ride. The lunar orbiters are barely possible with Atlas V 551 or Ariane V ECA or even (at Flagship cost level) DIVH/AVH. But the landers may not be, and the Europa submarine is probably the single greatest mission we can hope for in our lifetime (apart from optical interferometer space telescopes, for pretty much the same reason!)

   Jupiter 130 could really change that.

If we assumed that the HSF program were to pick up all of the fixed operational costs for the system, leaving only the costs of the vehicle and its unique operations to be paid by SMD, a Jupiter-130/DHCUS CaLV flight should costs somewhere around ~$180m to SMD.

   Even if the costs double to $400 million, that's no worse than DIVH. Ross, how much mass could J130+DHCUS inject into TJI? And -- while we're dreaming here -- how much could Jupiter 246 throw to Jupiter?

Yes, these missions wouldn't happen very often, but they are the missions that would *write* the history books.

  Now, what might be really nice is if it were feasible to fly Ariane V's ECA on J-130. For the big science missions, we are already sharing the cost of the probe with the Europeans, but someone's gotta pay for the launcher. Ariane V/ECA or Atlas V 551, there can be only one, since payment is in kind, not in cash. But if you could split it ... ?  Ehh, never happen with export controls.

Even if J-246 is a long way away, or ultimately unaffordable for science (with the exceptions above), J-130 could really make a difference. Just with the solid motors, the huge payload fairing would (I'm guessing) change the face of Mars landers, without a revolution in EDL technology. With Centaur or DHCSS, you get everything else.

   DIRECT would make a big difference to science. Ares I  (hey, a moot point nowadays? :) would do practically nothing, and Ares V/Godzilla is a whole 'nother story, probably an illusionary capability as far as science is concerned.

  We've already done a lot of the beginning stuff -- flybys and the first outer planet orbiters. Science would be very happy to piggyback on HSF paying the massive infrastructure costs, picking up only the incremental cost if J-130 is already flying often enough, as it does with Delta II, did with Shuttle/IUS, and would have done with Shuttle/Centaur. History turned out differently than planned, as in our collective dreams and nightmares and would-have-beens, could-have-beens about space-post-Apollo, and it's time to expunge those sins and disasters of history.

The irony is that that very salvation may come from the SSME and SLWT!

-Alex


Offline robertross

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Re: DIRECT v3.0 - Thread 1
« Reply #3271 on: 07/25/2009 10:44 pm »
A thought on stretching the Shuttle programme to close the gap with J-130.

Jupiter is founded on the idea of retaining the expertise on the ground necessary to fly reliably. This is stuff that's locked away in people's heads, and once they're gone, that knowledge is gone with them. How many of these are the famous grey-beards that won't be around forever anyway?

If the remaining Shuttle flights are stretched out, does that mean that the staff on the ground would be less busy day-to-day - at least until they start planning ops processes for Jupiter?

Would this give NASA the time to start a documentation programme - get a lot of that knowledge written down?

* The ops unique to Shuttle would be nice to have for historical purposes, but not critical.

* Document the Jupiter-relevant stuff as it exists now, and keep it updated as part of the development process for the new Jupiter ops.

The fixed costs for stretching the Shuttle programme are high. Would this be a way to demonstrate getting extra value out of those costs?

cheers, Martin

I like the way you think  :)
Great post.

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Offline alexterrell

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Re: DIRECT v3.0 - Thread 1
« Reply #3272 on: 07/25/2009 11:02 pm »

Los Alamos has a one megawatt Heat Pipe reactor which has a mass of 493 kilograms. Two hundred reactors like this would have a mass of 98.6 metric tons.

That's 1 MW Thermal.

Doesn't include the electrical generation equipment or the huge radiators needed.  Not to mention the inefficiency of conversion. 

True, but the point is that there is enough spare weight capacity to add those necessary features.  Either (or more likely both) NTP or NEP are necessary innovations if beyond-LEO flight is going to be more than occasional excursions to Mars and NEOs.  Such a lightweight reactor is a good starting place.
Not really. Getting a lump of plutonium or whatever to produce 600MW thermal is the light weight part. Dumping 400MW into space is the heavy weight part. And 200MWe spinning generator is going to be heavy.

Offline mars.is.wet

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Re: DIRECT v3.0 - Thread 1
« Reply #3273 on: 07/26/2009 01:31 am »
It also helps that our budget figures have also been packed with larger margins.

When all is said and done, J-130 development has roughly 20% additional margins on top of the 'standard' margins which are typically used.

Ross.

Could you describe and quantify what "typically used" means?

Offline mars.is.wet

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Re: DIRECT v3.0 - Thread 1
« Reply #3274 on: 07/26/2009 01:32 am »
Has to be space qualified too.  Sometimes that is a huge technology challenge.

Offline wannamoonbase

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Re: DIRECT v3.0 - Thread 1
« Reply #3275 on: 07/26/2009 02:05 am »
Has to be space qualified too.  Sometimes that is a huge technology challenge.

Oh I don't know, making something out of radioactive fuel that can survive the 8 minute paint can shaker ride to orbit should add to many tons.
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Offline Lab Lemming

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Re: DIRECT v3.0 - Thread 1
« Reply #3276 on: 07/26/2009 02:37 am »
These are all good points.  But it is worth pointing out that a number of other proposed missions get stranded at the study phase because they do not fit on an existing launch vehicle.  Mars and Venus sample return are good examples of this.  Mercury landers also fall into this category.  And that is just planetary.  We haven't even started talking big telescopes yet...

Ross, I understand you are pushing your booster, but there are serveral problems with your post:

Quote
The scale of *some* (certainly not all) of the missions which SMD wants to do today is pushing the limits of current ELV/EELV launch assets to their breaking point -- or at the very least to the point where it results in significantly higher overall costs in order to squeeze a payload into a vehicle which just isn't the right size.

If this were true, at least some projects would be using Delta IVH, the current maximum. Only they don't, not even missions in their planning stage (Outer planet flagship). SMD can't afford these. Both Atlas 551 launches are high energy (NH in 2006 and Juno in 2011, look how rare they are).
(...)
We had no flagship since Cassini in 1997. MSL may be one (kinda), but it is far from the EELV limit. This leaves JWST, 24 years after HST.
(...)
This is the timescale we are talking: Less than once per decade. As I said, even the rare expensive missions avoid Delta IVH. And you won't be cheaper than Delta IVH, considering you need an upper stage. I don't believe in your cost numbers, sorry.

   Analyst, I think your points are well taken; the fact is that nearly all science missions were flown on smaller boosters, essentially because that's all that science could afford. The obvious exceptions were the great flagships of Voyager and Viking on Titan IIIE (a time when NASA had no flying HSF), and Cassini on Titan IV, and what else? But as I understand it, this is not only a matter of cost, but of *historical accident*, pretty much caused by STS:

1) Titan IIIE (/w Centaur) was the key new platform enabling the big new science missions, but it was only flown 7 times because we were getting rid of expendables, replacing it with...

2) Shuttle + Centaur-G. IIRC, I've read that the USAF was mostly content with  flying the Transtage and IUS from the orbiter, and it was NASA that really pushed Centaur. This was supposed to be the launcher for Galileo, and also Cassini and Ulysses I assume, and would it have been the launcher for Mars Observer and other missions in the 1990s and even now that both happend and could-have-been? But like SLC-6, it was close to ready before 51-L changed everything.

3) Titan IV (/w Centaur) was, as I understand it, an emergency backup plan by the USAF to replace the extra-heavy GTO weight of Shuttle/Centaur-G and the quick-responsive launch of Shuttle/IUS. Since the missions were all classified anyways, who cares what it cost -- what, $400 million each?

  It's very notable that Titan IV was only used once by NASA (Cassini, presumably because they had no other choice), and not even for Galileo or Ulysses, which were saved only by inventive orbital mechanics. NASA had lots of other heavy stuff (like the TDRS satellites), which they could have launched that way. The average per-launch cost of shuttle is I guess similar to Titan IV, but -- and this is the key of course -- the fixed costs of STS were borne by HSF, and the *incremental* costs of flying an orbiter (/w Centaur-G, or IUS) were minimal.

4) Delta-IVH and Atlas VH -- there's a lot of talk about these, but as I understand it, they were both intended as a back-up replacement for Titan IV +IUS/Centaur for those same rare, extra-heavy, who-knows-or-cares-about-the-cost, classified GTO DOD missions. It's a kludge. Only the DOD could use them -- and rarely at that -- not science, not industry.

  So, from the perspective of deep-space science, STS has been horrible. We built Titan IIIE, then threw it away; built Centaur-G, and never flew it; built Titan IV, which finally regained the throw-weight ability lost 15 years earlier, but it was a kludge affordable only by the DOD; and replaced that with DIVH, another kludge only affordable by DOD.   Atlas V, either 551 or lesser varients, finally gives science a decent, semi-affordable high-energy launcher, 30 years later. Yes, it's still very expensive because a science mission has to go out and *buy it*, commercially, but of course It Wasn't Supposed To Be This Way (51-L).

But instead of harping on the past, what about the future of deep-space? We've done multiple Venus orbiters, the Jupiter orbiter, the Saturn orbiter, even a Mercury orbiter, and the Pluto Express. We're flying one more Jupiter orbiter (JUNO). But apart from Mars, what would planetary science really like to do?

   * Jovian *lunar* orbiters: Europa, Ganymede.
   * Saturnian *lunar* orbiter: Titan
   * Neptune orbiter
   * Europa lander. Europa *submarine*!
   * Titan lander

   These are all really high energy, high weight, because the basic task is to throw a giant mass of hydrazine out there, with some instrumentation going along for the ride. The lunar orbiters are barely possible with Atlas V 551 or Ariane V ECA or even (at Flagship cost level) DIVH/AVH. But the landers may not be, and the Europa submarine is probably the single greatest mission we can hope for in our lifetime (apart from optical interferometer space telescopes, for pretty much the same reason!)

   Jupiter 130 could really change that.

If we assumed that the HSF program were to pick up all of the fixed operational costs for the system, leaving only the costs of the vehicle and its unique operations to be paid by SMD, a Jupiter-130/DHCUS CaLV flight should costs somewhere around ~$180m to SMD.

   Even if the costs double to $400 million, that's no worse than DIVH. Ross, how much mass could J130+DHCUS inject into TJI? And -- while we're dreaming here -- how much could Jupiter 246 throw to Jupiter?

Yes, these missions wouldn't happen very often, but they are the missions that would *write* the history books.

  Now, what might be really nice is if it were feasible to fly Ariane V's ECA on J-130. For the big science missions, we are already sharing the cost of the probe with the Europeans, but someone's gotta pay for the launcher. Ariane V/ECA or Atlas V 551, there can be only one, since payment is in kind, not in cash. But if you could split it ... ?  Ehh, never happen with export controls.

Even if J-246 is a long way away, or ultimately unaffordable for science (with the exceptions above), J-130 could really make a difference. Just with the solid motors, the huge payload fairing would (I'm guessing) change the face of Mars landers, without a revolution in EDL technology. With Centaur or DHCSS, you get everything else.

   DIRECT would make a big difference to science. Ares I  (hey, a moot point nowadays? :) would do practically nothing, and Ares V/Godzilla is a whole 'nother story, probably an illusionary capability as far as science is concerned.

  We've already done a lot of the beginning stuff -- flybys and the first outer planet orbiters. Science would be very happy to piggyback on HSF paying the massive infrastructure costs, picking up only the incremental cost if J-130 is already flying often enough, as it does with Delta II, did with Shuttle/IUS, and would have done with Shuttle/Centaur. History turned out differently than planned, as in our collective dreams and nightmares and would-have-beens, could-have-beens about space-post-Apollo, and it's time to expunge those sins and disasters of history.

The irony is that that very salvation may come from the SSME and SLWT!

-Alex



Offline kevin-rf

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Re: DIRECT v3.0 - Thread 1
« Reply #3277 on: 07/26/2009 03:20 am »

Oh I don't know, making something out of radioactive fuel that can survive the 8 minute paint can shaker ride to orbit should add to many tons.

Don't most high energy high density small sized nuclear designs use metalic and not oxide fuels? If you use a Na coolant could you not let the Na solidify and then melt it once in space before starting the device for the first time?

RTG's, though not the poster child for high power or power density seem to do just fine on the paint shaker ;)
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Offline MKampe

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Re: DIRECT v3.0 - Thread 1
« Reply #3278 on: 07/26/2009 03:27 am »
OK-
 
A couple of questions / ideas:

1) A couple of pages back, there was a graphic of a ET with 4 SRBs strapped to it. The follow-up mentioned that while scary-capable, that beast was also HEAVY- as in crack-the floor, break-the-back-of-the=crawler and dig-ruts-in-the-crawler-way HEAVY. Well- what about using 3 SRBs, or adding two (or more) of the midget-solids that Delta uses? Any benefit there without pushing things beyond their Young's Modulus?

2) Whatever happened to the **Really Slick** mobile-VAB they were going to use for Shuttle Launches from Vandenburg? That was pure genius! Couldn't something like that be used for Jupiter-Stupid-Heavy? You wouldn't need to completely re-engineer VAB, Crawlers, or the Crawler-Way- Just the Launch Pad(s). To keep costs down, you could limit the extra "beef" to one pad specifically for lofting your mother-in-law, her Luggage, House, SUV, 27 cats and enough food and Tidy-Cat for a voyage to Titan.

Offline Lab Lemming

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Re: DIRECT v3.0 - Thread 1
« Reply #3279 on: 07/26/2009 05:16 am »
The current baseline already exceeds all proposed payload requirements, so the money for bigger rockets would be better sent on more missions.  The main point of direct is to minimize development costs and spend the money exploring space.

OK-
 
A couple of questions / ideas:

1) A couple of pages back, there was a graphic of a ET with 4 SRBs strapped to it. The follow-up mentioned that while scary-capable, that beast was also HEAVY- as in crack-the floor, break-the-back-of-the=crawler and dig-ruts-in-the-crawler-way HEAVY. Well- what about using 3 SRBs, or adding two (or more) of the midget-solids that Delta uses? Any benefit there without pushing things beyond their Young's Modulus?

2) Whatever happened to the **Really Slick** mobile-VAB they were going to use for Shuttle Launches from Vandenburg? That was pure genius! Couldn't something like that be used for Jupiter-Stupid-Heavy? You wouldn't need to completely re-engineer VAB, Crawlers, or the Crawler-Way- Just the Launch Pad(s). To keep costs down, you could limit the extra "beef" to one pad specifically for lofting your mother-in-law, her Luggage, House, SUV, 27 cats and enough food and Tidy-Cat for a voyage to Titan.

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