hyper_snyper - 11/1/2006 12:12 AM
Wow...this is sudden.
Didn't they want methane-fueled engines in the first place for lunar ISRU or am I mistaken?
Chris Bergin - 10/1/2006 11:47 PM
Article to come.
We think they are going to Hypergols
hyper_snyper - 10/1/2006 4:30 PM
What's the ETA on that article Chris? I'm really curious as to why they made this decision.
nacnud - 10/1/2006 6:07 PM
:( seems like Mars is getting further and further away.
Then again the rovers have shown that there is water on Mars so LH2 LOX is possible ISRU.
Does anyone know a big problem with methane engines beyond the technology readness level. On the face of it methane seems so much easier to work with than toxic hypos, what am I missing?
Dobbins - 10/1/2006 9:20 PM
One thing to keep in mind, the CEV is a modular system, it will still be possible to develop a Methane powered SM at some point in the future that can be placed behind the CM. This is one of the things I like about a modular system, you aren't locked into one design, a portion of it can be changed without having to redesign everything.
stargazer777 - 11/1/2006 4:38 AM
The CEV needs to be done by the end of the Bush Administration and the Lunar lander and HLV need to have made dramatic progress toward becoming a reality. That is perhaps the only thing that will prevent a future president, regardless of their political party, from canceling or radically scaling back the whole thing. Zubrin believes, and I must say I find him persuasive, that if we cut our losses on the shuttle and ISS and went full funding on the exploration program -- build the HLV and the other necessary equipment -- we could be ready to go by 2009. I think that is the only way to win this thing.
rmathews3 - 11/1/2006 1:02 PMThe LOX/Methane engine on the CEV was to be used for EOI from lunar orbit, it has a seperate RCS system. For replacing this engine, how about LOX/Kerosene, as used on the Soyuz? Or perhaps LOX/Alcohol? Are there any existing US engines of the right size, or perhaps a design could be licensed from the Russians (not unknown) or someone else?
There is no other operationally proven thruster, not CH4, not LH2, nothing but hypergols.
Justin Space - 11/1/2006 10:19 AM
Thing is the Shuttles can't be retired until the ISS is has the elements it has commitments to. So why doesn't Griffin go to Congress and say "Money now or your space program's going to implode"?
hyper_snyper - 11/1/2006 1:04 PM
Is there any word on how this will affect the schedule or anything else?
NASA_Langley_spammer - 11/1/2006 1:56 PM
LOX/Methane is changeing to LOX/LH2. Heard this from four people involved with the current design stages just today.
HarryM - 11/1/2006 9:19 PM
Oh, well. Maybe an RL-60?
Chris Bergin - 11/1/2006 5:19 PM
Source info: Stennis apparently had a hand in the decision to move away from methane. One source, hence not viable as an addition to the current report (as with most one-source info). We have to stick with an "unknown" on the alternative to methane (either LOX/LH2 or Hypergols) as I'd prefer several in-the-know sources to confirm.
That's not dismissing information posted here, that's just due diligence as a journalist.
Flightstar - 11/1/2006 8:19 PM
It'll be Lockheed Martin, by the way.
Flightstar - 11/1/2006 9:19 PM
The downselect and wining contractor's timeline is now very important. It'll be Lockheed Martin, by the way.
Avron - 11/1/2006 11:08 PMQuoteFlightstar - 11/1/2006 9:19 PM
The downselect and wining contractor's timeline is now very important. It'll be Lockheed Martin, by the way.
How good is that info?
Looking at the unpressurized CEV variant for ISS operations, we're not too far off from being able to launch ISS modules of Destiny's mass.
From the RFP summary: The Cargo Delivery Vehicle (CDV) Option is removed from the final RFP. Link (http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1242&posts=16#M15912) :(
rcaron - 12/1/2006 6:24 AMQuoting spacester from space.com: "They dropped the requirement for that particular fuel but they are not excluding it from the list of possiblities. The contractors can still propose methane engines from what I can tell."
Dropping methane is a huge mistake.
CuddlyRocket - 12/1/2006 7:08 AM
Quoting myself :): "Perhaps the contractors ... approached NASA and said: Look, we can perform the missions much more cheaply, or get the thing built much quicker, if you let us use something other than LOX/Methane? Given that Mars is decades away, that might be difficult to resist in this climate of limited budgets and development time."
Dobbins - 12/1/2006 9:25 AM
.... The ISS currently generates O2 by breaking down waste water and it vents H2 overboard as a waste product, so there's a source of free Hydrogen to be had for the ISS missions that will be flown until at least 2015, and likely longer.
...
simonbp - 12/1/2006 10:59 AM
Would that mean having to run an H2 line all the way from elektron to the US end?
rcaron - 12/1/2006 12:07 PM
Changing from LCH4 to a hypergolic would be a massive overhaul. New engines, new thrusters, new tanks, new feedline & thruster heating requirements, different corrosive/dedgredation properties. These differences are outlined in ESAS' propellant choice analysis in Ch4 & 5. In short, changing out the propellant types would be a massive overhaul of the SM.
vanilla - 12/1/2006 9:20 PMQuoteBruce H - 12/1/2006 8:51 PMWhy are we going to the Moon?
Although the point is we do. We know we're going to the Moon, so the Moon is requirement filled on available cash. If we go to Mars then we can worry about that then.
vanilla - 12/1/2006 11:29 PM
NASA's problem is not now, nor has ever been, a lack of funding. NASA is awash in funding. NASA's problems are more...fundamental. One of the worst mistakes we could make would be to assume that more funding would make things work better. Quite the contrary.
vanilla - 12/1/2006 11:14 PM
NASA's fundamental problem is a lack of relevance to the national constituency. This manifests itself in the form of presidential and Congressional apathy, with exceptions for congressional representatives in districts where NASA is locally relevant.
Health care is nationally relevant, so politicians discuss it and contrast their positions against others. So are education, defense, homeland security, and the environment.
NASA must find a mission for itself that is nationally relevant. The last time it had one was Apollo, and the national relevance was in the form of nationalism and the fear of Communist expansion. With the successful landing on the Moon, this rationale reached resolution and the national relevance abated. NASA has not had national relevance since.
All the funding in the world won't fix this basic problem--rather, additional funding will antagonize those constituencies who do not feel as though the expediture of funds has any relevance to them, which are basically all constituencies outside of the NASA field centers and major contractors.
This is an unpleasant fact to state, especially in a forum such as this, but it would be my fondest wish if we could put our heads together and uncover a mission for NASA that fulfills this basic need. I can state the problem, but the solution eludes me.
vanilla - 13/1/2006 12:33 AMQuotercaron - 12/1/2006 11:27 PM
NASA as a whole has the same problem that the Shuttle had during its design - its everything to everybody, and now excels at nothing.
While I agree with the general flavor of your argument, I must hasten to point out that there are quite a number of activities where NASA excels far and beyond any other group could even hope. I don't see anybody else putting rovers on Mars for two years that climb mountains and drive through craters. I don't see other countries smashing probes into comets and figuring out all the theories are wrong. I'm not sure who's planning to send another mission to Pluto.
NASA kicks butt in a lot of areas, and I'm super proud of that. But we are missing the central mission--the reason around which all other activities can be aligned. Before you tell me that is the "vision", ask yourself, honestly, if that mission is nationally relevant. If you believe it is, I won't attempt to alter your opinion.
gyro2020 - 12/1/2006 11:38 PM
Welcome Dr Doug, great to see you here. The ESAS report was superb, I hope we can find the money to follow it through.
Space, I have the threads in question book marked.
In order of release on NASAWatch and brought here by Keith Cowing:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1086&start=1 - First few pages of interest from yet to be published ESAS DRAFT Report debate thread
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1112&start=1 - Full DRAFT ESAS Report debate thread.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1145&start=1 = ESAS Final Report debate thread.
rcaron - 13/1/2006 12:38 AM
A strong space program can inspire education. One needs an education to value and continue the space program. Its a cycle that we've seem to have broken.
QUOTE]
Thats a great insight, --- humm, no spaceflight =>less education => poorly educated workforce=> less work.. fear angle
Doug Stanley - 12/1/2006 11:29 PM
Yes, I am THAT Doug Stanley...I just stumbled across this forum and you all seem very well informed and reasonable. Many of you have read our ESAS Report. What do you think of it and the architecture (good and bad)?
Doug Stanley - 12/1/2006 11:29 PM
Yes, I am THAT Doug Stanley...I just stumbled across this forum and you all seem very well informed and reasonable. Many of you have read our ESAS Report. What do you think of it and the architecture (good and bad)?
Doug Stanley - 13/1/2006 12:29 AM
Yes, I am THAT Doug Stanley...I just stumbled across this forum and you all seem very well informed and reasonable. Many of you have read our ESAS Report. What do you think of it and the architecture (good and bad)?
Doug Stanley - 12/1/2006 11:29 PM
Yes, I am THAT Doug Stanley...I just stumbled across this forum and you all seem very well informed and reasonable. Many of you have read our ESAS Report. What do you think of it and the architecture (good and bad)?
Chris Bergin - 10/1/2006 7:52 PM
Right, time to move this into the CEV section seen as the article is on site.
Chris Bergin - 7/2/2006 5:18 PMJust a (friendly!) correction - there was no decision to drop Methane. What was dropped was the requirement to include it, but it was open to the contractors to opt for it if they wanted. (Although, you could take it as a pretty big hint!)
NASA is now reviewing the decision to drop methane.
publiusr - 17/2/2006 5:15 PMI don't agree with you at all. Voyager was going to be launched two at a time. And this concept that big spacecraft have to be more expensive than small spacecraft is also wrong. To start of with--if my shroud is big enough, I don't have to have as many articulating parts. I can also have margin built in. As Bob Truax also said, this idea that larger launch vehicles have to be more expensive is also for the birds. Some upper stages cost as much if not more than the boosters from his experience. We have the Venus probe launched atop R-7--which was the HLLV of its day--which proves my point very well.
Jim - 18/2/2006 10:14 AM
This is not a "concept". It is proven that bigger spacecraft are more expensive than small spacecraft. Mass is $. Articulating parts are not always because of fairing size, but that the parts can not be launched in their operation position because loads and vibration etc.
publiusr - 24/2/2006 4:04 PM Just because big spacecraft have been more expensive doesn't mean it HAS to be. Some of the larger spysats have a lot more equipment. That doesn't mean the quick and dirty aprach can't be helpful. The ZENIT spysat is basically a Vostok hull, as is the FOTON IIRC. A big pressurized hull shields circuits after all. Both Europeans and the Russians had (then) larger LVs which allow them to dominate the market, leaving underpowered Delta IIs in the dust. Titan IV was quite expensive and wound up not being cheaper than Saturn IB. That 20 ton to LEO craft should have been kept alive. But that was an Army rocket--and I imagine the AIr Force types weren't about to have that. I just wish General Medaris had kept the ABMA alive. I'd rather have something like this:http://www.astronautix.com/craft/globis.htm
Jim - 11/2/2006 12:02 AM
Totally wrong. It doesn't matter if we had a HLLV today, you are not going to be able to fund "Mars sample return missions, Europa LANDERS, Pluto LANDERS Heavy interplanetary probes, and Very Large Space telescopes." It would take more than NASA's existing budget to fund all of those.
There always was launch vehicle available for big spacecraft
danw - 20/4/2006 12:07 PM>>Maybe the 25 metric ton Crew Launch Vehicle would suffice for such missions. That's more capability than anyone was planning on having to low earth orbit until exploration came around.Although a little sort of the CLV in LEO capacity, the Delta IV Heavy can put over 12MT on escape trajectory, more than the CLV, and its ready NOW. Let's start fighting for heavy payloads. JIMO (Jupiter Icy Moons Orbiter) would be a good start. New imaging technology, new prupulsion, a nuclear reactor. Now THAT'S new technology and new science. :)
impulse - 21/4/2006 12:28 PM Want to to know the solution to CEV weight problems? Eliminate the whole propulsion element entirely. It is totally superfluous for LEO ops. Existing EELV's can loft the CEV capsule with oodles of margin to orbit and the Centaur element just stays attached. It will have TONS of unburned propellant and you will be placed in a real orbit- not a bogus suborbital trajectory like CLV. Nearly unlimited power and cooling capacity during pre-dock operations and no pesky solar panels or giant radiators. Minor mods to the Centaur can provide months of orbital time with cryos or you can just ditch the propellant and use batteries and a simple RCS to deorbit the capsule at the end of mission. The key is that with an EELV you can now afford to visit the ISS roughly four times more often. Who cares about a docked requirement for 180 days? It is irrelevant.The whole CEV "TEI" propulsion concept in its present incarnation is a horrendous joke. It is a crutch to preserve an incompetent design for the CLV. The CLV just can't do what they need it to do so they create one of the most expensive kludges yet conceived.
Jim - 21/4/2006 10:20 AM
I agree that a modified EELV can be a CEV launcher
Bruhn - 22/4/2006 10:56 AMI don't know where this rumor got started that the CLV is having performance problems. The CaLV had some published performance problems but they are even more preliminary than the CLV is. If you eqivalence were NASA is on the Constellation program to where NASA was on the Saturn program, we are in about 1960. And we do not have near the same resources NASA had during the Space Race. The CLV has had exactly one design cycle so far. Now we are good, but we're not that good. It takes many design and test cycles to whittle the mass down while maintaining the appropriate margins of safety.I realize people need something to talk about, but before you nail the coffin shut you might want to wait until at least PDR.And in my copy of the ESAS report, EELVs were considered in the trade space. I can't remember why they were eliminated.
Jim - 22/4/2006 11:03 AM
Politics
simonbp - 23/4/2006 12:57 AMQuoteJim - 22/4/2006 11:03 AMPoliticsActually, it was safety.On page 382 of the ESAS, there is a summary table of different Crew Launch Vehicle designs, including man-rated heavy versions of both EELVs, a 5.4 m and a 8 m Atlases, and the two SRB CLVs (4-seg SSME and 5-seg J-2). The probability for Loss Of Mission for the heavies is about 1 in 150; 1 in 134 for the 5.4 m; and 1 in 79 for the 8 m. The SRBs, though, both have a LOM of about 1 in 450. With numbers like those, the baseline CLV makes the EELVs look like genuine deathtraps...Now, these numbers might be wrong, and if so please show me evidence to the contrary, but what we are talking about here is crew safety. The EELVs are very good at what they were designed to do, but the CEV is not a Lacross or a Navstar, and the loss of a launch vehicle (regardless of whether the crew survives or not) is not simply a financial write-off, but a national disaster that treatens the very existance of the manned space program.The fact is, the CLV will be an entirely new vehicle because no existing LV in the world today could fulfill its requirements without significant modifications. With that in mind, NASA is taking the tack that any new vehicle should be driven by safety, regardless of whether it is the best from a cost or performance perspective. I'm reall pround of NASA for doing this, and hope that they don't back down simply because of slight cost issues (or political pressure to use the EELVs)...Simon ;)
impulse - 22/4/2006 7:30 PM
1: Who says Centaur is the key? What about D-IV 2nd stageKnock yourself out- but I think you will not like the B2 engine quite as much and a dual engine variant is not possible.
2. Steel ballon around the ISS. Better to have a structurally stable Centaur/upperstageLets see- that steel balloon is what got you the performance you needed to do this cheap. Anything else is a strict payload compromise and you get to pay for that. Lets recalibrate here- an upper stage is the ultimate racing car. It must deliver astounding delta V and not weigh anything. You can insist on inefficient structures but you get to pay for that in additional complexity elsewhere. Like a higher Isp engine or a lighter avionics suite. Simple lightweight structures are cheap and well understood. Why on earth would you ever move the weight burden over to a more complicated system? Around ISS the tank pressures are maybe 5-10 psia- for a tank designed for over 50 psia. Not enough margin for you?
3. EELV upperstages donot have the right sized engines for rendezvous nor proper number of thrusters.Adding thrusters to do 6 DOF operations is a trivial task using hardware that has already been flown. If you insist on rapid motion because you are an impatient pilot then you get to pay for that. As it is we can handily maneuver Centaur with 9lbf thrusters- we used to do it with 6lbf. For a vehicle that weighs many tons fueled with a variable Cg. Delta V on orbit can be done with larger thusters in the Aerojet stable.
4. Avionic integration would be a nightmare. EELV avionic only can fly the upperstage. You want the CEV to control the upperstage for rendezvous?I can think of at least four solutions to this but recall that thrusters are commanded by an RCU that talks over a 1553 bus to a computer. With proper software you can hand over command to whatever computer you want to use. That is the beauty of a bus. The CEV will already be on this bus anyway so that you can watch the data and controls from the Centaur FTINU.5. Minor mods were for days not months onorbit for the cryo stage.This all depends on whether you plan on keeping cryos on board near ISS. Given that they are not required I would dump em. then you got no worries. Just about the worst cryo storage place within 1 AU of the sun is docked to the ISS. You cannot control vehicle attitude and are in a high heating environment clamped to a hot structure. Once you remove these constraints then all sorts of possibilities emerge. Storing LH2 in an arbitrary state is hard and expensive. Storing it with forethought about the environment is not that tough. It is far easier to store ice cream in an Alaska winter than in an Arizona summer.
6. The sub orbital injection by the CLV was for 2nd stage disposal, which would be used for EELV'sUnlike CLV the upper stage is light enough to take to orbit. It stays there until the CEV is ready to come home. Then you dump it like a Progress. The thing only weighs 2.5t and is a balloon as you said. Can't imagine a more "burn-up able" machine.
7. The CEV is designed for going to the moon. Additional mission is to go to the ISS. Moon drives the requirements, ISS gets what it can.This is certainly a laudable goal but as of right now the storable system is a major compromise that had to be done to meet an ISS schedule- not a lunar task. This is a prime example of a cart before the horse decision. NASA will have their hands full just getting the CEV CM done inside the schedule. Everyone knows the storable decision was a major loss to extensibility for real Lunar and Mars missions. Eventually you must make a cryo system. It will cost hundreds of millions to develop an essentially dead-end stage. Why would you EVER do this? Only because the CLV is not up to the job- it is a suborbital gizmo and NEEDS another stage to complete the real job. But to set the record straight it was never proposed to send an existing Centaur on a Lunar mission as a TLI stage. That too is a bad idea. What was proposed was the design of the Phase 1 Wide Body Centaur to do that task. That vehicle uses all existing technology and could be completed and flown multiple times long before the CEV CM ever is even ready for flight. It has the most reliable engines and a flight proven avionics suite. If you want to do a basic lunar mission it is a piece of cake to use even existing systems like the RCS. If you insist on jumping right into 180 day lunar orbit durations you will need a fancier propulsion system which also does not require magic but is more sophisticated. Total propellant load with boiloff reserves: 10mt. Yep this machine is half the size of a regular Centaur. If I was proposing crazy sh*t then I could see NASA spending $10 billion to get a much better CLV. The present CLV architecture is worse along nearly every assessment axis: cost, performance, demonstrated reliability, development risk etc. The present NASA course is not rational for sensible, risk-averse people. It is fraught with gratuitous new hardware and untested teams. Please note this: the American people are a patient bunch when they believe you are doing the right thing for the right reasons. If, however, you are abusing this trust by making insider interest based decisions there can be a terrible price to pay. NASA is risking not only a bunch of money but its future on this vision.
Kayla - 23/4/2006 10:30 AM
NASA should immediately contract with both Boeing and Lockheed Martin for crew and cargo launches on EELV supporting initially ISS and hopefully much sooner than 2018 for exploration missions. If other rockets are developed, and are reliable they should also be able to compete for this business.
Kayla - 23/4/2006 8:26 AM
Now start with a new launch vehicle (as CLV is) and tell me that the folks at MSFC can do better analysis on CLV than they can for the veteran Shuttle?
Kayla - 23/4/2006 5:26 PM
Likewise, ESAS assumes that the start failure rate is 1:3,333. Over the course of 116 (or so) Shuttle missions (348 engines) the Shuttle has had to abort 8 missions due to the lack of an SSME to start. From this one can derive the SSME as having a start failure rate of 1 in 44. As an air started engine, the lack of the engine to start is mission failure.
James Lowe1 - 23/4/2006 7:41 PM
I think what Jamie is asking is have these companies protested the plans, with a suggestion of better concepts?
Kayla - 23/4/2006 7:26 PM
With regard to the CLV/CaLV industry has worked with NASA on EELV derived alternatives. However, with the change in the guard at HQ a year ago, it was made clear to industry that any company not directly supporting SDLV will not win future contracts (CLV, CEV, LSAM, everything) supporting exploration. With that threat industry has pulled back alternatives that are believed to be superior. No company can afford to be shut out of a market as large as exploration, even if they believe that better alternatives exist.
Kayla - 23/4/2006 10:26 PM
However, with the change in the guard at HQ a year ago, it was made clear to industry that any company not directly supporting SDLV will not win future contracts (CLV, CEV, LSAM, everything) supporting exploration.
rcaron - 24/4/2006 1:06 AM
Tyranny? Yes, whenever the Administrator does something unpopular it MUST be tyranny.
rcaron - 24/4/2006 1:53 AM
Its clear that EELV does not suit NASA
Tap-Sa - 23/4/2006 6:37 PM
Maybe not 'as is'. But the Stick is still sort of soul-searching too. Would it be more cost-effective to modify existing real rockets to suit NASA, than trying to build something 'simple safe soon shuttle derived' (read: completely new launch vehicle with new engine and all) that aerodynamically resembles trying to shoot an arrow backwards, that is another question.
Bruhn - 23/4/2006 12:46 PMQuoteKayla - 23/4/2006 8:26 AMNow start with a new launch vehicle (as CLV is) and tell me that the folks at MSFC can do better analysis on CLV than they can for the veteran Shuttle?I can say with overwhelming confidence that the answer to this question is YES. I say that because comparing the CLV to the STS analytically is apples to oranges. A rocket is an order of magnitude easier to analyze than something as complex as STS was. A rocket can be analyzed with 1960s technology. You know the Saturn 1/1B was much harder to analyze than the Saturn V was with the Redstone and Jupiter tanks strapped together. In the late 50's early 60's, analyzing the coupled dynamics of those tanks strapped together was a challenge.There was no way a STS could be designed until the technology in analytical tools and computer technology was developed. Now you fast forward to today, and we are building a comparatively easy vehicle (analytically) AND we have all the latest analytical tools, AND we have all the heritage data, lessons learned, etc. So logically, the answer to your question is YES, MSFC can do better analysis on CLV than on STS.
Bruhn - 23/4/2006 12:46 PMQuoteKayla - 23/4/2006 8:26 AMNow start with a new launch vehicle (as CLV is) and tell me that the folks at MSFC can do better analysis on CLV than they can for the veteran Shuttle?I can say with overwhelming confidence that the answer to this question is YES. I say that because comparing the CLV to the STS analytically is apples to oranges. A rocket is an order of magnitude easier to analyze than something as complex as STS was. A rocket can be analyzed with 1960s technology. You know the Saturn 1/1B was much harder to analyze than the Saturn V was with the Redstone and Jupiter tanks strapped together. In the late 50's early 60's, analyzing the coupled dynamics of those tanks strapped together was a challenge.There was no way a STS could be designed until the technology in analytical tools and computer technology was developed. Now you fast forward to today, and we are building a comparatively easy vehicle (analytically) AND we have all the latest analytical tools, AND we have all the heritage data, lessons learned, etc. So logically, the answer to your question is YES, MSFC can do better analysis on CLV than on STS.
rcaron - 23/4/2006 5:06 PM I'm not sure where the big push for EELV usage is even coming from. Its not like the future of the EELV launch market is dependant on manned spaceflight. EELV is doing fine with DoD, commercial flights, and now even a NASA probe or two. Besides, the last thing we need is the entire U.S. launch profile being limited to what potentially is one company (United Launch Alliance). There needs to be diversity in the launch vehicles to have any robustness when problems arise (and in this business, they always arise).
kraisee - 23/4/2006 9:14 PMI know quite a few of the guys managing and working on the CLV today. The ones I know ALL seem to have good experience and I see the "right stuff" in them to get the job done well.I personally think the CLV is in pretty good hands at MSFC.
yinzer - 23/4/2006 11:52 PM
Indeed, NASA's experience at flying the Shuttle since STS-107 is not particularly stellar - one flight in three years? Two in four? Talk of cancelling it at that?
yinzer - 23/4/2006 11:52 PM
With NASA going to hypergolic propellants for lunar ascent and TEI, and something like half of the IMLEO being propellant, using the EELVs (built to support flight rates of 20 per year! each!) and doing on orbit propellant transfer has to be looking like a better way to go.
yinzer - 23/4/2006 11:52 PMTalk to the Europeans building the ATV (I had the fortunate opportunity to do so during a conference). The biggest difficulty they have had is the trying to replicate that Soviet computer technology and interface it with modern hardware. Also, given the # of EELV launches required for a lunar flight, the Soyuz/Progress has a very high risk of failing automatic. I don't have all the numbers offhand, but I distinctly recall automatic fouling up on more than one Soyuz/Progress occassion in recent past, and with 2 Soyuz/year and maybe 3 Progres/year, if you take the last 1.5 years or so of ISS history you have the equivilant difficulty of an EELV-lunar assembly. And, within the last 1.5 years, automatic docking has failed.
If it can be done by 70's era Soviet computer technology, how hard can it possibly be?
Jim - 23/4/2006 8:32 PMQuotekraisee - 23/4/2006 9:14 PMI know quite a few of the guys managing and working on the CLV today. The ones I know ALL seem to have good experience and I see the "right stuff" in them to get the job done well.I personally think the CLV is in pretty good hands at MSFC.
Good Experience? when has MSFC built anything flight worthy in house during the last two decades?
Bruhn - 24/4/2006 10:58 AMQuoteJim - 23/4/2006 8:32 PMIts not MSFC's mission to build flight hardware in house. We only have limited capability here. And I fail to see why you consistently heap all failure responsibilities on MSFC. How about spreading the negativity around some.If I were an astronaunt, and I truly wish I were, I would much rather place my life in the hands of a NASA developed LV where safety was the bottom line as opposed to an EELV whose bottom line was $$$. It has always been NASA's policy that human tended spacecraft/modules use factors of safety of 1.4. If you want to refer to this policy as 'bridge building', then thats your opinion.Quotekraisee - 23/4/2006 9:14 PMI know quite a few of the guys managing and working on the CLV today. The ones I know ALL seem to have good experience and I see the "right stuff" in them to get the job done well.I personally think the CLV is in pretty good hands at MSFC.
Good Experience? when has MSFC built anything flight worthy in house during the last two decades?
rcaron - 24/4/2006 4:22 AM
We're talking active guidance here, not some passive rocket. These things can handle the aerodynamic loads just fine.
the stick is more appealing to NASA since it uses existing procedures, hardware, and personell. is anybody really surprised here by this?
Bruhn - 24/4/2006 7:58 AM
If I were an astronaunt, and I truly wish I were, I would much rather place my life in the hands of a NASA developed LV where safety was the bottom line as opposed to an EELV whose bottom line was $$$. It has always been NASA's policy that human tended spacecraft/modules use factors of safety of 1.4. If you want to refer to this policy as 'bridge building', then thats your opinion.
yinzer - 24/4/2006 1:58 PMQuoteBruhn - 24/4/2006 7:58 AMIf I were an astronaunt, and I truly wish I were, I would much rather place my life in the hands of a NASA developed LV where safety was the bottom line as opposed to an EELV whose bottom line was $$$. It has always been NASA's policy that human tended spacecraft/modules use factors of safety of 1.4. If you want to refer to this policy as 'bridge building', then thats your opinion.How many safety waivers are there expected to be for the next Shuttle flight?And how many unmanned launches have failed due to insufficient (1.4/1.2) structural safety margin? These days launch vehicles fail due to poorly understood interactions between components and procedural errors, neither of which are particularly helped by higher structural margins, and both of which are made much, much worse by inexperience building and flying rockets. An EELV that has flown 20 or 30 times is going to be pretty well wrung out, especially compared to a CaLV that flies once or twice a year, and was designed by people who haven't designed a rocket that flew in 20 years.
Norm Hartnett - 24/4/2006 9:45 PM
Does not using the stick for the CLV preclude the CaLV?
If MSFC and the AF have been and are continuing to work on LOX/Methane engines why did the requirement get dropped in the first place? And what is the AF going to do with that engine anyway? :)
Norm Hartnett - 24/4/2006 8:45 PM
Well this thread has wandered well OT but it is such a good discussion that I can understand the Moderator not pulling in the leash.
rcaron - 24/4/2006 9:30 PM
If we want a one-shot heavy lifter the CaLV is the only option, whether or not you use the stick. There are proponents out there that think 6-8 EELV launches for one CaLV launch is a good idea; I refer to my previous comments on why I'd be very weary about relying on automatic dockings with a high failure probability (due to sheer # of dockings required), a launch rate that has yet to be demonstrated, and the potential of cyro boil-off due to inevitable delays.
rcaron - 24/4/2006 9:30 PM
The LOX/LCH4 drop was part of the "Lunar Sooner" effort to get rid of items that have a signifcant probability of delaying the timeliine. This is, of course, at the expense of Mars compatibility and getting ourselves a nice flight history with these engines before we rely on them for a 6 month return trip. Despite MSFC/USAF's noteworthy advancements it is still quite a long way from flight-capabale, and I'm sure bugs will crop up in the dev process. LCH4 is one of the more benign cyrogenics as far as storability requirements, so maybe USAF wants it for that? Only speculation, of course.
Norm Hartnett - 24/4/2006 10:51 PM
Without some form of station/tug for docking and fuel transfer the 6 to 8 EELV option seems out of the question even with a massive cost savings I should think.
Jim - 23/4/2006 9:32 PMQuotekraisee - 23/4/2006 9:14 PMI know quite a few of the guys managing and working on the CLV today. The ones I know ALL seem to have good experience and I see the "right stuff" in them to get the job done well.I personally think the CLV is in pretty good hands at MSFC.
Good Experience? when has MSFC built anything flight worthy in house during the last two decades?
rcaron - 24/4/2006 10:00 PM
A seperate station or tug is not required, and arguing pros/cons about such would definately be way out of left league.
rcaron
progress' docking system could refuel Sayult stations directly back in the day...
Norm Hartnett - 24/4/2006 11:30 PM
Err... They are still doing that on the ISS at two different ports are they not?
rcaron - 25/4/2006 6:30 AM
I refer to my previous comments on why I'd be very weary about relying on automatic dockings with a high failure probability (due to sheer # of dockings required)
Tap-Sa - 25/4/2006 7:27 AMQuotercaron - 25/4/2006 6:30 AM I refer to my previous comments on why I'd be very weary about relying on automatic dockings with a high failure probability (due to sheer # of dockings required)Ah unreliable/unreplicatable KURS. But you forgot to ask a very relevant question; how many times has acting of KURS resulted LOM? AFAIK never, at least not during ISS flights. It may be that the system has failed to do fully automatic docking, but then a mission controller on Earth grabs a joystick and does it on remote. So it's a nuisance if autopilot fails but because army of engineers is closely watching the mission anyway then plan B of going manual is not such a big deal.(Not that I'd expect fully EELV-based lunar missions ever see the daylight, just don't see real technical showstoppers for it)Btw a reliable docking system might make a good NASA Centennial Challenge competition. Start with purely software simulation. NASA provides API from which competing rendezvous&docking software packages get simulated sensory data (location, attitude, radar, laser rangers and whatnot) and can issue commands to virtual RCS. $250k would activate a lot of software/physics savvy nerds to attack the problem.
Jim - 25/4/2006 4:10 PM
Just a correction, it is a cosmonaut onboard that takes a joystick (TORU system) and guides in the Progress.
Jim - 25/4/2006 5:10 AMI've heard that statement before, but I'm not sure I buy it. Most of the dockings are still in automatic mode, and at least some recent ones done in manual mode seemed to have involved very real failures.
The cosmonauts get a bonus everytime they perform a manual docking for a Progress or Soyuz. Something always doesn't look right near the end of an KURS automated docking (nudge, nudge, wink, wink)
Avron - 24/4/2006 10:30 PMQuoteJim - 23/4/2006 9:32 PM
Good Experience? when has MSFC built anything flight worthy in house during the last two decades?
Humm was wondering when that would be noticed and noted...
publiusr - 30/4/2006 2:46 PMQuoteAvron - 24/4/2006 10:30 PMQuoteJim - 23/4/2006 9:32 PM
Good Experience? when has MSFC built anything flight worthy in house during the last two decades?
Humm was wondering when that would be noticed and noted...
No need to be ugly. MSFC has good people there who would do good work--if people would let them!
Now I will concede that when it comes to upper stages and in-space propulsion, Lewis and Stan B should rule the roost and Marshall should stay out of it. MSFC's mandate was to produce large heavy lift rockets--and in recent years they have done everything but. I know that. But there were a few folks who WANTED Marshall to go back to its heavy lift mandate--who have been ignored by the Goldin Hordes. Let's not throw the baby out with the bathwater.
Though there is an amusing rumor about how a replica of a Goddard rocket was built as a hobby by Sackheim...
And it didn't work.
That just means we need to get rid of all the deadwood and get Bill Eoff (of Magnum fame) back and beg him to take over. All money there must needs go to big rocket production, and get the non-HLLV advocates to quit getting into other centers territory. That I will concede.
But we have good people working in my state--it is just that the competant ones get ignored, throw their hands up, and walk out.
publiusr - 30/4/2006 3:46 PM
But we have good people working in my state--it is just that the competant ones get ignored, throw their hands up, and walk out.
But you see that everywhere now.
Avron - 30/4/2006 9:33 PM
And how I would like to see these good people move us forward, at the rate we saw for the Gemini and apollo teams, we have the tools, the people, something is stopping them, it is that what I Bash.
If we are to attract great talent to engineering, we cannot continue on the course, where the buracrate is king, That is killing the drive and free will of others, while producing Zero, other than meaningless words... while violating the basic concept of freedom... that I will bash, as it must be stamped out..
quark - 1/5/2006 1:14 AMI would like to see MSFC move on to something else. Like landers and rovers and habitats and in-space stages and other things exploration related.The centroid of LV development and operations has gone to industry. As it should have. NASA is a government agency. It should be on the frontier where there are not established private industry capabilities. The current ESAS approach has NASA in effect competing with industry, taking business away from industry, instead of its historical purpose of paving the way and opening up new markets.MSFC is staffed by great engineers and scientists, but they have no experience developing expendable launch vehicles. The course we are on is bad from many perspectives. It weakens the LV industrial base, and it risks the exploration program by putting the first critical step into inexperienced hands.
kraisee - 1/5/2006 3:54 AM
If it weren't for the life-blood-sucking program, we'd get CLV, CEV, CaLV, EDS and LSAM all years ahead of the current schedule, and with CaLV we could still finish the ISS around 2014 if we still wanted to.
kraisee - 1/5/2006 3:54 AM
I personally think Shuttle and ISS Construction are draining so much of the budget that its holding everything else up and squeezing the life out of virtually all the new development work. And it will continue to do so until it finally retires in 2010.
If it weren't for the life-blood-sucking program, we'd get CLV, CEV, CaLV, EDS and LSAM all years ahead of the current schedule, and with CaLV we could still finish the ISS around 2014 if we still wanted to.
Ross.
Kayla - 1/5/2006 10:11 PM
...you go on to try and suggest that shuttle is cheaper than EELV.
There again, the Shuttle-derived Ares vehicles NASA is building will ultimately be about two to three times more cost effective than the EELV's.
Tap-Sa - 2/5/2006 3:05 AM
Btw (1 - 1/87)17 yields 0.82 probability that remaining flights happen without disasters.
How come you bash the shuttle, vehicle NASA built, so freely and yet adamantly believe that another vehicle NASA insists on building will be a heaven sent delivering all promises made? Rather ... dualist thinking.
josh_simonson - 2/5/2006 2:38 PM
As I understand it, NASA is contractually obligated to pay for the shuttle through 2010 and dropping the program now doesn't save much money. If NASA defaulted on it's contracts, the contractors would demand more money up front for future projects because there would be a risk of default.
It's like trying to get ridd of car payments by throwing away the car. Doesn't work that way.
kraisee - 2/5/2006 3:47 AM
CLV, fundamentally is one of the simplest possible designs - A single solid motor for the first stage, with a single engine on a liquid upper stage and the crew module & full escape system placed on top. That's basically all there is to it. Nobody has made a conceptually simpler manned rocket since Mercury/Gemini!
Ross.
kraisee - 2/5/2006 3:47 AM
Yet individual elements of the Shuttle system actually work very well. For example, the SRB's now have 226 successful manned launches, and over 35 successful test firings under their belts - which is better than any other engine in America's arsenal. The SSME's have 337 successful manned launches under their belts, with just two premature shutdowns in the flight history, both caused by faulty instrumentation, not mechanical failure.
.
These good elements just do not work so well together when "combined" into the horrifically complicated STS system we continue flying today though. For example, if there were no Orbiters riding on the side of the ET, the tank foam shedding issue becomes completely irrelevant. Similarly, if there had been no external tank next to the SRB on the ill-fated STS-51L's flight, the burn-through the SRB suffered could not have caused the strut to fail, which caused the tank to rupture. Analysis shows that if an even worse burn-through were to occur on a CLV, it would not put the crew, nor the mission, at critical risk. The SRB's are actually fixed these days, so the CaLV can take that particular risk, also it is not so dangerous because it is not planned to actually launch with crew aboard it, just lots and lots of payload.
The basic elements of the Shuttle, if simply put together in a new way, can be made into vehicles which are far, far safer than Shuttle.
Ross.
Kayla - 2/5/2006 7:52 PMQuotekraisee - 2/5/2006 3:47 AM
Yet individual elements of the Shuttle system actually work very well. For example, the SRB's now have 226 successful manned launches, and over 35 successful test firings under their belts - which is better than any other engine in America's arsenal. The SSME's have 337 successful manned launches under their belts, with just two premature shutdowns in the flight history, both caused by faulty instrumentation, not mechanical failure.
.
You are slightly forgetting the RL10 with 400 or so flights and thousands of ground firings
And ATK's Gem solids on the Delta 2 with something like 800 firings and 1 failure.
There are other engines that have even more experience than the ATK SRB's
QuoteThese good elements just do not work so well together when "combined" into the horrifically complicated STS system we continue flying today though. For example, if there were no Orbiters riding on the side of the ET, the tank foam shedding issue becomes completely irrelevant. Similarly, if there had been no external tank next to the SRB on the ill-fated STS-51L's flight, the burn-through the SRB suffered could not have caused the strut to fail, which caused the tank to rupture. Analysis shows that if an even worse burn-through were to occur on a CLV, it would not put the crew, nor the mission, at critical risk. The SRB's are actually fixed these days, so the CaLV can take that particular risk, also it is not so dangerous because it is not planned to actually launch with crew aboard it, just lots and lots of payload.
The basic elements of the Shuttle, if simply put together in a new way, can be made into vehicles which are far, far safer than Shuttle.
Ross.
I love it when folks say just simply put to gether the various parts of a rocket and Wala, you have an even better rocket. This integration is what makes a Rocket Scientist!!! This is the hard, expensive and risky part. How do you get it all to work together.
kraisee - 2/5/2006 9:52 PMQuoteKayla - 2/5/2006 7:52 PM
You are slightly forgetting the RL10 with 400 or so flights and thousands of ground firings
And ATK's Gem solids on the Delta 2 with something like 800 firings and 1 failure.
There are other engines that have even more experience than the ATK SRB's
As susual, you jump to conclusions without actually reading my comments fully. Please note the words I have had to highlight in my quoted comments above.
Unless RL-10 or GEM solids have been flying some black-ops manned craft from Area 51 that we haven't heard of, they have not got any MANNED use under their belts at all, and in fact are not even rated for any manned use at all (RL-10 probably will be for the new program though).
Kayla - 2/5/2006 7:44 PM
If it is so simple why does it take well over $7B and 8 years to get there???? EELV's were accomplished in a fraction of that time for a fraction of the cost!
yinzer - 3/5/2006 3:20 AM
Look at the table on page 472 of the ESAS full report. An upper stage with 2 RL-10s is predicted to be more reliable than one with one J-2S. An upper stage with four RL-10s is vastly more reliable. "Man rating" is supposed to provide increased reliability; if you already have much higher reliability than engines that are considered acceptable for manned use, what's gained by going through the process?
Sergi Manstov - 3/5/2006 9:45 AM
Can users use civil talk when answering people's posts. We will remove those that cannot or lock threads. Zero tolerance.
Chris Bergin - 3/5/2006 5:27 AM
Any pissing matches and I'll lock threads faster than you can say "but he said my rocket's ISP was shit" ;)
Tap-Sa - 2/5/2006 2:05 AM
How come you bash the shuttle, vehicle NASA built, so freely and yet adamantly believe that another vehicle NASA insists on building will be a heaven sent delivering all promises made? Rather ... dualist thinking.
publiusr - 4/5/2006 2:24 PMQuoteTap-Sa - 2/5/2006 2:05 AMHow come you bash the shuttle, vehicle NASA built, so freely and yet adamantly believe that another vehicle NASA insists on building will be a heaven sent delivering all promises made? Rather ... dualist thinking.No, it is simple truth. You don't have an orbiter that keeps you in fits all the time. Keeping things civil here--no offence, but I prefer that NASA keep things in house and that we listen to spaceflight veterans there, rather than be subject to Primes who want to build it their way and charge us out the wazoo for multiple EELV assembly costs. That is what we should be suspect of. Griffin keeping things in house is a GOOD thing. NASA has put more craft in orbit than any one of us has, after all.With all the flak Griffin has been getting, I'd say he was on target.
Chris Bergin - 3/5/2006 4:27 AMAmen brother!
Everyone will respect, repeat, respect everyone's comments ... That's the only way to keep this forum away from the hell holes some of you came from...
kraisee - 3/5/2006 3:56 AMQuoteyinzer - 3/5/2006 3:20 AM
Look at the table on page 472 of the ESAS full report. An upper stage with 2 RL-10s is predicted to be more reliable than one with one J-2S. An upper stage with four RL-10s is vastly more reliable. "Man rating" is supposed to provide increased reliability; if you already have much higher reliability than engines that are considered acceptable for manned use, what's gained by going through the process?
There are a lot of different factors to consider when man-rating a vehicle. The process involves exhaustive testing, re-testing and analysis over and over again into more things than are checked for unmanned vehicles. Things like determining how an engine might fail is not so important for unmanned payloads because whether it never fires or blows up still normally results in a loss of the payload & the mission. On a manned craft you obviously want to make sure that your engines don't fail at all, but because that's impossible to do realistically, you have to assume failures will happen and make sure they are not going to be life threteneing when they do go wrong. They have to put a lot of work in to make sure that when it ever does fail, it shouldn't fail by blowing up the entire craft as it dies. That may require redesigning some parts to make them stronger, and more cble to survive critical failure modes, or it may just assess that a certain software controlled sequence would be able to shut the engine down safely in case of a detectable problem. Many of these sorts of issues are done on unmanned rockets too, just not as exhaustively and thoroughly as for manned craft.
Also, more generically, there will be an extensive analysis into trying to predict every single type of failure every single element of a vehicle can suffer from and if one failure here will have any effect on another element anywhere else in the vehicle. If you know how a piece can go wrong, you may be able to mitigate the amount of harm it can do when it fails by having already prepared some sort of backup system elsewhere.
Another key area will be the software which controls all the different elements of a craft. It will have to be critically examined far more thoroughly than for an unmanned launch, because it not just a dollar value you lose if things go wrong, it becomes a national disaster when crews are lost. Software qualification for manned flight ops tends to be a really long and incredibly expensive process, really only rivalled by the software qualification for controlling nuclear powerstations!
In short, its a process of far more comprehensive checking and mitigating process for problems than is implemented for unmanned boosters. It takes an awful lot longer, and costs an awful lot more.
Ross.
kraisee - 2/5/2006 12:47 PM
The basic elements of the Shuttle, if simply put together in a new way, can be made into vehicles which are far, far safer than Shuttle.
Ross.
Jim - 5/5/2006 2:01 AM
Who are going to build the ESAS LVs? The primes.
Kayla - 5/5/2006 6:43 AM
The question was about the RL10 engine. What specifically with the engine is wrong?
Tap-Sa - 5/5/2006 3:03 AMQuoteKayla - 5/5/2006 6:43 AM
The question was about the RL10 engine. What specifically with the engine is wrong?
Nothing but too low thrust ... IF the first stage is giant SRB with oodles of thrust and ISP that is sh... oops :) ... wanting.
With SRB the second stage + payload has to be massive enough in order to keep the G levels tolerable. The poor ISP and short burn time of SRB mean the second stage begins it's journey barely above atmosphere and has very limited time to deliver a lion's share of the speed required to get into orbit. The time limit requires considerable T/W from the beginning or the burn would take too long and stage falls back to Earth.
Kayla - 5/5/2006 7:03 AM
This is a great point. Contracting for a launch service in a competitive environment is the way to keep launch costs down.
publiusr - 5/5/2006 1:54 PMQuoteKayla - 5/5/2006 7:03 AMThis is a great point. Contracting for a launch service in a competitive environment is the way to keep launch costs down.No it isn't--or you will be paying for EELV evolutions and they will try to sell you a CaLV in the end anyway. Keep things in house and don't be dictated to. That is Griffins method that I support. And with ULA, there are only two groups--it and ATK. ATK won, and ULA lost. Time to move on.
Jim - 5/5/2006 2:15 PM
ULA does not exist. In house does not have experience
In house may not have experience, but that's not due to their lack of trying. Also, I want things in-house! NASA's internal technical competance has been eroding away over the decades as more and more things are contracted out. Compared to the NACA/original NASA, what we have now is much more management only. In-house technical capability needs to improve for NASA's survival, I mean we're in a very real since picking up where we left off 30 years ago, and yet the skillsets don't match anymore.
I should point out that the competitive environment mentioned doesn't actually work. If things were kept "competitive" then EELV would have been downselected to one manufacturer a long time ago. But of course traditional economic models don't work when the programs are government subsidized and government contracted.
The flight rate neccessary for EELV/CaLV has not been proven. Risks (both flight and development) associated with a half dozen dockings (where a crew is not yet on site, mind you) per mission are not trivial. The division of mass over so many vehicles is less efficient than a single shot. SDV/CLV has hardware commonality with SDV/CaLV in regards to the boosters and J-2X (and the CLV upper stage definately has ET heritage written all over it). SDV/CLV uses existing NASA personell.
Plus, and this is the biggest point, is that this has already been decided! I don't know why we're even still talking about SDV/EELV. Granted, there as the mass increases beyond the current capability, but the solution is to tweak booster performance, not replace the booster![/QUOTE]
You know you sound just like the folks in the late 70's who swore that Shuttle was going to eliminate expendables forever since it was such an awesome design. It turned out that a lot of bad decisions had been made in that design and we ended up paying for those with effectively three decades of stagnation in manned spaceflight. In the meantime there has been absolutely tremendous advancement in the commercial space arena. The failure of Shuttle to live up to its promises made that possible really. As such the centroid of knowledge for expendable vehicle design now is firmly centered over industry. NASA should learn from those with direct, recent experience. Learning is good right?
A lot of us are not motivated by what our badge says but by the realization that the same fundamental design errors are being made again- some of them for the same bad reasons. Some out of simple ignorance or fear. We designed these expendable launch vehicles for NASA not out of corporate greed but out of wanting to give the American public the launch system that they deserve. They deserve the best. ESAS is not even close to the best. We feel that being silent when we can see blatantly bad designs being foisted upon the lay public as the "best we can do" is a direct violation of the fundamental trust people place in engineers. If we want to avoid the mistakes of Shuttle then we cannot participate in a sick group-think that prevents open discussion. And let me mention that Mr Griffin himself forced the removal of multiple AIAA papers that were going to illuminate these alternatives to the ESAS last fall. He made the calls and dozens were pulled to avoid any alternatives being made public. This alone should be a warning that the culture of NASA senior management has some serious problems. In their blind drive to force a half-baked solution down everyone's throats they have stooped to a level that to me is a fundamental violation of acceptable behavior in science and engineering. How would we feel if this was done on nuclear reactor design?
We want to go to the moon and Mars and we want to do it in our lifetimes. We think that NOW is the time to force these architectures to stand on their own feet in the light of day and be fairly compared. Realistically they are mostly viewgraphs at present. There is still time for reason to prevail. You have heard many folks call for real competition to bring out the best in every entity both Government and industry. Maybe a competitive fly-off is pretty much the only fair way to get a ground-truth based decision. In any event, design by executive fiat is a poor path to follow.
What NASA is proposing to do now is effectively make their own airplanes so that they stay in practice. There is NO talk of advancing technology.That's not entirely accurate. The lox/lch4 engines were an advancement of technology proposed (in the original ESAS anyway) and the air-lit SSME was an obvious challenge. So, for a time perhaps, NASA was willing to advance technology. The fact that both were recinded is most unfortunate.
NASA should issue a spec for what the end mission is and let industry compete to meet that mission. Despite its inefficiencies it is the only proven way to suppress costs and get the best technology for the job.To make a worthwhile specification that makes sense to the contractors NASA needs to improve its technical know-how. The only way to improve technical know-how is to do things in house. Also, what exactly are the Phase 1 and Phase 2 CEV contracts than a competition?
The EELV program was highly competitive and resulted in a reduction in costs to orbit of roughly 50% of previous systems. Even with the collapse of commercial launch. That little fact is conveniently forgotten most of the time.From what I have heard, EELV economically is in very rough shape, which is what created the need for the ULA proposal. Perhaps the costs have been reduced too far, sacraficing sustainability of the programs?
This is why it is rather laughable to think that EELV are some sort of scary unreliable rocket- there are crucial national assets that directly impact the lives of real soldiers in the field that rely on these rockets. The criticality of these assets is probably an order of magnitude above any NASA activity.The requirements of orbital assets are very different than NASA requirements. Due to their very critality, the networks (GPS, communication transponders, et al) have inherent capability to deal with failures and absenses of spacecraft. GPS has robust margins, and systems continue to function even with the lost of a communications satellite or two earlier in the year on launch. Therefore, launch vehicle reliability, while high, doesn't have to be AS high as a NASA mission. Beyond TDRS, what network of anything does NASA maintain in space? Even assuming for the moment that the Shuttle was an unmanned vehicle, what do you think would have happened if we lost, say, the Destiny laboratory on launch? That was so expensive a backup could not be built. When manned flight is factored into the equation it becomes even more dire.
impulse - 6/5/2006 2:08 AMOf course high rates would be achieved if the necessary launch rate were approximately doubled! Also, to assume increased flight rate automatically improves reliability would be mistaken. Mistakes happen during high repeatability. People get complacent. With higher flight rates the launch range and facilities get backed up - reconfiguring the Eastern range can take weeks, and Falcon 1 had numerous delays despite having its own launch site due to the range being occupied for missile defense tests and the like. Plus, it isn't clear to me yet how EELV is of enormous benefit to the exploration program - it sounds more like an operational headache to me.
One of the key features of an EELV derived launch architecture is that there are enormous benefits to both programs. Even if the vehicles are not identical they share 90% of their critical hardware. This means that for the first time the vendors of engines, bottles, thrusters, valves and boxes will see high rates. That alone is worth billions to the two government parties. And with rate comes repeatability and even better overall reliability.
Use of existing EELV's "as is" is probably not optimal for the long run. They are totally adequate for near term stuff like ISS access. The evolution plan for Atlas to support NASA's exploration goals took the immediate steps to meet immediate goals. It took the next steps as the mission expanded. Despite what Mr Griffin thinks, this incremental "spiral" approach to modifying vehicle design is the only proven method for controlling cost and risk on ambitious technology programs.They are not "adequate" for even ISS access. To maintain sufficient abort windows the SM needs sufficient propellant to put the total payload requirements a couple mtons over capacity. Granted, the CEV is overkill for ISS flights (reference CEV's 5m diameter vs Dragon's 3.6m), but no nation has ever operated two different manned orbital spacecraft simultaneously. Now, before people start hitting me with technicalities, what I mean by this is that we never had Apollo in unison with the Shuttle, or the DynaSoar with Mercury. Even Russian's Buran, which overlaped the Soyuz program, was never manned. Thus, we're sending CEV to ISS because we need CEV for later. And, unless we talk about Atlas Phase 2 (and who's going to pay for it?) EELV can't make the cut.
You can be cavalier but if you "blank sheet of paper" it you will end up in deep trouble. Witness Ariane 5, Delta III, H2, Falcon. How NASA has the authority to behave in such an irresponsible manner with taxpayer money is a mystery to me.CLV/CaLV are hardly blank sheets of paper. These designs have flight-proven hardware and have been fleshed out for decades. The CaLV bears striking similarity to Zubrin's Ares. You simultaneously critizise NASA for using a "blank sheet of paper" (which its not) and not a lack of technology innovation (which requires at least some blank pages)...
Also, if you think through the exploration problem to the end, if you don't have autonomous docking and propellant transfer you have no business going to Mars or the moon. This problem that you seem to think is so tough has already been mostly solved. The technology is no more scary than an autopilot doing autoland. In fact it is much easier. I agree that doing gratuitous docking is foolish. But insisting that you can avoid ARD is just plain wrong.AR&D has not been solved. Instead of dwelling on my previous Kurs references, the two experimental USAF spacecraft to test AR&D were not entirely successful. ATV has been delayed for years in large part due to the automatic rendevous - and it doesn't even dock automatically! It is instead "caught" by the station's arm and subsequently berthed (much like the MPLMs are). I assume by gratuitous docking you're referring to many dockings - and that's exactly what an EELV-based exploration would require. Can AR&D be avoided completely of course not? Can you minimize the risks of AR&D? Absolutely. Besides, in the current architecture there's always a man-in-the-loop without radio latency. This would most definately not be the case if EELVs were to replace the CaLV.
You know you sound just like the folks in the late 70's who swore that Shuttle was going to eliminate expendables forever since it was such an awesome design. It turned out that a lot of bad decisions had been made in that design and we ended up paying for those with effectively three decades of stagnation in manned spaceflight. In the meantime there has been absolutely tremendous advancement in the commercial space arena. The failure of Shuttle to live up to its promises made that possible really. As such the centroid of knowledge for expendable vehicle design now is firmly centered over industry. NASA should learn from those with direct, recent experience. Learning is good right?I am in no way stipulating that CLV & CaLV are solutions to everything like the Shuttle was proclaimed. These vehicles are not flying DoD assets, they are not going to have two week turnaround times, reusability is not emphasized. Commercial space systems will not fly on these vehicles. Neither will ISS hardware. Science missions most likely not (Ulysses and Galileo's launch times were very much not optimal due to Shuttle delays - space science community would much perfer Delta/Atlas). The CLV & CaLV are not "awesome" designs - they rely on heritage hardware, don't expand the envelope appreciably, and despite ideas such as the ASRM and, LRB, and flyback boosters none of these will be implemented.
A lot of us are not motivated by what our badge says but by the realization that the same fundamental design errors are being made again- some of them for the same bad reasons. Some out of simple ignorance or fear.While I agree the aspects of ESAS with regards to the lunar side of things are not ideal (lack of L1 utilization, limited surface tme, no provisions for long duration facilities, etc). These problems are resultant of NASA wanting to mirror Apollo methodology since that's the only way that its ever been done. Dropping lox/lch4 is another such problem. But the CaLV is not, as you put it, a "fundamental design error". It will get the critical lunar hardware up in a single shot, and Mars hardware in a few shots. How many launches would it take from a D4-H or Atlas Phase 2 to make a Mars mission? 10? 20? We NEED a big booster.
We designed these expendable launch vehicles for NASA not out of corporate greed but out of wanting to give the American public the launch system that they deserve. They deserve the best. ESAS is not even close to the best.The American public does have the launch system they deserve for the assets so critical to its survival, what you deemed "an order of magnitude" more important to the nation than NASA activities. Space assets are critical to the economic and security interests of this nation, but a strong manned NASA exploration program has much greater impacts in the long run.
We feel that being silent when we can see blatantly bad designs being foisted upon the lay public as the "best we can do" is a direct violation of the fundamental trust people place in engineers. If we want to avoid the mistakes of Shuttle then we cannot participate in a sick group-think that prevents open discussion.Engineers do not live in a vacuum, and programs that do not consider political and economic viability are doomed to failure. NASP, SDI, X-33, X-38, the list goes on. All programs that would have been of value to this nation that were canceled for being too bold, too expensive, or not using the appropriate congressional districts. Granted, the long timeline of the VSE will be difficult to sustain, but that is a necessity of the economics. If you, say, fix the economics by stopping Shuttle/ISS you have international politics stopping you.
And let me mention that Mr Griffin himself forced the removal of multiple AIAA papers that were going to illuminate these alternatives to the ESAS last fall. He made the calls and dozens were pulled to avoid any alternatives being made public. This alone should be a warning that the culture of NASA senior management has some serious problems. In their blind drive to force a half-baked solution down everyone's throats they have stooped to a level that to me is a fundamental violation of acceptable behavior in science and engineering. How would we feel if this was done on nuclear reactor design?I was not aware of this restriction of papers. That is very unfortunate and it does tarnish my respect for Dr. Griffin (who I hold in high regard). However, I would not call a 2 month engineering study blind. Granted, when presented in the fall ESAS was not complete, what one may call "half-baked". However, the ESAS report itself was nearly there and the remaining issues in the are being worked. ESAS took into account prior designs and numerous lengthy reports that were previously written, including a lot of material on EELV.
We want to go to the moon and Mars and we want to do it in our lifetimes. We think that NOW is the time to force these architectures to stand on their own feet in the light of day and be fairly compared. Realistically they are mostly viewgraphs at present. There is still time for reason to prevail.I completely agree, if changes are to be made now is the time to make them. More important than reaching the Moon & Mars is making the program sustainable. Operational difficulties must be minimized and we need to prevent the crash in the program after Apollo.
You have heard many folks call for real competition to bring out the best in every entity both Government and industry. Maybe a competitive fly-off is pretty much the only fair way to get a ground-truth based decision. In any event, design by executive fiat is a poor path to follow.Government vs industry? huh? The very notion of flying the stick against an EELV is rediculous - it is a substantial waste of funds (both government and private) and were designed wth very different purposes. And, while design by executive fiat may not yield the ideal engineering solution, it does aid in making sure that the program does happen - instead of remaining as viewgraphs and dreams for history to dutifully record as "what could have been..."
impulse - 6/5/2006 2:08 AM
The EELV program was highly competitive and resulted in a reduction in costs to orbit of roughly 50% of previous systems. Even with the collapse of commercial launch. That little fact is conveniently forgotten most of the time.
kraisee - 6/5/2006 5:34 PM[The other 94.5% of the flights the DoD are planning to fly between now and 2020 are in the intermediate and medium categories - and the EELV's just are *NOT* as cost effective as the ELV's they replaced for these same missions. The costs are higher across these flights, and actually peak to around 300% higher per-flight in some cases!That is the true hidden facts behind the EELV Program.