BIG problems with Ares I - "the stick"

docm · Nov 12, 2006

As posted on http://nasawatch.com/ <blockquote>In reply to:<hr />Big Problems With The Stick Editor's note: Sources inside the development of the Ares 1 launch vehicle (aka Crew Launch Vehicle or "The Stick") have reported that the current design is underpowered to the tune of a metric ton or more. As currently designed, Ares 1 would not be able to put the present Orion spacecraft design (Crew Exploration Vehicle) into the orbit NASA desires. The Ares 1 SRR (System Requirements Review) was held last week at MSFC. Mike Griffin was in attendance. Others participated off-site via webex.com. It is widely known that both Mike Griffin and Scott Horowitz are reluctant (to say the least) about abandoning their current launch vehicle concept. Alternate approaches such as using EELVs are not welcome solutions by either Griffin or Horowitz. One possible solution to the Stick's current design problems is to add side-mounted solid rocket motors. Many inside the program are not so sure that this solution is worth the effort. Others suggest that starting from a clean sheet of paper may be the only prudent course of action. Stay tuned.<hr /></blockquote>OOPSIE.... <div class="Discussion_UserSignature"> </div>

subzero788 · Nov 12, 2006

Wow, how did this happen???

mikeemmert · Nov 12, 2006

Well, they could use the J-2T-250k aerospike engine... ...problem is, it's never been tested in flight. Matter of fact, LASRE and the X-33 were never flight tested, either. LASRE came close, but sprang an oxygen leak and then the program was cancelled for some reason. How annoying! "In theory the aerospike is slightly less efficient than a bell designed for any given fixed altitude, yet it outperforms that same bell at almost all other altitudes. The difference can be considerable, with typical designs claiming over 90% efficiency at all altitudes". It's kind of hard to build a wind tunnel to test this concept between mach 3 and mach 6, where the benefits of the aerospike are the greatest. As a result, specification sheets for the J-2T-250k only show ISP and thrust for the bottom and the top of the trajectory, and it's possible to design a bell nozzle that works slightly better at either end. One thing I'd like to know, and only empirical testing can find out, is how much excess hydrogen in the exhaust can burn in the air - in effect, if liquid oxygen can be replaced by air at certain speeds/altitudes. I don't think that will work sitting still on the ground. It's a dynamic thing. Maybe they don't want to test because the results would be to throw out the whole design and start with a clean sheet of paper. But I would advocate dragging all of those old aerospike engines out of the museums to finish the tests they were going to do on them. Do the LASRE first so that they will have a plane that can keep up with the J2 test and photograph it.

vogon13 · Nov 12, 2006

Surplus H2 is present in the SSME exhaust, burns in the (lower) atmosphere, and does not contribute to the thrust of the vehicle. I don't see how this effect would help an aero-spike unit either. <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

j05h · Nov 12, 2006

> OOPSIE.... Finally some credible info on the Stick's problems. We online-types have plenty of criticism, but it's nice to see NASA acknowleding some problems. It's plain stupid to replicate existing capabilities over and over, especially with such a Rube-Goldberg as the Stick. Just use EELVs for now until COTS or similiar come on. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

baktothemoon · Nov 12, 2006

Wow, even with a six segment SRB there isn't enough thrust? Never would have thunk it. NASA should just go with an Atlas V.

nyarlathotep · Nov 12, 2006

Wow, how did this happen??? The NASA political machine was given control of another launcher development project. What the hell did you expect would happen? I'm sure that they can completely fix this by reducing the CEV down to a sensible mass. Say, 10 tonnes.

j05h · Nov 12, 2006

The argument NASA used was that since the SRB existed, they should use it in a launcher. The problem is that it is a thoroughly non-optimal first stage, the tradeoffs were so great that the vehicle will quickly run into capability issues. Then the vehicle started to change, 5 segment, oddly proportioned upper stage with new engines, etc. There are already rockets that do the job better, for equivalent prices and without the development costs. The measure that makes the least sense is that the capsule is so massive. While smaller in seat number, Soyuz is 1/5th the mass at launch. If they based out of LEO instead of Earth, a reusable ferry and propellant depots make a lot of sense. Check out Jon Goff's writing at http://selenianboondocks.blogspot.com/ for a bunch of analysis on various lunar architectures. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

gunsandrockets · Nov 12, 2006

"I'm sure that they can completely fix this by reducing the CEV down to a sensible mass. Say, 10 tonnes." Exactly right. The real problem isn't that the Ares I has insufficient payload; the real problem is the Orion CEV is too massive. Reducing the CEV down to 10 tonnes would allow existing single core Atlas V rockets to easily launch it to LEO.

gunsandrockets · Nov 12, 2006

"The argument NASA used was that since the SRB existed, they should use it in a launcher. The problem is that it is a thoroughly non-optimal first stage, the tradeoffs were so great that the vehicle will quickly run into capability issues. Then the vehicle started to change, 5 segment, oddly proportioned upper stage with new engines, etc. There are already rockets that do the job better, for equivalent prices and without the development costs." In my opinion the reason for clinging to the stick is it subsidizes the cost of the sort-of-shuttle-derived HLV. "The measure that makes the least sense is that the capsule is so massive. While smaller in seat number, Soyuz is 1/5th the mass at launch." Basic conservatism could explain the choice of an Apollo-style capsule over the Soyuz configuration. But most of the other mass increase is an effort to fit the CEV to the expected capability of the stick (just as another way of justifying the stick). Which is completely backwards. The launcher should be sized to the capsule instead of sizing the capsule to the launcher! "If they based out of LEO instead of Earth, a reusable ferry and propellant depots make a lot of sense. Check out Jon Goff's writing at http://selenianboondocks.blogspot.com/ for a bunch of analysis on various lunar architectures." The point is, most of the basic underlying concept of the 1.5 lunar architecture NASA is so fond of could still work. But the desire to hold onto the stick for the CLV is likely to sink the whole plan. NASA could still make the 1.5 plan work in broadest outline, but NASA will have to make some changes to make it work. In fact I think I will start a new thread later tonight explaining exactly how.

vogon13 · Nov 12, 2006

Sounds like a job for the filament wound SRB . . . . <img src="/images/icons/rolleyes.gif" /> <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

Boris_Badenov · Nov 12, 2006

In my opinion the reason for clinging to the stick is it subsidizes the cost of the sort-of-shuttle-derived HLV. More likely it is to subsidize ATK Thiokol, & keep Spacex, SpaceDev & RPK from getting a contract to launch them on rockets that cost an order of magnitude less. "The measure that makes the least sense is that the capsule is so massive. I don't see it this way. The more people you can get into LEO in one shot, the better. The launcher should be sized to the capsule instead of sizing the capsule to the launcher! Again I don't agree. If Spacex builds the BFR, & you can put 100 tons into LEO, would'nt you like to put 100 people into orbit in one shot? But the desire to hold onto the stick for the CLV is likely to sink the whole plan. I could'nt agree with you more, there are already EELV's that could do a better job that don't have to be designed, or redesigned. <div class="Discussion_UserSignature"> <div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div> </div>

halman · Nov 13, 2006

Boris1961, Have Spacex, Spacedev, or RPK successfully flown full size hardware yet? Are we willing to wait for a totally new launch vehicle to be proven? Not just flown once or twice without failure, but a dozen times without significant failure? I have nothing against the new entries in the launch vehicle market, but it seems like several years since these new designs were announced, and nothing has flown successfully yet, to my knowledge. Could it be that NASA wants to keep Thiokol in the game because they have not written off the Space Shuttle completely? I know that contracts have been terminated, but new ones could be written. Any significant problems with launch vehicles at this point could put the return of Americans to space back several years beyond 2014, which is already a long lapse. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

gunsandrockets · Nov 13, 2006

"I don't see it [capsule too massive] this way. The more people you can get into LEO in one shot, the better. " It's not a question of crew size, it's a question of how much mass is used to do the job. A 9.5 to 8.5 tonne capsule for a four man lunar mission is grossly oversized. The entire mission mass scales based on things like the capsule size. If the capsule is 50% larger than neccessary the entire mass the launchers need to lift to orbit can go up by 50%. Let me put it this way. Would it have made sense to use the Saturn V/Apollo for the very first one man suborbital mission that NASA flew? Instead of using the Redstone/Mercury? Size the vehicles for the job, and minimize flight costs. All that using oversized vehicles will do is run NASA out of money and continue the Shuttle legacy of spending too much money for how much is accomplished.

tomnackid · Nov 13, 2006

NASAwatch.com is a rumor mill that has made many goofs and unsubstantiated claims in the past. I especially like how the article goes from saying the information comes from unnamed "sources inside the Ares I development program" then in the next paragraph talks about the System Review meeting that Griffin attended--implying that this information came out in the meeting. But notice they never actually say what was said in the meeting. Someone got a hold of a "worst case scenario" report regarding Ares I performance and has been spreading it around on the web as the current state of Ares I development. (Remember the "Kmart lunar lander a few months back?) There are other "sources inside NASA" that have been explaining that the Ares development is on track and that performance is well within what was expected. But that doesn't make for interesting news!

geminivi · Nov 13, 2006

I agree with Tomnackid on this one. I've had email conversations with that guy. Recently about Global warming he said to me in the email, he'd exaggerate the truth to get "the people" to take it more seriously. Add in his arrogance and his other agenda's, such as Nasa administrator bashing, and caveat emptor very much applies.

CalliArcale · Nov 13, 2006

<blockquote>In reply to:<hr />Basic conservatism could explain the choice of an Apollo-style capsule over the Soyuz configuration. But most of the other mass increase is an effort to fit the CEV to the expected capability of the stick (just as another way of justifying the stick). Which is completely backwards. The launcher should be sized to the capsule instead of sizing the capsule to the launcher!<hr /></blockquote> It's kind of a chicken-and-egg situation, but inevitably both will end up influencing one another. I imagine there's resistence to changing CEV, since the intention is to use it for more than just this particular mission profile. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

josh_simonson · Nov 13, 2006

They can always go back to methane in the SM to save weight as well. That'd be cheaper than a new composite SRB.

JonClarke · Nov 13, 2006

Most spacecraft and aircraft are overweight early in their development. I really don't see much to be alarmed at, long term. of course the engineers whose job it is to fix the problem can't be so complacent, but that's what they are paid tro do. I can't help seeing this as anything but a beat up by those who, for reasons best known to themselves, object to NASA, Ares 1, Orion, the contractors, or all of the above. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

propforce · Nov 13, 2006

<blockquote>In reply to:<hr />Most spacecraft and aircraft are overweight early in their development. I really don't see much to be alarmed at, long term. of course the engineers whose job it is to fix the problem can't be so complacent, but that's what they are paid tro do. <hr /></blockquote> I am not sure what you're saying is true. Most spacecrafts and rockets tend to UNDER ESTIMATE weight early in their design, and add more weight as a result. Haven't you've heard of phase of "... weight growth.. cost growth..." as a result? The most over-look problem in weight estimation, and Calli can (should be able to) attest to this, is wire-harness/ cable weights (just look at the Airbus A-380). We have had a somewhat painful lesson on the Delta IV with this issue. Who knew what appears to be a "line" on a drawing could weight that much! <img src="/images/icons/rolleyes.gif" /> Second most over-looked problem is the use of existing hardware, e.g., the SRB in this case. Often people think "hey, it flew on the (shuttle) before so it must be good enough to fly on (this) vehicle...", etc. But what happen usually is, as one start to put things together, the existing hardware need "additional work" to make it compatible with a new vehicle. Oh hey, we need just a little more burn on this SRB. Lo and behold, the so-called *existing/ heritage* hardware just become a brand new 5 segment SRB instead. People don't realize that, if you take the SRB from the Shuttle, the J-2X from the Apollo days and put them together, the resulting launch vehicle is a *brand new* vehicle. You'll find things are attached differently, parts may need to withstand a higher vibration/ acoustic level, so basically need to redesign it differrently and get it qualified again. Effectively a new *part* with the old name-plate. In this case, "the stick" is too long. Take a short pencile and try to bend it, it is difficult <div class="Discussion_UserSignature"> </div>

rvastro · Nov 13, 2006

What are the potential fixes being devised and is there a remote chance that the Delta IV or the Atlas V be selected as a primary launch vehicle for Orion?

halman · Nov 13, 2006

propforce, As someone with advanced technical knowledge and experience with launch vehicles, what solution do you suggest to getting the CEV off the ground? Is it something which can be done within 5 or 6 years? Or would we be better off buying launch capacity from the Russians, and screw national pride? The last option appeals to me, because we seem to be bent on reinventing the wheel. The real challenges are off planet, and that is where I think that our knowledge and abilities would shine. We have wasted many years since we had a new, top-of-the-line launch vehicle, and to put all of our efforts on hold while we come up with another one seems short sighted when there are excellent launch vehicles that have been well proven available for a fraction of the cost of anything that we can build. To take a truly international approach to off planet exploration and development means recognizing that there are some things that we do well, and some things that other countries do well. Wasting money competing with them, especially when we are starting at such a disadvantage, just doesn't make sense, when we could be putting our know-how to work doing the really critical work, like buildng a lunar lander, mobile habitats, and putting them to use. The Chinese are already making overtures to the Russians, in spite of a far older history of political disagreements. If we continue our arrogant, exclusionary tactics, we could easily find ourselves watching others make the next giant leaps. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

propforce · Nov 13, 2006

<blockquote>In reply to:<hr />propforce, As someone with advanced technical knowledge and experience with launch vehicles, what solution do you suggest to getting the CEV off the ground? Is it something which can be done within 5 or 6 years? Or would we be better off buying launch capacity from the Russians, and screw national pride? <hr /></blockquote> halman, The simple answer is that the current Delta IV Heavy can deliver the 25mT CEV payload now. It is the safest way to go because you're building upon an existing vehicle, rather than starting a *brand new* design. It is an American-built vehicle with American-built engines. If NASA wants to "man-rate" the vehicle to make it more reliable, the estimate provided to NASA is that it will cost $1 billion. I believe Atlas V has provided similar cost number. We can launch the CEV in less than 5 years. However; this is unlikely that it will happen. I believe that Mike Griffin and Scott Horowitz has dug their high heels too deep to get out of it. For some reason, both have an unholy alliance with the SRB manufacturer, ATK, and both are very stubborn in resisting this configuration change. An international alliance with foreign-made vehicle is out of question. This is NASA. You don't have to make sense, you don't even have to make enough money to break-even. But you do have to provide jobs to NASA and its contractors in order to gather support in Congress. You'll also need to show "American-made" hardware to reflect the national pride. Other countries will do the same. But since this is the George Bush's initiative, the chance of this VSE getting canceled is very likely with the next adminstration - particular if it's the Democrat, and the whole "space exploration" approach may get revisited with a *new* NASA adminstrator. Stay tuned. <div class="Discussion_UserSignature"> </div>

spacester · Nov 14, 2006

On the politics, in relation to the subject at hand, it is good to remember that the new blood can be expected to pursue a 'progressive agenda'. So nominally at least, a move to slow down a program based on nearly flat budgets would be in conflict with their agenda. Nominally. They already have enough to do without calling for change at NASA. Shifting to IMO, two factors are going to lead to proving the 'VSE will be cancelled' crowd wrong. Yes, I'm making a prediction here, and I'm willing to make a wager on it. Mike Griffin is not only the best man for the job, but second place is nowhere to be found. Now, it may be that other qualified folks were simply unwilling to work for dubya, but I still think that no incoming POTUS is going to spend much time looking for a new NASA Admin. Even if the new pres is a scary monster democrat, he'll have better things to do, and at that point in time Mike's agency will be on a roll piling success on success. No change required or desired, no one to fire and hire, why mess with success? Factor two: by then, Americans will have re-acquired their taste for progress (missing lo these last six years) and the new Prez will be in position to be a hero in space without even trying: Increase NASA's budget and hey presto the effective Dr. Griffin delivers and let's go second term, that's what the next pres will be in a position to do. Go ahead with the doom and gloom on VSE cancellation, but I aint buying it. My prediction is that the next POTUS will accelerate the program. <div class="Discussion_UserSignature"> </div>

mikeemmert · Nov 14, 2006

JonClarke said:<blockquote>In reply to:<hr />I can't help seeing this as anything but a beat up by those who, for reasons best known to themselves, object to NASA, Ares 1, Orion, the contractors, or all of the above. <hr /></blockquote>And propforce replied<blockquote>In reply to:<hr />You are politicizing potentially a "technical" problem by spinning as such. This *stick* performance short-fall has been known for quite sometime.<hr /></blockquote>Propforce then gives a detailed explanation about the problems of assembling archaeology from scattered bits and pieces that weren't designed to work together. Then he says<blockquote>In reply to:<hr />"...But since this is the George Bush's initiative, the chance of this VSE getting canceled is very likely with the next adminstration - particular if it's the Democrat,..."<hr /></blockquote>*/Post edited under moderator orders. See Suggestions and Announcements/* newsartist replies to propforce:<blockquote>In reply to:<hr />Not cancelled outright, ...delayed. No administration wants to go in the books as killing the space program, totally. Spread over a longer time, which raises the pricetag and reduces capability. <hr /></blockquote>I am in favor of retiring the stick and starting from scratch to build a better spacelaunch capability. And I don't think we should be afraid to ask for money, lots of it. We are not under time pressure and it would be much better to start from scratch and do the job right, no matter how long it takes or how much it costs. If we don't take the plunge, we will be stuck forever stacking mountain upon mountain of fuel to put a pea into orbit - until some foreign entity comes along and ta

BIG problems with Ares I - "the stick"

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