One other thing that has occurred to me, and if I'm wrong, Chuck, Ross, Mark or one of those guys who know all the science and numbers and what's going on can correct me.Since Orion has been downsized for weight, removing some of those pesky old safety features, would it not then allow re-introduction of some, if not most, if not all of them if an LV were able to lift it? Is this not reason alone, crew safety (in light of the NASA report on Columbia released today) to implement a booster system that is really a *system* that follows the mandate of law to reuse as much STS infrastructure and engineering as possible? Keeping all of those things in mind, why would the Obama Transition Team not want to check more deeply into a system that not only follows the law, and also can carry the safer Orion? Why is this not mentioned more? Its one of the things I pointed out in my letter to the NYT, but I have not, as yet, heard back from them.I think that the grass-roots effort to promote DIRECT ought to restate the safety issues with Orion, the compliance with the law, the jobs saved and economic stimulus, and the much reduced gap that will be the result of this LV system.
Wow, this thread has been really quiet this week. I guess everyone is just waiting for the days to pass....Meanwhile, elsewhere on the Interwebs, I continue my thankless task of promoting DIRECT when possible. Yesterday, Slashdot had a discussion on the recent NYT "NASA Fight Club" article. Someone (not me) posted a pro-DIRECT reference, who was then accused of drinking DIRECT "cool-aid". So I put my two cents in right here.So, if anyone has time to review my effort and give me feedback I would appreciate it. I know most of you here are hard core space techies, but I was trying to be informative and persuasive without alienating the general audience.So would you say I sounded: 1) informative? 2) persuasive? 3) relatively accurate? 4) too shrill? 5) tin-foil hatter? 6) correct level of detail? 7) anything else?Thanks
MarkI think it was just right. Thanks
You know I'm a Direct convert, looking at the two designs now I don't see how you couldn't go with Direct.
How ever a lot of time has passed since that decision had to be made and one thing I do agree with Dr. Griffin is that you can't keep stopping every year and try to redesign the rocket or you'll end up with nothing. That to me is my biggest fear.
Second the whole idea that Direct is safer is misplaced imho, as Direct refers to safer in regards to the Orion capsule. Orion will never fly if it's unsafe and Ares 1 was chosen because it was the safest launch vehicle they could produce which is something I think needs to be recognized.
Third how realistic is the Direct time table? If I was presented with the choices of Direct or Ares come Jan 20th I would be skeptical that Direct would be able to live up to it's promise. I've read the time lines presented and they seem to be very generous. I could be wrong or this information could already be ready for people more important than I but perhaps highlighting how Directs major technical hurdles will be over come and how are they much different that Ares (in regards to how Ares 1 problems can't be over come but Direct can be), every rocket has it's hurdles right?
Finally how well can all the restructuring of the contracts go? That's got to be a major concern since you're going to be asking out side sources to stop building what NASA told them to, and build a whole new design. How much money and time will be lost there? What happens if one of the contractors doesn't want to go along? We could end up with a big cow pie if things turn south.
Those are just a few concerns that come to mind from some one not inside NASA and don't feel the need to respond as I don't want to waste your time as I'm sure you're busy. I'm just expressing my internal conflict.
The clamor to change the program is a cry from people who know what's happening on the inside to return to a sane launch vehicle program so that we can get on with the VSE. What the fear is, and it is very real, is that when Ares goes down as many believe it will, it will take the entire VSE, and possibly the American manned spaceflight program, with it.
Yes, every rocket has its hurdles. But the timelines we have presented have been put together by the people at MSFC who do the scheduling of projects. It's NASA personnel that are saying we can do this. We are only relaying their conclusions.
Quote from: Khadgars on 12/31/2008 08:26 pm You know I'm a Direct convert, looking at the two designs now I don't see how you couldn't go with Direct. An awful lot of people agree with you. QuoteHow ever a lot of time has passed since that decision had to be made and one thing I do agree with Dr. Griffin is that you can't keep stopping every year and try to redesign the rocket or you'll end up with nothing. That to me is my biggest fear. Dr Griffin is right in that once a decision is made, you press forward with it. Otherwise nothing gets done. However, if you study the history of how NASA projects are run, there are decision points all along the way that must get a pass or the program is either terminated or replaced. Throughout all of NASA's history this has been followed, and many a NASA project has been cut because at these decision points they couldn't pass the grade. This time is different however. There have been several points in this program where Ares-I couldn't pass the decision node. But instead of doing the right thing and changing the program, the decision standards were actually lowered to the point that the LV passed. NASA then happily announced to the world that the Ares project has passed yet another milestone. I don't think it's a stretch to call this hypocrisy. This has led many to believe, rightly or wrongly, that Dr Griffin's goal was not to implement the VSE, but to build and fly the Ares rocket which he designed before he was the Administrator, back in his Planetary society days. The clamor to change the program is a cry from people who know what's happening on the inside to return to a sane launch vehicle program so that we can get on with the VSE. What the fear is, and it is very real, is that when Ares goes down as many believe it will, it will take the entire VSE, and possibly the American manned spaceflight program, with it. QuoteSecond the whole idea that Direct is safer is misplaced imho, as Direct refers to safer in regards to the Orion capsule. Orion will never fly if it's unsafe and Ares 1 was chosen because it was the safest launch vehicle they could produce which is something I think needs to be recognized. No, DIRECT refers to safer in terms of the launch vehicle. By every measure that matters, the Jupiter-120 is a safer launch vehicle than the Ares-I. For example it doesn't have to execute an engine start at high altitude - there is no extra staging event as there is on Ares-I. Also, the Jupiter-120 uses two main engines and can actually experience an engine out event at 45 seconds after launch and still achieve orbit. Such an experience on the Ares would trigger an immediate abort. The Jupiter-120 uses the 4-segment SRB that NASA has been flying for 30 years and has literally tons of heritage data on. We know how that system works, while the Ares-I uses a totally new SRB with no history and no heritage. It only "looks" like the old SRB. There are many other examples, but the bottom line is that the Jupiter-120 "launch vehicle" is safer than the Ares-I "launch vehicle".
And this is the the sort of unbalanced advocacy that costs Direct credibility.If adding a segment to an existing booster is a "totally new design" then what do you call a totally new design?Jupiter 120 has three staging events, 2*SRB plus 1* Orion. Ares I has two.Ares I removes a whole set of falure modes, like an SRB failure damaging the ET, or one SRB failing and sending the stack into a spin. Not so Jupiter 120.Jupiter 120 has new load paths, new propulsion system, new Oxygen tank, new flight dynamics.Engine out helps of you have a manufacturing defect in a particular engine. If you have a design or system problem, not so much.Assume for sake of argument that Jupiter 120 is about as safe as Ares 1. Once Direct goes to the moon, you are no longer using Jupiter 120. You are using Jupiter 232, with an air start upper stage, and a more complex vehicle overall than Ares I.
Quote from: Will on 12/31/2008 10:21 pmAnd this is the the sort of unbalanced advocacy that costs Direct credibility.If adding a segment to an existing booster is a "totally new design" then what do you call a totally new design?Jupiter 120 has three staging events, 2*SRB plus 1* Orion. Ares I has two.Ares I removes a whole set of falure modes, like an SRB failure damaging the ET, or one SRB failing and sending the stack into a spin. Not so Jupiter 120.Jupiter 120 has new load paths, new propulsion system, new Oxygen tank, new flight dynamics.Engine out helps of you have a manufacturing defect in a particular engine. If you have a design or system problem, not so much.Assume for sake of argument that Jupiter 120 is about as safe as Ares 1. Once Direct goes to the moon, you are no longer using Jupiter 120. You are using Jupiter 232, with an air start upper stage, and a more complex vehicle overall than Ares I.Will, Unbalanced advocacy? I thought that advocates always presented their positions in the best possible light. Short of lying or fabricating the numbers, that is. Have Ares advocates gone to any lengths to play up the pluses and minuses of Jupiter vs Ares? Or isn't it always "we can't under the laws of physics prove their numbers" or "dual-launch EOR of identical vehicles is vastly overdesigned for ISS logistics", or some other such evasive wording or testimony. The new Ares-I five-segment SRB must be treated as a whole new design because: 1) The added segment changes the behavior and characteristics of the combustion chamber, and 2) The propellant's internal shape has also been changed, and 3) The nozzle and TVC have been modifed, and 4) NASA has never used an SRB as the sole first stage of a manned vehicle. None of those concerns apply to J-120, since it uses the standard Space Shuttle SRB, in the standard Space Shuttle configuration. Ares-I has a whole new set of failure modes, like SRB thrust oscillation, residual thrust that could cause a collision after staging, second stage ignition failure modes, and probably more that I don't know about. Ares-I has a new booster stage, a totally new upper stage, new load paths, new J2-X engine, new avionics, new flight dynamics. How is this an advantage for Ares-I over J-120? Having no engine-out capability at all doesn't help you in any circumstance. If you have a design or system problem, it's even worse. When J-232 starts flying, we will already have four years of flight experience with J-120. Safety of J-232 will still be within ESAS designated margins for manned launchers.Have a happy new year!Mark S.Please tone it down...I think Mark is trying to say, if we look at the safety numbers of Ares I vs Direct 120, using the same criteria that Direct 120 would come ahead of the Ares I. If you want to stack the deck in anyone's favor, sure one vicheal can be made to look safer. But with a fair scale, I feel Direct 120 comes out on top of Ares I. Remember, Direct can also carry a heavier cupsule with all the saftey features left in, that Ares cannot carry. Even if we used the same capsule, I think that Direct would come out on top. Direct can carry up to 20 tons of additional shielding that Ares cannot carry. If you were going into battle , would you rather be in the Hummve (Ares) or in an M1A1 tank (Direct 120)t hat can carry that extra shielding.If you want to compare Ares V with Direct 232, I still think that I would go with Direct. Ares V might be able to carry all that weight, but remember now new five segment SRBs, etc. Direct is pretty much flying like the shuttle today expect for a capsule ontop of the tank and not the shuttle on the side. I would really like to see the currant LOM numbers for Ares V. I would be very suprised if it is lower than Direct. At the end of the day, Direct would be flying 8+ missions/year, Ares V 2-4 missions/year. The more you fly, the safer you can make the rocket. There will be failures in Direct, like any other rocket, but I would trust more a rocket that has flies 8+ times a year, than one that we will be luckly will fly 4+/years.
QuoteThe clamor to change the program is a cry from people who know what's happening on the inside to return to a sane launch vehicle program so that we can get on with the VSE. What the fear is, and it is very real, is that when Ares goes down as many believe it will, it will take the entire VSE, and possibly the American manned spaceflight program, with it.Yes that is my biggest fear, one in which I'm willing to see Ares go forward in order to preserve. As much as Direct is better over Ares, Ares is better than nothing and is quite capable of fulfilling VSE. And odd question but if Direct is shot down in the coming months (which I hope it's not) would the Direct team be willing to swallow the bullet and press ahead and try to make Ares as successful as possible in order to preserve American spaceflight? Quote Yes, every rocket has its hurdles. But the timelines we have presented have been put together by the people at MSFC who do the scheduling of projects. It's NASA personnel that are saying we can do this. We are only relaying their conclusions. Very reassuring, that's got to be a major strong point for the Direct case when presenting it to the powers that be. Would Direct be willing to keep Dr. Griffin on board if he was willing in order to prevent a major political shake up with in the agency? Stability will be key in seeing the program move forward with VSE.
Quote from: Will on 12/31/2008 10:21 pmAnd this is the the sort of unbalanced advocacy that costs Direct credibility.If adding a segment to an existing booster is a "totally new design" then what do you call a totally new design?Jupiter 120 has three staging events, 2*SRB plus 1* Orion. Ares I has two.Ares I removes a whole set of falure modes, like an SRB failure damaging the ET, or one SRB failing and sending the stack into a spin. Not so Jupiter 120.Jupiter 120 has new load paths, new propulsion system, new Oxygen tank, new flight dynamics.Engine out helps of you have a manufacturing defect in a particular engine. If you have a design or system problem, not so much.Assume for sake of argument that Jupiter 120 is about as safe as Ares 1. Once Direct goes to the moon, you are no longer using Jupiter 120. You are using Jupiter 232, with an air start upper stage, and a more complex vehicle overall than Ares I.Will, Unbalanced advocacy? I thought that advocates always presented their positions in the best possible light. Short of lying or fabricating the numbers, that is. Have Ares advocates gone to any lengths to play up the pluses and minuses of Jupiter vs Ares? Or isn't it always "we can't under the laws of physics prove their numbers" or "dual-launch EOR of identical vehicles is vastly overdesigned for ISS logistics", or some other such evasive wording or testimony. The new Ares-I five-segment SRB must be treated as a whole new design because: 1) The added segment changes the behavior and characteristics of the combustion chamber, and 2) The propellant's internal shape has also been changed, and 3) The nozzle and TVC have been modifed, and 4) NASA has never used an SRB as the sole first stage of a manned vehicle. None of those concerns apply to J-120, since it uses the standard Space Shuttle SRB, in the standard Space Shuttle configuration.
While I heartily disagree with your conclusions, I wish you a happy New Year. We both want to get more humans off Earth. We can argue about the way forward, but agree on the destination.
Tripe. Jupiter 120 has different load paths, different liquid engines, in a different location, with entirely different flight dynamics. It isn't the standard Shuttle configuration by any stretch of the imagination.
I think Will brings up some fair points. You do have to run a balanced analysis concerning all aspects of mission safety.- John