Quote from: kraisee on 07/24/2009 09:39 pmI think there's a bit of confusion above, so let me try to clarify:Prior to the committee, NASA came up with NASA's own numbers -- nobody else was ever involved. This is true for CxP and also for NSC as well.Ross.Then I was mistaken and I owe Gramps an apology. I thought they were involved with processing NASA's Ares numbers before the commission was announced.
I think there's a bit of confusion above, so let me try to clarify:Prior to the committee, NASA came up with NASA's own numbers -- nobody else was ever involved. This is true for CxP and also for NSC as well.Ross.
Quote from: cixelsyD on 07/24/2009 09:55 pmThanks Ross, that makes me feel a lot more confident about the commission.If we had ever tried to get them to analyse DIRECT for us, our little band of rebels could never have afforded their fee! :)QuoteNo oversight at all.Where is the guy looking over their shoulder?
Thanks Ross, that makes me feel a lot more confident about the commission.
No oversight at all.
Where is the guy looking over their shoulder? NASA administrator.President.GAO.
Quote from: zapkitty on 07/24/2009 08:35 amBut folded that would give you a 30 meter heat shield...There are lots of different folding techniques. You can get a 30m heatshield into a 7.5m diameter payload fairing. You basically have a core heat shield of 7.5m and segments from the outer heat shield folded upright around it all in the 10m length. And no, you don't need an EVA to assemble a segmented heathshield. Actually folding techniques have been used in space forever and they work. Automatic bolting works as well.I've always wondered why people dislike the segmented, folded heatshield for Mars payloads approach so much. As far as I see it, as long as we stay with conventional Mars descent techniques (that is a heatshield and later on parashutes and some powered descend for the last part) going with segmented heatshields makes the most sense. Rather than having to design your modules around constraints of a 10m, 12m or 15m heathshield (depending on the diameter of your payload fairing) you can just design your modules and design the appropriately sized heatshield for it.
But folded that would give you a 30 meter heat shield...
Quote from: fotoguzzi on 07/24/2009 11:27 pmWhere is the guy looking over their shoulder? NASA administrator.President.GAO.Griffin proposed it, so wasn't interested in questioning it.President wasn't a rocket scientist so didn't know How to question it.GAO Did question it, multiple times, but was ignored each time.Oversight Score: F Minus.Ross.
Without wanting to sound too optimistic, it seems Ares 1 / V is dead.If a "Direct" type of launcher is chosen, will NASA,a. Start from scratchb. Take the Direct concept, validate it, embrace it and deploy itOption b would save about 1 - 2 years, and a corresponding amount of money, because early concept design, prior to PDR, takes time.Option a risks heading off to a Not Invented Here hatchet job. Engineers who have been working on Part Number 3714 for Ares 1 really feel it ought to fit into the new "Direct" architecture.So how do you brainwash smart Ares engineers to love Direct?
It bears repeating. I said: "Ours and theirs cost profiles do not match line for line, but overall we are in the ballpark"Some have taken that to mean that the "validation" arrived at approximately the same number as us. Not true. I apologize if that's the impression given. What was "validated" was that our numbers were not "unreasonable". That's why I used the term "ballpark". Our numbers were "reasonable" enough to not be dismissed. That's an important distinction.To put this in perspective, "nobody's" cost figures worked out exactly as stated. To end up "in the ballpark" after scrutiny is like teeing off and the golf ball landing on the green. That doesn't get you a score yet, just puts you within range of the score. It validates your efforts to score and makes you a credible player. It recognizes you as a genuine contender. That's where we are.
I've never truly understood why NASA (or even the DIRECT team) simply didn't adopt the basic Mars Direct architecture. There would be no issues now. It has a heavy lifter. It has technology that can be used/tested on the moon. It gets a Mars program happening quickly and relatively cheaply.The only extra element needed is Delta IV or Falcon9H launch of Orion for LEO missions.
Ross/Chuck,Maybe you guys can take a guess at this, but for me the trouble with estimating the Ares program costs has always been which version of the Ares V rocket do you cost out. The old five engine RS-68 5.5 segment 10m core which is what the $35 billion figure is based on? Or the current 6 RS-68 engine 5.5 segment rocket, or the Godzilla-7 with RS-68 regenerative engines, 6 segment boosters, and an 11m-core monster that may be needed to close the performance gap?
DIRECT seems pretty reasonable to cost out since at worst it seems like you might need to go to 5 segment boosters or a J-2X upper stage if your upper stage mass fractions turned out to be as bad as NASA claims they would. But the Ares V could need something like 50 percent margins just to account for all the uncertainty with the design. I doubt Aerospace Corp would share with you much in the way of how they are dealing with this, but I was curious if anybody had any thoughts on this aspect of the Augustine Commission.John
We actually calculated that the mission would still be able to close CxP's 71.1mT thru TLI performance targets even if that Managers Reserve was increased to 5,000kg! And we informed Aerospace Corp of that finding too.We deliberately refrained from publicizing these details because we didn't want to tip-off the competition before Aerospace Corp was finished with its analysis.Ain't I a stinker!!!Muwahahahahahah! Ross.
Quote from: JMSC on 07/25/2009 12:11 amRoss/Chuck,Maybe you guys can take a guess at this, but for me the trouble with estimating the Ares program costs has always been which version of the Ares V rocket do you cost out. The old five engine RS-68 5.5 segment 10m core which is what the $35 billion figure is based on? Or the current 6 RS-68 engine 5.5 segment rocket, or the Godzilla-7 with RS-68 regenerative engines, 6 segment boosters, and an 11m-core monster that may be needed to close the performance gap?That $35m figure is for development of the current baseline launch vehicles, which is:-Ares-I - 5-seg, J-2X, 5.5m Upper StageAres-V - 5.5seg, 6x RS-68B (ablative), 10m Core Stage, J-2X, 10m Upper StageThis does include both manufacturing and launch facility modification costs as well.Regen RS-68 will be extra to develop. Estimated vary between $500m and $1bn for a human rated Regen variant.Godzilla-7 would be more expensive still. Most of the difference would be for extra infrastructure costs to support that vast Core Stage structure. But every flight would also require an extra RS-68 Regen too, which doesn't help their costs any.QuoteDIRECT seems pretty reasonable to cost out since at worst it seems like you might need to go to 5 segment boosters or a J-2X upper stage if your upper stage mass fractions turned out to be as bad as NASA claims they would. But the Ares V could need something like 50 percent margins just to account for all the uncertainty with the design. I doubt Aerospace Corp would share with you much in the way of how they are dealing with this, but I was curious if anybody had any thoughts on this aspect of the Augustine Commission.JohnActually, we took care of that already The EDS version which we actually submitted for review to the Augustine Committee included 2,500kg of additional "Managers Reserve" on the Upper Stage mass allocation, and was powered by a J-2X.This resulted in an Upper Stage dry mass of 14,656kg and a burnout mass of 16,431kg. The additional Manager's Reserve accounts for approximately 17% of the total mass allocation.The pmf (NASA calc method: Usable Propellant/GLOW, not Regular pmf calc method: Gross Propellant/GLOW) was thus a much more reasonable 0.9164!We did this to be extra-conservative, specifically for this review process to head-off the concerns about pmf and to ensure that any FUD spread by the competition could easily be discounted.We actually calculated that the mission would still be able to close CxP's 71.1mT thru TLI performance targets even if that Managers Reserve was increased to 5,000kg! And we informed Aerospace Corp of that finding too.We deliberately refrained from publicizing these details because we didn't want to tip-off the competition before Aerospace Corp was finished with its analysis.I sure don't mind if the competition expended all their energies fighting this pmf issue behind closed doors. They can bi*ch and complain about our pmf as much as they like -- because it was pretty irrelevant for the variant which was actually being studied!Ain't I a stinker!!!Muwahahahahahah! Ross.
Ross or anyone else in the know:If the Augustine commission picks Direct and General Bolden Obama, and Congress agree, who should run the Direct development so it gets done right? Does NASA have anyone that should be moved into the position that won't screw it up?
The main reason why Zubrin's In-Line launcher, also called "Ares", was not considered is because it has a few technical concerns.Firstly, it uses the more powerful 4-segment ASRM Boosters -- which were canceled for Shuttle after their costs went out of control. They were replaced by the SLWT, which produced a similar performance improvement.Second, the Upper Stage has an engine in the SSME thrust class, but which also needs to produce 465s vac Isp -- which is approximately 13s better than SSME, yet needs to be air-startable and then re-startable too.Both of these elements are pretty costly items which most people don't realize were included. You're talking about a similar cost ($1.8bn+) to the 5-segs in order to get the ASRM's and you're talking about a really serious development program ($2bn anyone?) to get that combined-higher-efficiency-SSME-air-start/re-start engine qualified for human use.But if you swap those for existing systems (or J-2X in the case of the US engine), the performance for the vehicle drops significantly. But if it drops, it can no longer support the size of mission Zubrin was hoping for -- and that short-circuits the plan Also, since that study was conducted its concepts have been refined a lot by Zubrin and the Mars Society. The "Mars Society Mission" seems to be the most recent iteration from that quarter and the mission size for MSM has grown since "Mars Direct" was first proposed. It wouldn't fit on two of Zubrin's Ares vehicles now anyway.Ross.
Do you recognize this concept? I've had it saved for a while and forgot about it.
re: ... mini-shipyard....... apparently if you name it Spacedock a spatial distortion automatically relocates it to a random L point and quadruples its facilities ...... a bit much for what's supposed to be an inexpensive and Direct-style beginning effort at a much-needed and long overdue bit of space infrastructure that will complement Direct...... not because of NASA EDS FUD, but because it would greatly expand the use of space-assembled probes and modules that don't need to carry expensive automated docking gear...... now... once the original has been proved out in LEO I can see another version being assembled by the original mini-shipyard and boosted out to wherever next gen space operations are staged... a starting seed package sort of deal...