Jon Goff has an interesting post on the potential use of the Kistler K-1 upper stage as a lunar transport vehicle, using aerobraking. He also wonders of the Ares 1 is already obsolete.

It needs to be forever put to rest the myth that an Atlas V is not reliable enough for the CEV.

Refer to this document on the NASA Technical Reports Server

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740021163_1974021163.pdf

OVERALL DESIGN.

Specific ground rules establish the baselines for each particular
vehicle mission. However, certain overall design requirements have
been upheld throughout the Saturn IB design program. These
requirements were levied to assure the success of all launch missions
assigned to the vehicle, and are summarized in the following paragraphs.
Reliability.
The launch vehicle must be reliable through the complete flight
phase. Reliability performance must be greater than or equal to
a 0.88 factor.

The Atlas V has a stated reliability exceeding 0.99.

The point is that NASA as it is today is too incompetent to figure this out. The only reason that NASA is going ahead with the stick as it is designed today is the pig headedness of Scott Horowitz and Mike Griffin.

NASA was more honest in 1972 and more competent.

It's entirely possible that Griffin's attitude is that, should COTS perform as hoped, it would then be politically possible to cancel the Stick. After all we don't know what deals had to be made to get this initiative going -- but based on history, it is highly likely that some were made. The stick is probably part of the deal.

As someone pointed out at DragonCon over the weekend... if the Stick were cancelled, then when SRBs go away after 2010, ATK would wind up charging the military a lot more for solid propellants for various missiles (Tridents, etc). So we can think of the existence of the Stick (rather than using Atlas or Titan for CEV) as a cost transfer from DOD that hits NASA's books...

Stephen,
Interesting thought. Of course, ironically enough the DoD still ends up losing out one way or another. By not launching CEV on existing (Delta IV or Atlas V) or future (Falcon 9) EELV class vehicles, the DoD is ending up having to subsidize BoeLock to the tune of about $.5B each per year, and pay higher launch costs to boot. I wonder how much they're really saving on the other solid boosters by having the Shaft built, and if your thought is right, which would really be the more cost effective option for the DoD to support.

~Jon

> if the Stick were cancelled, then when SRBs go away after 2010, ATK would
> wind up charging the military a lot more for solid propellants for various
> missiles (Tridents, etc).

That might be believable, except for one thing. DoD did not favor the Stick. This story almost certainly comes from NASA (or possibly ATK), not the Pentagon.

> The launch vehicle must be reliable through the complete flight phase.
> Reliability performance must be greater than or equal to a 0.88 factor.

> The Atlas V has a stated reliability exceeding 0.99.

> The point is that NASA as it is today is too incompetent to figure this out.

Actually, Mike Griffin has said almost the same thing -- Stick reliability is not particularly important as long as it has an escape system.

One problem. Escape systems are not foolproof. Even aircraft ejection seats, which have been developed and tested far more extensively than NASA's launch escape systems, have a high failure rate. Even a "successful" ejection may produce long-term, crippling injuries. Pilots call ejection "attempted suicide to avoid certain death."

It's now believed that there was in design flaw in the Apollo launch escape system and it did not have the power to clear a Saturn V first-stage explosion. That particular number never came up on Apollo, because NASA only spun the wheel a few times.

That was the difference between the engineers who worked on Apollo and those who worked on the X-15. One group came out of the professional flight test community and recognized dangers like that. The other came out of the German amateur rocket clubs. They learned to fear politicians (the SS) not Murphy's Law.

At least, up until Apollo 1.

With regard to aero breaking for lunar return, 2 things pretty much kill that idea outright; time and radiation. MRO just finished aero breaking into its final circular orbit around Mars and it took about 6 months. Lunar return could be done in a shorter period of time, but it would take weeks not hours. Each pass through the Van Allen belts is quite a dose; astronauts could never survive the number of passes necessary for aero breaking.

> Lunar return could be done in a shorter period of time, but it would take weeks
> not hours. Each pass through the Van Allen belts is quite a dose; astronauts
> could never survive the number of passes necessary for aero breaking.

Brian, you ought to read the article before commenting. Jon discusses the radiation belts and the difference between multipass aerobreaking and singlepass aerobreaking (which does not take weeks).

Also, Aviation Week reports Orion will use "a baselined 'skip-entry' approach that will take it in, out and back into the atmosphere." Apparently, NASA doesn't think it's "killed outright."

My group just doesn’t call “single pass aero breaking” aero breaking; we call a “skip reentry” a maneuvering reentry. I suppose you could call what the shuttle does aero breaking too. In fact one could say that the recent Geneses capsule also did aero breaking followed by some unfortunate ground breaking.

If you hit the atmosphere and retain enough energy to maintain orbit it’s aero breaking, if not it’s a direct entry even if you exit the atmosphere for a period of time. Though I’m not 100% certain, from a lunar return I don’t think it’s possible to maintain orbital energy and not pass the Van Allen belts. Any calculations to the contrary? I’ll look through some of our old stuff; problem is that the Van Allen belts aren’t just at a single altitude, so inclination matters.