Re: GRIFFIN'S DRIVE FOR SHUTTLE-DERIVED



Jeff Findley wrote:

The assumption that NASA needs a launch vehicle bigger than a Delta IV
Heavy/Atlas V Heavy is a terribly bad assumption. Launching components to
LEO and docking them together should allow the building of vehicles large
enough to return to the moon and go on to Mars.



But that way you end up with the parasitic weight of the rendezvous and docking gear on each of the modules, plus the necessity of interconnecting their control systems so that they function as one.

Furthermore, NASA is supposed to be bound by law to buy commercial launches
whenever it is possible.


NASA may have taken a dim view of the proposed LockMart-Boeing space services merger and what it would mean in regard to pricing of commercially bought boosters. If you are required to buy commercially, and you have a sole-source supplier, then you have a situation where that sole-source supplier can charge whatever it wants. Other firms may get a slice of the action in the small booster field, but the 500 pound gorilla that the merger will create is going to be awfully hard to beat in the medium/heavy lift category unless one is willing to to look to foreign manufacturers as able to bid on a launch on equal terms with American companies.

 Considering how hard of a time Atlas and Delta are
having, I'd hate to see NASA turn their backs on commercial launch vehicles
and build their own.

Lastly, any sort of shuttle derived vehicle is going to necessarily require
the retention of much of the shuttle ground infrastructure and "standing
army". Because of this, it also would retain the high cost of shuttle
launches. This is something that even NASA ought to be against. The low
flight rate and high cost of the shuttle should not be repeated by creating
a shuttle derived vehicle.


The SRB is a fairly low tech piece of machinery, and it could be stacked right at the launch site from its component sections, eliminating the need for the VAB and the crawler transporter, and then have the upper stage and CEV put on it after it was assembled. That would cut down on the manpower requirerments. It also has the fact that it is a proven design going for it- if considered separately, we've had 216 SRB flights with one failure; that makes it hands-down the single most reliable large booster rocket ever built, with a failure rate of better than .5%.

I hope that Congress realizes this and puts a stop to it now. They
certainly don't want a repeat of the shuttle/ISS experience (e.g. repeated
redesigns due to mounting costs).



Unfortunately, one can see that being exactly what happens based on recent NASA experience in regards to new spacecraft design. The project gets started, then around half way through, we decide that we don't need what we are designing or run into a technical snag, and start all over again from scratch.
They should have a real sit-down discussion and figure out exactly what they want and what it's designed to specifically do before they go rushing ahead with the design, like they seem to be doing now. The Soviets carefully thought out Soyuz before they built it, and the fact that they made the right decisions gave them a quite versatile spacecraft that could be kept in use at a economical price for decades to come.

Pat
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