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Author
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Topic: Military influence on space shuttle's design
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chris_petty
Member Posts: 14
From:
Registered: Nov 2015
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posted 11-12-2015 12:40 PM
  
Having recently researched the influence that the military were able to exert on the design of the space shuttle orbiter and consequently the whole STS system, I wonder what people's thoughts are on the following: - Would the other initial designs considered have been more effective in the long run?
- Would the single orbit mission the Air Force planned out of Vandenberg really have been practical?
My article is here for anyone interested. |
Jim Behling
Member Posts: 1463
From: Cape Canaveral, FL
Registered: Mar 2010
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posted 11-12-2015 01:56 PM
The single orbit mission was not the design driver as you state. Landing cross range was a driver for abort once around and not the single orbit mission.Film retrieval was not driver for the single orbit mission, it was deployment or retrieval of a spacecraft (friendly or otherwise) outside of USSR view. Payload bay size was not just USAF requirement. Station modules or high energy upper stages needed it too. I will provide a more detailed response later. |
chris_petty
Member Posts: 14
From:
Registered: Nov 2015
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posted 11-12-2015 02:34 PM
Thanks, I'd be really interested to hear more, I find this element of the shuttle's history extremely interesting. The information for the single orbit mission being a major design driver came from multiple sources, but I agree that the Faget style straight-wing design would have offered practically no abort options from a Vandenberg launch with such limited cross range so I don't doubt this was a major consideration. I apologise if my article doesn't give a fully accurate picture, I do my best to research my subjects in as much depth as I can, but I know that some readers here will have far greater knowledge, possibly first-hand, so I hope to learn more! |
Jim Behling
Member Posts: 1463
From: Cape Canaveral, FL
Registered: Mar 2010
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posted 11-12-2015 03:09 PM
The single orbit mission was formally called Baseline Reference Mission (BRM) -3 (A or B for deployment or retrieval). They were dropped in the early 70s. They did not drive the size, performance or cross range of the shuttle. They were to drive the rendezvous sensors and mission ops processes. I have a JSC document on the BRM-3 missions, but I just moved and it is inaccessible.The reference missions that drove shuttle size and performance were: - BRM-1 which was 65Klb to 150nm due east from KSC with 15' dia x 60' payload
- PRM-4 which was 32klb to 150 nm at 98 degree inclination from VAFB and land with same weight payload.
The 1100nmi or so cross range was derived from the intact abort requirement.See: STS reference missions. In the early 80s, I was on a USAF "test" team that assessed the shuttle's ability to meet DOD requirements. The product was called the Shuttle Assessment Report. The DOD shuttle requirements document was DOD-STS-100. |
chris_petty
Member Posts: 14
From:
Registered: Nov 2015
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posted 11-12-2015 04:14 PM
Jim, thanks so much for sharing your experiences on this. I was hoping to get some informed comments, but it's great to hear from somebody with real first-hand experience.That must have been a fascinating experience to be involved in. Most of the accounts I was referring to were dealing with the Phase 2 design stages, so I'm assuming were relating to discussions prior to the dropping of the BRM-3 (A/B) missions that you detailed. None mentioned the requirements had been officially dropped so thanks for setting that straight. I'll do some more research on this. |
pupnik
Member Posts: 114
From: Maryland
Registered: Jan 2014
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posted 11-12-2015 07:56 PM
I've heard apocryphally that NASA would have arrived at a delta-winged orbiter with or without USAF involvement because of its higher cross range and greater energy dissipating surface. |
chris_petty
Member Posts: 14
From:
Registered: Nov 2015
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posted 11-13-2015 03:35 AM
Certainly within the early development stages Alfred Draper at the Air Force Flight Dynamics Lab raised concerns over the straight wing approach. He suggested a delta wing would provide better characteristics across the wide Mach range the vehicle would encounter.There was also the increase in cross- range to consider, so yes I suspect many within NASA were 'won over' by these arguments, although Faget continued to push for the straight wing design well into 1971 when the discussion was essentially closed down despite his objections |
chris_petty
Member Posts: 14
From:
Registered: Nov 2015
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posted 11-13-2015 06:28 AM
Jim, regarding missions 3A/3B I managed to find this excerpt of a JSC Note from 1973 on Jim Oberg's site.Maybe this is the document you were referring to? Many thanks again for pointing me in the right direction on this matter. |
Jim Behling
Member Posts: 1463
From: Cape Canaveral, FL
Registered: Mar 2010
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posted 11-13-2015 06:44 AM
Yes, that is.
It will still take awhile for me to find my copy of the Shuttle Assessment Report. It will have excerpts of STS-100 requirements document. |
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