Author Topic: STS reference missions  (Read 3200 times)

Offline Jim

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STS reference missions
« on: 10/25/2006 02:22 PM »
Decided to dig up some old info.  These are the reference missions that the STS was originally designed to.

Mission 1 is a payload delivery mission to a 150 n.m. circular orbit. The mission will be launched due east and requires a payload capability of 65,000-lb. The purpose of this mission is either the placement in orbit of a 65,000-lb satellite or the placement in orbit of a 65,000-lb satellite and retrieval from orbit of a 32,000-lb satellite.

Mission 3A is a payload delivery mission to an orbit at 104 degree inclination and return to the launch site. The boost phase shall result in an insertion into an orbit with a minimum apogee of 100 n. mi., as measured above the earth's equatorial radius.

Mission 3B is a payload retrieval mission to an orbit at 104 degree inclination and return to the launch site. The boost phase shall result in an insertion into an orbit with a minimum apogee of 100 n. mi., as measured above the earth's equatorial radius.

Mission 4 is a payload delivery and retrieval mission of a modular spacecraft weighing 32,000 lb at lift-off. The mission will deploy a spacecraft weighing 29,000 pounds in a 150 n. mi. circular orbit at 98 degrees inclination within two revolutions after lift-off. A passively cooperative, stabilized spacecraft, weighing 22,500 pounds, will be retrieved from a 150 n. mi. circular orbit and returned to VAFB. The mission length, including contingencies, will be 7 days. For mission performance and consumables analysis, a cradle weight of 2500 lb will be assumed to be included in the ascent payload weight, but must be added to the retrieved payload weight..

The 1Y and 4Y missions are assumed to have the same payload requirements as 1 and 4, respectively, the missions are planned for one day with two crewmen.

The missions were referred to as "Baseline Reference Mission"  BRM, except number 4 which was called "Performance Reference Mission" PRM.  
BRM-1 set the structural capability of the orbiter with the 65klb payload.  It did not size the propulsive system of the the shuttle .  PRM-4, as it was called, did.  Even though PRM-4 only was a 32klb payload, the orbital altitude and inclination demanded more performance.   If the required performance of PRM-4 was translated to an east coast launch, the capability would be around 78klb.

Also of note, BRM-3A and 3B are one orbit missions.  This was to allow the missions to be done without overflight of the Soviet landmass.*  Also the 1Y and 4Y missions were relatively short with small crews.  

The inability to fulfill these requirements plagued NASA thoughout the development of the shuttle.  BRM-3's went away early when is was found that they were unachievable do to the workload and orbiter systems.  Same goes for the "Y" missions, but SAS had a bigger role in it.

Many solutions were sought to increase the lift capability of the shuttle system.  In addition to SSME power levels of 104% & 109% and light weight ET, other proposals were:  small SRM's that would be strapped on to the SRB's; Two Titan first stage engines (4 nozzles) and associated tankage placed under the ET, filament wound casings for the SRB's, Advanced SRM's and the one only that was incorporated, SLWET>



* This is what made the Soviets think that the shuttle was a weapon system.



Offline psloss

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Re: STS reference missions
« Reply #1 on: 10/25/2006 04:07 PM »
Thanks, Jim.  I'd heard about the single orbit missions, but don't recall seeing this in Jenkins, etc...

Offline nethegauner

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RE: STS reference missions
« Reply #2 on: 10/26/2006 11:59 AM »
Now this is interesting. One-orbit shuttle missions? Fascinating...

A number of Spacelab reference missions was also developed. I saw them listed in a German book from 1976, that I recently obtained via Amazon Marketplace. I will look it up...

Online Jorge

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Re: STS reference missions
« Reply #3 on: 10/26/2006 05:29 PM »
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psloss - 25/10/2006  10:50 AM

Thanks, Jim.  I'd heard about the single orbit missions, but don't recall seeing this in Jenkins, etc...

You'll probably see it in the fourth edition...  ;)
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Offline mkirk

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RE: STS reference missions
« Reply #4 on: 10/26/2006 06:11 PM »
It is really amazing when you compare how the shuttle is actually flown with what the initial operations concepts were.  From a training/crew ops perspective things are very different now compared to what Deke Slayton originally had in mind for the Astronaut office.  The total number of Astronauts in the office was supposed to be a fraction of what it is today (I thinks the planned number was in mid 30s).  

The Pilot Pool astronauts were expected to fly often without much flight specific training since their focus was to get the vehicle up and down.  Since they would fly so often recurrent training was supposed to be minimal.  

The Mission Specialists would handle the mission specific tasks for which they would be specifically trained.  Unlike now the Mission Specialist would not have had all of the Shuttle Specific training they get as ASCANS and during their Mission Specific training flows.


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Offline nethegauner

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Re: STS reference missions
« Reply #5 on: 10/27/2006 06:56 AM »
Here are the Spacelab reference missions as originally proposed by the JURG, the Joint User's Requirements Group:

A Astronomy
a pallet with an IR and a UV instrument, P/L crew: 2

B Solar physics
also pallets only, features a coronagraph and two additional instruments, P/L crew: 4

C Material science
a module, P/L crew: 2

D Atmosphere, magnetosphere, plasma
a module, a pallet and a free-fyer, P/L crew 4

E Biomedicine
also a module, P/L crew: 3

Quote
Jorge - 26/10/2006  7:12 PM

Quote
psloss - 25/10/2006  10:50 AM
Thanks, Jim.  I'd heard about the single orbit missions, but don't recall seeing this in Jenkins, etc...
You'll probably see it in the fourth edition...  ;)
Is a fourth edition actually coming?

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