dodson@convex.com (Dave Dodson) (01/23/90)
In article <15104@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes:
#How Bout That Dept.: The new AvWeek reports that NASA's going to
#qualify their first new flight computer in 19 years for the Shuttle,
#a 2 1/4 MIPS Raytheon supermini (licensed to DEC).
#The new system will be tested on a Hitchhiker payload bay experiment
#package this November. If tests are OK they'll repeat in 1992.
#(By the time it's hopelessly obsolete, it should be about ready to
#fly as real mission hardware.)
Don't forget about software. There are hundreds of man-years invested
in the current orbiter software. Recoding and requalifying that for the
new hardware, almost certainly incompatible with the current hardware,
probably will take well beyond 1992. When you consider the tenet that
you don't fix what isn't broken, it makes me wonder why they would even
consider changing the shuttle flight computer system.
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Dave Dodson dodson@convex.COM
Convex Computer Corporation Richardson, Texas (214) 497-4234mike@ames.arc.nasa.gov (Mike Smithwick) (02/01/90)
In article <4831@convex.convex.com> dodson@convex.com (Dave Dodson) writes: <In article <15104@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes: <#How Bout That Dept.: The new AvWeek reports that NASA's going to <#qualify their first new flight computer in 19 years for the Shuttle, <#a 2 1/4 MIPS Raytheon supermini (licensed to DEC). <#The new system will be tested on a Hitchhiker payload bay experiment <#package this November. If tests are OK they'll repeat in 1992. <#(By the time it's hopelessly obsolete, it should be about ready to <#fly as real mission hardware.) < I leanrned yesterday that NASA is also working of flight-qualifying a Mac II portable for onboard experiment control systems. It should first fly around 1992. *** mike smithwick *** "Never trust a surgeon with shaving cuts. . ." [disclaimer : nope, I don't work for NASA, I take full blame for my ideas]
steve@nuchat.UUCP (Steve Nuchia) (02/01/90)
In article <4831@convex.convex.com> dodson@convex.com (Dave Dodson) writes: >probably will take well beyond 1992. When you consider the tenet that >you don't fix what isn't broken, it makes me wonder why they would even >consider changing the shuttle flight computer system. Two reasons come to mind: weight -- modern computers are lighter per MIP and every kilo you don't spend on computer you get to spend on people, payload, food, or fuel. memory -- a major limitation on shuttle operations right now is that the computers don't have enough memory to hold the software for all the mission profiles. They have missed or nearly missed launch windows due to winds aloft not matching the profiles they had loaded in the onboard computers. More memory would directly translate into better system availability. -- Steve Nuchia South Coast Computing Services (713) 964-2462 "If the conjecture `You would rather I had not disturbed you by sending you this.' is correct, you may add it to the list of uncomfortable truths." - Edsgar Dijkstra