[FPSPACE] NASA WATCH: 5A To Slip 30-60 Days
Tue, 5 Sep 2000 14:54:48 EDT
NASA WATCH == 5 September 2000:
Launch of STS-98/ISS Flight 5A delayed. STS-92/ISS 3A may slip too.
Editor's note: according to sources at NASA, the launch of STS-98/ISS
Flight 5A (US Lab delivery) will be slipped 30-60 days as the result of PCS
(Portable Computer System), CCS (Command and Control Software) , and NSC code
Meanwhile, a temperature (Hall effect) sensor on the backup CMS (Control
and Monitor Subsystem) failed. This has been attributed to large stresses
associated with thermal cycling. There is apparently little if any time no
time to fix this problem since the CMGs (Control Moment Gyroscopes) are
schedued to be launched on STS-92/ISS 3A at the end of September 2000.
Three options are currently under consideration at the ISS Program Office:
Launch the CMGs with this known problem, and make some substantial changes to
the STS-98/ISS Flight 5A mission's GN&C (Guidance, Navigation and Control)
software and make wiring modifications to the Z1 Integrated Truss Structure
Postpone the launch of STS-92/ISS 3A until the CMGs canbe repaired. Thsi
could take cause a 12 to 15 month launch delay.
Take the CMGs off of the Z1 Integrated Truss Structure and launch the CMGs
larter when they are repaired.
It is expected that NASA will chose the first option.
JimO adds: I also hear that non-compliant fiber optics will be launched
anyway on other modules, and will require change-out on orbit before it can
function to spec levels. Back in 1990-1, when I was on the Blue Ribbon Panel
for the Fisher-Price Committee for EVA Maintenance, we looked at the Freedom
design and added in predictable ORU failure rates and concluded the design
would NEVER be completable -- that it would stall out at about 70% complete
and all subsequent up-cargo would be replacement parts for failing
components. I wonder if the improved ISS design will ever reach that 70%
JimO: I also wonder if this means Expedition-1 will stay longer on orbit? The
Russians want to delay the next Progress until AFTER the crew gets aboard
because it's the first side-docking, and having TORU backup seems prudent (I
agree). But critical crew equipment -- including toilet hardware --
supposedly is on board that supply ship.