Several letters commenting on Jerry Grey's lukewarm view of SSTO.
Loral to build a GPS-based attitude-sensing system for [LEO] satellites, using technology licensed from Trimble, based on the system designed for Gravity Probe B.
First H-2 launched successfully 4 Feb, after a two-day delay due to bad weather and a one-day delay for a mechanical problem.
Clinton FY95 budget hits NASA hard, jeopardizing shuttle developments like the new AlLi tank, and pushing NASA to consider drastic measures such as mothballing an orbiter. [That last has been officially denied.]
Discovery launched 3 Feb for the Wake Shield Facility mission.
The investigation of the TOS separation mess during ACTS deployment last year has reported... When separation from the shuttle was commanded, both the primary *and* backup explosive cords in the separation mechanism fired, rupturing the confinement tube and showering the cargo bay with debris, including 22 reinforcing plates from the separation joint. One of the plates punched a 1/8x1/2in hole in the aft bulkhead; others did various bits of minor damage to insulation blankets etc.
The problem was a design error. The "Fire 1" command went to the port-side detonators for both cords, instead of to the port and starboard detonators for the primary cord. ("Fire 2" was supposed to go to the backup cord. [They don't say, but I would guess, that "Fire 2" went to both starboard detonators.]) The wiring harness was designed incorrectly in 1984, and none of the later reviews found the flaw. Test equipment verified the design instead of checking for the desired end results. Documentation was incomplete, terminology inconsistent, and labelling "incomplete and confusing". There was no single schematic showing both electrical and mechanical subsystems of the separation system. "The technical reviews... had little chance of detecting the embedded error. Even after [we knew what to look for], detecting the design error through drawing reviews was difficult for experienced personnel..." A 1992 design review had some "to be determined" items for the separation system, and it is not clear why this didn't raise an alarm. The report recommends that payload safety verification procedures should test for end results, not conformance to the design; that the tests should be run on the flight hardware; and that in areas where full testing is impossible, such as pyro hardware, the people devising the verification procedures should not be the ones who designed the hardware.
US and Russia to informally share data from tracking of the Oderacs radar-calibration spheres being deployed from Discovery. The sharing will be informal partly because the last such effort, on tracking of the two Pion spheres released by Resurs F in 1992, was a bit of a fiasco: the Russians supplied poor data very late.
The main purposes of the Oderacs spheres is calibration of US debris- tracking radars, especially the Haystack radar. Precision tracking will also give useful data on the extreme upper atmosphere, since the spheres are in a fairly low orbit that's expected to last only a few months.
Telesat Canada initiates a $3M effort to rescue Anik E2, by developing software to use its maneuvering thrusters for attitude control. This will be somewhat of a first. The tricky part is that yaw sensing will have to be done from the ground, and equipment must be added for this. The ground-control equipment will also be made more redundant. The extra fuel consumption will cut 1-2 years off the satellite's life. (E2 is already a bit short on fuel because of the maneuvers done to free its stuck antenna shortly after launch.) The new control system will also be available as a backup in case Anik E1 loses its remaining momentum wheel. Most of E2's full-time traffic has been temporarily moved to E1 or Galaxy 6, but Telesat Canada will be unable to serve many occasional-use customers until E2 is restored. The six-month outage will cost Telesat tens of millions of dollars in lost revenue [plus the rent on those Galaxy 6 channels, I expect].
DC-X, on the brink of program termination, is saved... by NASA!?! By direct order from Goldin, NASA gives the program $1M from its Advanced Concepts And Technology funding, to preserve the hardware and team until the politics of continuation can be resolved. The vehicle has been cared for properly, and work will now begin on getting it ready for flight again, although flights cannot actually resume until the $5M that Congress allocated for it is actually delivered by DoD.
"...the Russians are coming, and the | Henry Spencer @ U of Toronto Zoology launch cartel is worried." - P.Fuhrman | henry@zoo.toronto.edu utzoo!henry