ISAS successfully test-fires a prototype M-5 first stage June 21, putting M-5 on track for 1996 operational capability.
NRC space-station committee says things are looking up lately, but some issues still need work, notably slow development of working relationships with Russian engineering groups.
NASA is re-examining Shuttle-Mir mission plans after discovering that the Russian docking system does not have quite as much redundancy as they'd thought: the docking-hook mechanical systems are dual-redundant, and all the shuttle-side hooks have pyro systems for emergency separation, but only half the hooks (the ones active on the Mir side) have pyro systems on the Mir side. A contributing problem is that NPO Energia is being slow about supplying performance data on the Russian pyros. NASA is examining EVA procedures as an emergency backup, but EVA disconnection of the docking system would be tedious: 96 bolts.
As a further complication, a qualification-test version of the docking system failed two out of five cold-conditions tests at NPO Energia last month: it doesn't react quickly enough to small misalignments during docking when it's cold.
All of this is at an awkward time, because the schedule for getting the first docking mission -- STS-71 -- off on time is tight already. For later missions, some consideration is being given to revising the docking hardware (on the shuttle side) to simplify EVA disconnection or add another pyro separation system.
House vote firmly rejects station termination. Clinton and Goldin have been lobbying hard, and the opposition is starting to lose heart. The Senate is still a harder sell, though.
Story on experiments planned for the second International Microgravity Lab mission, set for launch on Columbia this week.
Pegasus has its first total launch failure, as the first Pegasus XL is destroyed by Vandenberg range safety June 27 after drop from OSC's Tristar. It's bad timing, as Pegasus launch rates were about to ramp up sharply to try to clear some backlog. Launch of NASA's APEX payload on a standard Pegasus -- the last launch planned to use the NASA B-52 -- is still being prepared for July 7, but in practice it will probably slip at least a few weeks while the failure is investigated.
First hint of trouble was at ignition +35s, when the Pegasus dipped briefly and an object appeared to fall off, trailing vapor. Telemetry had been lost a few seconds earlier, but radar and visual tracking confirmed that the launcher was still accelerating on about the right path, although weaving slightly. It was not initially clear that the telemetry loss was a Pegasus problem rather than a ground problem. At about 75s, the launcher began to lose speed and fall below its nominal trajectory. Normal first-stage burnout would be at about 72s; it looks like the first stage performed roughly as expected but the second stage did not separate or ignite.
DC-X lands safely after being damaged by a pre-launch explosion. The damage is repairable, but the funding situation is confused. The problem appears to have been an unusual accumulation of the hydrogen vented during engine chilldown. When the engines lit, the vented hydrogen exploded, blowing in a section of DC-X's skin. The launch crew did not notice the damage, and DC-X made a normal liftoff. As speed built up, bits of skin began to fall off, and observers warned Pete Conrad that something was wrong. At about 1000ft, Conrad put DC-X into autoland abort mode. Existing upward velocity carried DC-X to about 2600ft before it began to descend. Descent was smooth and stable despite more bits of debris falling off. DC-X touched down on the gypsum sand -- autoland mode doesn't try for any particular landing site -- and momentarily disappeared in a dust cloud raised by the engines. Apart from the loss of a good bit of skin, damage looks minimal, and DC-X has enough performance margin to absorb the weight added by repairing rather than replacing affected components.
Telesat Canada reestablishes pointing control over Anik E2, despite loss of both primary and backup momentum wheels. TC says this is a unique accomplishment -- previous such failures have led to abandonment of the affected satellite -- and it has had inquiries from others interested in using the technology. Full commercial service is to be restored by August, and the estimated loss of useful life due to increased fuel consumption is about a year. The satellite is essentially being "flown" by ground computers now, with its own autonomous attitude-control system useless. The tricky part was that Anik has no on-board yaw sensor, since the defunct momentum wheels normally limited attitude changes on that axis; ground receivers are measuring shifts in Anik's antenna pattern to detect yaw changes.
Closeup image of Ida's moon shows large craters, indicating that it is probably as old as Ida itself, maybe a billion years. There is some surprise that it has stayed intact and in orbit that long; the theorists are not happy. Unfortunately, the moon's orbit cannot be determined very well, because the available observations are too close together to get a good measurement of the slow orbital motion. Orbital period is about a day, altitude is between 60 and a few hundred km, and the moon orbits roughly in Ida's equatorial plane. Its surface spectrum appears similar but not identical to Ida's, strengthening the theory that it is a fragment of the same original body but not a piece of Ida itself.
"It was blasphemy that made us free." | Henry Spencer -- Leon Wieseltler | henry@zoo.toronto.edu