henry@zoo.toronto.edu (Henry Spencer) (03/06/91)
[A slightly light week, because AW&ST is preoccupied with other things; it shouldn't be hard to guess what. :-)] Igor Volk selected as commander of first manned Buran mission, still quite some distance in the future due to funding shortages. Ulysses's nutation [a wobble in its spin] has been stopped. It is thought to have been caused by uneven heating of the 7.5m axial boom, since it started after boom deployment and was successfully eliminated after the boom went completely into shadow. Otherwise Ulysses is doing fine. [Famous last words... but communications problems appear to have been solved after some tense moments.] The Vulcain oxyhydrogen engine for Ariane 5's first stage successfully completed its first test series in December, including brief intervals at full thrust. Full-duration full-power runs planned later this year. NASA decides that its own restructuring plans for the space station do not go far enough, and a more drastic study -- like that recommended by the Augustine commission -- is in order. NASA will form a "special task force" with DoD to examine possibilities for near-term heavy-lift booster development. Iraq is still getting data from US weather satellites, despite this being of some military use, both for weather planning and as a very crude form of satellite reconnaissance. NOAA has not been asked to do anything about this yet, partly because shutting the satellites down during their passes over the region would also deny weather images to friendly nations. Soviets reveal details of their "Regatta" satellite project, intended for near-Earth solar and magnetospheric science and using solar-sail technology for attitude control and stabilization. Basically it's a fairly ordinary satellite with a very large skirt sticking out nearly at right angles from the spaceward end, and several little rectangular "solar rudders" mounted on the rim of the skirt for control. The intent is to provide an unusually clean environment for experiments by avoiding attitude thruster firings. IKI [the Space Research Institute], the developers, are also offering it to the NOAA/electrical-utilities consortium that wants a solar-storm warning satellite. USAF missile-warning satellites are providing about 90s notice to Israel and Saudi Arabia of incoming Scud missiles. At least two of the satellites have been maneuvered into position scanning the Gulf. Generally accurate impact-zone predictions can be made, although precision is limited by the Scuds' short flight time. The warning satellites were not designed for use against short-range missiles; they were designed around the brighter exhaust plumes and longer flight times of strategic missiles. Earlier experience with monitoring of the Iran/Iraq war and superpower missile tests suggested a useful capability against tactical missiles, and the 90s warning is considered useful despite being undesirably short. About 12s after launch, both satellites will have seen the plume and stereo imaging for impact prediction is available. Controllers at the USAF station in Alice Springs are alerted by an automatic alarm and confirm that the launch is real. Meanwhile, the data goes by satellite to Cheyenne Mountain. Both Alice Springs and Cheyenne Mountain compare the data against known Scud properties and predict the impact zone. The satellites get several more looks at the plume as the missile climbs, permitting some refinement of impact predictions. Reasonably good impact location predictions are available about 120s after launch, but it takes another 3 minutes or so to get the information to the targets. This leaves 90-120s of warning time, enough to get people under cover [and alert Patriot batteries, although this is not being mentioned yet]. The USAF had planned to cancel an Advanced Warning System satellite project to save money, but that decision is likely to change. CIA and USAF are maneuvering strategic-reconnaissance satellites to give better battle-damage assessment coverage. Small mobile ground terminals are starting to give field commanders rapid access to spysat data, the first time this has been done on the battlefield. Extensive solar flare activity in December, producing some doubts about the guess that the current solar cycle passed its peak a while ago. If this keeps up, significant communications disruption is possible. USAF Communications Command says the possible effects on military communications are "too sensitive for comment". -- "But this *is* the simplified version | Henry Spencer @ U of Toronto Zoology for the general public." -S. Harris | henry@zoo.toronto.edu utzoo!henry