henry@utzoo.uucp (Henry Spencer) (10/02/89)
[Aviation Week & Space Technology subscription address is 1221 Ave. of the Americas, New York NY 10020 USA. Rates depend on whether you're "qualified" or not, which basically means whether you look at the ads for cruise missiles out of curiosity, or out of genuine commercial or military interest. Best write for a "qualification card" and try to get the cheap rate. US rate is $64 qualified, higher for unqualified. It's weekly, it's thicker than Time or Newsweek, and most of it has nothing to do with space, so consider whether the price is worth it to you.] There is talk of switching the last two shuttle missions this year, for fear that LDEF will be too low for successful retrieval in December. Unusually-high solar activity has increased atmospheric drag. LDEF has always been planned for retrieval, so it has no transmitters and losing it would mean complete loss of all its data. Current plans are that STS-33 in November will carry a USAF payload and STS-32 in December will retrieve LDEF. Given the tendency of launch dates to slip, using the November slot would give much more margin for successful LDEF retrieval. (The October launch is Galileo, whose launch window does not permit it to be rescheduled.) Current guess is that LDEF will stay up until about the end of January, but there is a lot of uncertainty. Truly would have to make the switch decision, although he would undoubtedly want USAF consent [since in a pinch the USAF has final say, by presidential order]. Almost certainly the switch of missions would mean switching orbiters too, since there is felt to be little change of having Columbia ready for November (indeed, having it ready for December is rather dicey). This means a decision would have to be made soon, so Discovery can be prepared for the retrieval. NASA appoints four special investigating groups, in addition to the experiment sponsors, to examine LDEF and its payloads after 5.5 years in space. The groups are meteoroids/debris, materials/coatings, systems (covering assorted support subsystems which weren't originally thought of as experiments), and radiation effects. Voyager Aug 15 course correction cancelled as unnecessary. Hughes signs with General Dynamics for commercial launch of Navy's first "UHF follow-on" comsat, and options for nine more launches to cover the nine later satellites in the series (so far the Navy has ordered one plus long-lead parts for the others). In principle some of these could go up on the shuttle, but in practice nobody considers that very likely. Columbia arrives back at KSC. GAO says USAF's new satellite control system is five years behind schedule and badly over budget because of USAF over-optimism about cost and schedule. The USAF started modernizing its ground-control facilities in 1981, and the update was supposed to be finished in 1988. Fourth attempt to light Hipparcos's apogee motor fails; one more will be tried [it failed] and then contigency plans for operation from the lower orbit will be pursued. Astrotech's payload processing facilities in Titusville are finally in the black, as shuttle activity resumes and more expendable users use commercial processing. Morsviazsputnik, the Soviet comsat administration [well, one of several actually, although the others are military] signs agreement with Inmarsat to provide technical data on the Glonass navsats. Inmarsat is studying the idea of a Clarke-orbit system to complement the Navstar and Glonass systems by providing running reports on the health and accuracy of the navsat systems (something neither system really has provisions for, and which aviation users in particular badly want). [From Flight International, 15 July:] Igor Volk, Soviet shuttle test pilot, says that Buran's on-board systems are still so crude that there was no possibility of flying it manned for its first flight, and much work will be needed before manned flights are practical. -- "Where is D.D. Harriman now, | Henry Spencer at U of Toronto Zoology when we really *need* him?" | uunet!attcan!utzoo!henry henry@zoo.toronto.edu