henry@utzoo.uucp (Henry Spencer) (05/23/89)
US government braces itself for an expected application to launch a US commercial satellite on a Proton. [There have been informal inquiries, but nobody has actually taken the bull by the horns yet.] This will force the Bush Administration to state its formal policy on the matter. [The Reagan Administration's policy was "when Hell freezes over".] McDonnell Douglas and Aerojet General talk to Japanese about import of Japanese rocket technology for US launchers. The LE-7 large hydrogen engine meant for Japan's H-2 is of particular interest. [Rotsa ruck -- the last time this question was asked, about technology with rather less commercial potential, the answer was "forget it".] Cheney calls for termination of the Aerospace Plane, among other things, to help get the DoD budget under control. The White House does not like the idea, and is moving to reverse DoD's internal decision to provide zero funding for the project. DoD has decided that military applications are too far away to be worthwhile in the current budget climate. NASA provides some funding, but couldn't pick up the slack. Worse, a large chunk of the money has come from the contractors themselves, as a condition of participation in the program, and the White House is very concerned about what a cancellation would do to their willingness to bid on future contracts. The Japanese are already wooing some of them. DoD considers dumping plans to start full-scale development of the Boost Surveillance Tracking System in 1990, the first f-s-d for SDI. BSTS has been pushed as a logical successor to the current DSP early-warning satellites, but many think upgrades to the current DSPs would provide similar capabilities -- for the early-warning mission, not SDI -- at lower cost. Postponing BSTS would save money in the short term and postpone a battle with Congress over deployment of strategic defences. NASA picks Martin Marietta to build the Flight Telerobotic Servicer for the space station. [For those who don't know what this is, it's the $297M effort mandated by Congress to duplicate Canada's contribution to the space station. Such wonderful things happen in times of tight budgets.] Major coverage of impending Magellan launch, the first US planetary launch in over ten years. Magellan will make 1.5 orbits around the Sun before reaching Venus, a necessity because Galileo occupies the normal Venus launch window this year. Magellan has had its problems of late, with a broken nozzle on its IUS, a battery fire, the recent discovery of a wiring error that would have prevented firing of Magellan's Venus- orbit-injection motor, and various electronics problems. Atlantis has been stripped down for the Magellan launch, with only two small secondary payloads aboard, to give maximum yaw-steering performance to get Magellan into the right parking orbit. After launch, first the IUS will be checked out and then the Atlantis crew will spend over an hour shooting star sights and cross-checking the IUS's inertial systems against the orbiter's, for maximum guidance accuracy. Mission control will then transmit updated information on Atlantis's exact orbit, for transfer to the IUS's computers, before deployment. Somewhat unusually, Magellan's solar arrays will be deployed before the IUS firing; this is to keep them out of the way of IUS thruster firings, which could affect them in their stowed position. They have to be able to take the 10G (!) load of the Venus-orbit-injection firing anyway, so the 2G loads of the IUS firings aren't a structural problem. Arinc formally asks FCC for permission to build ground stations to provide satellite communications services for aircraft, using Inmarsat satellites. Arinc hopes to have Pacific service going by autumn, if the FCC approves. Arinc wants to lease satellite services directly from Inmarsat, rather than going through Comsat Corp, the US representative of Inmarsat. [28 April issue of Science has major coverage on the effects of Soviet orbiting reactors on gamma-ray astronomy satellites, including four technical papers. The story the technical papers tell isn't nearly as bad as media coverage would have it. The Solar Max gamma-ray instruments are not "blinded" by the reactors in any literal sense; it's just that the extra gamma output of the reactors fills up the rather limited data storage in the instruments. Also, the timings of reactor-caused gamma events are fairly predictable: Solar Max "sees" the reactors both directly and by their electron/positron emission (which produces gamma rays on arrival at Solar Max), but the direct gamma rays are "visible" only during close orbital passes and the particles travel along Earth's magnetic field in predictable paths. If the number and power output of orbiting reactors remain as they are now -- basically just the Soviet radarsat program -- they will be a nuisance rather than a disaster for gamma-ray astronomy. In fact, observations of the positron-produced gamma rays might be useful in atmospheric and magnetospheric studies, since the positrons follow magnetic field lines and are easily stopped by even traces of air -- the Solar Max data visibly shows the rise in high-altitude air density from rising solar activity in recent years. More and bigger reactors, especially in higher orbits, would create grave problems, however. The two Soviet tests of the Topaz reactor messed Solar Max up much more than the radarsats, because the Topazes were in higher orbits where reactor-emitted particles last much longer. The radarsats are in very low orbits to keep radar power requirements manageable (in fact, that's the whole reason why they use reactors -- solar panels would create too much air drag in such low orbits) and this minimizes their impact on astronomy.] -- Van Allen, adj: pertaining to | Henry Spencer at U of Toronto Zoology deadly hazards to spaceflight. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu