henry@utzoo.uucp (Henry Spencer) (09/20/88)
Arianespace completes technical negotiations with major contractors for a block order of 50 Ariane 4s, being done in hopes of driving costs down. Mitsubishi Electric to supply Japan's ETS-6 experimental satellite with a xenon-ion thruster, to replace conventional hydrazine station-keeping thrusters and increase the satellite's life. NASA braces itself to point the finger at Sept 29 for STS-26 launch. Revised shuttle manifest expected to show two fewer missions in 1989. Interest in small, lightweight satellites, and vehicles to launch them, grows. Potential uses are mostly classified, but major ones include scouting for Soviet mobile missiles, and tactical intelligence. John Pike of the Federation of American Scientists, after studying US spysat work, believes that DARPA's Lightsat project is primarily meant to provide a cheap replacement for the KH-12 for tactical intelligence. He says that US satellite-intelligence users split into three camps -- tactical commanders in the field, strategic planners, and arms-control verifiers -- with three different sets of requirements -- tactical real-time imaging of central Europe, quick imaging of the Soviet Union to find mobile strategic missiles, and ultra-high-resolution imaging of the Soviet Union in peacetime for missile counting -- and the three groups are going three separate ways in replacing the KH-12. The KH-12 was meant to serve all three groups, but this would create irreconcilable differences in priorities in a time of crisis. The final nail in the KH-12's coffin was the shuttle problems. So the CIA and friends are pushing for a big new satellite for arms control, the USAF wants a different big-satellite system for targeting Soviet mobile missiles for the B-2, and the tactical users are pushing Lightsat. In addition to DARPA's Lightsat, which is currently fighting to keep its budget, both the USN and the USAF recently started small-satellite projects. DARPA has awarded a contract to Defense Systems Inc to build a small constellation of experimental comsats; one or more of them will go up on the first Pegasus launch. DARPA has paid OSC+Hercules $6.3M for the first Pegasus launch, and has an option on another at the same price. These are firm fixed prices; "we're buying the services, not developing the vehicle", they say. DARPA *is* funding development of a small conventional launcher, with a major contract award due in Sept. DARPA says that it is not going to be a bulk customer for small launches on either launcher, since its job is to demonstrate technology for use by other military agencies. Discovery is pretty much ready to go. The shaft-travel problem in one of the pumps is now known to have been a false alarm (measurement error). The fix for the nitrogen-tetroxide leak is in place and is being pressure tested (succesfully, so far). The trace hydrogen leak in the orbiter/ET umbilical cavity is still a bit of a mystery, but it may have been there from the beginning -- this is the first time the cavity has been instrumented during an engine firing. The leading theory is that the seals in an auxiliary hydrogen line leak momentarily when they are suddenly chilled by the start of hydrogen flow. Amsat, the US amateur-radio satellite group, will deploy a US-built small satellite from Mir late next year. The satellite's job will be medical communications in remote areas; the ground side of it is a joint project of Soviet scientists and a Harvard group. The satellite will weigh less than 10 kg, and will go up on a Soyuz or Progress launch for deployment during an EVA. This is basically a demonstration mission; if more are built, they will go up in more orthodox ways on expendable boosters. The Soviets have agreed to do the deployment at no charge; approval for the project has come from very high levels. The satellite will need US export clearance, but it is hoped that this will not be a major problem. The US government is lukewarm about the whole thing because the Harvard group is on the wrong side of the political fence. NASA picks TRW to build AXAF (the Advanced X-ray Astrophysics Facility, the Hubble telescope's X-ray counterpart). NASA is trying to learn from its mistakes on Hubble, which had no single prime contractor (leading to coordination problems) and some extremely tight technical requirements, the result being a huge budget overrun. The AXAF approach is to build the high-risk parts first, before getting the bulk of the program rolling. AXAF is meant for shuttle launch. Charles Pellerin (NASA astrophysics boss) says he prefers the shuttle over expendables: he has no tight launch windows, he wants the most reliable launcher possible, and he values on-orbit servicing. Morton Thiokol settles out of court with Jane Smith, widow of Challenger's pilot. Reagan signs appropriations bill giving NASA $10.7G for FY89, $800M less than requested. The space station is well funded, but much of its funding is on hold until the next president okays it. Two Navy navsats launched from Vandenberg by Scout Aug 24. Big story on the Phobos missions and their landers: a fixed-base lander on each Phobos, and the "hopper" on Phobos 2. [Just as well it's on P2, since P1 is out of touch and believed defunct due to a command error that switched off its attitude-control system.] The lander missions are rather high-risk, because Phobos is rather irregular and its surface is not well known. For example, if the fixed lander is partly in shadow this will cut its life short, since it has little power to spare and there wasn't time to develop software for "smart" power management. Soviets study use of a satellite to deploy balloons into the middle of typhoons and hurricanes. [In itself unimportant, but it points out once again that the Soviets have what we lack: routine access to space. They can use space-based systems whenever it's convenient, not just when it's absolutely necessary.] Soviets studying Western suggestion to use Energia to put a multipurpose satellite network into Mars orbit for navigation and communications relay for landers, rovers, etc. Unfavorable comparisons made between Soviet willingness to listen to such notions and NASA's we-know-what's-best attitude. The Soviets had proposed a choice between heavyweight landers etc using Energia and medium-weight ones using Proton. The Westerners suggested staying with medium landers but using Energia's heavylift capability for a satellite network. The network's support services could make it possible for Japan or ESA (or even -- horrors! -- the US) to mount effective Mars missions using their smaller launchers. -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu