henry@zoo.toronto.edu (Henry Spencer) (02/26/91)
[This is an unusually thin issue, almost as if they were saving space in case something particularly newsworthy happened just before press time... :-)] NASA astronauts experimenting with using very bright lighting to shift their circadian rhythms for night-shift operations in space. Simply going to bed earlier and earlier does not work very well because the body still sees the day-night cycle. Very bright lights in workplaces and living quarters imitate sunlight well enough to make the body shift gears. The night-shift crew for Astro-1 report better results from four days of bright lights before launch than from up to six weeks of shifting sleep schedules before earlier launch attempts. Intelsat governors authorize the Intelsat 7A series contract going to Space Systems / Loral. Hughes and Spar selected to supply two satellites for US/Canada mobile communications starting in the mid-1990s. USAF asks Martin Marietta design bureau, er oops I mean Martin Marietta Inc, for a preliminary cost estimate for 20 more Titan IVs. The current contract is for 41, plus 8 options that would be among the new 20. First (British-built) NATO 4 comsat launched by Delta Jan 7. It will not be operational until April or May, because the older NATO birds are still functioning well and there is no rush. USAF is trying to figure out exactly what went wrong with the first advanced Navstar. On Dec 12, a fuse blew in the solar-panel control circuitry, and the bird has lost its ability to automatically control the position of its solar panels. For the moment the panel position is being controlled from the ground, but this is considered unsatisfactory in the long run. The big question is, is this a generic problem? The advanced Navstars use essentially the same solar panels and control systems as the earlier ones, but... The next Navstar launch was listed for February, but it is now considered likely that there will be a delay of at least six months to make changes to the birds now in the pipeline. Northwest Airlines receives two Soviet-built Glonass receivers for experimental use in evaluating the Glonass navsat system. This is part of a joint Soviet-Honeywell project aimed at a receiver that can use both Navstar and Glonass. The Soviets admit reliability problems with the Glonass satellites, but say they are being solved. The Soviets have given no indication of intent to deliberately degrade Glonass accuracy the way the US does with the Navstars, a matter of concern to some users. Inmarsat is still thinking about how to use the Navstar/Glonass-like signal transmission capability planned for the Inmarsat 3 series. The overall plan is to provide supplementary coverage plus a broadcast of up-to-date information on which Navstar and Glonass satellites are functioning correctly [something neither system does on its own]. One question is who's going to monitor the satellites (and accept responsibility for the accuracy of the information) and who's going to pay for it. Inmarsat is hoping that regional consortia of civil- aviation agencies will do the work for navsats over their regions, and pay a modest fee for the privilege. Department of Slightly Unbelievable News: Consortium of US government agencies, headed by SDIO, plans to buy a Soviet Topaz 2 space reactor. Even more remarkable, the Soviets like the idea. The agencies (DoE, NASA, USAF, SDIO) hope to get the US space nuclear power program going again with a transfusion of Soviet technology [!!!]. [There must have been steam coming from the ears of the technology-transfer paranoids in the Pentagon when this was proposed.] The Topaz 2 will be bought through International Scientific Products, a California company which has negotiated an agreement with the relevant Soviet bureau. It will be a fully workable reactor minus the actual fuel; electric heaters will substitute for the fission fuel during testing and evaluation. The price for the reactor plus Soviet-supplied test facilities will be circa $10M. Delivery date is tentatively midsummer. The Soviets are insisting that the technology be restricted to "peaceful, commercial" purposes, and safeguards are being negotiated. Later sales for in-space use are considered a possibility. SDIO intends to fund a five-year program costing about $100M to study the Topaz 2. This will be the first part of a two-phase program to build a US version that meets US safety and reliability standards. SDIO says that US research on thermionic power conversion, considered a backup technology to the thermoelectric system being built for SP-100, has been on a "starvation budget" that will never produce working hardware. SP-100 itself is not in good shape, with $400M+ already spent and flight hardware still "many years" away. SP-100 is aimed at 100kW power output; the Soviets say that relatively minor changes could get 30-40kW out of Topaz 2. US space-reactor experts who have toured the Kurchatov Institute of Atomic Energy are very impressed. "We couldn't reproduce their development facilities for a billion dollars, and the Soviets employ 1000 people where we have twelve." They have developed a number of supporting technologies, e.g. a single-crystal molybdenum-niobium alloy for core parts (a sample of which is now being tested at NASA Lewis, with results so far confirming Soviet claims of superior properties). -- "But this *is* the simplified version | Henry Spencer @ U of Toronto Zoology for the general public." -S. Harris | henry@zoo.toronto.edu utzoo!henry