Lockheed instrument meant to measure high-altitude winds before shuttle launches detects what appears to be a substantial layer of volcanic dust at 16-20km altitude, presumably from the Pinatubo eruption. This could partially counteract global warming effects from CO2, temporarily.
Georgia Tech investigation of optical components that spent six years in space on LDEF says some do suffer in the space environment; coatings of various kinds changed noticeably.
Political compromise permits NASA to spend $40M on Spacehab in FY1992, saving the project from disaster. (The original $25M would not have sufficed to keep Spacehab's loans paid.) There is still room for concern about the $50M needed next year. A similar compromise has eluded NASP, however, with NASA still forbidden to spend more than $5M.
The list of chores for the 1994 Hubble servicing mission is still growing. The low-voltage power supply on one side of the high-resolution spectrograph is misbehaving badly enough that a replacement has been requested. Alas, this looks like a 4-6hr job, which is too long, and there is a significant risk of contaminating optics. An alternative being investigated is just adding a cross-connection to let the bad side use the good side's electronics.
USAF reveals many details of Timberwind (without actually using that codename or admitting the connection). The objective is a particle-bed fission engine that would give about 75klbs of thrust at Isp of 1000s and thrust:weight ratio of 30:1. The particles, using a new coating to permit heat transfer without fission-product leakage, would be retained between porous frits to prevent them escaping. About $130M has been spent since 1987 with the objective of ground-testing a prototype in about eight years at a total cost of circa $800M. Congress is actually appropriating more than the USAF asked for in FY1992.
The USAF has ruled out using Timberwind at ground level, saying it is being considered only as an upper stage. The USAF missions for it have not been revealed. NASA is cautiously interested.
Russians say they have most of the technology needed to build a small nuclear-thermal rocket, thrust 5klbs, Isp 950s, T:W not much above 1:1.
The US State Dept is still obstructing the sale of a Topaz 2 space reactor to the US, but it is now thought that the problems have been sorted out and delivery will occur soon.
US nuclear types are concerned that the Topaz 2 may derail SP-100. There are already proposals to use T2 reactors for US space projects, although it is claimed to be technically inferior to (and it certainly is rather smaller than) SP-100. GE says that a mere $1G and five years would suffice to build a flight-test SP-100.
USAF pulls a classified experiment off Milstar, making room for a tactical communications package from the fourth satellite onward. (The first three will have ballast instead, since the new package will not be available soon enough.)
Scientific results from Hubble and Compton at the American Astronomical Society meeting. The gamma-ray people are still tearing their hair out trying to explain the distribution of gamma-ray burst sources, with new theories surfacing daily. Hubble has found blue globular clusters, derailing the standard theory which requires globulars to be very old (as most of them are). (This particular discovery is notable because it's a significant development, the view from space was crucial, it was made with the wide-field camera despite it being hard hit by the mirror botch, and it was made by accident during a study of a peculiar galaxy considered interesting for other reasons. The people who made it are waiting impatiently for the mirror fix, however, because that will make it much easier to measure the color and brightness of the blue clusters precisely. That would reveal whether they were all formed at about the same time, which is necessary for the current idea about their origin: that they were formed when two galaxies collided.) Hubble has made the most precise measurement yet of deuterium in space, expected to be a sensitive test of theories about the Big Bang. Galaxy M87 is now fairly definitely identified as having a black hole in its center, because there is something very small and very bright there (although measurements of star velocities there, crucial to confirmation, will probably have to wait for the mirror fix). Compton finds three immensely-powerful gamma-ray quasars. And the latest word on the gamma-ray bursts compounds the mystery about them: not only is their distribution in the sky wrong, so is their intensity distribution, with fewer low-intensity bursts than expected.
Painting of Galileo during Gaspra encounter, showing the fouled antenna.
Italy and Germany sort out a scuffle on Columbus project management: with the (German-led) free-flying module stalled by ESA budget wrangling but the (Italy-led) space-station lab still moving ahead, the German companies wanted to get a piece of the space-station lab. The result is a complex compromise.
FAA says flight tests reveal GPS lacks sufficient accuracy for precision instrument approaches, with vertical inaccuracy particularly unacceptable but horizontal results not good enough either. And differential GPS, although it helps, isn't enough to cure the problems: for Category III, the most severe blind-landing cases, its vertical accuracy is an order of magnitude short (plain GPS is two orders of magnitude short) and its horizontal accuracy also needs about a 60% improvement. Apart from accuracy, GPS also flunks on availability (mostly because of not enough satellites) and integrity (because there is no warning to pilots of accuracy deterioration). The integrity problem has three parts: detecting ailing satellites (which would require several more monitoring sites, or else having the satellites monitor each other), silencing them (a capability that the newer satellites already have), and alerting the pilots (best done by having enough satellites in the sky that a receiver can cross-check them against each other, although there are other ways).
Comsat and Morsviasputnik, in partnership, have established direct-dial telephone service (via Inmarsat) at major hotels in Moscow and Latvia, providing service far superior to that of the decrepit Russian phone network.
International Microgravity Lab mission aboard Discovery set to go, carrying European and Canadian payload specialists. Various experiments are planned in both life sciences and materials processing. Noteworthy among the life-sciences experiments is an investigation of free-fall back pain, fairly common in space for unknown reasons: a stereo camera will be used to photograph crew members' backs in hopes of determining exactly how the spine changes shape in free fall.
Rockwell layoffs imminent, as NASA moves shuttle maintenance to KSC and Columbia modifications are completed.
Magellan mapping to resume at a lower data rate after the high-rate modulator in the main data transmitter fails. The backup transmitter has a noise problem that makes it unusable at full rate, but careful juggling has made it usable at the lower fallback rate. The noise occurs at one frequency in the transmitter's output band, and that frequency drifts as transmitter temperature changes. By keeping the transmitter on constantly and taking other precautions, its temperature has been stabilized, and the fallback-rate transmission needs only part of the output band and has been adjusted to avoid the noisy part. The lower rate means mapping only about half as much surface area per orbit, but this is still sufficient for many purposes, and the problem doesn't affect the forthcoming gravity studies at all.
As yet uncertain is Magellan's funding in FY93. It actually has no money in the FY92 budget -- Congress did not insist on putting it back in after NASA didn't ask for it -- and is running on money reprogrammed from other projects. Although there is much yet to be done with gravity measurements, further radar studies including looking for volcanic activity, and the possibility of aerobraking into a lower orbit for much more detailed mapping, Magellan's case is weakened because it *has* pretty much completed its primary mission, the mapping of Venus's surface.
The X Window system is not layered, and | Henry Spencer @ U of Toronto Zoology it was not designed. -Shane P. McCarron | henry@zoo.toronto.edu utzoo!henry