Letter from David Morrison, Scott Hubbard, and Jack Dyer at Ames, correcting earlier numbers on the total cost of the Pioneer Venus orbiter ($157M to launch, in then-year dollars, equalling $442M now). "There may be correlation between recent cost escalation and the fact that Ames has been assigned no major science flight missions since Pioneer."
SDIO orders Army to cancel most of McDD's contract for the GSTS (Ground- based Surveillance and Tracking System) pop-up sensor program, citing budget cuts and the fact that deployment delays in strategic defences eliminate the need for a pre-Brilliant-Eyes sensor system.
Delta launch Nov 22 follows the Nov 6 pad abort. Investigation of the abort concluded that an ignition-detection wire across the main nozzle did not burn through as quickly as expected when the main engine started to ignite, leading to a precautionary shutdown.
SDIO's MSTI seeker-test satellite finally flies on Scout, after a long string of postponements.
GE Aerospace sold to Martin Marietta. More of a merger than a purchase, actually, although the MM name and HQ location will persist. One open issue is what will happen to GE's SDI business: it is SDIO's overall engineering and integration contractor, and is forbidden to compete on SDI hardware contracts to avoid conflict of interest, while MM is a big hardware-contract holder.
USN is evaluating differential GPS as a navigation aid for Antarctic operations. GPS coverage nearer the poles is not as good as near the equator, and a joint GPS/Glonass receiver would be particularly welcome (assuming Glonass survives the turmoil in the CIS) because Glonass has better polar coverage.
Another recent GPS project is a tiny combined GPS receiver and radio transmitter/receiver for use by downed pilots, to avoid the need to broadcast a beacon signal that unfriendly forces can pick up too. The receiver's exact location would be transmitted to rescue forces in a brief encrypted message.
Another new navigation scheme to get around the deliberate noise in GPS: relative navigation. This one resembles differential GPS, but is meant for situations like aircraft landings where what matters is only the relative position between two receivers. Instead of broad- casting the difference between GPS and true positions, the airport receiver simply broadcasts its current GPS position, and the aircraft receiver subtracts that from its own GPS readings. An advantage is that the airport receiver's position does not need to be surveyed to establish its exact true position. A disadvantage is that keeping errors down requires making sure that the two receivers are using the same satellites. An advantage is that most classes of GPS failures affect both receivers equally, so there is only a momentary error in the relative position when something fails.
Stanford researchers report success in measuring aircraft attitude accurately using several GPS antennas at different places on the aircraft. With accurate knowledge of the antenna positions, accuracy of 0.1 degree was achieved with a 3m baseline, and even fairly steep maneuvers did not block the antennas badly enough to ruin attitude sensing. GPS attitude sensing is attractive because it has no problem with magnetic variations and no gradual drift like a gyro system. As a bonus, they discovered that they could measure wing flexing to within 1.4mm, with the potential of using such data to measure accelerations.
Orbital Sciences looking for strategic partners for its Orbcomm low-orbit digital-data comsat system. OSC plans to spin Orbcomm off into an independent company (with a majority interest held by OSC) in 1995.
OSC is also working on various other projects, including upgraded versions of Pegasus and Taurus and possible remote-sensing projects to follow on after SeaStar (now in construction for launch by 1993).
STS-53, with Discovery carrying the last big military shuttle payload, slated to go up Dec 2. This could be either a KH-11 or a White Cloud ocean-surveillance cluster. Also on board are some secondary payloads, such as the Oderacs payload that will eject several metal spheres for calibration of orbital-debris-sensing radars, an experiment on the shuttle glow, a laser-communication experiment, and an experimental camera incorporating a gyro system that can (in theory) record the exact location of the Earth-surface areas it is photographing.
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry