space news from Jan 23 AW&ST
Henry Spencer
merger without informing the State Dept., etc. etc., that it was talking
to a foreign government. However, obviously its biggest botch was never
mentioning this to Eosat, which is supposed to be running Landsat. "We
didn't know about it until we read it in Aviation Week", says Eosat's
president. NOAA says it was inappropriate for Eosat to be involved,
and denies that Spot Image was involved on the French side. Spot Image,
however, says it was kept fully informed and provided input. France
thinks any merged scheme should be based on the French organization,
with data sales separate from -- and not expected to repay -- the
space segment's funding. Spot is calling the proposed system "Super Spot".
Meanwhile, Eosat asks for emergency funding to keep Landsats 4 and 5
running, with NOAA saying "it's your problem", and threatening to turn
the satellites off if no money is found. [It was found, in the end,
although not by Eosat.]
British Aerospace completes new solar arrays for the Hubble telescope,
with about 10% more output than the original ones, easing simultaneous
use of multiple instruments.
Formation of the National Space Council gets off to a bureaucratic start,
with some of Quayle's staff, who know little about space, in charge of
interviewing potential Council staff.
Sen. Barbara Mikulski, new chairman of NASA's Senate Appropriations
subcommittee, declares strong support for space but warns NASA that the
budget situation is bad and the space station needs better reporting
of life-cycle costs and better justification.
USAF cannot meet its 1989 launch targets: 70% will be good performance.
Titan 4 and Delta 2 have both slipped due to hardware problems associated
with re-starting closed facilities. Among other complications, storage
space at the Cape is so short that the USAF is asking the USN for the
loan of some warehouse space belonging to the Trident program.
Slight slip in Discovery's launch schedule, and the discovery of the
bearing crack that ended up causing a much larger slip.
Atlantis's tiles are not as badly damaged as first thought. Insulation
falling from both the external tank and the nose of the right SRB is
believed to have been to blame for the damage.
Controversy over space reactors grows. Scientists say that the new
Soviet Topaz reactors have been emitting enough gamma rays to shut down
Solar Max's gamma-ray spectrometer about half the time, and Japan's
Ginga X-ray satellite has also been affected. There is concern about
effects on the Gamma Ray Observatory, slated for launch next year.
Unfortunately, politics have gotten mixed in, with SDIO alleging
(correctly) that some of the anti-orbital-reactor people are motivated
more by SDI's dependence on nuclear power sources than by concern over
scientific impact of reactors.
USAF and SDIO plan $8G order in 1990 for the Boost Surveillance and
Tracking System, which will double as the first operational part of
SDI and a maneuverable, hardened early-warning system to replace the
current Defense Satellite Program satellites. Critics say that DoD
has at least eight DSPs in inventory at the moment, enough to last
until the year 2000, and there is no need for a replacement.
NASA FY90 budget requests full funding for the space station plus new
starts for a pair of planetary missions: Cassini (essentially a
Galileo mission to Saturn) and CRAF (Comet Rendezvous, Asteroid Flyby).
CRAF would launch in 1995 on a Titan-4-Centaur, for a 1998 flyby of
asteroid Hamburga [really] and rendezvous with comet Kopff in Aug 2000.
Cassini would leave for Saturn in Aug 1996, on a similar booster, with
arrival in 2002 after one or two asteroid flybys. The planetary missions
are probably safe, but the station funding is anyone's guess.
Pentagon asks 50% budget hike for SDI in FY90; absolutely nobody seriously
expects them to get it. Critics say many of the tests SDI is planning
in the next two years are on the edge of violating the ABM Treaty. Also,
that 50% includes the thin edge of the wedge labelled "Phase 1 Deployment",
and Congress will *not* like that.
Galileo's thrusters are fixed and re-acceptance tests are about to start.
This is on the critical path for launching on time in October. About
three weeks of margin remain if nothing goes wrong. The changes will
reduce thruster efficiency about 5%, and may require eliminating one of
the two asteroid flybys or one of the Jovian-satellite encounters,
although there is hope for the full mission. JPL is very grateful that
they didn't launch in 1986; a workaround for the thruster problems would
probably not have been possible. The problem was discovered during
experiments with TVSat 1, Germany's TV-broadcast satellite that was
written off after one solar array failed to deploy: it was being used
as an operational testbed when its thrusters failed. When run nonstop,
the thrusters tend to overheat and destroy themselves. Worse, there
is a "hot start" problem when pulsing the thrusters, which can ruin
the thrusters in seconds. MBB is investigating why these problems
weren't found during development. Minor design differences between
Galileo and TVSat 1 may account for the hot-start problem not showing
up on TVSat 1 (or on the French TDF-1, which has the same thrusters,
now being operated in pulsed mode to avoid the overheating problem).
Small plumbing changes remove the hot-start problem, and changes in
mixture ratio and flow rate remove the overheating problem. However,
the latter set of changes reduce specific impulse from 280 to 270 s,
cutting about 10 kg off Galileo's fuel reserve. This is of some
concern because the fuel reserve for Galileo's full mission varied
from 50 kg to zero, depending on what assumptions were made about
things like navigational error and launch date. If Galileo gets off
on time (Oct 12) and errors are at the 50% level, reserve should be
30-40 kg. Eliminating the second asteroid flyby would save about
40 kg, and eliminating one satellite encounter would save about 15.
Soviets plan to fly their MMU tethered to Mir, even though it is capable
of independent flight. They say "maybe later -- not needed right now".
Aerospatiale ERA deployable structure failed to deploy from Mir on
command, and efforts to open it using ERA's vibration system failed.
Soviet controllers conferred over options and French mission personnel
tried to figure out why it had jammed, while Mir went out of tracking-
station range for a few minutes. When contact was reestablished, the
cosmonauts reported that ERA was deployed. Video images transmitted
later show Volkov kicking the ERA canister; he says it deployed a few
centimeters per kick. Cause of the deployment problem is not fully
understood, but moisture inside the unsealed canister may have frozen.
The problem lengthened the Volkov/Chretien EVA from 5 hours to 6.
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