Tokyo
EFFORTS to monitor the world鈥檚 changing climate from space have suffered
a major blow, with the loss of Japan鈥檚 Advanced Earth Observing Satellite
(ADEOS). Ground controllers with NASDA, the Japanese space agency, lost contact
with the satellite on 30 June, after its solar panels stopped
functioning.
At first, NASDA officials thought the satellite had been hit by a piece of
space junk. But no firm evidence of a collision has emerged, and it is still
unclear what caused the sudden failure.
Advertisement
ADEOS had a troubled start: it had to use a backup propulsion system to reach
its planned orbit after launch last year
(This Week, 31 August 1996, p 9). But
since then, the satellite had been a star performer.
ADEOS carried eight sensors鈥攆ive Japanese, two American and one
French鈥攖o monitor changes in the Earth鈥檚 oceans and atmosphere. These
included a Total Ozone Mapping Spectrometer, used to monitor the destruction of
stratospheric ozone by CFCs and other chemicals, and a radar scatterometer
called NSCAT, built by NASA, which measured sea surface winds
(In Brief, 30 November 1996, p 10).
NSCAT鈥檚 loss is being felt particularly keenly. 鈥淲e had begun using ocean
surface wind products, derived from NSCAT, in weather forecasting,鈥� says Helen
Wood, director of satellite data processing at the US National Oceanic and
Atmospheric Administration.
NASDA is planning to launch a successor, ADEOS-2, in 1999, which will carry
similar instruments. But climatologists really wanted the two to overlap.
鈥淧erhaps the largest loss is the discontinuity of the long-term data set,鈥� says
Jim Graf, NSCAT project manager at NASA鈥檚 Jet Propulsion Laboratory in Pasadena,
California.
A NASDA spokesman says that the failure of ADEOS should not delay the launch
of ADEOS-2. But he adds: 鈥淲e will need to investigate the accident and find out
why it happened, because the design of the solar panels on ADEOS-2 is the
蝉补尘别.鈥�