SUN 19 DEC 1999 KNOWLEDGE Space

WEEKLY WHINE

Missions worth making a fuss over

There are to be many missions in the next several years, more than ever before. Some are not expected to be useful, but a few will be remarkably interesting. Most will not have fusses made over them, but some should.

MARS EXPRESS
The European Space Agency's next series of planetary explorers is highlighted by Mars Express, which lifts off in 2003. Mars Express's objectives are partly intended to fill the void created by the loss of Russia's Mars 96 mission. It will image the surface from orbit and characterize the subsurface environment. Together, these tasks and others will help assemble the puzzle of Mars's ancient climate. In addition, Britain's Beagle 2 lander will make firsthand measurements of soil composition.

SPACE TECHNOLOGY 3
NASA's New Millennium Program has led the push for new technologies in space. Deep Space 1 successfully tested an ion drive and eleven other technologies. Deep Space 2's attempt at penetrating the Martian surface was not successful. Deep Space 3, now called Space Technology 3, would like to emulate Deep Space 1 rather than Deep Space 2. ST3 will be the first optical interferometer in space; two spacecraft will be launched in 2003. They will be connected via trusses for the first part of the mission. Then the trusses will separate, leaving the spacecraft to fly separately. ST3 will test their ability to maintain accurate separations between one another over baselines of up to 200 m.

SPACE INFRARED TELESCOPE FACILITY
The thermal infrared band of light contains a variety of sources, nearly a million discovered so far. Many are dust clouds at cool temperatures, which absorb the light from stars. But by looking in infrared wavelengths, we can see the clouds themselves, reducing the amount of guesswork needed when calculating absorption between stars and ourselves. In addition, objects such as brown dwarfs do not radiate in visible light. Instead, they give off only infrared. The Space Infrared Telescope Facility will be a space observatory that collects infrared light. The Infrared Astronomical Satellite [IRAS] offered a first glimpse at infrared astronomy, paving the way for SIRTF. Due for launch in 2001, it will help settle some of the questions raised by IRAS about the infrared emissions of stars, planets, nebulae, and galaxies.

Some missions are also worth making a fuss over, but not quite as much of a fuss as the above three. Here they are:

MARS SURVEYOR 2001
MARS NETWORK
PLUTO-KUIPER EXPRESS
SPACE INTERFEROMETRY MISSION
FULL-SKY ASTROMETRIC MAPPING EXPLORER
MESSENGER
ROSETTA
SMART-1
SELENE