Planetary News ARCHIVE

April 16, 2003

All Set for MUSES-C to Soar 877,490 Names
Ready to Take Off for Destination on May 9

The Institute of Space and Astronautical Science, ISAS, has set the date for launching the MUSES-C spacecraft on May 9. The spacecraft will lift off between 1:00 p.m. and 2:00p.m from Kagoshima Space Center located in Kagoshima, the southernmost prefecture of mainland Japan. ISAS had been postponing the launch for about six months due to the broken O-ring of a regulator for spacecraft's altitude system.

MUSES-C is the world's first science mission to collect and bring back to Earth the surface samples of a minor planet, Asteroid 1998SF 36. The spacecraft will arrive at the asteroid in mid-summer 2005 as initially planned by following a shortcut trajectory on the way to Earth's swing-by scheduled for April 2004. The asteroid is a tiny body of about 700m x 300m, orbiting at a distance of approximately 300million km from the earth.

After a series of on-orbit scientific surveys, the spacecraft will move down close to the asteroid's surface to collect about a gram of sample material by means of a horn-like structure protruded from the bottom of spacecraft's main body. Collected samples will be stored within the onboard re-entry capsule. The insulated and cushioned re-entry capsule is 40cm in diameter and 25cm deep with a mass of 25kg.

Artist's concept of MUSES-C in a sample collecting phase

The target marker which carries 877,490 names to the "Little Star Prince" Courtesy: ISAS

MUSES-C will have finished all activities by the end of 2005. Then it will fire its engine to cruise back to Earth. The re-entry capsule will be detached from the spacecraft at a distance of about 400,000 kilometers from the earth and re-enter Earth's atmosphere in June 2007. Upon surviving a re-entry phase, the capsule will deploy a parachute to softland on the ground.

The spacecraft has a 1.5m x 1.5m x 1.2m box-shaped main body with launch mass of about 500kg. Due to long communication delay that prohibits ground-based real-time commanding, the spacecraft is equipped with highly autonomous function, enabling it to control itself by means of optical sensing as well as data processing. In a nutshell, MUSES-C is also the mission to verify major cutting-edge engineering technologies; electric propulsion by ion engines, autonomous navigation of a spacecraft, sampling of sample material under an asteroid's extremely low-gravity environment and re-entry into Earth's atmosphere.

Aboard the MUSES-C spacecraft are 877,490 names which will take off for a two-year-long journey in space. ISAS and The Planetary Society of Japan, TPS/J, conducted the public campaign, "Let's Fly to Meet Your Little Star Prince," asking people worldwide to send in their names to participate in the world's first sample return mission from an asteroid. Those names were etched on the aluminum foil sheet and enveloped inside the target marker, a softball-size ball to be released down on the surface of Asteroid 1998SF 36 as a guiding landmark for spacecraft's sample collecting.

The First Step toward Collecting Space Debris

The National Aerospace Laboratory of Japan announced that it successfully concluded an experiment to test software developed for identifying a small target in terms of space debris. The Laboratory has been studying to establish technology to collect and remove space debris. NAL is an agency specializing in designing and testing super-sonic aircraft and other advanced aeronautical technologies.

A small target, captured just after it was released from the satellite Courtesy: NAL/NASDA

The experiment was executed on March 14 by utilizing a micro-satellite, called u-Lab Sat developed by National Space Development Agency, NASDA. Aboard the satellite was a unit of a sensor composed of an image processing computer and a low-power-consuming color camera, an upgraded version of a digital camera with 350,000 pixels.

In the experiment, the small target, a disk of 10cm in diameter, was released from the satellite. The sensor successfully recognized the size, shape and direction of the small target which was moving away in strong sunlight with gleaming Earth in the background, and capture the pictures.

The NAL's spokesman told that the success is a small but important step toward achieving their goal.

Japanese Amateur Astronomers Discover Largest Number of New Worlds

Japan won the top position in the race to discover new celestial bodies last year. The National Astronomy Association of Japan announced that Japanese amateur astronomers discovered twelve new celestial bodies, including four comets, three stars and five supernovae. The number was largest-ever, exceeding that of nine recorded in 1996 and 1997.

The image of Comet Ikeya-Zhang, taken on March 14, 2003
Courtesy: The Arkansas Observatory

As for the number of new comets, Japan shared the top position with the United States. In the divisions of new stars and new supernovae, Japan was placed in the second and the third respectively.

Among those amateur astronomers was Kaoru Ikeya who discovered Comet Ikeya-Zhang in February 2002 for the first time in 36 years. The discovery brought the comet count he found up to six. Mr. Ikeya, one of the leading comet hunters of Japan, found Comet Ikeya in July 1965 which is enumerated as one of the brightest comets captured in the 20th century.