Japan’s Micro-Lab Sat mission

Japan’s Micro-Lab Sat mission

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The Micro-Lab Sat of Japan, which is in the post-mission phase, is now undertaking a new role in the “Moon tracking and satellite control experiment”. During the main mission period, the Micro-Lab Sat has carried out two experiments: one was to release a target from the satellite, acquire it with the onboard camera, and calculate its movement (relative location and attitude) using the onboard image processing computer (implemented mainly by the former NAL); and the other was to control the attitude of the Micro-Lab Sat to always acquire the released target in the center of a camera image (performed mainly by Tokyo University). Micro LabSat is currently flying in a polar orbit at the height of 800 km. Experiments with remote-testing technologies, using an installed camera, are now in progress.
During the post-mission phase, the onboard camera and computer were still functioning properly, but the two onboard targets had already been released for the planned mission. Another target was found, the Moon, which brightly reflected in the camera during experiments.

The “Moon tracking and satellite control experiment” aims to make the Moon an improvised moving target, calculate its location using the image processing computer, and control the satellite attitude to always acquire the Moon in the center of a camera image. On March 9, 2004, a functional verification test was carried out for the image processing system as a first step.

An image of the moon was taken by the satellite that was in spin control mode and the moon’s location and extracted images around the moon were calculated. The experiment with the Moon has time restrictions due to its waxing and waning (or the age of the Moon), and the next opportunity is in early April. The verified technologies used in the already performed experiments are closely related to future space activities or “the image feedback technology for location, attitude, and control that enables a space robot to safely and autonomously approach and acquire a malfunctioned and drifting satellite in space in order to refill propellant or repair it.”
Micro LabSat, weighing just 50 kg and with dimensions of about 70 cm x 50 cm, is a small satellite launched by the H-IIA F4 rocket from the Tanegashima Space Center (TNSC) on December 14, 2002. It is a unique in that it is “handmade” – fabricated mainly by young JAXA engineers. The project’s aim was to foster innovation among young engineers and enable them to learn technologies to design, assemble, and test satellites. Their team performed almost all of the development and operation of the satellite, and all of the installed software was developed by JAXA. Furthermore, with a view to being able to use commercial, off-the-shelf components in the future, JAXA has had devices of its own design manufactured by specialized private-sector companies. This project also serves as a test case for the production of small satellites more efficiently and at reduced cost.