Japan ends land observing mission after satellite trouble
BY STEPHEN CLARK
Posted: May 12, 2011
Japanese space officials have given up on recovering the crippled Advanced Land Observing Satellite, declaring the mission over after the craft lost power last month, the Japan Aerospace Exploration Agency announced Thursday.
Satellite controllers continued attempting to recover ALOS since the anomaly last month, but JAXA announced Thursday the spacecraft's mission was completed.
"JAXA had been trying to communicate with the Advanced Land Observing Satellite for about three weeks after its power generation anomaly on April 22, but we decided to complete its operations by sending a command from the ground to halt its onboard transmitter and batteries," the agency said in a statement.
The command was issued at about 0150 GMT (10:50 a.m. Japan time) "as we found it was impossible to recover communication with the satellite," JAXA announced on its website.
Nicknamed Daichi, the Japanese word for land, ALOS launched aboard an H-2A rocket Jan. 24, 2006. The satellite unfurled a 72-foot-long solar panel, the largest single deployable array on any Japanese spacecraft. It was designed to produce at least 4 kilowatts of power at the end of the satellite's life.
The ALOS mission was supposed to last at least three years, and the craft narrowly achieved JAXA's stated goal of five years of operations.
Two other electrical system failures have ended major Japanese satellite observation missions in the last 15 years.
The ALOS anomaly signature is similar to the failure of the Advanced Earth Observing Satellite 2, or ADEOS 2, which lost electricity in October 2003 and was never heard from again.
ADEOS 2 replaced another satellite that succumbed to structural damage on its solar panel less than a year after it launched.
JAXA said engineers are still investigating the cause of the loss of ALOS.
In its five-year mission, ALOS mapped the Earth's surface, created three-dimensional terrain models, snapped thousands of pictures and observed the aftermath of earthquakes, volcanos, hurricanes and the March 11 tsunami that ravaged Japan.
ALOS imagery showed Japan's inundated northeast coastline in the days after the tsunami, and its radar instrument detected parts of the Japanese island of Honshu were displaced by up to 10 feet by the 9.0-magnitude earthquake that spawned the tsunami.
The spacecraft's three payloads included PRISM, a stereo mapping imager to derive 3D elevation maps with a resolution of 2.5 meters, or 8.2 feet. AVNIR 2, an advanced visible and near-infrared radiometer, collected data on land use and vegetation. A synthetic aperture radar named PALSAR bounced radar signals off Earth's surface for day-and-night observations in all weather conditions.