Advanced Land Observation Satellite

Advanced Land Observing Satellite

ALOS spacecraft model

ALOS model exposed at Tokyo Museum of Modern Art
Mission type Earth observation
Operator JAXA
COSPAR ID 2006-002A
SATCAT № 28931
Mission duration 5 years, 3 months, 18 days
Spacecraft properties
Manufacturer NEC
Mitsubishi Electric
Launch mass 4,000 kg (8,800 lb)[1]
Dry mass 3,810 kg (8,400 lb)[1]
Dimensions 18.9 m × 27.4 m × 6.2 m (62 ft × 90 ft × 20 ft)
Power 7000 watts
Start of mission
Launch date 24 January 2006, 01:33 (2006-01-24UTC01:33Z) UTC[2]
Rocket H-IIA rocket
Launch site Tanegashima Space Center
End of mission
Disposal decommissioned
Deactivated 12 May 2011, 10:50
Orbital parameters
Reference system Geocentric
Regime Sun-synchronous
Semi-major axis 7,066 kilometres (4,391 mi)[3]
Perigee 693.8 kilometres (431.1 mi)[3]
Apogee 696.3 kilometres (432.7 mi)[3]
Inclination 98.0 degrees[3]
Period 98.5 minutes[3]
Epoch 27 January 2015, 09:27:58 UTC[3]
PRISM: Panchromatic Remote-sensing Instruments for Stereo Mapping, to measure precise land elevation
AVNIR-2: Advanced Visible and Near Infrared Radiometer type 2, which observes what covers land surfaces. 10-meter resolution at nadir
PALSAR: Phased Array type L-band Synthetic Aperture Radar, which enables day-and-night and all-weather land observation

Advanced Land Observing Satellite (ALOS), also called Daichi, is a 4-ton Japanese satellite launched in 2006. After five years of service, the satellite lost power and ceased communication with Earth, but remains in orbit.


ALOS was launched from Tanegashima, Japan, on 24 January 2006 by a H-IIA rocket. The launch had been delayed three times by weather and sensor problems.


The satellite contained three sensors that were used for cartography and disaster monitoring of Asia and the Pacific. JAXA initially hoped to be able to launch the successor to ALOS during 2011, but this plan did not materialize.

In 2008, it was announced that the images generated by ALOS were too blurry to be of any use for map making. Only 52 of 4,300 images of Japan could be updated based on data from ALOS.[4][5] Then, JAXA announced the problem was solved.[6]

ALOS was used to analyze several disaster sites.[7][8][9] Images of the devastated Japanese coast following the 2011 Tōhoku earthquake and tsunami were among the last major contributions from ALOS.[10][11]


Satellite orbital paths, as of October 2013.

In April 2011, the satellite was found to have switched itself into power-saving mode due to deterioration of its solar arrays.[10] Technicians could no longer confirm that any power was being generated. It was suggested that meteoroids may have struck ALOS, creating the anomaly which eventually led to its shutdown.[12]

On 12 May 2011, JAXA sent a command to the satellite to power down its batteries and declared it dead in orbit.[10][13]

See also


External links

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