ALOS-3
Advanced Land Observing Satellite 3, also called Daichi 3, was a failed 3-ton Japanese satellite launched on March 7 2023 which failed to reach orbit. It was to succeed the optical sensor PRISM carried on the ALOS satellite, which operated from 2006 to 2011. The ALOS-2 satellite and the ALOS-4 satellite carry synthetic-aperture radar.
The satellite was launched as the payload on the first launch of the H3 rocket in March 2023. A failure of the second stage engine to ignite led to the rocket along with its payload ALOS-3 being destroyed by use of Flight Termination System to prevent risk of falling debris.
Spacecraft details
ALOS-3 had a mass of 3 tonnes, and 7 reaction wheels.
Launch
ALOS-3 launched from Tanegashima, Japan by a H3 rocket on 7 March 2023. Initially the launch was scheduled for 17 February but was aborted seconds before liftoff.
Mission and sensors
If it had been successfully launched, ALOS-3 would have been an Earth [observation satellite] and was to be used to monitor natural disasters as well as for cartography. ALOS-3 carried OPS, a multi-band optical camera which is an upgrade from the PRISM sensor. OPS was capable of observing a wide strip of land on Earth. In addition to the RGB and infrared band covered by the predecessor ALOS satellite, ALOS-3 has two additional bandwidths: coastal and red edge. Coastal allows observation underwater up to a depth of 30m, while red edge was to be used to monitor vegetation growth.
Observation modes of ALOS-3
Source:
This was the default observation mode of ALOS-3. It observed in an area which was 70 km in width and 4,000 km in length in the direction of the orbital path.
Stereoscopic observation mode
This mode acquired stereo-pair image of a certain point from two different directions.
Pointing observation mode
This mode would have been capable of observing any given point in Japan within 24 hours after receiving the request to use the 'point observation mode' using pointing function of the satellite to point up to 60 degrees in all directions against the satellite nadir.
Wide-area observation mode
This mode was capable of observing a wide-area of over 200km by 100km with the help of multiple scan observations during an orbital path of the satellite.
Changing direction observation mode
Continuously observe an area, even if it is not along the trajectory, by controlling the attitude of the satellite and changing the direction of observation.