ALOS-3

Last updated
Advanced Land Observing Satellite 3
NamesDaichi 3
Mission typeRemote sensing
Operator JAXA
Website www.jaxa.jp/projects/sat/alos3/index_j.html
Mission duration13 minutes and 55 seconds
Spacecraft properties
Manufacturer Mitsubishi Electric
Start of mission
Launch date7 March 2023 1:38:15 UTC [1]
Rocket H3-22S
Launch site Tanegashima LP2
Contractor Mitsubishi Heavy Industries
End of mission
DisposalDestroyed via FTS
Last contactMarch 7 2023 1:55 approximately
Decay dateMarch 7 2023
Orbital parameters
Reference system Geocentric
Regime Sun-synchronous
Instruments
OPS: OPtical Sensor
IRS: InfraRed Sensor [2]
  ALOS-2
ALOS-4  

Advanced Land Observing Satellite 3 (ALOS-3), also called Daichi 3, was a 3-ton Japanese satellite launched on March 7 2023 which failed to reach orbit. It was to succeed the optical sensor PRISM (Panchromatic Remote-sensing Instruments for Stereo Mapping) carried on the ALOS satellite, which operated from 2006 to 2011. The ALOS-2 satellite and the ALOS-4 satellite carry synthetic-aperture radar.

Contents

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 (FTS) to prevent risk of falling debris.

Spacecraft details

ALOS-3 had a mass of 3 tonnes, and 7 reaction wheels. [3]

Launch

ALOS-3 launched from Tanegashima, Japan by a H3 rocket on 7 March 2023. [1] Initially the launch was scheduled for 17 February but was aborted seconds before liftoff. [4]

Timeline

MET TimeDate(UTC)Event
JST UTC
X-22:00:0012:37:5503:37:556

March2023

1st Go/No-Go Decision
X-18:00:0016:37:5507:37:55Airframe movement (VAB > LP2)
X-12:00:0022:37:5514:37:552nd Go/No-Go Decision
X-00:57:0009:40:5500:40:557

March2023

3rd Go/No-Go Decision
X-00:10:0010:27:5501:27:55Final Go/No-Go Decision
X-00:08:0010:29:5501:29:55Start of Countdown
X-00:07:0010:30:5501:30:55Safety System ready
X-00:07:0010:30:5501:30:55Completion of Firing System Preparation
X-00:05:0010:32:5501:32:55Satellite System ready
X-00:04:0010:33:5501:33:55Automatic Countdown Sequence Start
X-00:04:0010:33:5501:33:55Start of Pressurization of each tank
X-00:02:5010:35:0501:35:05Power Switching (External to Internal)
X-00:00:5510:37:0001:37:00Completion of each tank Pressurization
X-00:00:5310:37:0201:37:02Frame deflector operation
X-00:00:3510:37:2001:37:20Water Curtain operation
X-00:00:1810:37:3701:37:37Flight mode on
X-00:00:1510:37:4001:37:40Single-Stage Thermal battery activation
X-00:00:1510:37:4001:37:40All System are ready
X-00:00:12.10:37:43.01:37:43Pyrotechnic Torch Ignition
X-00:00:0610:37:4901:37:49LE-9 Engine Start
X+00:00:0010:37:5501:37:55SRB-3 Engine Start & Liftoff
X+00:01:0610:39:0101:39:01Max Q
X+00:01:5610:39:5101:39:51SRB-3 Jettision
X+00:03:3210:41:2701:41:27Satellite Fairing Separation
X+00:04:5610:42:5101:42:51Main Engine Cutoff (MECO)
X+00:05:0410:42:5901:42:591st and 2nd Stage Separation
X+00:13:5510:51:5001:51:50Flight Interruption

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. [3] ALOS-3 carried OPS (OPtical Sensor), a multi-band optical camera which is an upgrade from the PRISM sensor. [2] OPS was capable of observing a 70-kilometer (43 mi) wide strip of land on Earth. [5] 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. [5]

Observation modes of ALOS-3

Source: [6]

Strip map observation mode

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(path of the orbit).

Stereoscopic observation mode

This mode acquired stereo-pair image of a certain point from two different directions(it acquired a three dimensional picture of some point on earth).

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(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(attitude refers to the orientation of the satellite in space, or how it's pointing, relative to a reference frame like the Earth or the Sun. It's essentially describing the satellite's "direction" or "pointing angle") of the satellite and changing the direction of observation(the direction where the satellite is observing).

See also

References

  1. 1 2 "Launch Time and Launch window of the First H3 Launch Vehicle (H3TF1)Carrying the Advanced Land Observing Satellite-3 "DAICHI-3" (ALOS-3)" (Press release). JAXA. March 5, 2023. Retrieved March 7, 2023.
  2. 1 2 "先進光学衛星「だいち3号」概要説明書" (PDF) (in Japanese). JAXA . Retrieved 2023-03-07.
  3. 1 2 JAXA, JAXA (February 17, 2023). "h3 presskit" (PDF). JAXA (in Japanese). pp. 57pp. Retrieved 2023-02-17.
  4. Clark, Stephen (February 17, 2023). "First launch of Japan's H3 rocket aborted moments before liftoff". Spaceflight Now. Retrieved 2023-03-07.
  5. 1 2 Akiyama, Ayano (February 16, 2023). "射点に登場 打上げを待つJAXA新型基幹ロケット「H3」と12年ぶりの光学地球観測衛星「だいち3号」". Yahoo! Japan (in Japanese). Retrieved 2023-03-07.
  6. "JAXA | Advanced Land Observing Satellite-3 "DAICHI-3" (ALOS-3)". JAXA | Japan Aerospace Exploration Agency. Retrieved 2025-07-16.