# ALOS-3

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.
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.

## 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.

### Timeline

| MET | Time | Time | Date(UTC) | Event |
| MET | JST | UTC | Date(UTC) | Event |
| X-22:00:00 | 12:37:55 | 03:37:55 | 6 March 2023 | 1st Go/No-Go Decision |
| X-18:00:00 | 16:37:55 | 07:37:55 | 6 March 2023 | Airframe movement (VAB > LP2) |
| X-12:00:00 | 22:37:55 | 14:37:55 | 6 March 2023 | 2nd Go/No-Go Decision |
| X-00:57:00 | 09:40:55 | 00:40:55 | 7 March 2023 | 3rd Go/No-Go Decision |
| X-00:10:00 | 10:27:55 | 01:27:55 | 7 March 2023 | Final Go/No-Go Decision |
| X-00:08:00 | 10:29:55 | 01:29:55 | 7 March 2023 | Start of Countdown |
| X-00:07:00 | 10:30:55 | 01:30:55 | 7 March 2023 | Safety System ready |
| X-00:07:00 | 10:30:55 | 01:30:55 | 7 March 2023 | Completion of Firing System Preparation |
| X-00:05:00 | 10:32:55 | 01:32:55 | 7 March 2023 | Satellite System ready |
| X-00:04:00 | 10:33:55 | 01:33:55 | 7 March 2023 | Automatic Countdown Sequence Start |
| X-00:04:00 | 10:33:55 | 01:33:55 | 7 March 2023 | Start of Pressurization of each tank |
| X-00:02:50 | 10:35:05 | 01:35:05 | 7 March 2023 | Power Switching (External to Internal) |
| X-00:00:55 | 10:37:00 | 01:37:00 | 7 March 2023 | Completion of each tank Pressurization |
| X-00:00:53 | 10:37:02 | 01:37:02 | 7 March 2023 | Frame deflector operation |
| X-00:00:35 | 10:37:20 | 01:37:20 | 7 March 2023 | Water Curtain operation |
| X-00:00:18 | 10:37:37 | 01:37:37 | 7 March 2023 | Flight mode on |
| X-00:00:15 | 10:37:40 | 01:37:40 | 7 March 2023 | Single-Stage Thermal battery activation |
| X-00:00:15 | 10:37:40 | 01:37:40 | 7 March 2023 | All System are ready |
| X-00:00:12. | 10:37:43. | 01:37:43 | 7 March 2023 | Pyrotechnic Torch Ignition |
| X-00:00:06 | 10:37:49 | 01:37:49 | 7 March 2023 | LE-9 Engine Start |
| X+00:00:00 | 10:37:55 | 01:37:55 | 7 March 2023 | SRB-3 Engine Start & Liftoff |
| X+00:01:06 | 10:39:01 | 01:39:01 | 7 March 2023 | Max Q |
| X+00:01:56 | 10:39:51 | 01:39:51 | 7 March 2023 | SRB-3 Jettision |
| X+00:03:32 | 10:41:27 | 01:41:27 | 7 March 2023 | Satellite Fairing Separation |
| X+00:04:56 | 10:42:51 | 01:42:51 | 7 March 2023 | Main Engine Cutoff (MECO) |
| X+00:05:04 | 10:42:59 | 01:42:59 | 7 March 2023 | 1st and 2nd Stage Separation |
| X+00:13:55 | 10:51:50 | 01:51:50 | 7 March 2023 | Flight 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. ALOS-3 carried OPS (OPtical Sensor), a multi-band optical camera which is an upgrade from the PRISM sensor. OPS was capable of observing a 70-kilometer (43 mi) 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.