Delfi-C3 - ADCS ( Attitude Determination and Control Subsystem)

DELFI-C³ MISSION ELAPSED TIME

	DAYS				HOURS			MINUTES			SECONDS

Home

Delfi-C3 Satellite

Satellite Bus

ADCS

ADCS ( Attitude Determination and Control Subsystem)

The Attitude Determination and Control Subsystem (ADCS) essentially consists of two separate unconnected systems: an Attitude Determination System (ADS), which is not connected to the Attitude Control System (ACS).

ADS

The sun vector is determined by two angles alpha and beta, or at least by the incidence angle of the sun light on each solar panel.

We use for that:

The data given by the four photodiodes (one on each side of the satellite, on the solar panels,
The currents by each of the sensors of the AWSS.

The algorithm that we have to create must work without AWSS data since the device is part of the payload of the mission.

So as inputs of the algorithm we only have:

Currents from the photodiodes

We are constructing a logical algorithm which uses an optimization method.

ACS

The ACS is designed as a completely passive system, so it will never act on an input. The spacecraft will not have any active attitude control and is free to rotate about all its axes. However, in order to limit the rotation rates of the satellite to about two rotations per minute, magnetic hysteresis material will be employed to limit rotation rates using the Earth's magnetic field.

This document gives a detailed description about the ACS: ACS description

Newsflash

Delfi-C3 2 year anniversary

Today exactly 2 years ago Delfi-C3 was launched from India on a PSLV rocket at 3:53 AM UTC. Today we celebrate the fact that Delfi-C3 has been in orbit and fully operational for 2 continuous years or 10.809 orbits around the Earth. We would like to thank all the radio amateurs for their continued support and telemetry submission. Happy Birthday Delfi-C3!!

Delfi-C3 on Klokhuis

Delfi-C3 was featured on an episode of the Dutch children's program called Klokhuis (meaning 'apple core'). For more info and the episode itself please check our photo weblog.

In the meantime Delfi-C3 is approaching it's 1-year anniversary. The spacecraft is still performing well and returning science data through our own groundstation and the invaluable amateur radio data collection network.

Delfi-C3 back in science mode

On January 29th, after having been in orbit for 9 months and 1 day, Delfi-C3 has been put back in science mode. This decision was reached because of problems with the on-board transponder, which unfortunately prohibits proper operation of the transponder.