Ørsted Satellite

About the Ørsted Satellite

The Ørsted Satellite was the first Danish satellite launched in February 1999 to measure the Earth’s magnetic field.

The satellite was developed and built in collaboration with the technology company Terma (formerly Per Udsen Co. Aircraft Industry and CSI A/S) and several smaller companies.

The Ørsted satellite was equipped with two communication antennas and GPS navigation antennas for directional guidance, as well as an 8-meter-long boom that unfolded after launch, carrying two magnetometers and a star camera.

Project description

Once the satellite was released and stabilized, the antenna had to be unfolded and pointed precisely towards the ground stations to maintain radio contact with the satellite as it passed over Denmark. At GCM, we have developed and manufactured this mechanism.

It was necessary to control the unfolding of the antenna due to high centrifugal forces and to avoid damaging the 8m long antenna. Therefore, we developed a redundant and double-locked differential of Ø40 mm mounted with two Ø16 mm DC gear motors that controlled the speed of the differential and thus the speed of the unfolding.

The differential’s bearing, traction system, and motor functions were double-fault-proofed and made from ultra-lightweight titanium with a 0.3 mm Kevlar synthetic fiber pulling line that unfolds the antenna.

Despite the very limited space, low weight, and operation in total vacuum, the project was considered well executed.