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Pointing and Rotation Mechanism Assembly

One of KDA core competences is development and qualification of rotation and pointing mechanism with supportive drive electronics for satellites.

Our product philosophy is based on modular configurable systems with reuse of qualified components between different models to minimise the need of non-recurring activities to meet customer requirements.

The KARMA (Kongsberg Adaptiv Rotation Mechanism Assembly) is a family of producta comprising Solar Array Drive Mechanisms (SADM) for interplanetary missions, Geostationary (GEO) satellites, and Low Earth Orbiting (LEO) satellites and Antenna Pointing Mechanisms (APM) for LEO data down-link antennas.


The SADM has three prime functions, attaching the Solar Array Wing to the satellite, pointing the solar wings to expose it to the sun, and to transfer power from the solar wing to the satellite power system.

KDA's first SADM contract was in 1998 for the Rosetta ESA science mission. Recurring versions of the same mechanism were delivered to the Venus Express and Mars Express ESA science missions. These missions were launched in the period 2002-2004 and have been working flawlessly ever since and are still flying in 2013. The Rosetta SADM power transfer is 1kW per unit and uses an optical encoder as position sensor.

In 2009 Kongsberg won contracts for the Global Monitoring of Environment and Security (now Copernicus) satellites Sentinel-1 and Sentinel-3satellites. The SADM to Sentinel-1 and Sentinel-3 was based on the Rosetta design, but it is an updated and larger version that we call KARMA-4. KARMA-4 can be configured to the transfer 2-4 kW power per unit and uses currently a potentiometer to measure positions. It comes in two basic configuration, one with Twist Capsule (for limited rotation applications) and one with Slip Ring for continuous rotation. Both configurations completed their qualifications in medio 2013. The KARMA-4 is also contracted for the ExoMars and Solar Orbiter ESA science missions.

KDA is currently developing another version of KARMA-4 called the EuroKARMA covering the same power-range as the Sentinel versions. This is an ITAR free version with a KDA developed driveline. It maintaines the same interfaces to position sensor and power transfer unit as th KARMA-4.

An important and technically challenging contract is the development and qualification of a SADM including the drive electronics for a joint ESA and Jaxa (japanese space agency) called BepiColombo. BepiColombo is a mission for orbiting Merkur and the critical issue is the high temperatures (260 deg C) under which the SADM shall operate. The design is based on KARMA-4, but materials and solutions are customised for the extreme environments. The BepiColombo SADM capacity is 7,5 kW power transfer pr unit and shall be qualified in 2014.


Kongsberg won in beginning of 2014 a contract to develop a European Antenna Pointing Mechanism (APM) for Ka-band down-link antenna. The APM control the antenna in azimuth and elevation, and point the pencil beam toward the ground station that is actively tracked for the entire duration of the passage (typically 8-12 minutes), allowing high gain and high speed data transfer. The APM this application has been identified by ESA as critical new European technology, since no such European APM is presently available It is expected to be the product of choice for upcoming missions.