Powerful space laser locates space objects

On February 25th, 2020, the US company Northtrop Grumman succeeded in orbiting two commercial satellites together: At 02:15 local time, the MEV-1 (Mission Extension Vehicle-1) satellite successfully docked with the Intelsat-901 communications satellite - some 36,000 kilometers above the earth's surface. MEV-1 will be used to continue to supply the almost zero-emission satellite with fuel and thus extend its service life by at least five years. The aim of the mission is to counteract the steadily increasing number of discarded satellites and thus the increasing scrapping of space.

The MEV-1 supply satellite is equipped with sensor technology from the Thuringian space company Jena-Optronik GmbH. The integrated LIDAR (Light de-tection and ranging) laser system was developed in cooperation with scientists from Fraunhofer IOF. As part of the DLR project "LiQuaRD" ("3D-LIDAR Pre-Qualification for Rendezvous and Docking"), a powerful fiber laser was developed that is capable of detecting and locating dangerous space debris - from decommissioned satellites to fragments from space stations and the remains of space missions - with centimeter precision. The laser system was manufactured in two versions according to its different applications: The eye-safe laser operates with only one power stage (< 10 Mw) in order not to endanger the personnel stationed on the ISS. In addition, a further, more powerful version was designed, which can be switched in 3 stages (small/medium/large). This laser achieves an output of up to 400 mW. Up to now only eye-safe lasers have been used in space. With the new 3-stage laser system, for the first time there is a powerful laser in space, which reaches a range of several kilometres depending on the degree of reflection on the target surface.

In addition to the precise location of space objects, the data from the "space laser" can be used to prevent collisions with functioning satellites and space stations. The high range also ensures that some still open questions of space can be explored more closely.



The docking manoeuvre in progress

Satellite flying over the earth.
© Northrop Grumman
The docking took place in geosynchronous orbit.
Satellite shortly before docking with a second satellite.
© Northrop Grumman
MEV-1 took images as it came in to dock.
Docking maneuvers of two satellites.
© Northrop Grumman
Head docking camera of the approaching satellite.