ESA is continuing to develop a technology known as “lidar,” which stands for light detection and ranging, in order to improve accuracy for planetary missions.
Lidar works in a similar fashion to radar in that it can make distance measurements by bouncing light off a target object, except that lidar is performed with lasers. The shorter wavelength of the lasers allows for increased accuracy.
ESA’s Automated Transfer Vehicle already takes advantage of laser ranging when it is docking with the International Space Station, which means the distance between the two craft can be measured down a couple of centimetres.
3D imaging lidar is the next step forward, and this would be useful for Solar System missions as it could obtain a detailed 3D image of object such as a boulder.
A 3D imaging lidar would not be restricted by light conditions and would still function in dazzling sunlight or pitch black night.
Lidars already exist on Earth, but due to their large size they are unsuitable for work in space, which is why ESA are hoping to make them smaller and more powerful.
A 3D imaging lidar would have several important functions. It will be imperative for control of both planetary landers and rovers, and it will assist in the docking of craft in orbit around another planet. A sample return mission would have need of such technology.
It is hoped that a lidar will assist in the safe landing of ESA’s Lunar Lander in 2019.