BepiColombo Laser Altimeter
The BELA laser altimeter will be launched in October 2018 on board the European-Japanese BepiColombo mission to Mercury. BepiColombo will reach Mercury’s orbit in 2025 after several flybys of Earth, Venus and Mars. The mission is a joint project between ESA and JAXA and consists of a propulsion module and two orbiters: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). The mission carries a total of 16 experiments. Upon arrival of the MPO, BELA will use a laser to measure the surface of Mercury from altitudes up to 1000 kilometres. Ten laser pulses with 50 millijoule energy and a wavelength of 1064 nanometres are emitted per second in the direction of Mercury and detected a few milliseconds later by the instrument’s receiver. From the travel-time duration of the laser pulses, the scientists are able to obtain accurate information about the shape and surface of Mercury. Based on this data, the researchers determine the elevation model and topography of the planet.
BELA also provides information on rotation, tides and roughness of the surface. These parameters are important in order to calculate an exact surface model. In addition, from the determination of the state of rotation and the tides, conclusions can be drawn on the planet’s internal structure and development. Mercury is the innermost planet – accordingly, the MPO will be exposed to temperatures of up to 350 degrees Celsius during the scheduled one-year mission. In addition to comprehensive thermal and light protection on the instrument, eye-catching protection devices (baffles) prevent sunlight or scattered light from reaching the detector and affecting measurements. BELA was developed and built by DLR in collaboration with the University of Bern, the Max Planck Institute for Solar System Research, the Instituto de Astrofísica de Andalucia and industry. The DLR Institute of Planetary Research is responsible for operations and the evaluation of the scientifc data.
German Aerospace Center (DLR)
Ulrich Köhler · E-Mail: ulrich.koehler@dlr.de · DLR.de/en
