BepiColombo (BELA)

BepiColombo Laser Altimeter

BELA was successfully launched on board the BepiColombo mission on 20 October 2018. During the NECP (Near Earth Commissioning Phase) in November 2018, BELA was switched on for the first time in space showing excellent performance. BepiColombo will reach Mercury’s orbit in 2025 after several flybys of Earth, Venus and Mercury. 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 Mercury Planetary Orbiter, BELA will measure the surface topography of Mercury from altitudes up to 1000 kilometres. Ten laser pulses with 50 millijoule energy and a wavelength of 1064 nanometres will be 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 can obtain 3-D elevation models and determine the topography of the planet.

BELA also provides information on the 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 evolution. Mercury is the innermost planet – accordingly, the orbiter 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 the DLR Institute of Planetary Resarch, 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 scientific data.

German Aerospace Center (DLR)
Hauke Hußmann · E-Mail: hauke.hussmann@dlr.de · DLR.de/en