University of Bern’s Laser Altimeter BELA has been successfully tested during the last weeks and the last components will be delivered to ESA on 5 October. The first laser altimeter for inter-planetary flight to be built in Europe is part of the ESA BepiColombo mission to Mercury. Starting in 2024, it will provide data about the planet’s surface.
BELA (BepiColombo Laser Altimeter) has been developed by a Swiss-German-Spanish team led by the University of Bern. The instrument is designed to measure the topography of the planet Mercury, from onboard ESA’s space mission, BepiColombo, which is due to launch in April 2018. After an over 80 million kilometer journey, BepiColombo will go into orbit around Mercury in 2024.
Entering the third dimension
«Cameras give us a 2D picture of planet. BELA is designed to give us the third dimension», says Nicolas Thomas, co-Principal Investigator and the hardware leader of the project. BELA uses a high power laser to determine the distance from the spacecraft to the surface of Mercury. Short pulses from an infrared laser are fired at the planet.
The light is reflected from the planet’s surface back to a Swiss-designed ultra-lightweight telescope and the time of flight of the laser pulse is measured. This approach allows BELA to measure the topography of mercury to an accuracy of better than one meter from a distance of 1000 kilometers. Nicolas Thomas puts it more pictorially: «It is a bit like measuring the distance to the North face of the Eiger to one meter accuracy from Hamburg».
«Together with our industrial partners in Switzerland, Germany, and Spain, we have developed a really advanced piece of equipment», says Karsten Seiferlin, the BELA Project Manager. «On Earth, rangefinders are common these days, but putting one in space to range over distances of over 1000 kilometers and weighing under 14 kilograms is extremely challenging.»
The returned pulse is only a few hundred photons, requiring a sophisticated detection scheme. Constructing such a scheme was especially difficult because Mercury is the nearest planet to the Sun and so the team also had to worry about the temperatures which reach around 200 degrees Celsius on the spacecraft outer skin.
However, the huge power consumption of the laser in a very short time ended up being the biggest problem. «This produces noise on the electrical signals. We had to far exceed the requirements normally used for space instruments for grounding the electronics», Nicolas Thomas explains.
Inspired by Albert Einstein
«The electronics for BELA required six different organizations to work together. We ended up having to develop several, very new, technical solutions to make the experiment work», says Thomas. «But BELA will contribute a lot to understanding Mercury. Einstein’s studies of the motion of Mercury have been so important to the theory of general relativity. It is nice to think that with this instrument, the University of Bern, where he used to work, can play a leading role in studying this particular planet in detail.»
The BepiColombo mission comprises two spacecraft, the Mercury Planetary Orbiter (MPO) to be built by ESA and the Mercury Magnetospheric Orbiter (MMO) to be built by JAXA. The two spacecraft will fly to Mercury together in a coupled system until reaching Mercury orbit. The MMO will then be released into a 400 km x 19200 km orbit to allow detailed study of the magnetospheric interaction between the planet and the solar wind. The MPO will then descend to a 400 km x 1500 km orbit which is optimum for remote-sensing of the planet's surface.
Prof. Dr. Nicolas Thomas
Center for Space and Habitability, University of Bern
Phone +41 31 631 44 06 / email@example.com
Nathalie Matter | Universität Bern
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences