Finnish efforts to prepare for mission to twin asteroid Didymos

Researchers at the University of Helsinki are equipping a space mission with the purpose of studying a binary asteroid system, i.e. consisting of two bodies.

The spacecraft in the Hera mission, planned by European Space Agency ESA, will be equipped with two nanosatellites; the instruments carried by these nanosatellites will be making measurements on the surface of the asteroid. The nanosatellites are the size of milk cartons, and the Hera spacecraft itself is no larger than an ordinary desk.

This is the first time a binary asteroid system is the objective of a space mission. The nanosatellites will orbit the Didymos system and eventually land on the surface of the smaller asteroid. The advantage of the small nanosatellites is that they can transport the instruments closer to the surface of their target, so they are able to give a different perspective.

Finland specialises in mini-satellites

One of the two nanosatellites selected for the Hera mission is called APEX (Asteroid Prospection Explorer), and it was designed by a Finnish-Swedish-Czech-German consortium.

Academy Research Fellow Tomas Kohout from the University of Helsinki is Principal Investigator for the science in the APEX mission. The project manager of the group is Jan-Erik Wahnlund from Sweden. VTT, Aalto University, and Reaktor Space Lab are the other partners in the Finnish project funded by Business Finland.

Small satellites and hyperspectral imaging technologies are strategic development objectives of Business Finland, which funds national space programmes, and Finland has developed a unique know-how in these areas, even by international standards.

– Sending nanosatellites into deep space is a fairly new idea, but they seem to work, says Paolo Martino, lead engineer for the Hera space mission. A nanosatellite sent by NASA has landed on Mars last November, and the radio signals it has sent have been received on Earth.

APEX is designed to make spectral measurements of both bodies of the asteroid system. It will measure the spectrum of the sunlight reflected off Didymos, and by separating the colours it will study how the asteroids have changed with time and how their composition differs from each other. Further, APEX will measure magnetic fields to find out the composition and structure of the interior of the bodies.

The development work in Finland was launched by the Business Finland funding, and the funding for the Hera mission will be decided at a meeting at the ESA ministerial meeting at the end of 2019.

Link: European Space Agency, CubeSats joining Hera mission to asteroid system

More details:

Academy Research Fellow Tomas Kohout
Phone: +358 2941 51008

University Researcher Antti Penttilä
Phone: +358 2941 51227

Science communicator Riitta-Leena Inki
Phone: +358 50 448 5770
Twitter: @inkiriitta