Sustainable utilisation of space

Space is a rising international trend, and commercial microsatellites are becoming increasingly common. However, many technical details are still unknown in this re-invasion of space. The technology sent into space these days is often quite old and heavy. The unnecessary mass costs more to launch and remains as junk in orbit, unless satellites are brought back down after the mission is completed. At the moment, there is already over 5000 metric tonnes of junk in orbit.

One of the problems is how to make equipment radiation tolerant.

- Radiation protection is a problem for European space travel and equipment, since we don't have most radiation-tolerant technology, and the technology imported from the US is embargoed with cost and exportation controls, says the director of the Centre of Excellence, Minna Palmroth, professor of computational space physics from the University of Helsinki.

The Finnish Academy recently made a decision on funding Centres of Excellence for the years 2018-2025, and the consortium led by Minna Palmroth is one of the appointed CoEs. The CoE will bring together the top specialists in space science and technology in Finland, and aims at revolutionising experimental space physics with the help of nano-satellites. At the same time it hopes to save the orbits from threatening space junk.

Radiation-tolerant micro-satellites on the rise

The new CoE is focusing on two key factors for the utilisation of space: radiation-tolerance for micro-satellites and containment of space debris.

There are two ways to increase radiation tolerance. Firstly, Professor Palmroth wants to know more about the radiation conditions. In addition, the CoE will develop intelligent technologies with software-based radiation protection using technologies developed for industrial safety and the Internet of Things.

- The old way to protect satellites from radiation in space is based on costly special components and the armouring of more delicate parts. We are developing an active but cost-effective way to protect from radiation, based on commercial components, says Professor Rami Vainio from the University of Turku. 

Cost-effective control of debris

For the containment of space junk, the CoE is developing plasma-brake technology, which will bring down a satellite in a cost-effective and safe way after it has finished its mission.

- We recently showed that a plasma-brake module of a few kilograms can bring down up to 800 kilograms of satellite from an elevation of 850 kilometres, says Pekka Janhunen, Research Director at the Finnish Meteorological Institute, who is developing the brake technology within the CoE.

The amount of junk is growing fast, and there are 13,000 near misses every week. This endangers the functons of the satellite, such as communications and navigation. The utilisation of orbits has to be reformed for them to remain useful for coming generations, says Minna Palmroth.

The first collaboration within the consortium is Aalto-1

The CoE team has cooperated for a long time and participated e.g. in the Aalto-1 student satellite project. The Aalto-1 satellite will be launched into orbit on Midsummer.

- Aalto-1 is mostly a student project, but it includes a radiation monitor built in Turku and a plasma-brake test by the Finnish Meteorological Institute, says Professor Jaan Praks from Aalto University, leader of the Aalto-1 project.

The partners in the Centre of Excellence on sustainable space science and technology from the University of Helsinki are Assistant Professor Emilia Kilpua, who studies the data on radiation, and Minna Palmroth, who carries out computer modelling. From Aalto University, the group led by Jaan Praks focuses on building satellites and radiation protection, and from the University of Turku, Professor Rami Vainio's group will study instrument development and new methods for protection. Research Director Pekka Janhunen's group from the Finnish Meteorological Institute will study plasma-brakes and electric sails.

More details:

Professor of computational space physics Minna Palmroth, University of Helsinki, minna.palmroth@helsinki.fi, http://blogs.helsinki.fi/palmroth/

Professor in experimental space physics, Rami Vainio, University of Turku, rami.vainio@utu.fi, https://users.utu.fi/ravainio/

Research Director Pekka Janhunen, Finnish Meteorological Institute, pekka.janhunen@fmi.fi, https://www.electric-sailing.fi/

Assistant Professor in space technology, Jaan Praks, Aalto University, jaan.praks@aalto.fi, http://people.aalto.fi/jaan.praks, http://spacecraft.aalto.fi

Assistant Professor in space physics, Emilia Kilpua, University of Helsinki, emilia.kilpua@helsinki.fi, http://blogs.helsinki.fi/ekilpua/