Two major new space missions with significant UK involvement have just been given the green light. With funding from the UK Space Agency, space scientists and industry partners in the UK are set to benefit from two European Space Agency (ESA) projects - Euclid and Solar Orbiter.

The missions are part of ESA's Cosmic Vision programme and were originally selected from more than 50 missions. They will be launched between 2017 and 2019. Solar Orbiter has now been officially adopted by ESA and will go forward immediately. Euclid has been selected but has to complete its study phase before it can be fully adopted in June 2012.

Dr David Williams, Chief Executive of the UK Space Agency, said: "With strong UK involvement in these ambitious projects, we are set to maintain our country's position as a leader in space science within Europe. These exciting missions are a prime example of collaboration between academia and the UK high-tech industry and will not only further our knowledge of space science but could help us unlock some of the greatest mysteries of our Universe."

Solar Orbiter is designed to travel closer to our own star than any previous Sun-watching mission. It will use an elliptical orbit to take it up to the Sun's higher latitudes to image, for the first time ever, the polar regions of our star. This special path will also allow Solar Orbiter to keep pace with the Sun's rotation so that it can track specific features below it for several weeks at a time.

As it travels around the Sun, bombarded by the harsh solar wind, Solar Orbiter will carry out in-depth studies of the connections between the Sun and interplanetary space that could provide major breakthroughs in our understanding of how the inner Solar System is driven by solar activity.

The unique design of the spacecraft will allow it to withstand the scorching heat on the surface facing the Sun and the cold of space on the opposite surface, which would always remain in shadow.

Professor Tim Horbury from Imperial College London said: "Solar Orbiter is Europe's mission to the Sun. It will give us our first good view of the Sun's polar regions and by travelling closer in than Mercury, it will give us a unique close-up view of the Sun's atmosphere and how it blows off into space, past the Earth and into the far solar system."

The UK is already playing a major role in the design of Solar Orbiter as EADS Astrium Limited - based in Stevenage, Hertfordshire - is leading the industrial study of the spacecraft under contract from ESA. Meanwhile, UK scientists (University College London, Imperial College London and STFC Rutherford Laboratory) are involved in four out of the ten instruments which have already been selected by ESA for deployment on the spacecraft to study the Sun.

Professor Chris Owen from UCL's Mullard Space Science Laboratory is the Principal Investigator for the Solar Wind Analyser while Dr Tim Horbury from Imperial College London is the Principal Investigator for the spacecraft's Magnetometer.

Euclid will address key questions relevant to fundamental physics and cosmology, namely the nature of the mysterious dark energy and dark matter. At the heart of Euclid is a massive optical digital camera - one of the largest such cameras put into space - and UK astronomers are leading efforts to design and build this new instrument.

"This camera can take pictures of the sky more than 100 times larger than Hubble can" comments Professor Mark Cropper of Mullard Space Science Lab, UCL, who is project scientist for the VIS camera.

"Each VIS frame is the equivalent of nearly 300 HDTV screens, and one arrives every 15 minutes. It will image half of the sky in six years, reaching out to the distant parts of the Universe."

Current theory suggests that dark energy and dark matter dominate the ordinary matter of stars and planets. In particular, dark energy has been proposed to explain the observation that - contrary to expectations - the expansion of the Universe seems to be faster now than it was billions of years ago.

Euclid and the VIS instrument will effectively look back in time approximately 10 billion years, covering the period over which dark energy seems to have accelerated the expansion of the Universe, and capture the light from distant galaxies to map their distribution and reveal the underlying 'dark' architecture of the cosmos.

Nine UK institutions (University College London, Durham, the Institute for Astronomy in Edinburgh, UK ATC, Oxford, Portsmouth, Hertfordshire, the Open University and the University of Cambridge) have involvement in Euclid's instrument development or data/processing/analysis activities.

In addition to this participation, Astrium UK is already involved in Euclid for the European scientific community and the UK company e2v will likely supply the CCD detectors for the VIS camera, meaning Euclid will be a substantial contract for many UK space companies.