UK-built technology brings Solar Orbiter mission closer to launch.

Solar Orbiter Structural and Thermal Model (STM) during testing at Airbus Defence and Space. Credit UK Space Agency (Max Alexander).

A UK-based company Airbus Defence and Space the contract is building a Satellite STM which is thought to fly closer to the Sun than the planet Mercury, at a distance of only 0.28 Astronomical Units (42 million kilometers),in an orbit that takes it out of the ecliptic plane.From here, it can perform long-duration observations of the same region of the Sun’s surface, and have visibility of the Sun’s Polar Regions. It will be one of the closest approaches of the Sun by any spacecraft. To position itself in this challenging orbit, Solar Orbiter will make a complex series of gravitational-assist fly-bys past both Earth and Venus.

 At its closest approach, where sunlight is thirteen times more intense than it is for satellites orbiting the Earth, the spacecraft will have to survive intense thermal radiation and protect its instrument suite, while at the same time allowing those instruments to observe the Sun. To achieve this, the design includes a Heatshield and incorporates new high-temperature Solar Array technology. Integrated to the STM, the Heatshield is made of several protective layers of titanium, the outer of which is coated with a protective skin called SolarBlack. This has been developed specifically for Solar Orbiter. Slightly oversized beyond the spacecraft body, the Heatshield will ensure that the spacecraft remains in the shadow and that the radiated heat flux received is limited.

ESA awarded Airbus Defence and Space the contract to build Solar Orbiter in April 2012. It is the first mission in ESA’s Cosmic Vision programme to start its implementation phase. Solar Orbiter builds on hugely successful missions such as SoHO and Ulysses. Like those missions, it is a collaboration between ESA and NASA, including major scientific payloads from the United States, and the provision of a launch by NASA.

Design challenges include accommodating and resourcing a large suite of cutting-edge instruments and ensuring stringent magnetic and molecular cleanliness to enable the most sensitive scientific measurements to be made effectively.

The Sun is vital for life on Earth, but can also cause major problems for satellites and Earth based systems. The Sun releases bursts of high-energy particles (Coronal Mass Ejections), which can disrupt electrical power distribution systems, cause computers to crash, damage satellites and endanger astronauts. Solar Orbiter will provide scientific data to better understand the mechanisms on the Sun that cause these violent and disruptive outbursts.

source:
www.gov.uk