Flamsteed AS Dr Eric Dunsford Challenges of Space Science

Flamsteed Astronomy Society

‘Challenges’ in Space Science

by Dr Eric Dunford — March 5, 2007

Originally titled ‘Triumphs & Disasters in Space Science’ Eric Dunford thought that ‘Challenges...’ might be a better name for his talk. Eric was formerly Head of Research at Rutherford Appleton Labs (RAL) and drew on a wealth of personal experience. RAL’s impressive involvement in all kinds of space projects and technology seems to be one of Britain’s best kept secrets. Beats me why!

Eric began by explaining why doing science in space is difficult (expensive, can’t change it, hostile environment, size limits) and then went on to illustrate a series of ‘failure modes’ and miraculous escapes involving highly innovative and pioneering missions —

Financial/Political: Eric spent hundreds of hours along with the other members of the JET-X team (Joint European X-ray Telescope) working with the Soviets and Italians, only to see the entire innovative project shelved when the political climate shifted.

Pointing: The SOHO satellite (Solar & Heliospheric Observatory) was almost lost when a ground control error turned the satellite in the wrong direction and cut-off communication. Fortunately, communication was restored after 6 weeks and control was regained after a very anxious 4 months. SOHO has gone on to be a brilliant success.

Equipment: A highly specialised TV tube was developed for the IUE mission (International Ultraviolet Explorer). Only 36 tubes were made at a cost of $30,000 each. 32 failed under test leaving only 4 — the absolute minimum needed for the mission, but launch proceeded! IUE performed excellent for 18 years instead of the 2 years planned!

Environmental: The pioneering infrared telescope IRAS depended on cooling by liquid Helium which had a very limited lifetime as it boiled-off. After launch the team was horrified when the satellite insisted on automatic shutdown every orbit. Inspiration led to the fault being traced to a faulty bit in the sensor designed to turn the telescope away from the Sun, and new software was uploaded that solved the problem. IRAS ran superbly for 300 days and mapped 250,000 new astronomical infrared sources, including the first proto planetary disk around Vega.

Launch: The Cluster mission was a cornerstone of the ESA programme and planned to use the first Ariane 5 launch, free of charge, to orbit 4 satellites in one go, to monitor the Earth’s magnetosphere and surrounding environment for effects of the solar wind. In 1996 the Ariane 5 launch exploded — there is no free launch! The international team resolved to rebuild the mission which was successfully orbited in 2000 using two launches on the Russian Soyuz launcher. Cluster is still working very well.

See the web links on the left to read more about these missions.