April 20, 2011
There is an enormous dichotomy in the costs of access to space using various methods. NASA, ESA and other space agencies have a range of satellite programmes providing mission opportunities that deliver several years of data, but with price-tags of £100M and upwards. Satellite mission opportunities occur typically at a rate of only one every 2-3 years. Therefore, responses to mission calls usually result in massive oversubscription factors and many projects simply never happen.
Sub-orbital programmes through sounding rockets are more frequent and allow scientific data to be obtained for a few million pounds. However they only deliver a few minutes observing time above the atmosphere, restricting the scientific goals that can be achieved. For a typical astronomy payload, observations are limited to the brightest targets, usually one in any flight, and re-flight opportunities are quickly exhausted. Balloon programmes offer longer duration flights, up to a few days, but are only suitable for gamma-ray, visible light or infra-red studies. X-ray, extreme-UV and UV wavelength radiation emitted by astronomical objects does not penetrate far enough into the atmosphere to be detectable by instruments on balloons.
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