The Development of High Definition, Self-aligning, Ultra-low Mass Space Telescopes - the SUPER-SHARP Engineering Model (SSEM)

点击翻译按钮获取中文摘要

The project is to develop a system that allows a space telescope to continuously align its primary mirror segments (and the secondary optics) to give the sharpest possible images. This system will allow the telescope to be small and lightweight for the rocket launch and then unfold into a much larger configuration for actual use. Continuous self-alignment is needed because the light-weight telescope structure will not be well aligned on initial deployment and not dimensionally stable at the required level (~100nm) over long times scales. This concept has enormous potential for space telescopes and launch packages of all sizes. It essentially means that for a given mission cost a telescope that is 5-10 times bigger can be launched compared to current telescopes. This translates in to 5 - 10 times better ground resolution for Earth Observation (EO). For example, a 3U CubeSat version can unfold into a 60cm telescope in orbit and provide 30-60cm resolution on the ground for EO. At the other end of the scale a version which uses the full capacity of an Ariane 6 offers an effective primary mirror span of 24m and could detect the spectroscopic signatures of life on exoplanets or give 70cm ground resolution for EO from geostationary orbit. EO is a large and rapidly expanding market and the technology proposed has great commercial potential because it makes high definition EO from space much more affordable. It also has great potential for astronomy by making space telescope projects organised by academic consortia financially feasible.The alignment system uses an on-board laser to accurately and continuously measure the positions of the primary mirror segments. This information is used to control the actuators for the mirror segments so that precise alignment is constantly maintained. The system is therefore immune to external disturbances such as the solar radiation and the solar wind. It also allows an unfolding, light-weight telescope structure to be used - inherent stability is no longer a requirement. The laser light is completely decoupled from the light coming from whatever is being viewed and viewing and alignment happen at the same time.