Cryogenic Activities in the ESA Technology Research Programme - Past,Present and Future

Since 1975 ESA's TRP activities in the cryogenic domain have been steadily increasing. Before 1986 most of these activities were directed towards the development of cryogen technology. CRHESUS (CRyostat a HElium Superfluide pour Utilisation Spatiale) was a programme which helped develop superfluid helium technology within Europe. Since 1986 however a major step forward has been made in cryocooler technology, with an 80K cooler developed under TRP funding being recognised as the first viable space cryocooler. It is presently being sold by BAe (UK) as a commercial product. While keeping the basic design these cryocoolers are continuing to be developed down to lower temperatures. Coolers at 20K, 4K and 2.5K exist with 0.1K foreseen. Other cryogenic activities are discussed in the paper and the overall logic and direction of ESA's cryogenic TRP developments explained.