TEMPUS: A facility for containerless electromagnetic processing onboard spacelab

The electromagnetic containerless processing facility TEMPUS was recently assigned for a flight on the IML-2 mission. In comparison to the TEMPUS facility already flown on a sounding rocket, several improvements had to be implemented. These are in particular related to: safety; resource management; and the possibility to process different samples with different requirements in one mission. The basic design of this facility as well as the expected processing capabilities are presented. Two operational aspects turned out to strongly influence the facility design: control of the sample motion (first experimental results indicate that crew or ground interaction will be necessary to minimize residual sample motions during processing); and exchange of RF-coils (during processing in vacuum, evaporated sample materials will condense at the cold surface and may force a coil exchange, when a critical thickness is exceeded).