Kayser-Threde presents first concept for Tether mission
Kayser-Threde presents first concept for Tether mission
Keywords: Kayser-Threde, Space travel
Six months after taking up work, the international TSE project team,spearheaded by Kayser-Threde, presented its first concept for sample return from the International Space Station (ISS) by means of a tether system. Recently the European Space Agency (ESA) gave the go ahead for the second phase of this study worth one million Euro. The carrier vehicle will be selected and the tether system will be defined in detail. Furthermore, tests of the most important components will be carried out.
The TSE (Tether System Experiment) mission is prepared by Kayser-Threde,Bristol Aerospace, RST, Delta-Utec and DASA-RI. The mission's aim is to send an orbiting capsule on a re-entry trajectory by means of a 35km long tether. A tether offers the enormous advantage of generating the momentum necessary for re-entry into the Earth's atmosphere without any propulsion. This means that mass (for carrying along fuel) and consequently money can be saved.
In June 1998 Kayser-Threde started a 18-month study in preparation of a test mission that is to demonstrate the tether system's feasibility. Phase A was finished after six months followed by the presentation of the first concept. The tether system consists of a spool with a deployer and control mechanism. The behaviour of the tether under weightlessness can be controlled by the latter. Emphasis was primarily put on the algorithms which autonomously control the deployment process until the moment the tether is cut. Connected to the end of the tether is a capsule whose ejection by means of a spring mechanism represents the beginning of the tether mission.
In contrast to the later operational use, the capsule used in the test mission is decaying during the re-entry phase. The whole system has a mass of approx. 110 kg (tether mass only 7.5 kg!) and is scheduled for launch in 2001 either with a Progress capsule or with the upper stage of a Rocket launcher.
