R. Lainé - Palermo October 2003 1

eXosat, Xmm, ATV, Xeus

Robert Lainé

Palermo, 14 October 2003

R. Lainé - Palermo October 2003 2

A long history together• The X-ray community is a

long standing and strong group of dedicated people

• Together we have developed impossible X-ray telescopes

• Together we have succeeded

• I have learnt a lot from you, Thank you for inviting me.

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The common factor

Pushing the limits of technology– EXOSAT = PSPC, MCP + first replicated X-ray

optics– XMM = CCDs + large area thin X-ray optics– ATV = as far as science is concerned ? ?– XEUS = will build on the above for better X-ray

astronomy

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What good can ATV bring to Xeus ?

• ATV is a 20 tons Automated Transfer Vehicle– Automatic rendezvous, refuelling, reboost– Automatic docking and de-docking capability– Operations via data relay satellite

• Xeus is made of 2 satellites – ‘mirrors’ satellite assembled in orbit– ‘detector’ satellite flying in formation with mirrors

• Lessons learnt from going to the Space Station

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ATV

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ATV technology for Xeus (1)

• Optical relative navigation and guidance– Centimetre accuracy at docking– Direct automatic assembly of ‘mirrors’ satellite in

any orbit– Relative station keeping for the ‘detector’ satellite

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ATV technology for Xeus (2)

• Docking system with capability for exchange of electric power, data, fuel– ‘mirrors’ satellite resources increases as

modules are added– Redundancy increases as modules are added– Any module can be disposed off and replaced

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Lesson learnt from ISS

• Large international cooperation is not easy– Specially difficult if unbalanced or hidden agendas

– Be prepared to continue alone even at lower pace

• Presence of men doubles + cost– Rule Applies within 10 km from men in space!

• Modular construction has to be useable from ‘day 2’ to meet end users expectation

• => For Xeus: keep it simple and focused on scientific values as reality always catches up …

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From ATV to Xeus

Docking hub

Satellite mirror (x 6)