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Astrophysics Sounding Rocket Roadmap Panel

Sounding Rocket LCAS Mission CandidatesExtended X-ray Off-plane Spectrometer

(EXOS)

PI - Cash - CU Boulder• Goal

– Determine the composition, temperature and density of the local hot bubble

– Constrain models of charge exchange

• Objectives– Observe the soft (1/4 keV) x-ray background

during periods of low and high solar activity

• Significance – Increases our understanding of the true nature

of our local environment– Provides details into the relatively unknown

process of solar wind charge exchange

Experiment Innovations

Experiment Properties•Mass: 600 lbs.

•Length: 150 inches

•Width: 22 inches

•Onboard gas: Ar/CO2

Experiment Support Requests• TM (primary science)

– < 100 counts/sec → < 9 Mb/day

• Experiment Power– 5 Amps @ 28 Volts

• Pointing – Target acquisition within 5 arcmin

– Maintain pointing within 1 arcmin

• Duration–2 weeks for minimum success

–2 months for comprehensive success

Technological Advances:

•Off-plane gratings: being developed for use aboard IXO to achieve high spectral resolution in the soft x-ray bandpass

•GEM Detectors: a new, inexpensive, large format detector being studied for use aboard future space missions

•Wire grid collimators: An inexpensive and low mass method of collimating x-rays from extended sources.