SATLASX-ray · Space
ROSAT
Röntgensatellit
EndedEnded 12 February 1999, after starting 1 June 1990.
A German–US–UK X-ray observatory (1990–1999) with a Wolter-Igrazing-incidence opticsX-rays reflect only at angles of a degree or less, so X-ray telescopes use nested shells of paraboloid and hyperboloid mirrors seen almost edge-on (the Wolter-I design). More shells add effective area; figure accuracy sets the PSF. telescope, the PSPC and HRI detectors, and a Wide Field Camera for the extreme ultraviolet. Its 1990–91 survey was the first imaging all-sky surveyall-sky surveyObserving the entire celestial sphere to uniform depth, typically by scanning great circles or tiling fields. Produces catalogues and maps others select targets from. in soft X-rayshard X-raysThe higher-energy end of the X-ray band, conventionally above about 10 keV; soft X-rays are below about 2 keV. Hard X-rays penetrate absorbing gas, so they reveal obscured black holes. (0.1–2.4 keVelectronvoltThe energy an electron gains across 1 volt, 1.602 × 10⁻¹⁹ J. High-energy astronomy labels photons by energy: optical light is about 1.7–3.1 eV, X-rays 0.1–100 keV, gamma rays from about 100 keV to beyond 100 TeV. A 1 keV photon has wavelength 1.24 nm.), cataloguing more than 150,000 objects, and remained the reference until eROSITA.
- Operator
- DLR, NASA, UKSA
- Orbit
- Low Earth orbit
- Passband
- 0.1 keV – 2.4 keV
- Launch
- 1 June 1990
- End
- 12 February 1999
Passband
Sky coverage
An all-sky survey in its first six months (1990–91), deepest at the ecliptic poleseclipticThe plane of Earth's orbit projected on the sky; the Sun, Moon and planets stay close to it. Solar-system bodies and zodiacal light concentrate there, and spacecraft that must keep the Sun at a fixed angle often observe in strips perpendicular to it, so the ecliptic poles get the deepest coverage., then pointed observationspointed observationObserving chosen targets, usually selected by peer review in annual proposal cycles, as opposed to surveying the sky systematically. Gives depth on few objects; the total area observed stays small..
Archives
Sources
Verified 15 November 2026.