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Space telescope data has underpinned 1.5 million+ scientific papers since 1990.
| Attribute | Chandra X-ray Observatory (CXO) NASA · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | ||
|---|---|---|---|
| Agency | NASA | NASA | NASA |
| Status | Active | In Development | Retired |
| Wavelength band | x-ray | infrared | optical |
| Launch year | 1999 | 2027 | 2009 – 2018 |
| Orbit | Highly elliptical (perigee 10,000 km / apogee 140,000 km) | Sun-Earth L2 point | Earth-trailing heliocentric orbit |
| Mirror / aperture | 1.2 mas of [1]Four pairs of nested grazing-incidence mirrors; effective aperture 0.04 m² | 2.4 mas of [1]Same aperture as Hubble but 100× wider field of view ↑ Largest | 1.4 mas of [1] |
| Mass | 4,800 kgas of [1]Including HRMA mirror assembly ↑ Heaviest | ~4,200 kgas of [1]Estimated; uses repurposed NRO mirror donated to NASA | 1,052 kgas of [1] |
| Wavelength range | 0.1–10 keV (soft to medium X-ray) | 0.48–2.3 μm (optical + NIR) | 0.43–0.89 μm (optical) |
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| Summary | NASA's flagship X-ray telescope and one of the Great Observatories. Chandra's angular resolution is 100× better than previous X-ray telescopes, enabling detailed imaging of supernovae remnants, galaxy clusters, and the region around supermassive black holes. Still operating after 25+ years despite being designed for a 5-year mission. | NASA's next flagship astronomy mission. Roman's 300-megapixel Wide Field Instrument (WFI) has Hubble-equivalent resolution but covers 0.28 square degrees per pointing — 100× wider than Hubble. Its 5-year primary mission will census dark matter, dark energy, and exoplanet populations across the Milky Way. | The mission that proved planets are abundant throughout the galaxy. Kepler monitored 150,000+ stars continuously for 4 years, finding that most stars host planets. A reaction wheel failure in 2013 ended the primary mission; the repurposed K2 mission (2014–2018) found 1,000+ additional planets before fuel ran out. |
All 9 major space telescopes with primary-source citations from NASA, ESA, STScI, and JPL. Pure URL state — bookmark or share the link and the comparison reproduces exactly.