Pick up to 4 telescopes to compare side-by-side. State lives in the URL — share the link and the comparison loads exactly as you left it.
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 | Retired | Retired |
| Wavelength band | x-ray | optical | infrared |
| Launch year | 1999 | 2009 – 2018 | 2003 – 2020 |
| Orbit | Highly elliptical (perigee 10,000 km / apogee 140,000 km) | Earth-trailing heliocentric orbit | Earth-trailing heliocentric orbit |
| Mirror / aperture | 1.2 mas of [1]Four pairs of nested grazing-incidence mirrors; effective aperture 0.04 m² | 1.4 mas of [1] ↑ Largest | 0.85 mas of [1] |
| Mass | 4,800 kgas of [1]Including HRMA mirror assembly ↑ Heaviest | 1,052 kgas of [1] | 950 kgas of [1] |
| Wavelength range | 0.1–10 keV (soft to medium X-ray) | 0.43–0.89 μm (optical) | 3.6–160 μm (mid-to-far infrared) |
| Key missions |
|
|
|
| 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. | 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. | NASA's infrared Great Observatory, operating 2003–2020. Best known for discovering the TRAPPIST-1 system of 7 Earth-sized planets, including 3 in the habitable zone (with ground telescopes). Ran out of cryogen in 2009 but continued 'warm mission' until retirement in January 2020. |
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.