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 | Fermi Gamma-ray Space Telescope NASA/DOE/international · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | James Webb Space Telescope (JWST) NASA/ESA/CSA · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | |
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| Agency | NASA/DOE/international | NASA/ESA/CSA | NASA |
| Status | Active | Active | Retired |
| Wavelength band | gamma-ray | infrared | infrared |
| Launch year | 2008 | 2021 | 2003 – 2020 |
| Orbit | Low Earth Orbit (LEO) ~550 km, 25.6° inclination | Sun-Earth L2 point (~1.5 million km from Earth) | Earth-trailing heliocentric orbit |
| Mirror / aperture | — | 6.5 mas of [1]18 gold-coated beryllium hexagonal segments ↑ Largest | 0.85 mas of [1] |
| Mass | 4,303 kgas of [1] | 6,200 kgas of [1]Includes 2,447 kg for the primary mirror assembly ↑ Heaviest | 950 kgas of [1] |
| Wavelength range | 20 MeV – 300 GeV (LAT); 8 keV – 40 MeV (GBM) | 0.6–28.5 μm (optical red through mid-IR) | 3.6–160 μm (mid-to-far infrared) |
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| Summary | The most sensitive gamma-ray telescope ever flown. Fermi's Large Area Telescope (LAT) has detected over 6,000 gamma-ray sources — pulsars, blazars, gamma-ray bursts, and potentially dark matter annihilation signals. Its GBM instrument records ~300 gamma-ray bursts per year. | The most powerful space telescope ever launched. Operating at -233°C at the L2 point, JWST can observe the universe's first light from ~100 million years after the Big Bang. Its first full-color images, released July 2022, immediately set records for the most distant galaxies observed. | 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.