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 | Hubble Space Telescope (HST) NASA/ESA · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | Fermi Gamma-ray Space Telescope NASA/DOE/international · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | |
|---|---|---|---|
| Agency | NASA/ESA | NASA | NASA/DOE/international |
| Status | Active | Retired | Active |
| Wavelength band | multi | optical | gamma-ray |
| Launch year | 1990 | 2009 – 2018 | 2008 |
| Orbit | Low Earth Orbit (LEO) ~547 km | Earth-trailing heliocentric orbit | Low Earth Orbit (LEO) ~550 km, 25.6° inclination |
| Mirror / aperture | 2.4 mas of [1] ↑ Largest | 1.4 mas of [1] | — |
| Mass | 11,110 kgas of [1] ↑ Heaviest | 1,052 kgas of [1] | 4,303 kgas of [1] |
| Wavelength range | 0.115–2.5 μm (UV, optical, near-IR) | 0.43–0.89 μm (optical) | 20 MeV – 300 GeV (LAT); 8 keV – 40 MeV (GBM) |
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| Summary | The most scientifically productive telescope ever built. Launched in 1990 and serviced five times by Space Shuttle crews, Hubble has logged over 1.6 million observations and contributed to more than 21,000 peer-reviewed publications. Its image of the Hubble Deep Field fundamentally changed our understanding of galaxy formation. | 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. | 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. |
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.