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 | James Webb Space Telescope (JWST) NASA/ESA/CSA · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | Chandra X-ray Observatory (CXO) NASA · 🇺🇸 Active · Last updated 2026-06-01Trust: Agency-primaryⓘ Last verified Remove × | |
|---|---|---|---|
| Agency | NASA | NASA/ESA/CSA | NASA |
| Status | In Development | Active | Active |
| Wavelength band | infrared | infrared | x-ray |
| Launch year | 2027 | 2021 | 1999 |
| Orbit | Sun-Earth L2 point | Sun-Earth L2 point (~1.5 million km from Earth) | Highly elliptical (perigee 10,000 km / apogee 140,000 km) |
| Mirror / aperture | 2.4 mas of [1]Same aperture as Hubble but 100× wider field of view | 6.5 mas of [1]18 gold-coated beryllium hexagonal segments ↑ Largest | 1.2 mas of [1]Four pairs of nested grazing-incidence mirrors; effective aperture 0.04 m² |
| Mass | ~4,200 kgas of [1]Estimated; uses repurposed NRO mirror donated to NASA | 6,200 kgas of [1]Includes 2,447 kg for the primary mirror assembly ↑ Heaviest | 4,800 kgas of [1]Including HRMA mirror assembly |
| Wavelength range | 0.48–2.3 μm (optical + NIR) | 0.6–28.5 μm (optical red through mid-IR) | 0.1–10 keV (soft to medium X-ray) |
| Key missions |
|
|
|
| Summary | 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 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 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. |
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.