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Every Space Telescope, One Live Hub

The complete, continuously-updated directory of every operational space telescope, from Hubble in low Earth orbit to JWST and the brand-new Nancy Grace Roman Space Telescope at Sun-Earth L2. Live positions, current science targets, mission history and instrument details for every active observatory, plus the retired legends that reshaped astronomy.

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SUN EARTH L2 SUN-EARTH 1.5M km JWST halo orbit ROMAN CRUISE
Featured Trackers Active Fleet NICER on the ISS Deep Space L2 Comparison By Orbit Retired Legends FAQ
Last updated: · auto-refreshes on every visit
9
Active NASA Telescopes
+ 1 ESA at L2
9
Live Trackers Here
real-time positions
2
Missions at L2
3 when Roman arrives
10+
Retired Legends
Kepler, Spitzer, Herschel, WISE...
The Active NASA Fleet

Six More Space Telescopes Currently in Orbit

Beyond the three Great Observatories, NASA operates a fleet of highly specialised space telescopes. Every one has a live position tracker on Orbital Radar built on the same real-time tracking engine as our ISS Tracker.

Chandra X-ray Observatory
NASA · 1999
HEO · 63.5 h period · NORAD 25867
NASA's flagship X-ray telescope, the third Great Observatory. Sees black holes, supernova remnants and hot cosmic gas at arc-second resolution from an orbit reaching a third of the way to the Moon.
X-ray 1.2 m eq. mirror STS-93 deployed
LIVE TRACKER →
TESS
NASA · 2018
Lunar-resonant HEO · 13.7 d · NORAD 43435
The Transiting Exoplanet Survey Satellite. Hunting for planets around the brightest and nearest stars, 600+ confirmed exoplanets and rising. First and only spacecraft ever flown in a P/2 lunar-resonant orbit.
Optical 4× CCD cameras Full-sky survey
LIVE TRACKER →
SPHEREx
NASA · 2025
Sun-synchronous LEO · ~650 km · NORAD 63182
NASA's newest space telescope. All-sky spectral survey in 102 near-infrared bands, mapping the ingredients of the early universe and the biogenic molecules threaded through our Galaxy.
Near-IR Spectral mapping SpaceX Falcon 9
LIVE TRACKER →
Swift Observatory
NASA · 2004
LEO · ~335 km · NORAD 28485
The gamma-ray burst hunter, Swift slews to any burst on the sky within 90 seconds. Three instruments cover gamma-ray, X-ray and UV/optical. A commercial reboost mission has been contracted to raise its decaying orbit.
Gamma-ray X-ray UV / optical
LIVE TRACKER →
NuSTAR
NASA · 2012
LEO · ~550 km · NORAD 38358
The Nuclear Spectroscopic Telescope Array, the first space telescope to focus hard X-rays above 10 keV. Sees the highest-energy photons from black hole accretion, supernova remnants and the Sun's corona.
Hard X-ray 10-metre boom Pegasus XL
LIVE TRACKER →
IXPE
NASA · 2021
Equatorial LEO · ~545 km · NORAD 49954
The Imaging X-ray Polarimetry Explorer, the world's first X-ray polarimetry mission. Measures the direction of vibrating X-ray light waves to reveal the geometry of black holes, pulsars and magnetars.
X-ray polarimetry 3× telescope units ASI partnership
LIVE TRACKER →
Bolted to the Station

NICER, the X-ray Telescope on the ISS

Not every space telescope is a free-flyer. NICER is bolted to the ExPRESS Logistics Carrier 2 on the International Space Station, so its live position is the ISS's position, but its science story is entirely its own.

P6P4P3 S0 S3S4S6 DRAGON SOYUZ ELC-2 · S3 TRUSS NICER 56 X-ray optics INTERNATIONAL SPACE STATION ~420 km · 51.6° incl · 7.66 km/s
Payload · Attached to ISS · Live

NICER, the Neutron star Interior Composition Explorer

NASA · Launched 3 June 2017 · Mounted on ExPRESS Logistics Carrier 2
NICER is a 56-optic soft X-ray telescope bolted to the ISS truss. It gave astronomers the first precise measurement of a neutron star's radius, discovered surface hot-spot geometries that rewrote what we thought a pulsar looks like, and hosts SEXTANT, the technology demonstration that used pulsars as a natural GPS for deep space navigation. Because NICER rides the station, its live position is the ISS's position, updated every second on our ISS tracker.
Waveband
0.2, 12 keV
Mass
~370 kg
Detectors
56 co-aligned
Papers
500+
Track NICER's Position → NICER Glossary →
Deep Space at Sun-Earth L2

Europe's Neighbours at L2, Euclid & Gaia

JWST and (soon) Roman are not alone at Sun-Earth L2. ESA's Euclid surveys the dark universe from a nearby halo orbit, and Gaia mapped the galaxy from L2 for over a decade before its 2025 retirement. Both journeys are tracked on our Deep Space Tracker.

Euclid
ESA · 2023
Halo at Sun-Earth L2 · 1.5M km out
ESA's dark-universe surveyor mapping 1.5 billion galaxies across a third of the sky. Two instruments, a visible-light imager and a near-IR spectrograph, probe dark energy and dark matter.
Optical Near-IR Dark universe
DEEP SPACE →
Gaia
ESA · 2013
Worked at Sun-Earth L2 · retired 2025
Charting the positions, distances and motions of 1.8 billion stars in the Milky Way to microarcsecond precision, the most detailed 3D map of our Galaxy ever made. Science operations ended in January 2025 and the spacecraft was retired to a heliocentric orbit that March.
Optical astrometry 1.8B stars Retired 2025
DEEP SPACE →
The Numbers Side By Side

Every Space Telescope, Compared

A quick-reference comparison of every active NASA-led space telescope plus the two ESA missions at L2. Mirror sizes, orbit types, current status and the year each began science.

Telescope Wavelength Mirror Orbit Launched Status Tracker
HubbleOptical / UV2.4 mLEO 480 kmApr 1990● ActiveLive
JWSTInfrared6.5 m segmentedSun-Earth L2Dec 2021● ActiveLive
RomanWide-field IR2.4 mSun-Earth L2 (cruise)Aug 2026◐ CruiseLive
ChandraX-ray1.2 m equivalentHEO 14k×134k kmJul 1999● ActiveLive
TESSOptical4×10 cmLunar-resonantApr 2018● ActiveLive
SPHERExNear-IR20 cmSun-sync LEOMar 2025● ActiveLive
Swiftγ / X / UV30 cm UVOTLEO ~335 kmNov 2004● ActiveLive
NuSTARHard X-rayFocusing opticsLEO ~550 kmJun 2012● ActiveLive
IXPEX-ray polarimetry3× focusingEquatorial LEODec 2021● ActiveLive
NICERSoft X-ray56 detectorsMounted on ISSJun 2017● ActiveVia ISS
EuclidOptical / NIR1.2 mSun-Earth L2Jul 2023● ActiveDeep Space
GaiaOptical astrometry1.45×0.5 m ×2Sun-Earth L2Dec 2013○ Retired 2025Deep Space
KeplerOptical0.95 mHeliocentricMar 2009○ Retired 2018Retired
SpitzerMid-IR0.85 mHeliocentricAug 2003○ Retired 2020Retired
Grouped by Where They Sit

Space Telescopes by Orbit Type

Where an observatory lives determines what it can see, how long it lasts and how you can find it in the sky. See our Types of Orbits primer for the physics.

Low Earth Orbit
Highly Elliptical / Resonant
Sun-Earth L2 & Beyond
The Museum in the Sky

Retired Legends of Space Astronomy

Every space telescope has a service life measured in fuel, coolant or component drift. These missions are done, but the data still shapes today's astronomy.

Retired · 30 Oct 2018
Kepler
2009-2018 · Earth-trailing heliocentric
The exoplanet mission that changed astronomy. 9 years, 2,700+ confirmed planets, and the discovery that terrestrial-sized worlds are common. Now drifting behind Earth as a silent memorial in solar orbit.
 Retired · 30 Jan 2020
Spitzer Space Telescope
2003-2020 · Earth-trailing heliocentric
The fourth Great Observatory. Sixteen and a half years of infrared astronomy, from newborn stars in dust cocoons to the atmospheres of hot Jupiters. Ran out of thermal margin as it drifted away from Earth.
What Is a Space Telescope?

Why We Put Telescopes in Space

Every space telescope exists to solve one problem: Earth's atmosphere. Water vapour, carbon dioxide and ozone absorb most of the infrared, ultraviolet and X-ray light arriving from the universe, and turbulence in the air blurs whatever visible light does make it through. Get above the atmosphere and every waveband opens up.

The world's first space telescope was OAO-2, launched in 1968. Since then more than seventy space telescopes have flown. In September 2026 nine major NASA-led observatories are operating simultaneously, the largest fleet of astrophysics missions in history.

The Great Observatories

NASA's Great Observatories programme flew four flagship telescopes designed to cover the electromagnetic spectrum together: Hubble (visible / UV), the Compton Gamma-Ray Observatory (gamma-ray, deorbited 2000), Chandra (X-ray) and Spitzer (infrared). Three of the four have retired or been deorbited, but Hubble and Chandra are still returning science more than 25 years after launch.

JWST is often called the successor to Hubble but it is really the successor to Spitzer, an infrared observatory of unprecedented sensitivity, parked at Sun-Earth L2 to keep it cold. Roman is the successor to Hubble in a stricter sense: same 2.4-metre mirror class, wide-field imaging where Hubble did pinpoint work.

Why L2 Is the Prime Real Estate

Two telescopes currently orbit the Sun-Earth L2 point 1.5 million kilometres beyond Earth on the anti-Sun side, JWST and ESA's Euclid; Gaia worked there too until its 2025 retirement. Roman will make it three by early December 2026. L2 lets a telescope keep the Sun, Earth and Moon all on the same side of the sky, which means a single sunshield can point away from every warm source at once. That is essential for infrared telescopes that must run at a few tens of kelvin.

How to Read a Space Telescope's Orbit

Different missions live in dramatically different orbits. Hubble is in a shallow low Earth orbit so the Space Shuttle could service it. Chandra was placed in a highly elliptical orbit that carries it a third of the way to the Moon so it can spend most of its time above the Van Allen radiation belts. TESS uses a P/2 lunar-resonant orbit no other spacecraft has ever flown. Each choice trades servicing access, science return and stability. Our Types of Orbits primer walks through why.

People Also Ask

Space Telescopes, Frequently Asked

What telescopes are in space right now?
In September 2026 the following major space telescopes are operating: Hubble (LEO), JWST (Sun-Earth L2), Roman (cruising to L2, arrival early December 2026), Chandra X-ray Observatory (HEO), TESS (lunar-resonant HEO), SPHEREx (LEO), Swift (LEO), NuSTAR (LEO), IXPE (LEO), and NICER (mounted on the ISS). Beyond NASA, ESA operates Euclid at L2, where Gaia also worked until its 2025 retirement. Kepler and Spitzer are retired but still drift in heliocentric orbit.
Can you give me a list of space telescopes?
Currently active: Hubble, JWST, Roman (cruise), Chandra, TESS, SPHEREx, Swift, NuSTAR, IXPE, NICER and Euclid. Retired but historically important: Gaia, Kepler, Spitzer, Compton Gamma-Ray Observatory, Herschel, Planck, WISE, GALEX, IUE, COBE, OAO-2. Orbital Radar maintains live trackers for every active mission where an orbital position can be computed.
What are the four main telescopes in space?
The four flagship NASA missions of the Great Observatories programme were designed to cover the electromagnetic spectrum together: Hubble (visible and ultraviolet), the Compton Gamma-Ray Observatory (deorbited in 2000), Chandra (X-ray) and Spitzer (infrared). Two of the four are still operating in 2026: Hubble and Chandra. JWST and Roman are often referred to as the modern successors.
What is the most powerful space telescope?
By primary mirror area and infrared sensitivity, JWST is by a wide margin the most powerful space telescope ever flown: its 6.5-metre segmented mirror is more than seven times the collecting area of Hubble's 2.4-metre mirror. Roman matches Hubble's mirror size but has a wide-field camera 100 times bigger than Hubble's, so surveys the sky far faster. Chandra remains the sharpest X-ray telescope ever built, with arc-second resolution that no successor mission has yet exceeded.
How many space telescopes are currently operating?
Nine major NASA-led space telescopes are operating in September 2026, Hubble, JWST, Roman (cruising to L2), Chandra, TESS, SPHEREx, Swift, NuSTAR and IXPE, plus NICER on the ISS truss. Add Europe's Euclid at L2 and the active fleet stands eleven strong. Retired instruments including Kepler and Spitzer remain in heliocentric orbit but no longer return science.
What is the largest space telescope?
JWST holds the crown with a 6.5-metre segmented primary mirror. Hubble's monolithic 2.4-metre mirror was the largest for three decades. Roman uses a 2.4-metre mirror donated by the NRO but a wide-field detector 100 times bigger than Hubble's Wide Field Camera 3. Chandra's mirrors are grazing-incidence nested cylinders, not comparable in aperture terms.
What is the difference between Hubble and JWST?
Hubble is a 2.4-metre optical and near-ultraviolet telescope in a 480-km low Earth orbit, launched 1990 and still returning science. JWST is a 6.5-metre infrared telescope parked at Sun-Earth L2 1.5 million km away, launched Christmas 2021. Hubble sees visible light; JWST sees heat, which lets it look further back in cosmic time. They are complementary, not competitive.
Where is Hubble right now?
Hubble orbits Earth at about 478 km altitude, roughly 15.3 orbits per day at 7.6 km/s. Its position updates every second on our live Hubble Tracker with the current sub-satellite point, altitude, speed and next visible pass from your location.
Where is JWST right now?
JWST is in a halo orbit around the Sun-Earth L2 Lagrange point, 1.5 million kilometres from Earth in the anti-Sun direction. Our JWST Tracker shows its live distance, halo phase, current observing target from the live observing schedule and Deep Space Network contact status.
When will the Roman Space Telescope see first light?
Roman launched on 30 August 2026 aboard Falcon Heavy from LC-39A. It is currently mid-cruise to Sun-Earth L2 with insertion expected early December 2026. NASA has said first science images are expected early 2027 after commissioning.
Are Kepler and Spitzer still working?
No. Kepler ran out of fuel and was retired on 30 October 2018 after discovering more than 2,700 confirmed exoplanets. Spitzer was shut down on 30 January 2020 after 16 years. Both remain in Earth-trailing heliocentric orbits and can still be located, but neither returns science.
What does Chandra X-ray Observatory do?
Chandra is NASA's flagship X-ray telescope, launched by Space Shuttle Columbia in 1999. It images X-rays from black holes, supernova remnants, galaxy clusters and hot cosmic gas at arc-second resolution, 25 times better than any previous X-ray observatory. Its highly elliptical orbit takes it a third of the way to the Moon and back every 64 hours.
What is TESS looking for?
TESS, the Transiting Exoplanet Survey Satellite, hunts for planets around the brightest and nearest stars using the transit method. Launched in 2018, it has now confirmed more than 600 exoplanets and identified thousands of candidates in a lunar-resonant orbit that no other spacecraft has flown.
Which space telescopes are at L2?
Two active telescopes currently occupy halo orbits around Sun-Earth L2, JWST and ESA's Euclid dark-universe surveyor. ESA's Gaia star-mapper worked from L2 until it was retired to a heliocentric graveyard orbit in 2025. The Nancy Grace Roman Space Telescope will make three once it arrives in early December 2026. L2 is prized for infrared missions because the Sun, Earth and Moon all sit on one side of the sky.
How can I see space telescopes from Earth?
Hubble is the only NASA space telescope routinely visible to the naked eye, it passes overhead at roughly magnitude 2-3 when illuminated. Our Satellite Pass Predictions tool gives visible pass times for Hubble from your location. Chandra and Swift are theoretically visible in dark skies with binoculars near perigee. JWST, Roman and the other L2 missions are far too distant to see without a large telescope.
What new space telescopes are planned?
NASA's next flagship after Roman is the Habitable Worlds Observatory, currently in early design for the 2040s. ESA's PLATO exoplanet surveyor is due for launch in 2026-2027 and ARIEL in 2029. NASA-JAXA's LiteBIRD cosmic microwave background mission targets 2032. China plans its Xuntian survey telescope co-orbiting with Tiangong.
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Interplanetary missions and every spacecraft beyond Earth orbit.
Lagrange Points
Why so many telescopes park at Sun-Earth L2.
Types of Orbits
LEO to GEO and everything above, a primer.
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The agency running eight of these missions.
See Hubble Tonight
Visible pass times for Hubble from your location.