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Frequently asked questions about space
All the answers to your questions about space exploration, missions, spacecraft and discoveries — aggregated from the TRACKER-1 catalog.
General questions
What is TRACKER-1?
TRACKER-1 is a space exploration tracker: it follows active space telescopes, probes, rovers, stations and landers that observe or explore space. The catalog currently tracks 31 missions.
How many space missions does TRACKER-1 track?
TRACKER-1 tracks 31 active or in-transit space missions, from the Sun to interstellar space.
Are the data up to date?
Yes: the catalog is curated and enriched with real-time feeds (news, discoveries, photos from NASA and ESA). Each mission page links to primary sources.
Can I cite TRACKER-1?
Yes, mention the site and the relevant mission. For scientific facts, cite the primary sources listed (NASA, ESA, publications).
What is the difference between a telescope and a probe?
A space telescope observes from afar (Hubble, Webb), while a space probe travels to its target to study it up close (Voyager, Parker Solar Probe).
How many scientists are documented in the catalog?
76 scientists are associated with catalog missions, including principal investigators, project scientists and researchers.
By exploration target
Which spacecraft explore Moon?
4 mission(s) in the catalog study Moon: Europa Clipper, JUICE, Chandrayaan-3, TESS. See the Moon topic for details.
→ View topicWhich spacecraft explore Asteroids & comets?
4 mission(s) in the catalog study Asteroids & comets: Hera, Psyche, OSIRIS-APEX, New Horizons. See the Asteroids & comets topic for details.
→ View topicWhich spacecraft explore Deep universe?
4 mission(s) in the catalog study Deep universe: Euclid, James Webb, Gaia, Chandra X-ray. See the Deep universe topic for details.
→ View topicWhich spacecraft explore Sun?
4 mission(s) in the catalog study Sun: Aditya-L1, Solar Orbiter, Parker Solar Probe, SOHO. See the Sun topic for details.
→ View topicWhich spacecraft explore Jupiter & moons?
2 mission(s) in the catalog study Jupiter & moons: Lucy, Juno. See the Jupiter & moons topic for details.
→ View topicWhich spacecraft explore Earth & orbit?
3 mission(s) in the catalog study Earth & orbit: Tiangong, Station ISS, Hubble. See the Earth & orbit topic for details.
→ View topicWhich spacecraft explore Mars?
6 mission(s) in the catalog study Mars: Perseverance, Tianwen-1 / Zhurong, MAVEN, Curiosity, Mars Reconnaissance Orbiter, Mars Express. See the Mars topic for details.
→ View topicWhich spacecraft explore Mercury & Venus?
2 mission(s) in the catalog study Mercury & Venus: BepiColombo, Akatsuki. See the Mercury & Venus topic for details.
→ View topicWhich spacecraft explore Interstellar space?
2 mission(s) in the catalog study Interstellar space: Voyager 1, Voyager 2. See the Interstellar space topic for details.
→ View topicBy spacecraft type
Which space telescopes are tracked?
6 space telescopes tracked: Euclid, James Webb, TESS, Gaia, Chandra X-ray, Hubble.
→ View topicWhich space probes are tracked?
20 space probes tracked: Europa Clipper, Hera, JUICE, Psyche, Aditya-L1, Lucy, Solar Orbiter, Tianwen-1 / Zhurong, BepiColombo, Parker Solar Probe, OSIRIS-APEX, MAVEN, Juno, Akatsuki, New Horizons, Mars Reconnaissance Orbiter, Mars Express, SOHO, Voyager 1, Voyager 2.
→ View topicBy agency
Which missions does CNSA participate in?
CNSA participates in 2 mission(s) in the catalog: Tiangong, Tianwen-1 / Zhurong.
→ View topicWhich missions does CSA participate in?
CSA participates in 2 mission(s) in the catalog: James Webb, Station ISS.
→ View topicWhich missions does ESA participate in?
ESA participates in 11 mission(s) in the catalog: Hera, JUICE, Euclid, James Webb, Solar Orbiter, BepiColombo, Gaia, Mars Express, Station ISS, SOHO, Hubble.
→ View topicWhich missions does ISRO participate in?
ISRO participates in 2 mission(s) in the catalog: Aditya-L1, Chandrayaan-3.
→ View topicWhich missions does JAXA participate in?
JAXA participates in 3 mission(s) in the catalog: BepiColombo, Akatsuki, Station ISS.
→ View topicWhich missions does NASA participate in?
NASA participates in 21 mission(s) in the catalog: Europa Clipper, Psyche, Euclid, James Webb, Lucy, Solar Orbiter, Perseverance, TESS, Parker Solar Probe, OSIRIS-APEX, MAVEN, Juno, Curiosity, New Horizons, Mars Reconnaissance Orbiter, Chandra X-ray, Station ISS, SOHO, Hubble, Voyager 1, Voyager 2.
→ View topicWhich missions does Roscosmos participate in?
Roscosmos participates in 1 mission(s) in the catalog: Station ISS.
→ View topic