Mars Reconnaissance Orbiter and HiRISE

What is the Mars Reconnaissance Orbiter?

MRO is a NASA orbiterOrbiterAn orbiter circles Mars without landing, studying the planet from above — and many also relay rover data back to Earth.More in the glossary that studies Mars from 255 to 320 km (158 to 199 mi) up and passes data between the rovers and Earth.[1][6] It launched on an Atlas V rocket from Cape Canaveral, Florida, on Aug 12, 2005, and reached Mars on Mar 10, 2006, firing its engines for about 27 minutes to be captured into orbit.[1][2] It then spent six months dipping in and out of the top of the atmosphere to shrink its orbit, a technique called aerobraking, and began science in November 2006.[1][2][4]

NASA sent MRO to find out whether water lasted on Mars’s surface long enough to give life a chance.[1] The plan was two years of science, then two years as a relay.[26] It is still doing both.

NASA figures as of the dates shown. The lap and data totals are the latest NASA has published that we found; both have grown since.[1][2][6][7][3][8]

What is HiRISE?

HiRISE, the High Resolution Imaging Science Experiment, is MRO’s telescopic camera and the sharpest camera orbiting Mars.[5][26] From 300 km (186 mi) up, each pixel covers about 30 cm (12 in), so it can make out things about 1 m (3 ft) across, the size of a kitchen table. Each picture is a strip about 6 km (3.7 mi) wide and up to 60 km (37 mi) long. Only the middle of each strip is in color.[4] NASA describes HiRISE as the largest camera ever flown on a planetary mission.[1]

Ball Aerospace built HiRISE in Boulder, Colorado, and the University of Arizona runs it.[3] It took its 100,000th image on Oct 7, 2025: mesas and dunes in Syrtis Major, about 80 km (50 mi) southeast of Jezero Crater. A high school student had suggested the spot. “HiRISE hasn’t just discovered how different the Martian surface is from Earth, it’s also shown us how that surface changes over time,” said Leslie Tamppari of JPL, MRO’s project scientist.[3]

What else does MRO carry?

MRO launched with six science instruments, and five still work.[2][10] It also carries Electra, a radio for talking to landers and rovers.[4]

• 01CTX, the Context Camera. Black-and-white pictures at about 6 m (20 ft) per pixel. It has photographed nearly all of Mars and is especially good at spotting impact craters.[4][25]
• 02MARCI, the Mars Color Imager. Makes a daily weather map of the whole planet, tracking clouds and dust storms.[2][25]
• 03MCS, the Mars Climate Sounder. Measures temperature, water vapor and dust through the atmosphere. Its pointing mount became unreliable in 2024, so it now relies on the whole spacecraft rolling.[4][10]
• 04SHARAD, the Shallow Radar. From the Italian Space Agency, it sends radio pulses below the surface and can tell rock, sand and ice apart.[10]
• 05CRISM, the mineral mapper. For 17 years it found minerals that form in water, such as clays and sulfates, and its maps helped pick the landing sites for Curiosity and Perseverance. NASA switched it off on Apr 3, 2023.[9]

How does MRO relay data from the rovers?

Curiosity and Perseverance send most of their data up to orbiters passing overhead, and MRO is one of four that pass it on to Earth.[6] A rover can talk to an orbiter at up to 2 megabits per second, and MRO can point its dish at Earth while it is still talking to a rover, which cuts the wait. NASA says every image seen from the surface of Mars since 2004 has come home through this relay network.[6]

When Perseverance landed in 2021, MRO received its landing data as it happened and sent it straight on to Earth. After NASA’s MAVEN orbiter fell silent in December 2025, the other orbiters took on its share, and MRO’s average daily relay volume nearly doubled.[6]

Average data each orbiter transmitted, in megabits (Mb), from NASA’s Mars Relay Network page. NASA ended MAVEN’s mission on Jun 3, 2026.[6]

NASA has also ordered a dedicated relay orbiter from Blue Origin, expected to be working at Mars by 2030.[28] Our story on the award covers Rocket Lab’s protest of it.

What has MRO seen?

A Mars that is still changing: avalanches, new craters, moving dunes, and other spacecraft on their way down.[3][16]

• 01Landers on their parachutes. On May 25, 2008, HiRISE photographed NASA’s Phoenix landerLanderA lander touches down on Mars and works from one spot, unlike a rover, which drives.More in the glossary under its parachute, the first time one spacecraft had photographed another landing on Mars.[12] It caught Curiosity in August 2012,[13] and Perseverance on Feb 18, 2021, from about 700 km (435 mi) away.[14]
• 02Ice just under the ground. New impact craters have dug up bright water ice, which HiRISE has watched fade as it turns to vapor.[17] A meteoroid that hit on Dec 24, 2021 left a crater about 150 m (490 ft) wide, ringed by boulder-size chunks of ice, closer to the equator than ice had been found before.[18]
• 03Avalanches. HiRISE has caught avalanches in progress.[3][5] In 2015 it photographed a chunk of carbon dioxide frost 20 m (66 ft) wide in free fall.[16]
• 04Dark streaks on slopes. Streaks called recurring slope lineae grow down steep slopes in warm seasons and fade in winter. In 2015 NASA said salts found in them were “the strongest evidence yet” of liquid water flowing on Mars today.[19] A 2017 study of HiRISE images found they end on slopes that match dry, slipping sand instead. How they form is still unexplained.[20]
• 05Probably no lake under the south pole. In 2018 scientists using Europe’s Mars Express reported a radar signal they read as a buried lake. In November 2025 SHARAD’s team, with MRO rolled 120 degrees for a clearer view, reported only a faint signal there, more likely from rock and dust.[11]
• 06A visitor from interstellar space. On Oct 2, 2025, MRO turned HiRISE away from Mars to photograph the interstellar comet 3I/ATLAS, about 30 million km (19 million mi) away.[21]

It also watches the rovers. On Jun 13, 2026, HiRISE photographed Perseverance as a green speck at the end of its tracks, a day before the rover passed the length of a marathon.[15]

Where can I see HiRISE images?

On the HiRISE team’s website, uahirise.org, which posts a captioned picture of the day.[24] Full-resolution files and raw data are in the Planetary Data System archive at hirise-pds.lpl.arizona.edu.[23][27]

• 01They are free to use. The team says all HiRISE images are in the public domain, with no restrictions, and asks for the credit “NASA/JPL/University of Arizona” where possible.[22]
• 02The colors are not what your eye would see. HiRISE color images are “false color,” which makes different materials stand out.[23]
• 03You can pick a target. On the team’s HiWish page anyone can suggest a spot to photograph.[3]
• 04See the whole planet. Caltech’s Bruce Murray Laboratory stitched 110,000 CTX images into a zoomable map of Mars that anyone can browse online.[25]

Our Mars photos page shows the newest raw images from Perseverance and Curiosity.

Is MRO still working?

Yes, though after two decades in space some parts are wearing out.[6][27] In 2025 a NASA review panel found all of MRO’s spacecraft systems working, with propellant to last “well beyond another three years.” The team proposed a seventh extended mission, for fiscal years 2026 to 2028, and the panel rated its science highly.[27]

• 01Gyroscopes. To save its aging gyroscope units, JPL taught MRO in 2017 and 2018 to sense which way it is pointing from its star trackers alone.[26] In 2025 this “all-stellar” mode was in use about 93% of the time.[27]
• 02HiRISE. Since mid-2023 one of its detectors has returned data only about half the time, leaving gaps in some images.[24]
• 03Radio. The review listed a failed Ka-band radio part and an aging X-band amplifier as known risks, but judged the risk of the amplifier failing during the 2026–2028 extended mission to be minimal.[27]
• 04New tricks. Since 2023 the team has rolled MRO up to 120 degrees, nearly upside down, so SHARAD’s radar signal comes back 10 times stronger or more. It plans to do this more often.[10][27]

Mission timeline

1. Aug 12, 2005Launches from Cape Canaveral.[1]
2. Mar 10, 2006Enters orbit around Mars.[1][2]
3. November 2006Begins science from its final orbit.[2]
4. May 25, 2008Photographs Phoenix landing.[12]
5. Feb 18, 2021Photographs Perseverance landing and relays its landing data live.[14][6]
6. Apr 3, 2023NASA switches off CRISM.[9]
7. Oct 7, 2025HiRISE takes its 100,000th image.[3]

Sources

1. NASA Science — Mars Reconnaissance OrbiterPrimary · checked Oct 6, 2026
2. NASA NSSDCA — Mars Reconnaissance Orbiter (2005-029A)Primary · checked Oct 6, 2026
3. NASA — One of NASA’s Key Cameras Orbiting Mars Takes 100,000th ImagePrimary · checked Oct 6, 2026
4. NASA Science — Mars Reconnaissance Orbiter: Science InstrumentsPrimary · checked Oct 6, 2026
5. HiRISE, University of Arizona — About Us: Principal and Co-InvestigatorsPrimary · checked Oct 6, 2026
6. NASA Science — Mars Relay NetworkPrimary · checked Oct 6, 2026
7. NASA — NASA’s MRO Completes 60,000 Trips Around MarsPrimary · checked Oct 6, 2026
8. NASA — NASA’s Mars Reconnaissance Orbiter Undergoes Memory UpdatePrimary · checked Oct 6, 2026
9. NASA JPL — NASA Retires Mineral Mapping Instrument on Mars OrbiterPrimary · checked Oct 6, 2026
10. NASA JPL — NASA Mars Orbiter Learns New Moves After Nearly 20 Years in SpacePrimary · checked Oct 6, 2026
11. NASA JPL — NASA Orbiter Shines New Light on Long-Running Martian MysteryPrimary · checked Oct 6, 2026
12. NASA JPL — Camera on Mars Orbiter Snaps Phoenix During LandingPrimary · checked Oct 6, 2026
13. NASA JPL — Curiosity Flying Over Mars (PIA15983)Primary · checked Oct 6, 2026
14. NASA JPL — HiRISE Captured Perseverance During Descent to Mars (PIA24270)Primary · checked Oct 6, 2026
15. NASA JPL — NASA’s HiRISE Captures Perseverance Marking a Milestone on Mars (PIA26726)Primary · checked Oct 6, 2026
16. NASA — Avalanches, Icy Explosions, and Dunes: NASA Is Tracking New Year on MarsPrimary · checked Oct 6, 2026
17. NASA JPL — Underground Ice on Mars Exposed by Impact Cratering (PIA12217)Primary · checked Oct 6, 2026
18. NASA — NASA’s InSight Lander Detects Stunning Meteoroid Impact on MarsPrimary · checked Oct 6, 2026
19. NASA — NASA Confirms Evidence That Liquid Water Flows on Today’s MarsPrimary · checked Oct 6, 2026
20. NASA JPL — Recurring Martian Streaks: Flowing Sand, Not Water?Primary · checked Oct 6, 2026
21. NASA — NASA’s Mars Spacecraft Capture Images of Comet 3I/ATLASPrimary · checked Oct 6, 2026
22. HiRISE, University of Arizona — Image Usage PolicyPrimary · checked Oct 6, 2026
23. HiRISE, University of Arizona — Frequently Asked QuestionsPrimary · checked Oct 6, 2026
24. HiRISE, University of Arizona — HiRISE: High Resolution Imaging Science Experiment (home page)Primary · checked Oct 6, 2026
25. NASA — New Interactive Mosaic Uses NASA Imagery to Show Mars in Vivid DetailPrimary · checked Oct 6, 2026
26. NASA JPL — Mars Reconnaissance Orbiter Preparing for Years AheadPrimary · checked Oct 6, 2026
27. NASA Planetary Science Division — 2025 Planetary Mission Senior Review: Final ReportPrimary · checked Oct 6, 2026
28. NASA — NASA Selects Blue Origin as Mars Telecommunications Network ProviderPrimary · checked Oct 6, 2026