Five ways to lose a Mars mission
Every failure on this page ended in one of five places, and each place has its own causes. The causes below come from NASA, ESA and the agency investigations. Where an inquiry couldn't settle a cause, the page says so.
At launch and just after
Five spacecraft never reached Earth orbit, and six more stayed there. The launch losses include both Soviet attempts of October 1960, Mars 1969A and 1969B, and NASA's Mariner 8 in 1971, when its Centaur stage lost control. The stranded ones had a different problem: a stage that was meant to send them to Mars failed. Sputnik 22's escape stage exploded, Kosmos 419's timer was mis-set, and Mars 96 failed to escape Earth orbit on November 16, 1996. Phobos-Grunt, launched on November 8, 2011, never fired its engine for departure, and Russia's failure report blamed electronics parts that weren't qualified for use in space. China's Yinghuo-1 orbiter was riding with it.
On the way
Four spacecraft were lost between the planets. Mars 1 and Zond 2 went silent in the early 1960s, and Mariner 3's shroud didn't separate, so its solar panels couldn't open. Phobos 1 was lost in late August 1988 after a faulty ground command sequence switched off its attitude thrusters.
On arrival
Four spacecraft arrived and weren't captured. Mars 7 missed the planet in 1973. Mars Observer lost contact in 1993, three days before orbit insertion. Nozomi had propulsion, power and communications problems. Mars Climate Orbiter was lost on September 23, 1999 because the effect of its thruster firings had been underestimated by a factor of 4.45.
On landing
Three were lost on the surface, or just before it. Mars Polar Lander was lost on December 3, 1999, and the review of its loss pointed to the premature shutdown of the descent engines. The two Deep Space 2 penetrators never returned a signal. Beagle 2 landed but never called home.
Where they were lost
Lost at launch means the rocket failed before the craft reached Earth orbit. Stranded means the craft reached Earth orbit but the stage that should have sent it to Mars failed. Lost on the way is anything between Earth and Mars, such as a dead radio. Lost on arrival is a failed orbit burn or approach. Lost on landing is a crash or loss during descent or just after touchdown.
Who lost what
The Soviet Union and Russia account for 13 of the failures and the United States for 6. 12 of the 22 came before 1975, when sending anything to Mars was new. The Mars success rate page shows how steeply that has changed.
All 22
| Launched | Mission | Country | Where it was lost | What happened |
|---|---|---|---|---|
| October 10, 1960 | Mars 1960A | Soviet Union | Lost at launch | Third-stage failure prevented Earth orbit and the intended Mars flyby. |
| October 14, 1960 | Mars 1960B | Soviet Union | Lost at launch | Third-stage ignition failed; the spacecraft never reached Earth orbit. |
| October 24, 1962 | Sputnik 22 | Soviet Union | Stranded in Earth orbit | The escape stage exploded in Earth orbit, preventing the Mars flyby. |
| November 1, 1962 | Mars 1 | Soviet Union | Lost on the way | Contact was lost in transit; no observations were returned from the Mars encounter. |
| November 4, 1962 | Sputnik 24 | Soviet Union | Stranded in Earth orbit | The escape stage failed and the intended Mars lander remained in Earth orbit. |
| November 5, 1964 | Mariner 3 | United States | Lost on the way | The shroud didn't separate, preventing solar-panel deployment and Mars science. |
| November 30, 1964 | Zond 2 | Soviet Union | Lost on the way | Communications failed before arrival; no Mars encounter science was returned. |
| March 27, 1969 | Mars 1969A | Soviet Union | Lost at launch | Third-stage launch failure prevented Earth orbit and the intended Mars orbit mission. |
| April 2, 1969 | Mars 1969B | Soviet Union | Lost at launch | First-stage failure destroyed the launch attempt before Earth orbit. |
| May 9, 1971 | Mariner 8 | United States | Lost at launch | Centaur lost control during launch, preventing Earth orbit and Mars orbital science. |
| May 10, 1971 | Kosmos 419 | Soviet Union | Stranded in Earth orbit | The escape-stage timer was mis-set; the spacecraft never left Earth orbit. |
| August 9, 1973 | Mars 7 | Soviet Union | Lost on arrival | The lander missed Mars; cruise measurements didn't fulfill its primary Mars landing investigation. |
| July 7, 1988 | Phobos 1 | Soviet Union | Lost on the way | A command error disabled attitude control and the craft was lost before reaching Mars or Phobos. |
| September 25, 1992 | Mars Observer | United States | Lost on arrival | Communications were lost before Mars orbit insertion, preventing the primary mapping mission. |
| November 16, 1996 | Mars 96 | Russia | Stranded in Earth orbit | Failed to escape Earth orbit, losing the orbiter, two landers and two penetrators. |
| July 3, 1998 | Nozomi | Japan | Lost on arrival | Propulsion, power and communications problems prevented Mars orbit insertion and the primary atmospheric investigation. |
| December 11, 1998 | Mars Climate Orbiter | United States | Lost on arrival | Lost at Mars orbit insertion before the intended atmospheric mapping and relay mission. |
| January 3, 1999 | Deep Space 2 | United States | Lost on landing | Neither penetrator returned a signal after arrival, so impact-survival and subsurface technology objectives weren't demonstrated. |
| January 3, 1999 | Mars Polar Lander | United States | Lost on landing | Contact was lost during landing; no surface science was received. |
| June 2, 2003 | Beagle 2 | United Kingdom | Lost on landing | Landed but didn't fully deploy or communicate; none of its planned surface science was returned. |
| November 8, 2011 | Phobos-Grunt | Russia | Stranded in Earth orbit | Its propulsion module never fired for departure from Earth orbit, preventing Phobos landing and sample return. |
| November 8, 2011 | Yinghuo-1 | China | Stranded in Earth orbit | The host Phobos-Grunt spacecraft remained in Earth orbit, preventing release into Mars orbit. |
8 more missions had a partial result: they returned some of what they were built for before the end. They're on the full list of Mars missions.
Beagle 2: a failure that took years to explain
Most failures were obvious within hours. Beagle 2 wasn't. The small British lander was released from Mars Express on 19 December 2003, and no signal ever came. For more than eleven years nobody could say whether it had landed. On 16 January 2015, a NASA orbiter's images showed it on the surface. The ledger grades it a failure because it landed but didn't fully deploy or communicate, and none of its planned science came back. It's the closest this list comes to a missing-persons case.
What the failures have in common
The causes change over time. The early losses were mostly rockets and upper stages. Later ones come from communication between people and from software. Phobos 1 was lost to one faulty command sequence, Mars Climate Orbiter to a units mismatch, and Mars Polar Lander to software that was vulnerable to transient signals. Phobos-Grunt was lost to a failure in its flight computer, and published accounts differ on the root cause. Some losses have no answer at all, like the two Deep Space 2 probes.
The timing says something about the planet too. 11 of the 22 failures were lost at launch or stranded in Earth orbit, before the spacecraft ever had a chance to reach Mars. The recent record is cleaner than the early one, as the success rate by decade shows. The partial results sit on the full list, and the planet itself is described on its page.
When they happened
Counted by launch decade, the failures fall in the 1960s (9), 1970s (3), 1980s (1), 1990s (6), 2000s (1) and 2010s (2). The shape matches the success rate page: a heavy early toll, a bad run in the 1990s, then far fewer.
Partial isn't failure
8 missions are graded partial, not failed: Mars 2, Mars 3, Mars 4, Mars 5, Mars 6, Phobos 2, ExoMars 2016 and InSight. Each got something back. InSight is the clearest case. It landed on November 26, 2018 and its seismometer recorded 1,319 marsquakes, but its heat probe failed to dig deep enough, and NASA ended those efforts in January 2021. The mission met its seismology goals and missed one it needed, so it sits between the two columns.
How to read the table
The last column in the table below is the ledger's own reason for each loss, written from NASA, ESA and agency records. Where the table says only that contact was lost, that's all the record supports. Anything more would be a guess, and the page leaves those guesses out.
Failures by program
Counted by the program that flew them, the 22 failures are the Soviet Union / Russia 13, the United States 6, Japan 1, the United Kingdom 1 and China 1. The programs with the most failures are the ones that flew the most missions, so the counts mostly track how often each program tried. A spacecraft that survives launch still faces months in transit, which the travel time page works out.