Mars is a hard place to reach. While there have been many notable success stories in getting probes to the Red Planet, the historical record is full of bad news. Counting all Soviet/Russian, U.S., European, and Japanese attempts, more than half of Mars missions have failed, either because of some botched rocket launch on Earth or a systems malfunction en route to or at the planet. The success rate for actually landing on the Martian surface is even worse, roughly 30 percent. Set to touch down on Aug. 5, NASA’s newest Mars rover, Curiosity, will be the largest man-made object ever placed on another planet, requiring a never-before-attempted landing sequence. With its carefully orchestrated parachutes, rockets, hovering UFO-like platform, and sky crane, the descent has to go off in a pitch perfect order to avoid the rover becoming a fiery crater on the Martian surface. With this in mind, NASA officials have been nervous about their $2.5 billion flagship probe’s chances of successfully reaching the ground, alternating between anxious and hopeful tenors when talking about the mission in recent weeks. The agency at least can take comfort in the fact that three out of four landers and every rover built in the good-old U.S. has made it down safely thus far. Though we sincerely hope that Curiosity doesn’t join them, here we take a look at the challenging history of Mars mission failures and the vast robotic graveyard of probes that didn’t make it. Image: The surface and atmosphere of Mars taken by the Viking Orbiter. NASA

Marsnik 1 and 2 The earliest planned Mars missions were the Soviet Mars 1M series of spacecrafts, known in the U.S. as Marsnik 1 and 2. Both probes were meant to fly by Mars and return images of its surface as well as study the effects of extended spaceflight on electronics to pave the way for future interplanetary travel. Marsnik 1 was launched on Oct. 10, 1960 but failed to get enough thrust to make it out of Earth’s atmosphere. This early attempt, undertaken behind the secrecy of the Soviet space program, has been denied by some scientists involved with the flight. It’s a strange face-saving effort considering that Marsnik 2, launched four days after Marsnik 1, suffered the same failure to achieve Earth orbit as its predecessor. Image: The Marsnik 1 spacecraft. NASA

Mars 1 Two years after their first tries, the Soviets were at it again with a suite of three robot attempts at Mars. On Oct. 24, 1962, they launched Sputnik 22, a Mars flyby mission that exploded in Earth orbit before it was able to fire its rockets to head to the Red Planet. This satellite would be of little historical note if it hadn’t almost triggered World War III. The poorly timed launch occurred during the Cuban missile crisis and, when the U.S. Ballistic Missile Early Warning System radar detected debris from the shattered spacecraft, it was momentarily feared to be the start of a Soviet nuclear missile attack. Seemingly undeterred by their failures, the Soviet space program launched the Mars 1 probe eight days later. This probe was designed to image the Martian surface and send back data on cosmic radiation, micrometeoroid impacts, Mars’ magnetic field, and search for possible life. Despite a leak in one of the gas valves in the orientation system, Mars 1 started out in good working condition, achieving Earth orbit and rocketing off to Mars. But a few months later, the spacecraft ceased communicating, possibly from failure of the orientation system. The last Soviet attempt of this era, Sputnik 24, launched three days after Mars 1. It would have deployed the first lander to reach the surface of Mars. Unfortunately, the probe broke up in Earth orbit shortly after launch and reentered the atmosphere in pieces a few months later. Image: The Soviet Mars 1. NASA

Mariner 3 While the Soviets seemingly had a monopoly on Mars spacecraft failures during this time, at least they were trying. NASA wasn’t even in the game yet — the first American attempt at a Mars flyby didn’t come until 1964, with the launch of Mariner 3. And this attempt failed when a protective shield didn’t eject properly. The extra weight prevented the spacecraft from reaching its intended orbit. NASA’s Mariner 4, launched a few weeks later, was the first probe to successfully fly by Mars, finally returning pictures of its surface from close up. Image: The Mariner 3 spacecraft. NASA

Zond 2 Days after the launch of the successful Mariner 4, the Soviet space program launched a rival probe, Zond 2. Much like the earlier Mars 1, this probe was intended to carry out scientific exploration of the Red Planet, take pictures of its surface, and brought with it a descent craft to reach the Martian surface. (Soviet probes at this time were all designed basically the same, with engineers learning from the mistakes of previous spacecraft.) Though its launch went smoothly, Zond 2 reported serious problems from the beginning of its mission. Out in space, one of its solar panels seems not to have deployed, giving the probe only half the expected amount of power. Several months later, the spacecraft’s communication system began sending back irregular updates, eventually succumbing to a critical failure somewhere on the way to Mars. To this day, no one knows exactly what happened to the probe but its believed that Zond 2 went by Mars on August 6, 1965 – just a few weeks after Mariner 4’s successful flyby — and drifted silently off into interplanetary space. Image: Zond 2. NASA

Twin Failures The Soviets rounded out the 1960s with a pair of twin Mars probes that failed spectacularly shortly after launch. Launched in 1969, the Mars 1969A and 1969B probes each carried three television cameras designed to record the Martian surface in detail that surpassed Mariner 4. Both rockets experienced terrible launches. The first spacecraft, 1969A, lifted off the launch pad, experienced a malfunction, caught on fire, shut down its engines, exploded, and had its remains crash into the Altai Mountains. The second probe suffered a rocket stage explosion 0.02 seconds after liftoff, which caused the rocket to tip over as it climbed. About half a mile above the surface, all the engines shut down, and the rocket hit the ground and exploded 41 seconds after launch, less than 2 miles from the launch pad. Image: Rockets similar to this Proton carried the Mars 1969A and 1969B probes and both suffered failures. NASA

Mariner 8 and Cosmos 419 By the 1970s, Martian flybys were passé and both the U.S. and Soviet space agencies were racing to be the first to orbit a probe around Mars. NASA was first out of the gate with the Mariner 8 probe, which launched May 8, 1971. Unfortunately, the probe’s rocket began to wobble after liftoff, eventually tumbling out of control and returning to Earth. Two days later, the Soviet Cosmos 419 probe launched. Though its NASA rival crashed, many believe that part of Cosmos’ mission was to overtake the U.S. spacecraft during the voyage to Mars and enter orbit around the planet first. The Soviets may have gotten a quick laugh at their American counterparts. But an erroneous ignition timer in Earth orbit sent the Soviet spacecraft quickly plummeting back to the ground. Image: Mariner 8. NASA

Mars 2 and 3 Mere weeks after the back-to-back Mariner 8 and Cosmos 419 failures, both the U.S. and Russia were attempting to achieve Martian orbit again. On May 19 and 28, 1971, the Soviets launched the Mars 2 and 3 probes. Two days later, NASA’s Mariner 9 spacecraft launched. The three probes raced to Mars, each hoping to bring glory to their country’s space program and engineering prowess. While it launched slightly later, the U.S. probe beat the Soviet spacecraft by a mere fortnight and Mariner 9 became the first man-made object to ever orbit another planet. During its mission, Mariner 9 mapped 70 percent of the Martian surface and studied changes in the planet’s atmosphere. Though slightly late, Mars 2 and 3 also entered Martian orbit. Each spacecraft imaged the Martian surface and clouds, and studied the planet’s temperature, pressure, and composition. Mars 2, which arrived slightly before its companion, has the distinction of sending the first attempted lander to the surface of Mars. This dome-shaped landing robot contained two cameras to provide a 360-degree view of its landing area, and a mechanical scoop to search for organic matter and signs of life. It was meant to slow down using parachutes and rockets and make the first soft landing on Mars. Once on the ground, four triangular petals that opened like a flower were meant to right the probe. Perched atop the dome was a small black rover (left) that “walked” on two skis, and could travel about 50 feet away from its base while remaining connected via a communication cable. The orbiters were both a success, but their landers did not fare as well. The Mars 2’s descent landing sequence failed, bringing the probe in too fast. The lander exploded when it hit the surface. Mars 3’s lander actually made it to the ground, achieving the first touchdown on another planet and sending back an image from the surface of Mars, a blurry and static-filled shot. Inexplicably, the lander stopped transmitting about 20 seconds after it hit the ground, never resuming transmission. The failure may have been related to an extremely powerful and unfortunate Martian dust storm taking place at the time, which could have damaged its communications system. Images: 1) The Mars 2 lander. 2) The Mars 2 rover. NASA via Alexander Chernov and the Virtual Space Museum.

Mars 4, 5, 6, and 7 Between July 21 and August 9, 1973, the Soviets launched what basically amounts to an armada at Mars. Four spacecraft lifted off, one after the other in close succession. Unfortunately, not a single one was entirely successful. Mars 4 (above) launched fine and was safely on its way to Mars when a computer chip malfunction prevented a necessary rocket from firing. Subsequently, the probe was going way too fast when it reached Mars, bypassing the planet entirely and drifting off into interplanetary space. Its companion, Mars 5, fared better, entering Martian orbit but then operating for only a few days before shutting down. Mars 6 and 7 were each flyby missions that deployed a lander as they approached Mars. Mars 6 successfully released its descent probe, which traveled down to the surface but then crashed, likely from a misfired rocket. It did transmit a few minutes of data on its way down — the first information returned from the atmosphere of Mars. But the mission was a comedy of errors, and much of the data were unreadable because a computer chip error degraded the records during the probe’s journey to Mars. The Mars 7 spacecraft fared much worse, missing the planet entirely due to an on-board malfunction. Image: The Soviet Mars 4 probe. NASA

Phobos 1 and 2 Just before the collapse of the Soviet Union, the country’s space agency sent out two more ambitious Mars probes, Phobos 1 and 2. The Cold War was nearly thawed and the missions relied on the help of 14 other nations, including the U.S. Both probes were designed to study one of Mars’ moons, Phobos, and release a lander to the tiny body’s surface. Phobos 1 worked fine until a communication failure, ultimately traced back to a software error that caused the solar panels to face away from the sun, depleting the spacecraft’s batteries. The lesson for programmers is: always check your code! Phobos 2 was slightly more successful, entering orbit around Mars and returning some data. But before the spacecraft could release its lander to the moon Phobos, it too suffered a communication failure, ending the mission. Image: Phobos spacecraft with the moon and Mars nearby. NASA

Mars Observer NASA’s Mars Observer was meant to study the climate and geology of Mars from space. The $813 million robot launched in 1992 and cruised its way to Mars. Though no one is sure exactly what happened, the probe never came through. Engineers suspect that a fuel line ruptured and caused the spacecraft to spin uncontrollably in interplanetary space. The probe lost contact with mission control three days before it was meant to enter Martian orbit. Image: NASA

Mars 96 The first Mars probe in the post-Soviet Russian era, Mars 96 was an ambitious spacecraft and the heaviest probe launched up to that point. With instruments from several countries, including the European Union and the U.S., the bloated spacecraft carried an orbiter, two landers to explore the surface, and two penetrators that would have hit and delved about 17 feet into the ground, analyzing the Martian underground for the first time. The mission launched in November 1996 but failed to make it to Earth orbit. The spacecraft was a dramatic disaster, crashing back to Earth and breaking up in a 200-mile stretch over the Pacific Ocean, Chile, and Bolivia. Though it was initially believed that most of the spacecraft burned up in the atmosphere, later assessments suggested that pieces of the probe hit the ground, possibly including its 200-gram plutonium fuel tank. No part of the spacecraft or upper stage has been recovered to this day. Image: A model of the Mars 96 probe. NASA

Nozomi The Japanese space agency (JAXA) has one entry in this field with its Nozomi spacecraft. Nozomi (meaning hope) was meant to study the upper Martian atmosphere and its interaction with the solar wind. Launched in 1998, the probe took a long, circuitous route, using the Earth and moon several times as gravity assists to save on fuel. In April 2002, as Nozomi was approaching Earth for the gravity assist maneuver, powerful solar flares damaged the spacecraft’s on-board communications and power systems. Though the spacecraft flew by Mars the next year, engineers were no longer able to properly control the spacecraft. It was unable to complete its mission and enter Martian orbit and was abandoned that year. Image: NASA

Mars Climate Orbiter and Polar Lander Proving that even NASA engineers can have problems with math, one of the most well-known and embarrassing failures in space history came in 1998. The Mars Climate Orbiter was meant to study Martian dust storms, weather systems, clouds, surface features, and erosion. When the spacecraft reached Mars, it completed a burn to enter into orbit around the planet. When the probe went behind Mars, it briefly lost radio contact with mission control. For some reason, it never reestablished the connection. Engineers later determined that the spacecraft had encountered a navigation error stemming from a few commands being sent in English units instead of getting converted to metric. Rather than entering Martian orbit 90 miles above the surface, the probe plunged straight into the atmosphere, where it burned up due to friction. The other half of the mission, NASA’s Mars Polar Lander, which was meant to descend to the ground near the planet’s South Pole, also suffered a failure. Before reaching the surface, the lander ceased communicating with Earth. Though officials aren’t sure of the exact cause, it is likely that one of the probe’s rockets stopped firing too early, causing the lander to slam into the surface at high velocity. Image: NASA/JPL

Beagle 2 The British Beagle 2 lander was named after Charles Darwin's famous ship and was planned to study the transition between the Martian ancient southern highlands and northern plains. The small probe carried stereo cameras, a microscope, and a small drill, and would have searched for signs of life, past or present. After its scheduled landing, ESA attempted to hail the Beagle 2 lander but heard nothing. Mission control kept trying to call the Beagle for a month after its descent, to no avail. No known cause has been determined for the failure, though electronic glitches, a gasbag puncture, damage to a heat shield, a broken communications antenna, and collision with an unforeseen object could all be possible explanations. Image: NASA