Why the Mars probe went off course [accident investigation] Abstract: On 23 September, through a series of still-baffling errors, flight controllers at the Jet Propulsion Laboratory, a California Institute of Technology facility under contract to NASA, sent erroneous steering commands to the Mars Climate Observer as it neared the target planet.
The loss of the Mars probe was the latest in a series of major spaceflight failures this year that destroyed billions of dollars worth of research, military and communications satellites or left them spinning in useless orbits.
Data exchanges for the Global Surveyor, which has been orbiting Mars since 1997, have been conducted exclusively in the metric system, Hinners said. Mission controllers expect to use the Surveyor as a relay station in place of the lost orbiter. If found formally at fault by an accident review board, Lockheed will face financial penalties.
The 1980s saw the Soviet Union’s two Phobos missions, both of which failed because of computer issues. The 1990s weren’t particularly good for Mars landings, either. Russia’s Mars 96 failed during launch. Happily, Nasa’s Sojourner rover touched down in 1996, becoming the first Martian rover success story.
Three things make Mars landings difficult – the planet’s gravity, Mars’ atmosphere and our distance from the red planet. Mars is less massive than Earth, but its atmosphere is also perilously thin.
NASA's Mars Climate Orbiter was designed to study Mars from orbit and to serve as a communications relay for the Mars Polar Lander and Deep Space probes. The mission was unsuccessful due to a navigation error caused by a failure to translate English units to metric.
Propulsion systems have leaked and exploded. Power systems have short-circuited. Observation instruments have failed to work or have been pointed in wrong directions. But until this year no CFIT had occurred in outer space.
Mars Polar Lander remains lost. The cause of the communication loss is not known. However, the Failure Review Board concluded that the most likely cause of the mishap was a software error that incorrectly identified vibrations, caused by the deployment of the stowed legs, as surface touchdown.
NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.
The first to contact the surface were two Soviet probes: Mars 2 lander on November 27 and Mars 3 lander on December 2, 1971—Mars 2 failed during descent and Mars 3 about twenty seconds after the first Martian soft landing. Mars 6 failed during descent but did return some corrupted atmospheric data in 1974.
On 15 July, barely 1 hour before a scheduled launch, the mission was aborted. The reason, ISRO soon discovered, was a leak in a pressure-supplying system. ISRO plugged the leak just in time to launch the mission on 22 July. Some experts believe India needs to improve its space technology.
The mission ended with disappointment on August 22, 1993, when contact was lost with the spacecraft shortly before it was to enter orbit around Mars. Science instruments from Mars Observer were reflown on two other orbiters, Mars Global Surveyor and 2001 Mars Odyssey.
No one has seen any evidence of the ill-fated craft — until now. Courtesy NASA/JPL. In December 1999 NASA's Mars Polar Lander (MPL) was supposed to touch down near the red planet's south pole. But shortly after it entered the Martian atmosphere, the spacecraft disappeared without a trace.
As of 2022, 21 lander missions and 8 sub-landers (Rovers and Penetrators) attempted to land on Mars. Of 21 landers, the Curiosity rover, InSight Mars Lander, Perseverance rover, and Tianwen-1 are currently in operation on Mars.
687 daysMars / Orbital periodThe Earth zips around the Sun at about 67,000 miles per hour, making a full revolution in about 365 days - one year on Earth. Mars is a little slower, and farther from the sun, so a full circuit takes 687 Earth days - or one Mars year.
coldIs Mars red hot? Mars may look hot, but don't let its color fool you -- Mars is actually pretty cold! In orbit, Mars is about 50 million miles farther away from the Sun than Earth. That means it gets a lot less light and heat to keep it warm.
about -81 degrees F.Temperatures on Mars average about -81 degrees F. However, temperatures range from around -220 degrees F. in the wintertime at the poles, to +70 degrees F. over the lower latitudes in the summer.
On its arrival near Mars, the probe was aimed to pass above the planet's north pole, within 200 km of the surface but beyond the atmosphere. This last, though much thinner at the surface than Earth's atmosphere, still extended fairly far out because of Mars's lower gravity. It was not a particularly challenging route. Previous probes had been guided very accurately--for example , in 1997 the Mars Global Surveyor, still orbiting the planet today, missed its target altitude by a mere 4 km.
The climate probe was also to serve as a communications relay (in the UHF band) for other probes on the planet's surface. The launch of the Mars Climate Orbiter had gone according to plan. A Delta-I I booster lifted it from Cape Canaveral, in Florida, on 11 December 1998.
Because it used momentum wheels for fine pointing control, the Mars Climate Orbiter also performed momentum dump operations periodically during its cruise out to its destination. The flight controllers at JPL observed the jet firings that occurred to control the probe's orientation during these maneuvers. And they then would have taken into account the minor--but critical--translational cross-coupling forces that the jet firings had induced.
Like many other spacecraft in terrestrial orbit and beyond, the Mars Climate Orbiter maintained control of its attitude, or orientation in space, through th e use of momentum wheels. These metal disks, measuring about 10 cm in diameter, and resembling the wheel in a child's gyroscope, are spun up or down by electri c motors. Top speed is 3000 revolutions per minute. With one momentum wheel for each axis, they serve to turn the spacecraft in different directions or to steady its orientation against disturbing torques, and do so gently and with fine control. Gas jet thrusters, which are also available to turn the spacecraf t as needed, do so forcefully and with coarser accuracy.
Sometimes they use magnetic torquers--a device that has a current runnin g through a wire loop--to push against Earth's magnetic field.
Previous probes had been guided very accurately--for example , in 1997 the Mars Global Surveyor, still orbiting the planet today, missed its target altitude by a mere 4 km. During the long cruise outward from home, flight controllers had navigated using the spacecraft's radio link to Earth for orbit determination.
One down, one to go. NASA had urgently needed an explanation for the failure since a sister probe was also nearing Mars. Due to arrive on 3 December, the Mars Polar Lander neede d to approach with even greater precision, since it would directly enter the Red Planet's atmosphere for a landing near the southern pole.
The Soviet Union launched its Mars 2 probe, consisting of an orbiter and a descent module. While the orbiter sent back data successfully, the descent module didn’t work as planned and crashed on the Martian surface.
Happily, Nasa’s Sojourner rover touched down in 1996, becoming the first Martian rover success story. Unfortunately, America’s Mars Polar Lander failed just before touching down on the planet in 1999. First panoramic view by Viking 1 from the surface of Mars, 1976. NASA. The 2000s didn’t start out much better.
A space physicist explains why that's such a big deal. Trying to use retrorockets would subject a lander to so much turbulence that the craft could be ripped apart. What’s more, any craft trying to land on Mars suffers from the effects of friction as it hurtles through the atmosphere, risking burning up.
Mars’ atmosphere is too thin for that sort of Earth-like gentle gliding, but as a craft plummets towards the Martian surface it can reach speeds of more than 12,000 mph. Read more: So a helicopter flew on Mars for the first time. A space physicist explains why that's such a big deal.
If it doesn’t, a crash landing could quite literally shatter thousands of hopes and dreams.
The first Mars launch was in 1962, five years after the space age began with the launch of Sputnik. The then Soviet Union tried to launch a satellite into orbit around Mars, but problems with the rocket that launched it meant the satellite never left Earth’s orbit and ultimately decayed in our atmosphere. The rover Mars 3 landed on Mars, which ...
China’s rover Zhurong, named after the mythological fire god, successfully touched down on Mars on May 14 – the first time that China has successfully landed a rover on the red planet.
1999: A disaster investigation board reports that NASA’s Mars Climate Orbiter burned up in the Martian atmosphere because engineers failed to convert units from English to metric.
1999: A disaster investigation board reports that NASA's Mars Climate Orbiter burned up in the Martian atmosphere because engineers failed to convert units from English to metric.
And the last few signals from the orbiter indicated that it was dipping dangerously low into the Martian atmosphere, about 105 miles lower than it was supposed to go.
Ultimately, the Mars Climate Orbiter came within 37 miles of the Martian surface. Simulations showed that, at any altitude lower than 53 miles, atmospheric friction would tear the fragile craft apart. The whole thing could be written off as a miscommunication.
Not only did the rovers both land safely and complete their original 90-day mission, but they're still running six years later.
The New York Times ran a preview article Sept. 21 titled " Beginning a Bargain-Basement Invasion of Mars ," foreshadowing the disasters to come. The Mars Polar Lander, which launched 23 days after Mars Climate Orbiter, also disappeared on the way to the planet's surface.
But there was an underlying issue in the culture of NASA's space exploration at the time, Cook said. "'Better, faster, cheaper' was the mantra at the time," Cook said. "Certainly that project was trying to do a whole lot for a limited amount of money.".