Viking 2 orbiter shutdown

VikingLess than two years after arriving at Mars, the “mothership” orbiter that delivered the Viking 2 lander to the red planet is permanently shut down. Having lost most of its fuel to a leak, the Viking 2 orbiter can no longer be commanded to change orbit, and is placed in a parking orbit. Without an orbiter to relay its findings to, Viking 2 continues operating on the surface of Mars for two more years, sending data directly to Earth at a lower bit rate.

Viking 2 signing off

VikingTwo years after the shutdown of its orbiter leaves it sending observations of the Martian environment back to Earth at a low bit rate, the Viking 2 lander’s batteries are depleted and the second spacecraft to land on Mars shuts down permanently. Its three-and-a-half-year operational lifespan has been a bonus round for a robotic vehicle expected to function for a few months in Mars’ harsh weather.

Viking 1 shuts down

VikingAfter over six years of continuous operation and data gathering on the planet Mars, the Viking 1 lander – having outlived the power supply aboard its orbiter and now transmitting its observations directly to Earth – is inadvertently silenced during what is intended to be a remote upgrade of its on-board software. Ground controllers are never able to establish contact with Viking 1 again. Its record of continuous operation on another planet is not broken until 2010, when Viking 1 is outlasted by NASA’s Opportunity rover.

Phobos 1 launched

PhobosThe Soviet Union launches the first of two unmanned Phobos space probes, designed to investigate the largest of Mars’ two asteroid-like moons and deliver a lander to analyze that moon’s surface. With multiple nations pitching in resources to help the mission succeed, including the United States, the Phobos program is intended to be the definitive Mars exploration program of the 1980s, as well as the debut of a new Soviet interplanetary vehicle to take over from the Zond/Venera design in use since the 1960s.

Phobos 2 launched

PhobosThe Soviet Union launches the second of two unmanned Phobos space probes, designed to investigate the largest of Mars’ two asteroid-like moons and deliver a lander to analyze that moon’s surface. The Phobos program is intended to be the definitive Mars exploration program of the 1980s, as well as the debut of a new Soviet interplanetary vehicle to take over from the Zond/Venera design in use since the 1960s; only Phobos 2 will actually reach its target intact, but it will still fail to complete all of its mission objectives.

Phobos 1 and the curse of Mars

PhobosThe Soviet Union loses contact with the Phobos 1 unmanned Mars probe during its interplanetary flight and is unable to re-establish contact. The cause of the vehicle’s loss is later traced to a typo in a single line of command code uplinked to its computer from the ground; this error changes a routine command to a command to shut down attitude control, leaving Phobos 1 tumbling through space, unable to point its antenna toward Earth. The mission is a complete loss.

Phobos 2 arrives at Mars

PhobosThe Soviet Union’s unmanned Mars probe Phobos 2 successfully arrives in orbit around the red planet after over half a year of interplanetary travel (and after the loss of its identical twin, Phobos 1). Phobos 2 begins taking pictures of both Mars and Phobos and begins a series of orbital maneuvers that will eventually lead it to a very close approach to Phobos, where it is expected to release a pair of surface landers, the first of their kind to study a Martian moon.

Phobos 2 and the curse of Mars

PhobosThe Soviet Union loses all contact with the unmanned Mars probe Phobos 2 during a close flyby of the inner Martian moon Phobos, where the vehicle had been programmed to deposit a pair of surface landers. Unable to reacquire communications with Phobos 2, Soviet ground controllers later discover a fatal error in the programming of the probe’s on-board computer, leading to a loss of attitude control similar to the incident that doomed Phobos 1 in 1988. Since delivery of the landers never occurs, the mission is deemed a failure.

The future of Mars exploration

PathfinderA tech demonstration at the Jet Propulsion Laboratory leads to a rethink of the upcoming Mars Environmental Survey mission (MESUR). A self-contained “rover” named Rocky IV convinces mission planners to include a similar rover on an upcoming Mars mission; although the rest of MESUR is eventually scrapped due to budget cuts, the one portion of it to be salvaged is the Mars Pathfinder lander, which will deliver the rover (later to be named Sojourner in a nationwide contest) to the Martian surface sometime in the late ’90s.

Pathfinder en route to Mars

PathfinderNASA/JPL’s low-cost Mars Pathfinder mission lifts off for a date with Mars. The first American Mars lander since the Viking missions of the 1970s, Pathfinder is practically an interplanetary tech demonstration, showing off new landing techniques (aerobraking and landing airbags), new lander designs (a fixed station delivering a wheeled “rover”), and the beginning of a new commitment to exploring Mars. By the time operations are wrapped up on the Pathfinder mission, the total amount of money spent is under $300,000,000.

Pathfinder bounces onto Mars

PathfinderUsing a never-before-attempted system of landing, the Mars Pathfinder unmanned probe employs an aerobraking maneuver to slow down in the planet’s atmosphere, and an all-encompassing layer of airbags to “bounce” onto the surface without using rockets to slow the vehicle down. The weighted landing station rolls to the correct orientation, deflates the airbags, and deploys on schedule, proving the merits of a landing technique that will deliver future Mars landers already in the planning stages.

Red planet rover, please come over

PathfinderSojourner, the original Mars rover, rides out on the Martian surface, getting close-up looks at nearby rocks and demonstrating technologies that are vital to upcoming Mars missions, including automatic hazard detection and avoidance. Sojourner’s ability to “see” obstacles and navigate around them without advice from ground controllers will be essential to later Mars rovers, since it takes seven minutes for a signal to reach Earth, and seven more minutes for instructions to return. The rover captures the public imagination and is even immortalized as a Hot Wheels toy.

Pathfinder falls silent

PathfinderIts ability to recharge its power supply depleted, the Mars Pathfinder lander – now dubbed Sagan Memorial Station – ceases its transmissions to Earth, also cutting off communication with the Sojourner Mars rover. Originally intended for a month-long mission, Pathfinder and Sojourner last three times that long, and give scientists and engineers a wealth of data for planning the twin Mars Exploration Rovers. NASA declares the Pathfinder mission a complete success in early 1998.

Mars Odyssey arrives at the red planet

2001 Mars OdysseyNASA’s 2001 Mars Odyssey probe reaches Mars and settles into an orbit which will gradually be corrected by aerobraking (using the friction of the planet’s atmosphere to slow the vehicle down). Unlike the Mars Surveyor mission, Odyssey does not contain a landing probe, but will instead look at the planet from orbit. Another unique feature of Odyssey’s mission plan is the fact that it won’t be shut down when its scientific investigation has come to an end; it will be left in Mars orbit to serve as a communications relay satellite for future missions.

2003 Robot Hall Of Fame inductees

R2-D2SojournerThe first four inductees – two real and two fictional – are inducted into the Robot Hall Of Fame created by Carnegie Mellon University’s School of Computer Science.

  1. Unimate (1961, General Motors) – the first robotic arm used in car assembly
  2. HAL-9000 (1968, from 2001: a space odyssey)
  3. R2-D2 (1977, from Star Wars)
  4. Sojourner (1996, NASA) – the first successful Mars rover

The panel of judges in future years will pare down the number of nominations awarded to fictional creations. R2-D2 actor Kenny Baker and Douglas Rains, the voice actor behind HAL, are in attendance.

Spirit lands on Mars

SpiritThe first of two new American Mars rovers lands successfully on the red planet. The Mars rover Spirit enters the Martian atmosphere (and cleaves a path right through a dust storm), deploying thick layers of airbags that allow it to bounce safely until landing upright. This is the same landing system employed by the Pathfinder mission in 1997, but the unmanned robot probe in this case is much more sophisticated. Among the primary scientific objectives of Spirit’s mission is to determine if water existed on the surface of Mars for a significant length of time. The Spirit rover will undergo a series of diagnostics and won’t begin its mobile mission for several days. Its identical twin, a rover named Opportunity, will land in three weeks.

Spirit’s murky memory

SpiritJPL engineers begin experiencing severe difficulty communicating with the Spirit Mars rover, which had successfully rolled off of its landing platform the previous week. Just as the rover is ready to begin its travels on the surface of Mars, it stops communicating with Earth, or with any orbiting spacecraft overhead. A command is transmitted to force Spirit to report its condition, and the resulting telemetry indicates that the rover has been continuously rebooting its internal computer system. By the weekend, after worries and warnings that Spirit would probably never regain 100% functionality, JPL’s engineers re-establish communications and received enough diagnostic information to narrow the problem down to Spirit’s flash memory and handling software. Engineers soon resolve the problem, transmitting instructions to work around the potentially corrupted memory, and restoring Spirit so it can continue its exploration.

Opportunity lands on Mars

OpportunityThe Opportunity rover, identical to Spirit, lands on schedule and on target in Mars’ Meridiani Planum region, but initial readings from the surface of Mars indicate that the landing pod containing Opportunity has come to rest on its side. Telemetry signals from Opportunity announce that the the rover has arrived safely and intact, ready to begin its mission, and the opening of the landing vehicle returns Opportunity to its intended upright position. As with Spirit, Opportunity will remain on its landing platform for several days undergoing a series of diagnostic tests before rolling off to the Martian surface for independent exploration, and engineers are keeping a close eye out for signs of a computer problem that has plagued Spirit for several days.

Not just water, but salt water, on Mars

MarsNASA scientists unveil new findings from the two Mars Exploration Rovers, Spirit and Opportunity. While both rovers have found evidence of water erosion in rocks at their respective landing sites, the scientists now say that Opportunity’s landing site – a large crater – features rocks which show conclusive evidence of a large body of salt water, not unlike Earth’s oceans. While no definitive signs of life have been found by Opportunity or its identical twin, these findings continue to add up to a picture of Mars as a place where life once could have thrived.

Mars Rovers’ mission extended

OpportunityNASA announces that the Spirit rover has exceeded its mission goals of 90 continuous Martian days of operation since landing, with over 600 meters of the Martian surface covered. NASA applies for, and receives approval on, a plan to keep Spirit and Opportunity roving through September, almost tripling the rovers’ planned life span. The extended mission, made possible by a budget boost of $15 million, will give engineers the chance to try handing control over to the Rovers’ built-in systems, and it’ll afford a greater opportunity to examine the unusual rocks and evidence of past bodies of water on the Martian surface.

Rosetta at Mars

Rosetta at MarsESA’s unmanned Rosetta space probe, carrying the Philae lander bound for a 2014 rendezvous with Comet 67/P Churyumov–Gerasimenko, makes a gravity-assist flyby of planet Mars to alter its trajectory. As Rosetta will be only 160 miles from the Martian surface at its closest approach, the spacecraft is put into a safe mode for this critical part of its trip, and emerges unscathed. Its next gravity assist will come from Earth itself later in the year.

Mars in asteroid’s crosshairs

MarsAstronomers put the red planet on red alert after predicting 1-in-75 odds for an asteroid to collide with Mars on or near January 30th. The asteroid, discovered in November 2007, is on a trajectory that poses no threat to Earth but has better-than-usual odds of packing quite a wallop for Mars. The impact, if it does happen, could take place on the equator, near the Opportunity rover’s stomping (or, perhaps, roving) grounds, though NASA says it would pose no risk to Opportunity. A crater as large as Arizona’s Meteor Crater could be carved out of the Martian surface by any direct hit that does happen. Scientists prepare to watch the event with keen interest, as this event would be potentially cataclysmic if Earth was in danger, but provides a once-in-a-lifetime opportunity for observation on Mars.

Phoenix successfully lands on Mars

PhoenixRadio signals from the Martian surface indicating the successful landing of NASA’s unmanned Phoenix probe near the north pole of Mars. (To put this feat in perspective: the past several unmanned probes to land safely on Mars used a “bouncing airbag” approach; the last time a lander actually made it to the surface intact with braking thrusters and landing pads – and no airbags – was in 1976, when NASA’s Viking 1 and 2 landers successfully touched down on the planet.) The first stationary (i.e. non-rover) Mars lander since the Viking probes of the 1970s, Phoenix will stay in one spot to conduct three months of studies. Also like the Vikings, Phoenix has a soil-sampling arm and an on-board laboratory to help it determine the presence of water or water ice in its polar vicinity.

Phoenix finds water on Mars, but toxic soil

Phoenix on MarsNASA’s Phoenix lander samples the soil of Mars, and it finds not only water, but an unusual soil composition which would make living off the land unlikely for human travelers. The soil sample in question contains perchlorate, a chemical used on Earth to make solid rocket fuel. So while a hypothetical Mars colony couldn’t use the planet’s own soil for farming, it could certainly launch a rocket or two. But missions scientists are quick to point out that while the presence of perchlorate in the Martian dirt may be unfriendly to humans, there may still have been life on the planet at some point which adapted to that chemical; it may also be a localized phenomenon unique to Phoenix’s polar landing site. (There are some plants on Earth capable of processing perchlorate-infused soil, but they’re generally not regarded as viable crops.) The Phoenix probe’s mission is extended to the end of September so it can continue its studies, and could be extended again at the end of that period, though the harsh Martian winter is likely to deny the non-roving Phoenix the kind of longevity enjoyed by its more mobile siblings, Spirit and Opportunity.

Spirit’s sticky situation

SpiritNASA’s Spirit Mars rover becomes stuck in an area of soft, dusty soil in which its wheels can no longer gain traction. Efforts to simulate the problem on Earth begin, as well as studies to see if Spirit can free itself, but attempts to wiggle or rotate the rover’s wheels on Mars produce no results (and eventually wear out the independent motor of another of its wheels). The attempts to free Spirit from its Martian sandtrap continue through early 2010.