Entries in Rover (3)


Mars Opportunity Rover: Nine Years and Still Going

Cornell/JPL/NASA(NEW YORK) -- When the Mars rover Opportunity settled on the Martian surface nine years ago on Friday, mission managers at NASA said they would be pleased if it lasted for 90 days.

Instead, it's been 3,201 days, and still counting.  The rover has driven 22.03 miles, mostly at a snail's pace, from one crater to another, stopping for months at a time in the frigid Martian winters.  The six motorized wheels, rated to turn 2.5 million times, have lasted 70 million, and are all still working.

"Opportunity is still in very good health, especially considering what it's gone through," said John Callas, manager of NASA's Mars Exploration Rover project.  "The surface of Mars is a pretty tough place; there can be temperature fluctuations of a hundred degrees each day.  That's pretty hard on the hardware."

When Opportunity and its twin rover, Spirit, reached Mars in January 2004, there was a fair bit of sniping that NASA, with all that 90-day talk, was playing down expectations.  It escalated when Steve Squyres of Cornell University, the principal investigator for the missions, said things like, "We're on Sol 300 of a 90-Sol mission."  (A Sol is a day on Mars, and lasts 24 hours, 39 minutes.)

Callas and others have insisted that the prediction was based on engineering, not a nod to public relations.

"There was an expectation that airfall dust would accumulate on the rover, so that its solar panels would be able to gather less electricity," said Callas.  "We saw that on Pathfinder," a small rover that landed on Mars in 1997. "The cold climate was also expected to be hard on the rovers' batteries, and changes in temperature from night to day would probably pop a circuit or two."

Instead, the temperatures weren't quite as tough as engineers had expected, and the rovers proved tougher.  They did become filthy as the red Martian dust settled on them, reducing the sunlight on the solar panels -- but every now and then a healthy gust came along, surprising everyone on Earth by cleaning the ships off.

Spirit, in hilly territory on the other side of the planet, finally got stuck in crusty soil in 2009, and its radio went silent the next year.  But Opportunity, though it's had some close calls, is still going.

In its first weeks, NASA said Opportunity found chemical proof that there had once been standing water on the surface of Mars -- good news if you're looking for signs that the planet could once have been friendly to life.  Since then, it's been sent to other places, with rocks and soil that are probably older, and with clay that may have been left by ancient rivers.

About 20 NASA staff members still work full-time on Opportunity at the Jet Propulsion Laboratory in Pasadena, Calif.  Another 60 split their time between Opportunity and other projects, such as the Curiosity rover that landed last August.  About 100 scientists, doing research on Mars, pop in and out.

Copyright 2013 ABC News Radio


WATCH: NASA's Viral Video on Curiosity Rover's Mars Landing

NASA Jet Propulsion Lab(HOUSTON) -- At NASA they've called it "Seven Minutes of Terror" -- the white-knuckle moments as the new Curiosity rover, scheduled to land on Mars on the night of Aug. 5, goes tearing into the Martian atmosphere and, engineers hope, lands safely seven minutes later.

NASA made a computer-animated video of the landing sequence, and found it has a hit on its hands.  With almost a month to go until landing, the video has been viewed more than half a million times on YouTube alone, and it's appeared on countless other websites as well.

"We've got literally seven minutes to get from the top of the atmosphere to the surface of Mars -- going from 13,000 miles an hour to zero, in perfect sequence, perfect choreography, perfect timing," said Tom Rivellini, a NASA engineer who appears in the video.

NASA has been very good at visualizing its robotic missions, and, in fact, did similar videos (with the same title) for previous Mars landings in 2004 and 2008.  But none went viral the way Curiosity's has.

The Curiosity rover, known originally as Mars Science Laboratory, is about the size of an SUV.  Behind schedule and over budget, it was a decade in the making and has cost $2.5 billion.  The nickname Curiosity came from a schoolchild who won a NASA contest to pick something memorable.

Because of its size, Curiosity cannot just fly to Mars and come to a stop.  It enters the Martian atmosphere encased in a heat shield, then lets out a parachute, then fires retro rockets, then is lowered by cables from a landing stage and finally -- if it hasn't left a $2.5 billion crater in the Martian soil -- sends a signal that it's safely down.

And all this has to happen automatically.  Mars will be 150 million miles from Earth on Aug. 5 -- so distant that radio commands from Earth, travelling at the speed of light, would take 14 minutes to get there.

NASA has tried to play down expectations that Curiosity could find life on Mars.  But if there ever were living microbes, the rover probably has the equipment to see signs that they were there.

An earlier rover, Opportunity, is still functioning after eight years on the Martian surface.  It found geological evidence that scientists say shows Mars was once warm and wet, with pools of briny water that dried up eons ago.

NASA would like to expand on that find, which is why it has sent the larger and more ambitious Curiosity rover.

Copyright 2012 ABC News Radio


Mars Rover Spirit: Mission Over After 7 Years on Martian Surface

PRNewsFoto/NASA(WASHINGTON) -- The mission of the Mars rover Spirit is finally over after seven remarkable years roaming the cold Martian surface, NASA said Tuesday. Spirit landed on Mars in January 2004, and was expected at the time to last about three months. Instead, it kept going for more than five years.

"We always knew we would get to this point," said John Callas, the project manager for Spirit and its twin rover Opportunity, which is still operating. "We're here today because we wore Spirit out."

You may recall that the rover got stuck in 2009 on the edge of a small crater, and when controllers on Earth couldn't free it after months of trying, they knew the clock was ticking.

Among other things, they couldn't move the rover to a sun-facing slope for the six-month-long Martian winter, so that its solar panels could gather at least enough energy to run heaters and the rover's radio system. The solar panels are considered essentially useless unless the sun shines almost directly down on them.

Without heaters, the temperature of the rover's electronics, NASA says, probably dropped to something like 65 degrees below zero Fahrenheit. Its last confirmed signal came on March 22, 2010.

After the Martian winter ended, engineers tried repeatedly to get the rover's computer to respond to signals. They sent hailing signals once a week. No joy. They said they would make one more try overnight and then stop.

Spirit's twin, Opportunity, is still driving slowly on the opposite side of the planet, making a forced march toward a large crater called Endeavour. It landed a month after Spirit arrived.

A reminder: NASA's gotten its money's worth out of the rovers. When Spirit landed, NASA (perhaps playing down expectations), said it planned a mission that would last 90 "sols," or Martian days. Today was sol number 2,537.

"Yes, there's a sadness that we have to say goodbye to Spirit, but we also remember what a massive overwhelming success it was," Callas said in a teleconference with reporters.

Copyright 2011 ABC News Radio

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