Over the Hills and through the Sand: Six Years of Driving on Mars

John Wright
John Wright

I almost didn’t get to drive the rovers.

As one of the five developers of the software used to build the command sequences and rehearse and visualize the rover activities, I really wanted to be one of the people using it in flight. Unfortunately, only three members of the team were selected to be Rover Planners (a job title we believe was chosen in place of Rover Drivers to make the job sound very boring and reduce competition for it). I was not one of them.

I was originally slated to be a downlink analyst looking at the telemetry from the rover to assess the driving and arm operations. This entailed months of training to learn how to run somebody else’s software, a much more difficult task than using your own. Fortunately for me, and unfortunately for someone else, a position opened up on the Rover Planner team and I was transferred over. This entailed more months of training to learn the procedures, but the fuse was very short since Spirit was careening towards its landing. The fact that I knew the software tools already was the saving grace that allowed me to be ready to go on landing day.

Looking back on these six years, I’m tired, but amazed, when I think about how much we’ve accomplished and continue to accomplish. During the prime mission, I remember hearing Steve Squyres say how much we would like Spirit to go explore the hills in the distance but that we would never get there. Well, we have driven to the top of those hills and down the other side.

I remember when Opportunity drove into Purgatory and the Rover Planners immediately said that we needed to back out of the sand dune. After months of testbed activities and review, the decision was made to back out of the sand dune. I can remember looking over at Scott Maxwell, another Rover Planner, and saying to each other “This is so cool!!” (We still say that).

Some of my favorite memories are of giving talks to school kids about what I do, though one of my saddest was being asked by one of the kids, an honor student, if the moon landings were faked. I especially enjoyed calling up Car Talk and asking the guys how to keep our electric vehicle running through the winter on Mars. I laugh when I think about a recent talk I had with Scott when the right front wheel of Spirit seemed to work again after four years of being dragged around. Scott said he didn’t know if we were driving with six wheels or only five. Immediately I jumped in, Dirty Harry-style, with, “I know what you’re thinking punk. Are we driving with six wheels or only five? To tell the truth, I don’t know myself. The question you have to ask yourself is, ‘Do I feel lucky?’ Well, do ya’, punk?”

As we work on getting Spirit out of the current sand trap, I feel manic-depressive about our chances. One day I am sure we will have no problem but the next day I am equally convinced that all is lost. This is about the toughest situation we have ever had to get out of. When we are stuck, it seems as if we are always running out of daylight, which translates to power. It happened at Tyrone, it happened at Tartarus, and it has happened at Troy.

Hmmm, maybe we should stop giving names to locations that start with T.

    11 Responses to “Over the Hills and through the Sand: Six Years of Driving on Mars”

  1. Bob in Texas Says:
    January 1st, 2010 at 2:31 am

    Have you thought about using the arm as a cantilever to tilt Spirit? Or having it scoop up some soil or get a rock on the end of it (if that is in any way possible) to add weight before cantilevering it over the opposite side you want lifted? Even commanding it up and down in very short jerky movements at a cantilver position while on the opposite side spinning a wheel.

    JPL Media Relations responds:

    Thank you for your suggestions. The engineers have analyzed several possible uses of the robotic arm. It actually has very little strength and could not lift, push or pull the rover enough to benefit. One possible use still under consideration as of Jan. 15 is to try pushing a small rock or two under the left-front wheel (the only operable one within reach of the arm).

  2. Fred Hutto Jr. Says:
    January 1st, 2010 at 7:26 pm

    I saw on t.v. about the mars rover Spirit. I wonder why the wheels wernt a lot biger?Made out of solid rubber? And if you would put signal relays betwean Earth and Mars insted of 20 min. to get a command it would take 20 sec.And have the relays so they can adjust to diffrent missions.And for power the rover dident have a battery power storage?And if it had a problem in dark places why not have a 50 ft. cord with a baloon on it with some kind of solor power device on it to get power.And then when power is done reel it in.

    JPL Media Relations responds:

    Thank you for your suggestions. If the wheels had been made of rubber, they would have worn away against the rough rocks on Mars long before Spirit had driven for more than five years. The size of wheels and other components were set to enable accomplishing the mission goals (which was done years ago) while matching the vehicle to its launch vehicle. A larger launch vehicle adds significantly to the budget. The next Mars rover, Curiosity, will use bigger wheels and a bigger launch vehicle, but its mission, Mars Science Laboratory, will include only one rover instead of two. Signal relays would not shorten the time of sending radio signals between Earth and Mars. The signals already travel at the speed of light. Spirit and Opportunity do have batteries that allow spreading out the time of use of electricity generated by the solar panels during sunshine hours. The amount of solar energy would be lower in the winter even if the solar panels were 50 feet aloft. Designs for lasting a long time in harsh environments generally minimize the number of moving parts.

  3. Tony Says:
    January 4th, 2010 at 12:25 pm

    I am watching in great anticipation Spirit’s attempts to free itself from the sand. Could the team not try to use the robotic arm to push the rover backwards? What about retracting the front wheels? Probably already done. Good luck!

    JPL Media Relations responds:

    Thank you for your suggestions. The engineers have analyzed several possible uses of the robotic arm. It actually has very little strength and could not lift, push or pull the rover enough to benefit. The extending of the wheels after landing was a one-time process that cannot be undone or repeated.

  4. Paul Says:
    January 10th, 2010 at 11:27 pm

    Even if Spirit never gets out of its sand trap it has fired the imaginations of people all over the country. I am sure that a new generation of rover drivers will be coming along in a few years. It has renewed the interest of those like me who were around for the Mariners & Vikings. Thank you.

  5. Paul Mirowsky Says:
    January 25th, 2010 at 10:30 am

    Perhaps it is possible to take advantage of reflected light off nearby hills or mountains instead of
    direct sunlight during winter months.
    Has there been a geological reflection test to the environment as compared to the solar cell power production?

    JPL Media Relations responds:

    The most significant secondary source of photons for the solar array is the diffuse glow from the sky, rather than reflection from rock surfaces. Even this glow provides very little power compared with the amount from direct sunlight.

  6. Gary Says:
    January 31st, 2010 at 12:21 pm

    What new features and functionality will be designed into the new rover given what has been learned during the past six years of the mission?

    JPL Media Relations responds:

    The biggest differences in design for Curiosity are based on the different mission goals for the Mars Science Laboratory than for the Mars Exploration Rovers, rather than on lessons learned from Spirit and Opportunity. In terms of rover design, the main lesson learned from having Spirit and Opportunity operate for more than 24 times the planned mission is that the designs worked extremely well. Curiosity is designed to allow choice of a landing site farther from the equator (thus with less winter sunshine and lower winter temperatures), to carry a more massive set of science instruments, and to drive farther and work longer than the mission goals set for Spirit and Opportunity. Thus, it has uses heat from a radioisotope to generate electricity, instead of photovoltaic panels; it is larger, including larger wheels; and its motors are a new design, for durability at lower temperature. Because Curiosity is heavier to carry a heavier set of instruments, a new landing system also was designed for getting it to the surface of Mars.

  7. Andrew Says:
    March 3rd, 2010 at 8:15 pm

    I like sciecne, its my fav subjuct :D

  8. Terri Says:
    March 4th, 2010 at 3:52 pm

    I have just one question. Why has non one ever turned the rover’s camera’s up to look and see the twin moons? That is one thing I would really love to see, just once, from the planet’s surface.

    JPL Media Relations responds:

    You’re in luck, Terri. Spirit’s views of Mars’ moons and some other sights in the Martian sky have been available for years. Shots of the moons taken by Spirit, including moons transiting the sun and a Phobos lunar eclipse, are among the images at http://photojournal.jpl.nasa.gov/target/Deimos and http://photojournal.jpl.nasa.gov/target/Phobos . Spirit’s photo of Earth from the surface of Mars is at http://photojournal.jpl.nasa.gov/catalog/PIA05547 and, without labels, at http://photojournal.jpl.nasa.gov/catalog/PIA05560 .

  9. am Says:
    June 20th, 2010 at 9:42 am

    you should be glad you avoided official rover driver designation, your insurance rates are probably much better off as a result, on a more serious note two recent developments, DAWN’s ion propulsion MPG record setting performance and the JAXA/NASA Habayashy (sp) project returning samples from distant objects, is opening the door for consideration of retrieving the Spirit Rover from its landlocked position on Mars and placing it on Earth orbit until a vehicle is developed with capability to bring it back to terra firma……
    measuring the wear and tear of a man made vehicle that has spent a while on Mars would be a priceless project well received by the worldwide tecchie community, and a boon to future lander vehicle designers

  10. am Says:
    August 7th, 2010 at 8:55 am

    and another thing, if Spirit Rover is experiencing energy weakness, as the solar panel collectors may not be gathering enough light to maintain onboard temperatures, then it behooves us to R&D alternative sources of energizing vehicles in similar situations, albeit, retrofitting orbiters with lasers able to wirelessly transmit light or electrical charges to solar groundbased panels… in sufficient volumes to restore some degree of operational functionality in the hapless Spirit Rover ..having said that, it should be begrudgingly admitted that knowledge which laserable light wavelenght is most likely to yield the greates efficiency is neophyte….wireless transmission of electricity came to a standstill on terra firma when JP Morgan pulled the plug on Nikki Tesla’s R&D in the early 1900s….the widespread popular acceptance of broadband in the first decade of this third millennium AD, bids interested parties revisit the field of wireless transmission of electricity as Mother Theresa used to say “the predicament may seem drastic, but it is not hopeless.”

  11. xenki Says:
    January 7th, 2011 at 2:50 pm

    one of the subjects that i like the most

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