Mars Rover Driving Leaves Distinctive Tracks

When NASA's Opportunity Mars rover uses an onboard navigation capability during backward drives, it leaves a distinctive pattern in the wheel tracks visible on the Martian ground.

The pattern appears in an image posted at http://photojournal.jpl.nasa.gov/catalog/?IDNumber=PIA14129.

The rover team routinely commands Opportunity to drive backward as a precaution for extending the life of the rover's right-front wheel, which has been drawing more electrical current than the other five wheels. Rover drivers can command the rover to check for potential hazards in the drive direction, whether the rover is driving backward or forward. In that autonomous navigation mode, the rover pauses frequently, views the ground with the navigation camera on its mast, analyzes the stereo images, and makes a decision about proceeding.

When the drive is backward, the drive-direction view from the navigation camera is partially blocked by an antenna in the middle of the rover. Therefore, at each pause to check for hazards, the rover pivots slightly to the side to get a clear view. If it sees no hazard, it turns back to the direction it was going and continues the drive for about another 4 feet (1.2 meters) before checking again. This set of activities leaves tracks showing the slight turnout on a rhythmically repeated basis, like a dance step.

Opportunity has driven more than 1.6 miles (about 2.6 kilometers) since leaving "Santa Maria" crater in late March and resuming a long-term trek toward the much larger Endeavour crater. Opportunity has now driven more than 18 miles (29 kilometers) on Mars.

Opportunity and its twin rover, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued in years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit has not communicated with Earth since March 2010.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.

Fast-Rotating Asteroid Winks For Astronomer's Camera

Video imaging of newly discovered asteroid 2011 GP59 shows the object appearing to blink on and off about once every four minutes.

Amateur astronomers, including Nick James of Chelmsford, Essex, England, have captured video of the interesting object. James generated this video of GP59 on the night of Monday, April 11. The video, captured with an 11-inch Schmidt-Cassegrain telescope, is a compilation of 137 individual frames, each requiring 30 seconds of exposure.

At the time, the asteroid was approximately 3,356,000 kilometers (2,081,000 mile) distant. Since then, the space rock has become something of a darling of the amateur astronomy community, with many videos available. (Here is one recent posting: http://www.youtube.com/watch?v=O7wsAZNr56E )

"Usually, when we see an asteroid strobe on and off like that, it means that the body is elongated and we are viewing it broadside along its long axis first, and then on its narrow end as it rotates ," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. "GP59 is approximately 50 meters [240 feet] long, and we think its period of rotation is about seven-and-a-half minutes. This makes the object's brightness change every four minutes or so."

2011 GP59 was discovered the night of April 8/9 by astronomers with the Observatorio Astronomico de Mallorca in Andalusia, Spain. It will make its closest approach to Earth on April 15 at 19:09 UTC (12:09 p.m. PDT) at a distance just beyond the moon's orbit - about 533,000 kilometers (331,000 miles).

"Although newly discovered, the near-term orbital location of asteroid 2011 GP59 can be accurately plotted," said Yeomans. "There is no possibility of the small space rock entering Earth's atmosphere during this pass or for the foreseeable future."

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch .

NASA's Jupiter-Bound Spacecraft Arrives in Florida

NASA's Juno spacecraft has arrived in Florida to begin final preparations for a launch this summer. The spacecraft was shipped from Lockheed Martin Space Systems, Denver, to the Astrotech payload processing facility in Titusville, Fla., today. The solar-powered Juno spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere.

"The Juno spacecraft and the team have come a long way since this project was first conceived in 2003," said Scott Bolton, Juno's principal investigator, based at Southwest Research Institute in San Antonio. "We're only a few months away from a mission of discovery that could very well rewrite the books on not only how Jupiter was born, but how our solar system came into being."

Next Monday, Juno will be removed from its shipping container, the first of the numerous milestones to prepare it for launch. Later that week, the spacecraft will begin functional testing to verify its state of health after the road trip from Colorado. After this, the team will load updated flight software and perform a series of mission readiness tests. These tests involve the entire spacecraft flight system, as well as the associated science instruments and the ground data system.

Juno will be carried into space aboard a United Launch Alliance Atlas V rocket lifting off from Launch Complex-41 at the Cape Canaveral Air Force Station in Florida. The launch period opens Aug. 5, 2011, and extends through Aug. 26. For an Aug. 5 liftoff, the launch window opens at 8:39 a.m. PDT (11:39 am EDT) and remains open through 9:39 a.m. PDT (12:39 p.m. EDT).

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute at San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, is building the spacecraft. The Italian Space Agency in Rome is contributing an infrared spectrometer instrument and a portion of the radio science experiment. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida. JPL is a division of the California Institute of Technology in Pasadena.

Mars Rover's 'Gagarin' Moment Applauded Exploration

The team using Opportunity to explore the Meridiani Planum region of Mars since 2004 chose "Gagarin" for what they would call the rock that the rover examined beside "Vostok" crater. A target for close-up examination on Gagarin is called "Yuri."

To commemorate Gagarin's flight, a color image of the rock on Mars has been posted at http://photojournal.jpl.nasa.gov/catalog/PIA13984. The image combines frames taken through three different filters by Opportunity's panoramic camera.

Early accomplishments in the Space Age inspired many of the researchers exploring other planets robotically today, who hope their work can, in turn, help inspire the next generation.

"The 50th anniversary of mankind's first fledgling foray into the cosmos should serve as an important reminder of the spirit of adventure and exploration that has propelled mankind throughout history," said Mars rover science team member James Rice of NASA Goddard Space Flight Center, Greenbelt, Md. "We are a species of explorers; it is encoded into our very DNA."

Rice continued, "Half a century ago Yuri Gagarin was lofted into a totally unknown, remote and hostile environment and in doing so opened up a new limitless frontier of possibilities for mankind. A mere 23 days later another brave human, Alan Shepard, climbed aboard a rocket and ventured into the starry abyss. Their courage and vision continue to inspire and lead us into the unknown. Hopefully, one day in the not too distant future it will lead humanity on a voyage to Mars."

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued in years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit has not communicated with Earth since March 2010. Opportunity remains active. This month, it has passed both the 27-kilometer and 17-mile marks in its total driving distance on Mars.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington. For more information about the rovers, see http://www.nasa.gov/rovers.

Mars Rover's 'Gagarin' Moment Applauded Exploration

A flat, light-toned rock on Mars visited by NASA's Mars Exploration Rover in 2005 informally bears the name of the first human in space, Yuri Gagarin, who rode into orbit in the Soviet Union's Vostok-1 spacecraft on April 12, 1961.

The team using Opportunity to explore the Meridiani Planum region of Mars since 2004 chose "Gagarin" for what they would call the rock that the rover examined beside "Vostok" crater. A target for close-up examination on Gagarin is called "Yuri."

To commemorate Gagarin's flight, a color image of the rock on Mars has been posted at http://photojournal.jpl.nasa.gov/catalog/PIA13984. The image combines frames taken through three different filters by Opportunity's panoramic camera.

Early accomplishments in the Space Age inspired many of the researchers exploring other planets robotically today, who hope their work can, in turn, help inspire the next generation.

"The 50th anniversary of mankind's first fledgling foray into the cosmos should serve as an important reminder of the spirit of adventure and exploration that has propelled mankind throughout history," said Mars rover science team member James Rice of NASA Goddard Space Flight Center, Greenbelt, Md. "We are a species of explorers; it is encoded into our very DNA."

Rice continued, "Half a century ago Yuri Gagarin was lofted into a totally unknown, remote and hostile environment and in doing so opened up a new limitless frontier of possibilities for mankind. A mere 23 days later another brave human, Alan Shepard, climbed aboard a rocket and ventured into the starry abyss. Their courage and vision continue to inspire and lead us into the unknown. Hopefully, one day in the not too distant future it will lead humanity on a voyage to Mars."

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued in years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit has not communicated with Earth since March 2010. Opportunity remains active. This month, it has passed both the 27-kilometer and 17-mile marks in its total driving distance on Mars.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington. For more information about the rovers, see http://www.nasa.gov/rovers.

Alternatives Have Begun in Bid to Hear from Spirit

Hopes for reviving NASA's Spirit Mars rover dimmed further with passage last week of the point at which the rover's locale received its maximum sunshine for the Martian year.

The rover team has tried to contact Spirit for months with strategies based on the possibility that increasing energy availability might wake the rover from hibernation. The team has now switched to communication strategies designed to address more than one problem on the rover. If no signal is heard from Spirit in the next month or two, the team at NASA's Jet Propulsion Laboratory, Pasadena, Calif., will shift to single-rover operations, continuing to operate Spirit's active twin, Opportunity.

"The commands we are sending starting this week should work in a multiple-fault scenario where Spirit's main transmitter is no longer working and the mission clock has lost track of time or drifted significantly," said JPL's John Callas, project manager for Spirit and Opportunity.

Spirit landed on Mars Jan. 4, 2004 Universal Time (Jan. 3, Pacific Time) for a mission designed to last for three months. After accomplishing its prime-mission goals, Spirit worked for more than five years in bonus-time extended missions.

Spirit has not communicated since March 22, 2010. Power output from its solar array had been waning prior to that, and the rover had been expected to go into a low-power hibernation mode. With drive motors on two of its six wheels no longer working, Spirit had been unable in preceding months to maneuver much in its sand-trap location. The rover could not get to a favorable tilt for its solar panels as Martian winter approached.

During the Martian winter with most heaters turned off, Spirit experienced colder internal temperatures than in any of its three previous winters on Mars. The cold could have damaged any of several electronic components that, if damaged, would prevent reestablishing communication with Spirit.

However, attempts to regain contact have continued for more than eight months in the possibility that the seasonal increase in solar energy available at Spirit's location would revive the rover. NASA's Deep Space Network of antennas in California, Spain and Australia has been listening for Spirit daily. The rover team has also sent commands to elicit a response from the rover even if the rover has lost track of time, or if its receiver has degraded in frequency response.

The available solar energy at Spirit's site was estimated to peak on March 10. Revised commanding began March 15, including instructions for the rover to be receptive over UHF relay to hailing from the Mars orbiters for extended periods of time and to use a backup transmitter on the rover.

Spirit and Opportunity both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Opportunity landed three weeks after Spirit.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Science Mission Directorate, Washington.