Today, Jan. 24, 2011 marks the 7th anniversary of the safe landing of the Opportunity Mars Exploration Rover (MER). Opportunity will soon celebrate another remarkable milestone – 2500 Sols, or Martian days, roving the red planet. Together with her twin sister Spirit, the NASA rovers surely rank as one of the greatest feats in the annals of space exploration.
“No one expected Spirit or Opportunity to go on this long,” says Ray Arvidson in an interview from Washington University in St. Louis. Arvidson is the deputy principal investigator for the Spirit and Opportunity rovers.
7 Years ago today on Jan. 24, 2004, NASA’s Opportunity rover daringly smashed into the Martian atmosphere at about 12,000 MPH on a one shot, do or die mission with no certainty as to the outcome. Thus began “The Six Minutes of Terror” as the plummeting probes heat shield endured temperatures exceeding 1400°C (2600 F) during the fiery entry, descent and landing phase (EDL).
The spectacular plunge was slowed by atmospheric friction on the heat shield and a complex pre-programmed combination of parachutes and retro rockets, and in the last moments by inflatable airbags designed to allow the robot to bounce about two dozen times and gently and gradually roll to a complete stop.
Ultimately, Opportunity survived intact just like her twin sister Spirit who landed safely three weeks earlier on Jan. 3, 2004. EDL was the culmination of a seven month interplanetary cruise of over 250 million miles from Earth. Both rovers were launched from Cape Canaveral, Florida in the summer of 2003 on board Delta 2 rockets. The dynamic duo landed on opposite sides of the Red planet.
Opportunity is now 84 months into the 3 month mission – still alive and blazing a trail of Exploration and Discovery across the Meridiani Planum region of Mars.
The amazing Martian robot has driven more than 16.5 miles (26.7 km) and snapped over 148,000 pictures. She has suffered remarkable few mechanical failures and they have only minimally impaired her ability to traverse across the surface and conduct science operations.
Both rovers survived far beyond the mere 3 month “warranty” proclaimed by NASA as the mission began with high hopes following the nail biting “Six Minutes of Terror”. At the time, team members and NASA officials hoped they might function a few months longer.
“The rovers are our priceless assets” says Steve Squyres, of Cornell University who is the Principal Scientific Investigator for the mission. Squyres and the entire rover team treat every day with a “sense of urgency” and as “a gift to science”.
Since 2004, the rover’s longevity has surpassed all expectations and nobody on the science and engineering teams that built and operate the twins can believe they lasted so long and produced so much science.
“We have a new Opportunity overview article publishing shortly in the Journal of Geophysical Research (JGR). The Spirit overview paper appeared recently. In addition, there will be about 24 new scientific papers coming out in the new few months as JGR special issues covering more of the MER results. ”
The incredible longevity is “way beyond the wildest expectations of even the people who built the twin sisters” according to fellow Cornell University Professor Jim Bell. “To say the rovers have surpassed expectations is an understatement. We’ve blown them out of the water”. Bell is the lead scientist responsible for the rovers’ high resolution color imaging system called Pancam.
“After 7 years it is still very exciting,“ Arvidson told me. “I am delighted to come to work every day. It’s great to work on the engineering plan for driving and operating the rovers and then see the results the next day.”
Spirit and Opportunity have accomplished a remarkable series of scientific breakthroughs, far surpassing the wildest dreams of all the researchers and NASA officials. Indeed both Mars rovers are currently stationed at scientific goldmines.
Opportunity is currently exploring the outskirts of the stadium sized ‘Santa Maria’ Carter – some 295 feet wide (90 m) – which holds deposits of water bearing minerals that will further elucidate the potential for habitability on the red planet.
The rover arrived at the western edge of the relatively fresh impact crater on Dec. 16, 2010 (Sol 2451). This intermediate stop on the rovers 19 km long journey from Victoria Crater to giant 22 km wide Endeavour Crater will provide important ground truth observations to compare with the orbital detection of exposures of hydrated sulfate minerals. Read more on Santa Maria in the next feature story.
Santa Maria is just 6 km from the western rim of Endeavour which shows spectral signatures of phyllosilicates, or clay bearing minerals, which formed in water about 4 billion years ago and have never before been directly analyzed on the Martian surface.
Phyllosilicates form in neutral aqueous conditions that could have been more habitable and conducive to the formation of life than the later Martian episodes of more harshly acidic conditions in which the sulfates formed that Opportunity has already been exploring during her 7 year long overland expedition.
Since the moment she landed inside ‘Eagle’ crater, Opportunity has been on a Martian crater tour her entire lifetime.
Opportunity “scored a 300-million mile interplanetary hole in one,” Steve Squyres said at that time, by improbably rolling to a stop smack inside the small 66 foot wide ‘Eagle’ crater (see map) after bouncing across the virtually flat and featureless dusty plains of Meridiani. She has been a lucky princess from the moment of her birth, spying layered sedimentary rocks in a bedrock outcrop from first light in her cameras a mere 26 feet or so away. That’s unlike any previous lander.
Seven days later she drove off the landing pad, drilled into the outcrops and collected the “ground truth” science data to prove that hematite was present and liquid water had indeed flowed at Meridiani as a lake or shallow sea on ancient Mars.
After completing her science campaign, she climbed up and over the rim, departed ‘Eagle’ and arrived at ‘Endurance’ about 3 months after landing day.
After numerous tests, Opportunity was commanded to slowly crawl down into the crater. She gradually descending about 30 vertical feet, frequently drilling into the sedimentary rocks and layers to reveal Mars watery past in unprecedented scientific detail for about six months.
In Dec. 2004, Opportunity departed for “Victoria” crater, which many believed would be her final destination. The robot nearly perished in a sand trap at Purgatory along the way during a nearly two year drive across the treacherous martian sand dunes.
Opportunity arrived in Sept. 2006 to unveil Victoria’s Secrets in color. The rover actually wound up spending two years driving to different vantage points around the rim of and then inside the half mile wide crater before departing in Sept 2008 for the unimaginable goal of giant ‘Endeavour’ crater.
The rover team hopes to reach the slopes of Endeavour sometime later in 2011 if all goes well – before her 8th anniversary !
See below some of the best images taken by Opportunity during her 7 Year Martian TrekAstronomy Picture of the Day (APOD) on 2 Oct. 2006 in high resolution
Check out this spherical projection panorama of Opportunity descending inside Victoria Crater on Sol 1332. Credit: NASA/JPL/Cornell/Nasatech.net
Relive Opportunity’s landing:
Dr. Ken Kremer is a speaker, research scientist, freelance science journalist (KSC area,FL) and photographer whose articles, space exploration images and Mars mosaics have appeared in magazines, books, websites and calendars including Astronomy Picture of the Day, NBC, FOX, BBC, SPACE.com, Spaceflight Now, Science and the covers of Aviation Week & Space Technology, Spaceflight and the Explorers Club magazines. Ken has presented at numerous educational institutions, civic & religious organizations, museums and astronomy clubs. Ken has reported first hand from the Kennedy Space Center, Cape Canaveral, NASA Wallops, NASA Michoud/Stennis/Langley and on over 80 launches including 8 shuttle launches. He lectures on both Human and Robotic spaceflight – www.kenkremer.com. Follow Ken on Facebook and Twitter