NASA?snext red planet probe, the Mars Science Laboratory ? now dubbed Curiosity ? hasbeen years indevelopment and overcome numerous hurdles. Now engineers are taking a closelook at the car-sized rover?s nuclear power plant.
Engineerspreparing the Curiosityrover for its planned launch in 2011 found a slightly faster than expecteddegradation rate in the rover?s multi-mission radioisotope thermoelectricgenerator, or MMRTG for short.
TheMMRTG is designed to enhance the rover?s range and operability and lifetime onthe red planet. The unit uses some 10 pounds (4.8 kg) of plutonium dioxide,mostly plutonium-238, as a heat source.
?Rightnow we are working with Department of Energy to try and understand it,?McCuistion told SPACE.com, ?but to-date the only impact is expected to be someoperational work-arounds in Martian winter?slower operational pace essentiallybecause it?ll take longer to charge the batteries.?
Curiosity?s MMRTG power plant is currently fully fueled and storedat the Idaho National Laboratory, where it is awaiting delivery to the rover?slaunch site in Cape Canaveral, Fla., next year [Graphic: HowMars Science Laboratory works].
Optimisticfor Mars
The radioisotopethermoelectric generator oddity is the latest in a host of technologicalteething problems of the now roughly $2.3 billion mission led to a slip in itslaunch from 2009 to next year.
Althoughchallenges still remain in getting the nuclear-powered rover spiffed up andready for sendoff to Mars, many of those problems have been resolved ? includinga potentially serious issue with the probe?s metal skeleton.
Acontractor had falsified documentation as to the qualityof titanium it had supplied to the aerospace community. That forced NASA tobacktrack through paperwork to assure that the Curiosity rover didn?t use batches ofthe ?wrong stuff.?
Thepaperwork to sort through the use of titanium on Curiosity is now over 90percent complete, ?and no show stoppers, so I am feeling cautiously optimisticthat MSL will not be impacted,? said Doug McCuistion, Director of the NASA MarsExploration Program in Washington, D.C.
Whereto land
Meanwhile,the science community is revving up to make use of Curiosity and its suite of sciencegear.
?Thekey technological and schedule problems are being solved and the Mars communityis quite pleased,? noted John Mustard of Brown University in Providence, RhodeIsland. He?s also chair of the Mars Exploration Program Analysis Group, chartedby NASA to assist in planning the scientific explorationof the red planet.
ThisSeptember Mars scientists will take part in the fourth landing site workshop for Curiosity.That meeting will focus on the outstanding science questions and relativemerits of the final Mars Science Laboratory?s potential landing sites thatremain under deliberation.
According to JohnGrant of the Smithsonian?s Center for Earth and Planetary Studies and MattGolombek of the Jet Propulsion Laboratory -- the co-chairs of the Mars LandingSite Steering Committee -- the process of selecting Curiosity?s landing site isconverging.
Nearly 60 sites for themission?s planned touchdown have been mulled over for more than three years.Only Eberswalde crater, Gale crater, Holden crater, and Mawrth Vallis remain.
Grant and Golombekreport that each of these sites represents exciting science opportunities forMSL and has been highly rated by the science community. A fifth site may beadded to the list, a decision that will be forthcoming in May by the MSLproject with input from the MSL Landing Site Steering Committee.
Avatar in red?
Along with animpressive array of research duties, the Curiosity rover?s imaging andscientific suite will be the most capable education and public outreach packageever placed on the surface of another planet ? and given a successfulMars landing promises to provide awesome images and movies.
One new capacitybeing re-evaluated is to imbue Curiosity with a zoom 3D camera capability. Malin Space ScienceSystems in San Diego, California is building it for Oscar-winning director,James Cameron, who recently delivered Avatar, his blockbuster cinematic experience.
Cameron is a memberof the MSL science team, firmly focused on video documentation and traversescience using the rover?s MastCam, the Mars Hand Lens Imager (MAHLI), and theMars Descent Imager (MARDI) that will record in ?ride-along video? fashion thefinal two minutes of landing.
Earlier plans to haveMastCamzoom were scrapped to meet acceptable technical, schedule and cost riskstandards in 2007. But the idea is back on the table, maybe.
Today, the rover?s fixed MastCam is already built and delivered,and can fly on MSL as planned if the zoom version doesn?t come together intime.
?But if it does, and if it passes qualification tests withoutholding up the MSL schedule, it could be swapped onto the rover,? NASA spokesman?Dwayne Brown told SPACE.com. ?NASA has tentatively agreed, and is paying forthe new work on the zoom, which is expected to cost about $5 million. However,nothing has been confirmed at this time.?
- Images? Rovers on Mars
- MostAmazing Mars Rover Discoveries
- Video? Building the Mars Science Laboratory Curiosity
LeonardDavid has been reporting on the space industry for more than five decades. Heis past editor-in-chief of the National Space Society's Ad Astra and SpaceWorld magazines and has written for SPACE.com since 1999.
