Date: November 24, 2011
Title: Mars Science Laboratory
Podcaster: Tony Rice
Link: Tony’s blog: http://utprosim.com/
Video podcast version of this podcast: http://tinyurl.com/365msl
Description: On Saturday, November 26th, the launch window for the Mars Science Lab mission and it’s Curiosity rover will open at 10:02 am for a 354 million (570 million km) trip to mars. Curiosity is the largest, most complex and most capable robotic vehicle to be sent to the surface of another planet. JPL Mars scientists describe it as their dream machine. You can watch the launch live on NASA TV or online at mars.jpl.nasa.gov.
Bio: I’m an amateur astronomer from Cary, North Carolina and a volunteer in the NASA/JPL Solar System Ambassador Program. I get to go into schools, visit with scout programs and talk about space.
Sponsor: This episode of “365 Days of Astronomy” has been sponsored ‘For Lilah, who dreams of being the first girl to live on the moon! Happy 6th Birthday!’
Transcript:
On Saturday, November 26th, the launch window for the Mars Science Lab mission and it?s Curiosity rover will open at 10:02 am for a 354 million (570 million km) trip to mars. Set atop a 19 story Atlas V-541 launch vehicle at Launch pad 41 at the Kennedy Space Center in Florida. This massive rocket is needed to provide the velocity to help the large rover to escape Earth?s gravity. Fully fueled the vehicle weighs in at 1.17 million pounds (531,000 kg) or about 14 fully loaded big rigs. You can watch the launch live on NASA TV or online at mars.jpl.nasa.gov.
Curiosity is the largest, most complex and most capable robotic vehicle to be sent to the surface of another planet. JPL Mars scientists describe it as their dream machine. It?s over 6 feet tall and weighs over 2000 pounds and includes 10 science instruments that can perform in situ or in place gathering testing of materials never before possible. NASA has partnered with agencies in France, Germany, Canada, and Spain to bring together a wide array of instruments, which will search, for signs of life on the red planet.
This is the 3rd rover to be sent to the surface of Mars.
1997?s Mars Pathfinder Mission sent Sojourner, a rover about the size of a milk crate the Ares Valley in the northern hemisphere. Sojourner and it?s instrument equipped lander Pathfinder taught us that Mars was more Earth-like than previous believed. Rounded pebbles and abundant particles indicated that while Mars may have been water rich at some point, that point wasn?t in recent history.
2003?s Mars Exploration Rover Mission sent the golf-cart sized Spirit and Opportunity rovers to ?follow the water? in their investigations of the Martian landscape. Opportunity landed in the Eagle crater near the equator while Spirit landed in the Gusev crater further south and on the opposite side of Mars. Spirit and Opportunity were each planned for 90 sols or Martian days which are about 37 minutes longer than an Earth day. As of this podcast, Opportunity was on Sol 2785 or nearly 31 times it?s planned duration. That?s not unlike the family car lasting 300 years.
The Curiosity rover builds on those missions that came before it and focuses on seeking the signs of life on Mars. Unlike previous rovers equipped with abrasion tools that could peer only a few millimeters into rocks, Curiosity is fitted with a jackhammer drill and swappable drill bits capable of reaching ten times deeper beneath the rock?s surface. It?s even equipped with a dust removal tool to keep observation points tidy.
Drilled material is then analyzed, onboard the rover, for it?s mineral as well as chemical makeup. Samples are analyzed by dumping them sample cups, heating the material which causes outgassing that can be analyzed by onboard instruments. One instrument is devoted to looking for organic materials that might indicate conditions to support life.
The Mars Hand Lens Imager is capable of imaging details smaller than the width of a human hair enabling close-up pictures of rocks, soil and, if present, ice.
Curiosity?s mission is scheduled for 1 Martian year but anticipation is high that Curiosity can continue the tradition of longevity started by it?s predecessors. Unlike Spirit and Opportunity, Curiosity is powered by a radioisotope thermoelectric generator (RTG) which produces electricity from the heat of decaying plutonium-238. That heat is also used to warm electronics within the rover.
The use of the RTG for power also helps free the rover from complications that come with solar power on mars including the minimal sunlight during winter and dust which reduces the efficiency of solar cells.
Like a curious child darting around a museum, previous rovers have surveyed their surroundings to learn more about the Martian landscape. This observation is critical identify geologically interesting spots to rove to. Curiosity can do this as well but adds the ability to analyze the makeup of rocks up to 30 feet away. The ChemCam instrument focuses a laser with the equivalent of a million light bulbs for 5 one-billionths of a second, remotely ionizing the rock then analyzes the resulting plasma with a spectrometer. This allows the rover to determine the sample?s atomic makeup without lifting so much as a wheel. This will be invaluable in planning the rover?s day to day tasks.
In addition to the geologic instruments, instruments will monitor weather above the rover and look for minerals and the existence of water in the ground beneath. NASA?s Exploration Systems Mission Directorate along with the German Space Agency have provided an instrument which measures radiation near the surface of Mars for determining what kind of shielding might be needed to ensure success of future human missions.
All that data will be transmitted back to Earth via three antennas. two communicated directly with NASA?s Deep space Network antennas on Earth . The third is a ultra-high frequency antenna used to communicate with the Mars Orbiters circling the planet.
Curiosity has a pair of identical computers onboard which include radiation hardened CPUs based on PowerPC 750 architecture and operate at 200 megahertz. Each computer has 256MB of RAM and 2GB of flash memory, about 8 times as much as Spirit or Opportunity)
Like other rovers, Curiosity?s team of drivers wont be sitting behind a steering wheel in Pasadena, California. It takes light over 12 minutes to reach Mars from the sun and nearly as long for commands from JPL to reach the rovers. Commands including driving directions are send in batches and like all rovers, Curiosity will be driven slowly. Despite it?s large size, it wont be tearing around the landscape and will likely be driven 8 hundredths of a mile per hour. There?s no rush on Mars.
In July of this year, Gale crater just south of the equator, was selected as the landing site for Curiosity when reaches Mars in August of 2012. Described as the Neapolitan of landing sites, this 100 mile wide crater has always been high on scientist?s lists of locations to visit because it offers multiple interesting features and unique 3 mile high mound consisting of layered rock. It?s those layers that scientists are eager to study. The sediment left in layers starting with clays and sulfates topped with just sulfate salts represent a virtual time machine of Mars early history and giving clues about climate change and helping us understand whether Mars may have been able to support microbial life.
While rover missions to Mars have enjoyed good success rates, getting to Mars is no simple task. Since the first attempted flyby mission experienced launch failure in 1960, Russian, Japanese, European and American agencies attempting to send spacecraft to mars have had a 50/50 chance of success overall. As recently as 2 weeks ago, the Russian Fobos Grunt mission which was to reach the Martian moon Phobos and return samples to Earth was stuck in low Earth orbit having failed to burn its engines to start the journey towards Mars.
The knowledge gained from engineering this mission along with the science gained from operating it will prove valuable to designing a mission to take humans to the surface of Mars someday.
For a video version of this podcast, visit my blog at http://utprosim.com/msl and don?t forget to look up in the morning sky for your own view of Mars.
End of podcast:
365 Days of Astronomy
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