NASA Plans to Visit a Near-Earth Asteroid   
       
   August 16, 2011: In a few years a NASA spacecraft will seek the building   
   blocks of life in a shovelful of asteroid dirt. The OSIRIS-REx(1) spacecraft,   
   targeted for launch in September 2016, will intercept asteroid 1999 RQ36,   
   orbit it for a year, and then reach out a robotic arm to touch its surface.   
       
   "We call it 'touch and go,'" explains principal investigator Michael Drake of   
   the University of Arizona. "OSIRIS-REx will approach the surface at 0.1 m/sec   
   (only 0.2 mph, less than a tenth of walking pace) and, without landing,   
   stretch out its arm equipped with a sample collector. We'll simply agitate the   
   asteroid's surface with ultra-pure nitrogen to stir up material for capture."   
       
   http://www.youtube.com/watch?v=e6XbYLGWmOs   
       
   A YouTube video shows how OSIRIS-REx will approach the asteroid, gather   
   samples, and propel the sample capsule back to Earth.   
       
   Asteroids appear to be as lifeless as Yorick's skull, yet material captured   
   from 1999 RQ36 could hold clues to life's origin on Earth.   
       
   Some scientists believe Earth's surface was sterilized(2) soon after the   
   planet was formed some 4.5 billion years ago. Planetoids and other debris left   
   over from the genesis of planets pummeled Earth, turning it into a cratered   
   wasteland. The tremendous kinetic energy from the collisions heated Earth to   
   the boiling point.   
       
   "Earth at 'time zero' had a steam atmosphere that was wrung out to make a   
   boiling hot ocean," says Drake. "Imagine standing on a lava lake in Hawaii,   
   but it's a planet-wide, 600 mile deep lake. You and everything else, including   
   any organics and any one-celled organisms, would be converted to carbon   
   dioxide and water. Gone."   
       
   In this scenario, an infusion of organics from elsewhere might be required to   
   ignite life here. The building blocks for life on our planet may have come, at   
   least in part, from asteroids.   
       
   "Observations by ground-based telescopes suggest that asteroid 1999 RQ36 has a   
   wealth of carbon-based compounds, but we don't know exactly what is there. Are   
   there amino acids? To find out, we need to bring a sample home where we have   
   sophisticated, exquisitely precise instruments, plus the ability to react to   
   new discoveries."   
       
   Obtaining that sample is a key part of OSIRIS-REx's mission.   
       
       
   OSIRIS-REx's sampling arm stirs up the topsoil using pure nitrogen. [97 MB   
   movie] Upon reaching 1999 RQ36 in 2019, the spacecraft's suite of cameras and   
   instruments will spend a year photographing the asteroid and measuring its   
   surface topography, composition, and thermal emissions while its radio   
   provides mass and gravity field maps. This information will increase our   
   understanding of asteroids as well as help the mission team select the most   
   promising sample site.   
       
   Like the ancient Egyptian god Osiris, the OSIRIS-REx mission is associated   
   with death as well as life, with both our destiny and our origin. That's   
   because 1999 RQ36 is the Near Earth Object "Most Likely to Succeed" - in   
   affecting our destiny, that is. It has a 1/1800 chance of hitting Earth by the   
   22nd century.   
       
   Evidence suggests that a 6-mile wide asteroid smashed into Earth about 65   
   million years ago, wiping out the dinosaurs and altering the history of life.   
   Instead of dinosaurs prevailing, mammals flourished, evolving into humans.   
       
   "We're the first species that can mitigate asteroid extinction," notes Drake.   
   "With enough information, we can project the orbit of a threatening asteroid."   
       
   If researchers can track an NEO's precise path, they can devise a way to nudge   
   the object out of a collision course with Earth. OSIRIS-REx wil help NASA   
   learn to navigate near an asteroid, laying the groundwork for landing on one.   
   That could be pretty tricky, considering asteroids like 1999 RQ36 have so   
   little gravity.   
       
   "If you simply pushed your finger into the surface, you'd fly off into space,   
   disappear, and never come back!"   
       
   OSIRIS-REx, however, will hang close, and its cameras will give us window   
   seats to watch its delicate sampling maneuvers. The mission team plans   
   near-live coverage of the operations. But the real action starts, says Drake,   
   when the sample is returned to Earth in 2023.   
       
   A future story from Science@NASA will explain how the sample will be handled   
   upon return and lay out some of the experiments researchers will do with it.   
   Stay tuned.   
       
       
   Author: Dauna Coulter | Editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   More Information   
   1.OSIRIS-Rex is short for Origins-Spectral Interpretation-Resource   
   Identification-Security-Regolith Explorer. Dante Lauretta, Deputy Principal   
   Investigator, came up with the acronym when he was jotting down a list of   
   goals for the mission. "Dante is interested in Egyptian mythology. He was   
   doodling with a pad and pen, and he reached over to show me OSIRIS, and how   
   each letter stood for one of the mission goals. I wasn't' aware of the   
   mythological significance at first. But we'll be taking this prebiotic stuff   
   from the asteroid, chopping it up, and distributing it around the planet for   
   scientists to study where we came from. The mythological figure was also   
   chopped up and distributed."   
       
   "OSIRIS of Egyptian mythology is the god of life and fertility, the god who   
   taught Egyptians agriculture," said Lauretta, also with the University of   
   Arizona. "There's an analogy to the proposed 21st century space mission. We're   
   looking at the kind of object that we think brought life to Earth; that is,   
   objects that seeded Earth with early biomolecules, the precursors of life." As   
   for the acronym, "O" stands for the scientific theme, origins. "SI" is for   
   spectral interpretation, or taking images of the NEO at wavelengths that will   
   reveal its composition. "RI," or resource identification, is surveying the   
   asteroid for such useful resources as water and metals. "S" stands for   
   security, learning how to predict the detailed motion of Earth-approaching   
   asteroids.   
       
   2. In this context, to say that "Earth was sterilized," doesn't mean life was   
   present at the beginning. "There is no evidence for life in the Solar System   
   before the formation of the planets so there was likely nothing to be   
   sterilized," notes astrobiologist Michael New of NASA HQ. It simply means that   
   the heavy bombardment and heating would have sterilized any hypothetical life   
   that might have been present.   
       
   Credits: NASA's Goddard Space Flight Center in Greenbelt, Md., will provide   
   overall mission management, systems engineering, and safety and mission   
   assurance for OSIRIS-REx. Lockheed Martin Space Systems in Denver will build   
   the spacecraft. The OSIRIS-REx payload includes instruments from the   
   University of Arizona, Goddard, Arizona State University in Tempe and the   
   Canadian Space Agency. NASA's Ames Research Center at Moffett Field, Calif.,   
   the Langley Research Center in Hampton Va., and the Jet Propulsion Laboratory   
   in Pasadena, Calif., also are involved. The science team is composed of   
   numerous researchers from universities, private and government agencies. This   
   is the third mission in NASA's New Frontiers Program. The first, New Horizons,   
   was launched in 2006. It will fly by the Pluto-Charon system in July 2015,   
   then target another Kuiper Belt object for study. The second mission, Juno,   
   will launch in August to become the first spacecraft to orbit Jupiter from   
   pole to pole and study the giant planet's atmosphere and interior. NASA's   
   Marshall Space Flight Center in Huntsville, Ala., manages New Frontiers for   
   the agency's Science Mission Directorate in Washington.   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.64   
    * Origin: NCS BBS (1:3828/7)