Tag Archives: maven

MAVEN Completes Commissioning And Begins Its Primary Science Mission

The MAVEN spacecraft completed its commissioning activities on November 16 and has formally begun its one-year primary science mission.  The start of science is actually a “soft start”, in that the instruments started making science measurements beginning almost as soon as we were in orbit, and some instrument calibration activities will be continuing throughout the mission.

Spacecraft commissioning, in what the MAVEN team called its “transition phase”, included adjusting the orbit to get into its science orbit, deploying the booms that hold a number of the instruments away from the spacecraft, ejecting the Neutral Gas and Ion Mass Spectrometer (NGIMS) instrument cover, turning on and checking out each of the science instruments, and carrying out calibration activities for both the spacecraft and the instruments.  This period also included the close approach of Comet Siding Spring, which whizzed by Mars at a distance of only ~135,000 km on October 19.

During this transition phase, we were able to get some early science observations.  We made observations from MAVEN’s initial 35-hour capture orbit immediately after the large Mars Orbit Insertion maneuver on Sept. 21.  From this capture orbit, which took the spacecraft to much higher altitudes than our science-mapping orbit will, we used the Imaging Ultraviolet Spectrograph (IUVS) instrument to observe the extended clouds of hydrogen, carbon, and oxygen surrounding the planet.  These “coronae” extend out to more than ten planetary radii, and this orbit allowed us to make measurements of the clouds’ spatial extent to higher altitudes than we can during the primary mission.  We also took time off from commissioning to observe the comet and to take before and after observations of the Mars atmosphere to look for changes.  IUVS and NGIMS observations both revealed a tremendous quantity of metal ions that came from cometary dust that entered the atmosphere.  Their presence was unexpected, in that the nominal models of the paths taken by dust grains, calculated prior to the comet passage, indicated that no dust would make it all the way to Mars.  We’re certainly glad that we took precautions to protect us from dust during the encounter!

During science mapping, the spacecraft will carry out regular observations of the Martian upper atmosphere, ionosphere, and solar-wind interactions.  MAVEN will observe from an elliptical orbit that gets as low as about 150 km above the surface and as high as 6000 km.  The nine science instruments will observe the energy from the Sun that hits Mars, the response of the upper atmosphere and ionosphere, and the way that the interactions lead to loss of gas from the top of the atmosphere to space.  Our goal is to understand the processes by which escape to space occurs, and to learn enough to be able to extrapolate backwards in time and determine the total amount of gas lost to space over time.  This will help us understand why the Martian climate changed over time, from an early warmer and wetter environment to the cold, dry planet we see today.

From the observations made both during the cruise to Mars and during the transition phase, we know that our instruments are working well.  The spacecraft also is operating smoothly, with very few “hiccups” so far.  The science team is ready to go!  Of course, standing behind the science team are literally hundreds of engineers who designed, built, tested, and integrated together the spacecraft and the science instruments, and who operate the spacecraft daily (and, when called upon, even in the middle of the night).  The MAVEN team consists of researchers at the University of Colorado, NASA’s Goddard Spaceflight Center, University of California at Berkeley, Lockheed Martin, and NASA’s Jet Propulsion Laboratory, as well as colleagues at numerous other institutions who participated in developing the flight hardware and in doing the science analysis.  Space exploration is a “team sport”, and the success of the whole team allows us to do our science.

With the formal start of our science mission, we’re on track to be able to carry out our full mission as planned, and the science team is looking forward to an incredibly exciting year!

Bruce JakoskyMAVEN Principal Investigator at NASA’s Goddard Space Flight Center, Greenbelt, Maryland

Source: NASA

NASA Prepares its Science Fleet for Oct. 19 Mars Comet Encounter

NASA’s extensive fleet of science assets, particularly those orbiting and roving Mars, have front row seats to image and study a once-in-a-lifetime comet flyby on Sunday, Oct. 19.

Comet C/2013 A1, also known as comet Siding Spring, will pass within about 87,000 miles (139,500 kilometers) of the Red Planet — less than half the distance between Earth and our moon and less than one-tenth the distance of any known comet flyby of Earth.

Siding Spring’s nucleus will come closest to Mars around 2:27 p.m. EDT, hurtling at about 126,000 mph (56 kilometers per second). This proximity will provide an unprecedented opportunity for researchers to gather data on both the comet and its effect on the Martian atmosphere.

“This is a cosmic science gift that could potentially keep on giving, and the agency’s diverse science missions will be in full receive mode,” said John Grunsfeld, astronaut and associate administrator for NASA’s Science Mission Directorate in Washington. “This particular comet has never before entered the inner solar system, so it will provide a fresh source of clues to our solar system’s earliest days.”

Siding Spring came from the Oort Cloud, a spherical region of space surrounding our sun and occupying space at a distance between 5,000 and 100,000 astronomical units.  It is a giant swarm of icy objects believed to be material left over from the formation of the solar system.

Siding Spring will be the first comet from the Oort Cloud to be studied up close by spacecraft, giving scientists an invaluable opportunity to learn more about the materials, including water and carbon compounds, that existed during the formation of the solar system 4.6 billion years ago.

Some of the best and most revealing images and science data will come from assets orbiting and roving the surface of Mars. In preparation for the comet flyby, NASA maneuvered its Mars Odyssey orbiter, Mars Reconnaissance Orbiter (MRO), and the newest member of the Mars fleet, Mars Atmosphere and Volatile EvolutioN (MAVEN), in order to reduce the risk of impact with high-velocity dust particles coming off the comet.

The period of greatest risk to orbiting spacecraft will start about 90 minutes after the closest approach of the comet’s nucleus and will last about 20 minutes, when Mars will come closest to the center of the widening trail of dust flying from the comet’s nucleus.

“The hazard is not an impact of the comet nucleus itself, but the trail of debris coming from it. Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated. Mars will be right at the edge of the debris cloud, so it might encounter some of the particles — or it might not,” said Rich Zurek, chief scientist for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

The atmosphere of Mars, though much thinner that Earth’s, will shield NASA Mars rovers Opportunity and Curiosity from comet dust, if any reaches the planet. Both rovers are scheduled to make observations of the comet.

NASA’s Mars orbiters will gather information before, during and after the flyby about the size, rotation and activity of the comet’s nucleus, the variability and gas composition of the coma around the nucleus, and the size and distribution of dust particles in the comet’s tail.

Observations of the Martian atmosphere are designed to check for possible meteor trails, changes in distribution of neutral and charged particles, and effects of the comet on air temperature and clouds. MAVEN will have a particularly good opportunity to study the comet, and how its tenuous atmosphere, or coma, interacts with Mars’ upper atmosphere.

Earth-based and space telescopes, including NASA’s iconic Hubble Space Telescope, also will be in position to observe the unique celestial object. The agency’s astrophysics space observatories — Kepler, Swift, Spitzer, Chandra — and the ground-based Infrared Telescope Facility on Mauna Kea, Hawaii — also will be tracking the event.

NASA’s asteroid hunter, the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), has been imaging, and will continue to image, the comet as part of its operations. And the agency’s two Heliophysics spacecraft, Solar TErrestrial RElations Observatory (STEREO) and Solar and Heliophysics Observatory (SOHO), also will image the comet. The agency’s Balloon Observation Platform for Planetary Science (BOPPS), a sub-orbital balloon-carried telescope, already has provided observations of the comet in the lead-up to the close encounter with Mars.

Images and updates will be posted online before and after the comet flyby. Several pre-flyby images of Siding Spring, as well as information about the comet and NASA’s planned observations of the event, are available online at:

http://mars.nasa.gov/comets/sidingspring

Source: NASA