[meteorite-list] MSL Adjusts Path, Tests Instruments

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.cfm?release=2012-088  

Mars-Bound NASA Craft Adjusts Path, Tests Instruments
Jet Propulsion Laboratory
March 26, 2012

Mars Science Laboratory Mission Status Report

PASADENA, Calif. -- NASA's Mars Science Laboratory spacecraft, halfway
to Mars, adjusted its flight path today for delivery of the one-ton
rover Curiosity to the surface of Mars in August.

Tests completed aboard Curiosity last week confirmed the health of
science instruments the mission will use to learn whether an area
holding an extensive record of Martian environmental history has ever
offered conditions favorable for microbial life.

In the second of six planned trajectory correction maneuvers during the
cruise to Mars, the spacecraft ignited thrusters for nearly nine minutes
today.  Spacecraft data and Doppler-effect changes in radio signal from
the craft, monitored in the mission control room at NASA's Jet
Propulsion Laboratory, Pasadena, Calif., indicate the maneuver succeeded.

"It is satisfying to get the second maneuver under our belts and know we
are headed in the right direction," said JPL's Erisa Hines, systems lead
for the maneuver. "The cruise system continues to perform very well."

"We are now on a trajectory that will put us much closer to the point we
want to hit on Aug. 5," added Tomas Martin-Mur, navigation team chief
for the mission.

The halfway point of the trip from Earth to Mars will be April 1, in
terms of duration.  The mission launched Nov. 26, 2011. It will land the
evening of Aug. 5, 2012, PDT (early Aug. 6, EDT and Universal Time).

One of Curiosity's 10 science instruments, the Radiation Assessment
Detector (RAD) has been collecting data for three months, monitoring the
natural radiation environment in interplanetary space. This information,
particularly effects RAD has measured from recent solar flares, is
crucial for design of human missions to Mars.

In the past two weeks, the rover team has checked the status of the
other nine of Curiosity's science instruments, powering them on for the
first time since before launch. All the instruments passed these checkouts.

"The types of testing varied by instrument, and the series as whole
takes us past the important milestone of confirming that all the
instruments survived launch," said Betina Pavri of NASA's Jet Propulsion
Laboratory, Pasadena, Calif., science payload test engineer for the
mission. "These checkouts provide a valuable calibration and
characterization opportunity for the instruments, including camera dark
images and a measurement of zero pressure in the vacuum of space for the
rover weather station's pressure sensor."

Curiosity's landing site is near the base of a mountain inside Gale
Crater, near the Martian equator. Researchers plan to use Curiosity to
study layers in the mountain that hold evidence about wet environments
of early Mars.

First, the spacecraft must get there. Today's maneuver nudged the
spacecraft one-seventh as much as the flight's first course adjustment,
on Jan. 11. After the first maneuver, the trajectory would have put
Curiosity about 3,000 miles (5,000 kilometers) and 20 minutes away from
entering Mars' atmosphere at the right place and time. Like that
maneuver, today's combined two ways of using thruster engines while the
whole spacecraft spins at two rotations per minute. 

The spacecraft's cruise stage carries eight thrusters grouped into two
sets of four. The maneuver began with about three minutes of firing one
thruster in each set to change velocity along the direction of the axis
of rotation. Then, to push the spacecraft in a direction perpendicular
to the axis, each set of thrusters was used for five-second pulses when
the spacecraft's rotation put that set at the correct orientation. The
maneuver used more than 60 of these pulses spaced about 10 seconds apart.

"The purpose is to put us on a trajectory to the point in the Mars
atmosphere where we need to be for a safe and accurate landing," said
Mau Wong, maneuver analyst at JPL.

The descent from the top of Mars' atmosphere to the surface will employ
bold techniques enabling use of a smaller target area and larger landed
payload than were possible for any previous Mars mission. These
innovations, if successful, will place a well-equipped mobile laboratory
into a locale especially well suited for its mission of learning. The
same innovations advance NASA toward capabilities needed for human
missions to Mars.

As of March 29, the spacecraft will have traveled about 196 million
miles (316 million kilometers) of its 352-million-mile
(567-million-kilometer) flight to Mars.

JPL, a division of the California Institute of Technology in Pasadena,
manages the mission for the NASA Science Mission Directorate,
Washington. More information about Curiosity is online at
http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ .  You can
follow the mission on Facebook at:
http://www.facebook.com/marscuriosity and on Twitter at:
http://www.twitter.com/marscuriosity .

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Guy.Webster at jpl.nasa.gov 

2012-088