August 2nd 05, 09:00 PM
http://messenger.jhuapl.edu/news_room/press_release_8_02_05.html
MESSENGER Completes Successful Earth Swingby
Gravity Assist Sends Mercury-Bound NASA Probe Toward Inner Solar System
August 2, 2005
NASA's MESSENGER spacecraft, headed toward the first study of Mercury
from orbit, swung by its home planet today for a gravity assist that
propelled it deeper into the inner solar system.
Mission operators at the Johns Hopkins University Applied Physics
Laboratory (APL) in Laurel, Md, say MESSENGER's systems performed
flawlessly as the spacecraft swooped around Earth, coming to a closest
approach point of about 1,458 miles (2,347 kilometers) over central
Mongolia at 3:13 p.m. EDT. The spacecraft used the tug of Earth's
gravity to change its trajectory significantly, bringing its average
orbit distance nearly 18 million miles closer to the Sun and sending it
toward Venus for another gravity-assist flyby next year.
Launched Aug. 3, 2004 from Cape Canaveral Air Force Station, Fla., the
solar-powered spacecraft is about 581 million miles (930 million
kilometers) into a 4.9-billion mile (7.9-billion kilometer) voyage that
includes 14 more loops around the Sun. It will fly past Venus twice and
Mercury three times before moving into orbit around its target planet.
The Venus flybys in October 2006 and June 2007 will use the pull of the
planet's gravity to guide MESSENGER toward Mercury's orbit. The Mercury
flybys in January 2008, October 2008 and September 2009 help MESSENGER
further match that planet's speed, setting up the maneuver in March
2011
that starts a yearlong science orbit around Mercury.
"This Earth flyby is the first of a number of critical mission
milestones during MESSENGER's circuitous journey toward Mercury orbit
insertion," says Sean C. Solomon, the mission's principal investigator,
from the Carnegie Institution of Washington. "Not only did it help the
spacecraft sharpen its aim toward our next maneuver, it presented a
special opportunity to calibrate several of our science instruments."
MESSENGER's main camera had snapped several approach shots of Earth and
the moon over the past week, and today is taking a series of color
images, beginning with South America and continuing for one full Earth
rotation, that science team members will string into a "movie"
documenting MESSENGER's departure. On approach the atmospheric and
surface composition spectrometer also made several scans of the moon in
conjunction with the camera observations, and during the flyby the
particle and magnetic field instruments spent several hours measuring
Earth's magnetosphere. The team will download the data and images
through NASA's Deep Space Network over the next several weeks,
continuing its assessment of the instruments' performance.
MESSENGER will conduct the first orbital study of Mercury, the least
explored of the terrestrial ("rocky") planets that also include Venus,
Earth and Mars. Over one Earth year - or four Mercury years - MESSENGER
will provide the first images of the entire planet and collect detailed
information on the composition and structure of Mercury's crust, its
geologic history, the nature of its atmosphere and magnetosphere, and
the makeup of its core and polar materials.
MESSENGER, short for MErcury Surface, Space ENvironment, GEochemistry,
and Ranging, is the seventh mission in NASA's Discovery Program of
lower
cost, scientifically focused exploration projects. APL designed, built
and operates the MESSENGER spacecraft and manages the mission for
NASA's
Science Mission Directorate.
Media Contacts:
Michael Buckley
Johns Hopkins University Applied Physics Laboratory
(240) 228-7536 or (443) 778-7536
Dolores Beasley/Erica Hupp
Headquarters, Washington
(Phone: 202/358-1753/1237)
[Image]
Earth loomed large in MESSENGER's field-of-view on July 30, 2005, as
the
spacecraft approached its home planet for a gravity-assist flyby. The
Narrow Angle Camera in MESSENGER's Mercury Dual Imaging System snapped
this image, showing clear morning skies over Australia, when the
spacecraft was about 655,570 miles (1.05 million kilometers) from
Earth.
The contrast has been adjusted slightly to bring out the darker
features
(such as land and water) on Earth's surface.
The flyby on Aug. 2 - during which MESSENGER flew within 1,458 miles
(2,347 kilometers) over central Asia - sent the solar-powered NASA
spacecraft toward the inner solar system and set up a flyby of Venus in
October 2006. MESSENGER, short for MErcury Surface, Space ENvironment,
GEochemistry, and Ranging, will fly by Venus twice and Mercury three
times before starting an unprecedented, yearlong science orbit around
the innermost planet in March 2011.
Credit: NASA/Johns Hopkins University Applied Physics
Laboratory/Carnegie Institution of Washington/Northwestern University
MESSENGER Completes Successful Earth Swingby
Gravity Assist Sends Mercury-Bound NASA Probe Toward Inner Solar System
August 2, 2005
NASA's MESSENGER spacecraft, headed toward the first study of Mercury
from orbit, swung by its home planet today for a gravity assist that
propelled it deeper into the inner solar system.
Mission operators at the Johns Hopkins University Applied Physics
Laboratory (APL) in Laurel, Md, say MESSENGER's systems performed
flawlessly as the spacecraft swooped around Earth, coming to a closest
approach point of about 1,458 miles (2,347 kilometers) over central
Mongolia at 3:13 p.m. EDT. The spacecraft used the tug of Earth's
gravity to change its trajectory significantly, bringing its average
orbit distance nearly 18 million miles closer to the Sun and sending it
toward Venus for another gravity-assist flyby next year.
Launched Aug. 3, 2004 from Cape Canaveral Air Force Station, Fla., the
solar-powered spacecraft is about 581 million miles (930 million
kilometers) into a 4.9-billion mile (7.9-billion kilometer) voyage that
includes 14 more loops around the Sun. It will fly past Venus twice and
Mercury three times before moving into orbit around its target planet.
The Venus flybys in October 2006 and June 2007 will use the pull of the
planet's gravity to guide MESSENGER toward Mercury's orbit. The Mercury
flybys in January 2008, October 2008 and September 2009 help MESSENGER
further match that planet's speed, setting up the maneuver in March
2011
that starts a yearlong science orbit around Mercury.
"This Earth flyby is the first of a number of critical mission
milestones during MESSENGER's circuitous journey toward Mercury orbit
insertion," says Sean C. Solomon, the mission's principal investigator,
from the Carnegie Institution of Washington. "Not only did it help the
spacecraft sharpen its aim toward our next maneuver, it presented a
special opportunity to calibrate several of our science instruments."
MESSENGER's main camera had snapped several approach shots of Earth and
the moon over the past week, and today is taking a series of color
images, beginning with South America and continuing for one full Earth
rotation, that science team members will string into a "movie"
documenting MESSENGER's departure. On approach the atmospheric and
surface composition spectrometer also made several scans of the moon in
conjunction with the camera observations, and during the flyby the
particle and magnetic field instruments spent several hours measuring
Earth's magnetosphere. The team will download the data and images
through NASA's Deep Space Network over the next several weeks,
continuing its assessment of the instruments' performance.
MESSENGER will conduct the first orbital study of Mercury, the least
explored of the terrestrial ("rocky") planets that also include Venus,
Earth and Mars. Over one Earth year - or four Mercury years - MESSENGER
will provide the first images of the entire planet and collect detailed
information on the composition and structure of Mercury's crust, its
geologic history, the nature of its atmosphere and magnetosphere, and
the makeup of its core and polar materials.
MESSENGER, short for MErcury Surface, Space ENvironment, GEochemistry,
and Ranging, is the seventh mission in NASA's Discovery Program of
lower
cost, scientifically focused exploration projects. APL designed, built
and operates the MESSENGER spacecraft and manages the mission for
NASA's
Science Mission Directorate.
Media Contacts:
Michael Buckley
Johns Hopkins University Applied Physics Laboratory
(240) 228-7536 or (443) 778-7536
Dolores Beasley/Erica Hupp
Headquarters, Washington
(Phone: 202/358-1753/1237)
[Image]
Earth loomed large in MESSENGER's field-of-view on July 30, 2005, as
the
spacecraft approached its home planet for a gravity-assist flyby. The
Narrow Angle Camera in MESSENGER's Mercury Dual Imaging System snapped
this image, showing clear morning skies over Australia, when the
spacecraft was about 655,570 miles (1.05 million kilometers) from
Earth.
The contrast has been adjusted slightly to bring out the darker
features
(such as land and water) on Earth's surface.
The flyby on Aug. 2 - during which MESSENGER flew within 1,458 miles
(2,347 kilometers) over central Asia - sent the solar-powered NASA
spacecraft toward the inner solar system and set up a flyby of Venus in
October 2006. MESSENGER, short for MErcury Surface, Space ENvironment,
GEochemistry, and Ranging, will fly by Venus twice and Mercury three
times before starting an unprecedented, yearlong science orbit around
the innermost planet in March 2011.
Credit: NASA/Johns Hopkins University Applied Physics
Laboratory/Carnegie Institution of Washington/Northwestern University