June 21st 06, 09:54 PM
http://messenger.jhuapl.edu/news_room/status_report_06_21_06.html
MESSENGER Flips Sunshade Toward the Sun
June 21, 2006
The MESSENGER spacecraft performed its final "flip" maneuver for the
mission on June 21. Responding to commands sent from the MESSENGER
Mission Operations Center at The Johns Hopkins University Applied
Physics Laboratory (APL) in Laurel, Md., through NASA's Deep Space
Network antenna station near Goldstone, Calif., the spacecraft rotated
180?, pointing its sunshade toward the Sun.
The 16-minute maneuver, designed to keep MESSENGER operating at safe
temperatures as it moves closer to the Sun, wrapped up at 9:34 a.m.
EDT,
with successful reacquisition of signal from MESSENGER's front-side
antenna. The spacecraft was 196.5 million kilometers (122.1 million
miles) from Earth and 144.6 million kilometers (89.8 million miles)
from
the Sun when the maneuver occurred.
MESSENGER had been flying with its back to the Sun since a March 8
"flop," allowing it to maintain temperatures within safe operating
ranges at Sun distances greater than 0.95 astronomical units (1 AU is
Earth's distance from the Sun). Mission plans call for the spacecraft
to
keep its sunshade facing the Sun for the remainder of its cruise and
science orbital operations around Mercury.
"Initial indications look very good" says MESSENGER Mission Operations
Manager Mark Holdridge, of APL. "Spacecraft temperatures are coming
down
as expected and all systems and instruments are nominal."
The team will now turn its attention to preparing for the first Venus
flyby on October 24. "We have mission simulations and flight tests
coming up to test particular operations that will have to occur during
the Venus flyby," Holdridge says. "There will be a 57-minute solar
eclipse during the October operation, so we will so be testing the
flight systems in the flyby configuration to verify they will behave
properly during the eclipse period."
On August 11, for instance, the team will conduct a flight test of the
new autonomy that will power off components prior to the solar eclipse,
allow the battery to discharge by approximately the same amount as
during the real eclipse, and then power on components again once the
battery is recharged, all in a more controlled setting with real-time
visibility. This test will be combined with a battery reconditioning.
Later in August and through September, during the approach to Venus,
MESSENGER's navigation team will use the Mercury Dual Imaging System
cameras onboard the spacecraft to take a series of optical navigation
pictures. These images are not required for the Venus flyby but will be
used by the MESSENGER navigation team for calibration and as practice
for the optical navigation imaging to be utilized at Mercury.
Mercury Science: From Mariner 10 to MESSENGER
It takes hard work and the dedication of scores of individuals to make
MESSENGER run smoothly - and through the remainder of the mission we'll
introduce you to the Instrument, Engineering and Science Team members
who make this mission happen. First up is Robert G. Strom, a founder of
modern planetary geology, an expert in surface morphology, and the only
person on the MESSENGER team to have also served on the first mission
to
Mercury, Mariner 10. As a member of the Science Team's Geology Group,
he
will lead the analysis of Mercury's geologic history and participate in
the analysis of Mercury Atmospheric and Surface Composition
Spectrometer
spectral measurements of the surface. He's just finished writing a book
about global warming. Find out more by going to
http://messenger.jhuapl.edu/who_we_are/member_focus.html.
------------------------------------------------------------------------
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and
Ranging) is a NASA-sponsored scientific investigation of the planet
Mercury, and the first space mission designed to orbit the planet
closest to the Sun. The MESSENGER spacecraft launched on Aug. 3, 2004,
and after flybys of Earth, Venus and Mercury will start a yearlong
study
of its target planet in March 2011. Dr. Sean C. Solomon, of the
Carnegie
Institution of Washington, leads the mission as principal investigator.
The Johns Hopkins University Applied Physics Laboratory built and
operates the MESSENGER spacecraft and manages the Discovery-class
mission for NASA.
MESSENGER Flips Sunshade Toward the Sun
June 21, 2006
The MESSENGER spacecraft performed its final "flip" maneuver for the
mission on June 21. Responding to commands sent from the MESSENGER
Mission Operations Center at The Johns Hopkins University Applied
Physics Laboratory (APL) in Laurel, Md., through NASA's Deep Space
Network antenna station near Goldstone, Calif., the spacecraft rotated
180?, pointing its sunshade toward the Sun.
The 16-minute maneuver, designed to keep MESSENGER operating at safe
temperatures as it moves closer to the Sun, wrapped up at 9:34 a.m.
EDT,
with successful reacquisition of signal from MESSENGER's front-side
antenna. The spacecraft was 196.5 million kilometers (122.1 million
miles) from Earth and 144.6 million kilometers (89.8 million miles)
from
the Sun when the maneuver occurred.
MESSENGER had been flying with its back to the Sun since a March 8
"flop," allowing it to maintain temperatures within safe operating
ranges at Sun distances greater than 0.95 astronomical units (1 AU is
Earth's distance from the Sun). Mission plans call for the spacecraft
to
keep its sunshade facing the Sun for the remainder of its cruise and
science orbital operations around Mercury.
"Initial indications look very good" says MESSENGER Mission Operations
Manager Mark Holdridge, of APL. "Spacecraft temperatures are coming
down
as expected and all systems and instruments are nominal."
The team will now turn its attention to preparing for the first Venus
flyby on October 24. "We have mission simulations and flight tests
coming up to test particular operations that will have to occur during
the Venus flyby," Holdridge says. "There will be a 57-minute solar
eclipse during the October operation, so we will so be testing the
flight systems in the flyby configuration to verify they will behave
properly during the eclipse period."
On August 11, for instance, the team will conduct a flight test of the
new autonomy that will power off components prior to the solar eclipse,
allow the battery to discharge by approximately the same amount as
during the real eclipse, and then power on components again once the
battery is recharged, all in a more controlled setting with real-time
visibility. This test will be combined with a battery reconditioning.
Later in August and through September, during the approach to Venus,
MESSENGER's navigation team will use the Mercury Dual Imaging System
cameras onboard the spacecraft to take a series of optical navigation
pictures. These images are not required for the Venus flyby but will be
used by the MESSENGER navigation team for calibration and as practice
for the optical navigation imaging to be utilized at Mercury.
Mercury Science: From Mariner 10 to MESSENGER
It takes hard work and the dedication of scores of individuals to make
MESSENGER run smoothly - and through the remainder of the mission we'll
introduce you to the Instrument, Engineering and Science Team members
who make this mission happen. First up is Robert G. Strom, a founder of
modern planetary geology, an expert in surface morphology, and the only
person on the MESSENGER team to have also served on the first mission
to
Mercury, Mariner 10. As a member of the Science Team's Geology Group,
he
will lead the analysis of Mercury's geologic history and participate in
the analysis of Mercury Atmospheric and Surface Composition
Spectrometer
spectral measurements of the surface. He's just finished writing a book
about global warming. Find out more by going to
http://messenger.jhuapl.edu/who_we_are/member_focus.html.
------------------------------------------------------------------------
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and
Ranging) is a NASA-sponsored scientific investigation of the planet
Mercury, and the first space mission designed to orbit the planet
closest to the Sun. The MESSENGER spacecraft launched on Aug. 3, 2004,
and after flybys of Earth, Venus and Mercury will start a yearlong
study
of its target planet in March 2011. Dr. Sean C. Solomon, of the
Carnegie
Institution of Washington, leads the mission as principal investigator.
The Johns Hopkins University Applied Physics Laboratory built and
operates the MESSENGER spacecraft and manages the Discovery-class
mission for NASA.