Activation of the Aura spacecraft, launched July 15, is
continuing, with the mission going very well so far.
Just over an hour after launch, the spacecraft separated from
the launch vehicle. This was followed shortly by solar array
deployment and transition to Sun Point Mode (SPM). The next
day, the spacecraft transitioned to Earth Point Mode, where it
remained another day before transitioning to Fine Point Mode,
the normal operating mode. S-band communications with the
Space Network (SN) began immediately, followed by routine
Ground Network (GN) contacts. X-band playbacks from the Solid
State Recorder to the GN are now ongoing as well.
All spacecraft subsystems have demonstrated readiness to
support science operations, though science operations cannot
begin until the instruments are fully activated and Aura has
reached its nominal orbit altitude.
With respect to orbit altitude, four of six planned ascent
burns have been completed. The fifth ascent burn is planned
for Friday. The Aura ascent plan anticipates reaching nominal
altitude of 705 km (about 438 miles) this month.
All four instruments are powered and are systematically being
activated; the following are some of the highlights that have
occurred so far. The Antenna Launch Latch for the Microwave
Limb Sounder (MLS) primary reflector has been released, and
the receivers are undergoing characterization activities. Good
output power from the MLS THz Module Gas Laser Local
Oscillator has been confirmed. The Tropospheric Emission
Spectrometer (TES) translator has been unlatched, as has TES'
Pointing Control System (PCS) gimbals. The sun-shield door for
the High Resolution Dynamics Limb Sounder (HIRDLS) has also
been released. Transition of TES, HIRDLS and the Ozone
Monitoring Instrument (OMI) to science mode is paced by their
significant outgassing requirements, which last about 30 days.
"From what we have seen so far, satellite performance appears
very solid. Also, the performance of the entire operations
team has been tremendous. Not only are all the team members
inherently sharp and well-trained, many of them have extensive
experience with Aqua, which is paying great dividends," said
Rick Pickering, Aura Project Manager at NASA's Goddard Space
Flight Center, Greenbelt, Md.
Aura, a mission dedicated to the health of the Earth's
atmosphere, will help us understand and protect the air we
breathe.
Aura will help answer three key scientific questions: Is the
Earth's protective ozone layer recovering? What are the
processes controlling air quality? How is the Earth's climate
changing? NASA expects early scientific data from Aura within
30-90 days.
Each of Aura's four instruments is designed to survey
different aspects of Earth's atmosphere. Aura will survey the
atmosphere from the troposphere, where mankind lives, through
the stratosphere, where the ozone layer resides and protects
life on Earth.
With the launch of Aura, the first series of NASA's Earth
Observing System satellites is complete. The other satellites
are Terra, which monitors land, and Aqua, which observes
Earth's water cycle.
Aura's four instruments are: the High Resolution Dynamics Limb
Sounder (HIRDLS); the Microwave Limb Sounder (MLS); the Ozone
Monitoring Instrument (OMI); and the Tropospheric Emission
Spectrometer (TES). HIRDLS was built by the United Kingdom and
the United States. OMI was built by the Netherlands and
Finland in collaboration with NASA. NASA's Jet Propulsion
Laboratory in Pasadena, Calif., constructed TES and MLS.
Goddard Space Flight Center manages the Aura mission.
For Aura information and images on the Internet, visit:
http://www.gsfc.nasa.gov/topstory/2004/0517aura.html
and
http://www.nasa.gov/aura
