[meteorite-list] MRO's Orbit Insertion

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri Mar 10 11:43:00 2006
Message-ID: <200603101640.k2AGexD15292_at_zagami.jpl.nasa.gov>

We've added the following Mars Orbit Insertion info to the
MRO website.

MRO MOI Sequence of Events (also appended below)
http://mars.jpl.nasa.gov/mro/mission/tl_moi-soe.html

Live Doppler Plot - updated every 15 seconds.
http://mars.jpl.nasa.gov/mro/mission/tl_moi-soe.html

Simulated Trajectory Animations
http://mars.jpl.nasa.gov/mro/mission/tl_moi-trajanim.html

Video: The Challenges of Getting to Mars: Burn and Capture
http://mars.jpl.nasa.gov/mro/gallery/video/index.html#BurnAndCapture

MOI Press Kit
http://mars.jpl.nasa.gov/mro/newsroom/presskits/

NASA TV Coverage (Pacific time)
-----------------------------------
9AM - Pre-Arrival News Briefing
12:30PM - 2:45PM - MOI commentary
4:30PM - Post-Arrival News Briefing


Ron Baalke

-------------------------------------------------------------


http://mars.jpl.nasa.gov/mro/mission/tl_moi-soe.html

Mission Timeline: Mars Orbit Insertion - Sequence of Events

Follow along with the Mars Reconnaissance Orbiter team during each
critical step of Mars Orbit Insertion. All times listed below are when
the signals from the orbiter are received on Earth. All times PST.

12:49 p.m. Step One: Pressurize
Valves between helium tank and main fuel tank open. Two small
pyrotechnic charges electrically ignite, opening valves in tubing about
the diameter of a pencil. Each charge breaks open a seal and creates a
clear line to allow the pressurant -- helium gas -- to flow into the
fuel tank.

1:03 p.m. Step Two: Switch to Low-gain Antenna
Telecommunications channels switch from the spacecraft's high-gain
antenna to the low-gain antenna for receipt of commands. The low-gain
antenna is less powerful, but it can receive and send signals without
having to face Earth. The high-gain antenna must be pointing toward
Earth to be able to communicate with the Deep Space Network antennas in
Goldstone, California and Madrid, Spain. The low-gain antenna will send
telemetry data at 160 bits per second from now until about an hour later.

1:07 p.m. Step Three: Turn spacecraft
Pre-programmed commands turn the spacecraft to position it for the burn
that will capture the spacecraft in orbit around Mars.

1:24 p.m. Step Four: Commence Firing for Orbit Insertion
A valve electrically opens to allow fuel to flow into the six main
engines. The fuel flows over high-temperature catalyst beds that cause
it to "explode" and exit the rocket nozzles at very high speed. The
rockets fire for nearly 27 minutes, decreasing MRO's speed by 2,200
miles (3,541 kilometers) per hour.

Flexible extensions on the spacecraft, such as the solar panels, will
vibrate lightly in response to the initial engine firing. The small
reaction-control thrusters strategically mounted on various parts of the
spacecraft will fire to correct any oscillation in the spacecraft's
orientation, keeping the main engine pointed in the right direction for
orbit insertion.

1:46 p.m. Step Five: Bye For Now, MRO!
The firing continues as the spacecraft passes behind Mars, and the Deep
Space Network temporarily loses the spacecraft signal as planned. This
time may be the most excruciating period for flight controllers. They
must withstand the silence and trust that all's going as planned.

1:51 p.m. Step Six: Burn Ends
While hidden behind the red planet, Mars Reconnaissance Orbiter's main
engines cease firing. The duration of the planned burn is meant to put
the spacecraft in the optimal position to be captured by Mars' gravity.

The Mars Reconnaissance Orbiter team now stands by and waits for their
spacecraft to break the long silence and report on its condition. On the
spacecraft itself, the reaction wheels turn the spacecraft to point the
high-gain antenna toward Earth to prepare to resume communications with
Earth.

2:16 p.m. Step Seven: Hello Again, MRO!
At last, from Earth's point of view, the spacecraft emerges from behind
Mars, and the Deep Space Network antennas seek to lock on to the
spacecraft's carrier signal. The spacecraft continues transmitting data
at 160 bits per second; the Deep Space Network will take several minutes
to lock on to the low-rate data stream.

Navigators expect that Mars Reconnaissance Orbiter will be captured into
an initial elliptical orbit that will take about 35 hours for the
spacecraft to round the planet.

2:30 p.m. Step Eight: Check Health and Status
By this time, spacecraft controllers will get limited data informing
them of the state of the spacecraft and the result of its orbital
insertion burn.
Received on Fri 10 Mar 2006 11:40:59 AM PST