[meteorite-list] EPOXI Mission Status Report - June 28, 2010

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sat, 3 Jul 2010 20:25:27 -0700 (PDT)
Message-ID: <201007040325.o643PR3R016424_at_zagami.jpl.nasa.gov>

http://epoxi.umd.edu/1mission/status.shtml

EPOXI Mission Status Report
Michael A'Hearn
June 28, 2010

This past weekend, our spacecraft flew past Earth Closest approach was
at approximately 22:04 UTC on 27 Jun at a geocentric distance of
0.000246 AU or approximately 36,860 km. The purpose of this flyby was to
retarget the spacecraft onto its final trajectory to comet 103P/Hartley 2.
Data are expected beginning later today that will be analyzed to
determine how accurately we achieved our goal but our general experience
is that nearly all the maneuvers with this spacecraft, both simple thruster
maneuvers in deep space and gravity assists, have all gone with high
precision. The new orbit, which will change slightly but not much due to
subsequent maneuvers to optimize the flyby, has an orbital period of about
14 months, with perihelia near Earth's orbit. The details of the flyby of
comet Hartley 2 will be set up in subsequent maneuvers, but the nominal
distance of closest approach is 700 km at several minutes before 14:00 UTC
on 4 November.

Meanwhile, the science team and the operations team are busy studying
the planned observations at encounter to ensure that everything will
execute properly and return the scientific results that we are aiming
for. Observations of the comet will begin on 5 September, 2 months prior
to closest approach, and continue through 25 November, 3 weeks after
closest approach. A routine recalibration of the instruments after the
flyby will be the last scientific activity on this mission. Since all of
the observations are pre-programmed, with simple commands from the
ground to start long sequences, everything must be thoroughly tested on
simulators on the ground (we have such testbeds both at JPL and at Ball
Aerospace) to wring out all the little things that can go wrong. The
science team is also working very hard to obtain the best possible
calibration of the instruments, which will enable us to obtain higher
quality data at Hartley 2 than we were able to obtain at comet Tempel 1
and also to recalibrate the data from comet Tempel 1.
Received on Sat 03 Jul 2010 11:25:27 PM PDT