MESSENGER Update - April 18, 2005

http://messenger.jhuapl.edu/news_roo..._04_18_05.html

MESSENGER Status Report
April 18, 2005

The mission operations and spacecraft teams continue to check out
MESSENGER's science payload - and prepare for additional instrument
operations in the weeks ahead.

The team checked and commissioned the Energetic Particle and Plasma
Spectrometer (EPPS) instrument over the past week. On April 8 they
wrapped up a two-day look at the EPPS Fast Imaging Plasma Spectrometer
(FIPS) element, during which they carefully and gradually turned it up
to its highest operating voltage. Then the team moved on to a similar
test with the EPPS Energetic Particle Spectrometer component, ending it
successfully on April 13. The X-Ray Spectrometer underwent a full
functional test on April 14.

FIPS observed the solar wind for an hour on April 15 while spacecraft
operators watched MESSENGER's power levels and temperatures around the
propellant tanks and rear antenna. Overall the spacecraft is in good
health and operating normally.

Visit http://solar-heliospheric.engin.umich.edu/ for additional
information on the FIPS solar wind observations.

This month the team also plans to check on the Neutron Spectrometer
component of the Gamma-Ray and Neutron Spectrometer instrument, as well
as Mercury Atmospheric and Surface Composition Spectrometer.

Stat Corner: MESSENGER is about 85.9 million miles (138.2 million
kilometers) from the Sun and 23.1 million miles (37.3 million
kilometers) from Earth. At that distance, a signal from Earth reaches
the spacecraft in 2 minutes, 4 seconds. The spacecraft is moving around
the Sun at 71,869 miles (115,662 kilometers) per hour. MESSENGER's
onboard computers have executed 37,887 commands from mission operators
since launch on Aug 3, 2004.

New Look for the Education Web Site: The MESSENGER Education Web site
has a whole new look! Check out the improvements at
http://btc.montana.edu/messenger/main/epo.htm, from new graphics and
easier navigation to new materials for students, teachers and the
community.