WIRE Latest Info

April 3, 1998


The electromagnetic interference and compatibility testing went well last week. We finished Thursday, moved back to the Big Top cleanroom, and performed the spacecraft functional last Friday. Here are two pictures from the EMI chamber. On the left side of the left picture is one of the antennas used to receive the radiated electromagnetic emissions from the spacecraft. All of the harnessing is wrapped in aluminum foil for electrical shielding. This view is of the -x side of the spacecraft. The deployed solar array is visible on the left side (+y) side of the spacecraft. The communications antenna which is on the end of the array is visible as a white circle. The right photo is more toward the -y side of the spacecraft, so more of the back of the -x solar array is visible. The one solar module on the array which is white on the back is the concentrator experiment.

This week we moved to the vibration chamber. The first photo shows George Mooney, Shirley Paul, and Gary Cooper just after the spacecraft was installed for the x-axis vibration. There is a bag over the spacecraft to protect it from airborne contaminates. The large gray object on the right is the shaker. It drives the table on which the spacecraft is mounted. We shake the spacecraft to simulate the rocket ride to orbit. The second photo shows Pete Rossoni and Daniel Kaufman on the left and Giulio Rosanova on the right. This view shows the +y side of the spacecraft with the arrays stowed. The third photo shows the -y and +x side of the spacecraft. The shaker is visible to the left. The fourth photo shows the spacecraft team eagerly awaiting the signal from the vibration crew that it is time to power up the spacecraft. Pictured are Taylor Hale, Tawanda Jacobs, Cindi Lewis, Shirley Paul, and George Mooney. The fifth photo shows Suk Yoon and Giulo adjusting the solar array--it rattled slightly during the shake. The red wires run from accelerometers on the spacecraft to the facility test equipment. The accelerometers measure the acceleration of different parts of the spacecraft as it shakes. From that information we can determine where we have resonances and how much stress various joints will experience. The last photo shows Gary Cooper connecting the arming connectors just prior to the y-axis shake.

We are preparing for the z-axis shake today. The shaker has been turned, and the spacecraft is on top. Monday we will perform the separation shock test. We will bolt the Pegasus separation system to the spacecraft, then initiate the pyros which release the clamp band and separate the spacecraft from the launch vehicle.

The spacecraft functional is scheduled for Tuesday after we double-check our alignment between the star tracker, gyros, and sun sensor. Then we will start preparations for thermal vacuum including installation of the instrument thermal simulator and the flight battery.


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Previous updates:

August 18, 1997
October 20, 1997
October 31, 1997
November 7, 1997
November 14, 1997
November 21, 1997
December 5, 1997
December 23, 1997
January 9, 1998
January 16, 1998
January 23, 1998
January 30, 1998
February 6, 1998
February 20, 1998
March 12, 1998
March 23, 1998