Hubble Science Data Formatting Computer

HST SIC&DH


Previous page of SM-4 (Mission Preparations)

The official name for the Science Data Formatting Computer is the Science Instrument Command & Data Handler, or SIC&DH.  This is a mouthful, but after a while, you learn to say the letters quickly.  At the time of the failure in space, we had a spare unit on the ground that was delivered to Goddard around 1992.   Parts of it were used on an electrical test bed, so we had to reassemble and certify the unit for flight.


The entire unit during its reassembly and preparation for flight.  Only the 'tray' with the black
boxes will fly in space.  My role on this new science data computer is the Electrical Lead Engineer.

The first major environmental qualification test was EMI/EMC (Electromagnetic Interference and Compatibility).  This occurred in a shielded cleanroom facility at Goddard, and we moved into the facility just before Christmas 2008.  We did not exit until the end of January 2009.


Inside the EMI/EMC test facility at Goddard.

During these set of tests, we verify that the flight hardware is tolerant to the electrical noise that is expected on Hubble, and that it will not impact the operation of other hardware that is already present in space.  We do that by connecting current sensor probes to the power lines (as shown above), and by using sensitive antennas to measure the output of the hardware.


The flight hardware is bombarded by high amounts of radiation to evaluate its effects on the
operation of the hardware.

After EMI/EMC, the next test we performed was vibration.  During these test, we shake and accelerate the hardware vigorously to verify it was designed and built to be strong enough to withstand the rigors of launch and operation in space.  The setup and test time for this was only a week.


Tom Huber and an assistant are bolting down the SIC&DH tray onto the vibe table for a test.


Finally, the last environmental test is Thermal/Vacuum, or "Thermal-Vac".  During this test, the hardware is inserted into a steel chamber, and all air is pumped out.  The hardware is then cycled in the extremes of temperature it is expected to encounter while it is in space.  We installed the tray into the chamber around February 6.


The SIC&DH Tray has been placed on this platform where it will be rolled into the steel vacuum chamber.
The entrance to the vacuum chamber can be seen open in the background


This view shows the tray rolled into the chamber.


Once inside, I perform the electrical tests to allow it to be hooked up to our test system.


Here I am debugging a problem in the Ground Support Equipment
with Randy Stevens.  We are setup next to the Thermal-Vac chamber,
and in some tight quarters there.

Our start of Thermal-Vac was mentioned in the press here.

Ship to the Cape


About 6 months after we were directed to have a replacement unit ready,
we arrive at the Kennedy Space Center at the PHSF.  The flight unit is in the
grey steel box that is being unloaded.



Here we are with our first checks with the shipping container open.
This image by Jack Pfaller from the NASA website.



Here I am with Brian Gambina, the lift coordinator.
This image by Jack Pfaller from the NASA website.



Here is the flight unit in front of the carrier that will carry it into space.
This image by Jack Pfaller from the NASA website.



Once in the cleanroom at KSC, we had a astronaut crew training session.
Here, Drew Fuestel is practicing turning the bolts that will be used
to fasten the tray to the HST door.



On 4/2/09, the Science Data Computer (SIC&DH) was fastened onto the MULE
carrier which will carry it into space.  Note the gravity off-load system that
was in use to position it onto the carrier.  This image is also from the NASA
site mentioned above.



Here is the unit installed onto the carrier with the protective thermal cover open.
After six month's effort, it is great to see it ready for the mission!

The above image shows the SIC&DH installed onto the carrier that will take it into space.  The carrier itself is the "D" shaped object in orange.  It is held by the blue metal stand, called the "Blue Goose".  This is the same carrier we used during the HOST mission.  On the left, the white dome is the Low Gain Antenna cover.  It is temporarily installed by the astronauts onto HST to protect the antenna from being bumped.  To the right of that are the Latch Over Center Kits (LOCKs).  These devices are used to enable quickly opening and closing the HST doors in space.  The large silver box to the right of that is the Contingency ORU Protective Enclosure (COPE).  This holds backup hardware that may be used during space walks.  On the right side is the SIC&DH itself.  At the top of the image, one can see the three Rendezvous and Navigation System (RNS).  It is used to photograph HST upon approach and departure.  Finally, the large orange box on the top left is the New Outer Blanket Enclosure (NOBLE), which houses new blanket covers for the HST doors with deteriorating blanketing.

It is really amazing to see how far we have come in only six months of teamwork.

To see the installation of this unit onto Hubble, go to the...
Next Page of the SM-4 mission


Main Missions Page

Back Home

(c) 2009, Edward Cheung, all rights reserved.