SOFIA Passes Cabin Proof Pressure Test

Waco, Texas --The Universities Space Research Association (USRA) announced on April 25, 2004 that SOFIA has successfully completed the Cabin Proof Pressure Test.

This is a significant event in verifying the integrity of the aircraft structural modifications as well as the Telescope Assembly's capacity to support cabin pressure. The 12.5 psi test pressure is 33% above the 9.4 psi cabin relief valve setting and 40% above the 8.9 psi normal cabin operating pressure experienced at observing altitudes. It produces 680,000 lbs of axial loading on the Pressure Bulkhead and 105,000 lbs on the Telescope and its supporting Vibration Isolation System. In many ways it is the most significant structural loading case for the Observatory. In addition to passing the test, the aircraft was thoroughly instrumented with strain gages allowing us to begin the process of validating the analytical Finite Element Model that was developed for the structural design development.

The Universities Space Research Association is a private nonprofit corporation founded in 1969. Comprised of 95 college and university institutional members, USRA provides a mechanism through which universities can cooperate effectively with one another, with the government, and with other organizations to further space science and technology, and to promote education in these areas. Its mission is carried out through its institutes, centers, divisions, and many diverse programs. Most of USRA's activities are funded by grants and contracts from the National Aeronautics and Space Administration.