Less flight vibration, better pictures for world’s largest infrared telescope

Air suspension system makes use of sensors, controls, to see more.
By Control Engineering Staff March 4, 2008

Hanover/Stuttgart, Germany — Air suspension system maker ContiTech reported that a custom suspension system it built for of the Stratospheric Observatory for Infrared Astronomy (SOFIA) research airplane turned in an outstanding performance in the first test flight using sensors and controls. The air suspension system ensures vibration-free operating conditions for the world’s largest infrared observatory telescope, company says.

At an altitude of 14 kilometers, SOFIA carries out research into the formation of stars and planetary systems as well as the origin of the solar system. The telescope at the heart of the research aircraft weights 37,500 lb (17,000 kg) instrument and peers through a hatch in the aircraft’s tail. The telescope rests on a vibration-isolation system (VIS) consisting of an air spring system and silicon-oil-filled dampers.

In the 5.5-hour test flight, the telescope, with all its subsystems, was tested for the first time under regular operating conditions. ContiTech says the air suspension system completed the test with flying colors. It demonstrated its ability to absorb vibrational interference emanating from the aircraft itself or from windflow when the hatch is open.

Assisted by its control electronics and sensors, the air suspension system holds the telescope exactly in position relative to the plane’s fuselage. This ensures that the ultra-sensitive instrument is always aimed directly at the target of observation, the prerequisite for perfect images. The German SOFIA Institute (DSI) in Stuttgart reported that the vibration-isolation system “performed excellently when the plane was diving, climbing, and spiraling.”

ContiTech Air Spring Systems in Hanover manufactures the existing system, composed of 24 single- and double-convolution air springs. The company’s sales partner,

CFM Schiller GmbH

, assumed engineering responsibility, from design calculations through to final assembly at the U.S. NASA base.

ContiTech Air Spring Systems says it is the largest manufacturer of air suspension systems in Europe and number two worldwide. The company’s products equip primarily commercial vehicles, buses, cars, rail vehicles and machines and systems.

C.G. Masi , senior editor
Control Engineering News Desk
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