Chamber A
Johnson Space Center’s Chamber A is a 16.8 m (55 ft) diameter x 27.4 m (90 ft) high, thermal-vacuum test facility and is famous for testing the Apollo spacecraft, with and without the mission crew. Its usable test volume and high-fidelity space simulation capabilities are adaptable for thermal-vacuum testing of a wide variety of test articles, including entire space vehicles. Test articles are normally inserted into the chamber by means of a precision, mobile crane. The dual crew-locks, when configured for human testing, provide a means for the test crew to move from ambient air pressure to the thermal-vacuum environment and back. They also provide for the maintenance of rescue personnel at convenient intermediate pressures during crew test operations. When the inner door is bolted, either of the crew-locks can be used as an altitude chamber for independent tests.
Additional test support equipment includes mass spectrometers, infrared cameras and television cameras. The numerous flanges at all levels provide ample pass-throughs for electrical, instrumentation and gasses to support large systems.
Chamber A is currently undergoing a major reconstruction effort in support of the James Webb Space Telescope test program. Once construction is completed, the chamber will include an ultra-clean hydrocarbon-free high vacuum pumping systems and the ability to simulate the extremely low temperatures of deep space (35K) within a 45 foot diameter by 80 foot tall shroud volume. The chamber systems will also be able to maintain class 10,000 clean room conditions for ambient operations.
Specifications:
| Outside Dimensions: | 19.8 m (65 ft) diameter x 36.6 m (120 ft) high |
| Working Dimensions: | Inside LN2 shroud: 16.8 m (55 ft) diameter x 27.4 m (90 ft) high Inside He shroud: 45ft. diameter x 80ft. high |
| Test Article Weight: | Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit NASA.gov for current information |
| Access: | a) 12.2 m (40 ft) diameter side-hinged door b) Dual crewlocks at floor level and 9.4 m (31 ft) level, measuring 2.4 m high, 3.4 m wide, and 3.9m long (8 x 11 x 12.8 ft) c) 13.7 m (45 ft) diameter (180( rotating floor d) Door at 18.9 m (62 ft) level e) Catwalk platform at 9.4 m (31 ft) and 18.9 m (62 ft) levels |
| Types of Pumps: | Staged roughing pumps, valved turbo molecular and cryo absorption pumps, and 20 K (-424 F) helium refrigeration units |
| Pumpdown Time: | 12 hours to Low Earth Orbit test conditions |
| Pumping Capacity: | 2 x 107 liters/sec condensibles and 3 x 105 liters/sec noncondensables at 1 x 10-6 torr pressure; Note: Usual chamber inleakage less than 8 x 105 liters/sec of air at 1 x 10-6 torr pressure |
| Repressurization: | Controllable using dry gas purge and heated shroud |
| Full Chamber Shroud: | Subcooled 90 K (-298 F) LN2 shroud 330,000 W total heat absorption capacity, 1615 W/m2 (150 W/ft2) maximum heat flux, can be heated to 312 K (102 F) with GN2 |
| Wall Emissivity: | 0.95 |
| Measurement: | Data system capable of 1000 test article channels |