{"nrhp_refnum":"85002812","name":"Twenty-Five Foot Space Simulator","other_names":[],"category":"structure","location":{"address":"Jet Propulsion Laboratory","address_restricted":false,"city":"Pasadena","county":"Los Angeles County","state":"CA","lat":34.202581672000036,"lon":-118.17388860882666,"geom_source":"nps_gis"},"listed_date":"1985-10-03","is_nhl":true,"nhl_designated_date":"1985-10-03","areas_of_significance":["Other","Engineering"],"significance_levels":["national"],"summary":{"what_it_is":"A stainless-steel space simulation chamber at the Jet Propulsion Laboratory in Pasadena, California, built in 1961 to test spacecraft under space-like conditions. It is housed in Building 150 and owned by NASA.","why_significant":"The nomination argues the simulator has technological capabilities in recreating the space environment and strong ties to the unmanned space exploration program. It is described as the only NASA facility producing true interplanetary cold, vacuum and intense solar radiation in a 25-foot test chamber. Its collimating-mirror solar system was the first of its type when installed in 1966, and spacecraft such as Ranger, Surveyor, Mariner and Voyager were tested there.","narrative":"Inside Building 150 at the Jet Propulsion Laboratory in Pasadena, a stainless-steel vessel 27 feet in diameter and 85 feet high recreates the conditions spacecraft face beyond Earth. Built in 1961, the Twenty-Five Foot Space Simulator can produce extreme cold, high vacuum and intense, uniform solar radiation. Its walls are lined with cryogenic shrouds cooled by nitrogen, and an array of 37 xenon arc lamps feeds a collimating mirror that directs a simulated solar beam into a test volume 20 feet wide and 25 feet high. The facility was recognized because it is the only NASA facility able to combine true interplanetary conditions with a chamber large enough for most modern spacecraft. Its mirror-based solar system was the first of its type when installed in 1966. Ranger, Surveyor, Mariner and Voyager craft were tested there, letting engineers find and fix problems before launch. Engineers from Europe and Japan studied its support systems. It remains in use by NASA.","period_of_significance":"1961-Present","architect_builder":"NASA","architectural_style":null,"criteria":[],"status_note":"Described as in excellent condition, on its original site, and still in use by NASA and likely to remain so for many years.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:32.069903-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/85002812_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/85002812/b1b9fee57f-800.webp","url_1600":"https://nationalhistoricalregister.com/media/85002812/b1b9fee57f-1600.webp","licence":"Public domain","author":"NASA/JPL","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Msl20110531_PIA14131-deckpan-full.jpg\" rel=\"noopener\">NASA/JPL</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Msl20110531_PIA14131-deckpan-full.jpg"},"district":{"nrhp_refnum":"16000468","name":"Big Creek Hydroelectric System Historic District","url":"https://nationalhistoricalregister.com/districts/california/big-creek-hydroelectric-system-historic-district-16000468/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123857948","wikipedia":"https://en.wikipedia.org/wiki/Twenty-Five-Foot_Space_Simulator","wikidata":"https://www.wikidata.org/wiki/Q7857721"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/los-angeles-county/twenty-five-foot-space-simulator-85002812/"}