Twenty-Five Foot Space Simulator
Why it's listed
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.
Significance in brief: 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.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 85002812, listed October 3, 1985. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | Jet Propulsion Laboratory, Pasadena |
|---|---|
| County | Los Angeles County |
| Listed | October 3, 1985 |
| Reference number | 85002812 |
| Resource type | Structure |
| Period of significance | 1961-Present |
| Architect / builder | NASA |
| Areas of significance | Other, Engineering |
| Level of significance | National |
| National Historic Landmark | Yes, designated October 3, 1985 |
| Status (as stated in the nomination) | Described as in excellent condition, on its original site, and still in use by NASA and likely to remain so for many years. |
| Acreage | 0.9 |
| Within district | Big Creek Hydroelectric System Historic District |
| Coordinates | 34.20258, -118.17389 (NPS GIS) |
What listing means for this property
National Register listing is honorary: it recognises significance and does not restrict what a private owner may do without federal money or permits. It unlocks the 20% federal rehabilitation tax credit for income-producing buildings, state credits in many states, and Section 106 review when federal agencies are involved. See what listing means in practice.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 85002812.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q7857721
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.