Take a look inside the US' Manned Orbiting Laboratory, a Cold War-era crewed spy satellite that never made it to space

The Manned Orbiting Laboratory (MOL) was a joint project between the US Air Force and the National Reconnaissance Office and prompted by the need for rapid and reliable intelligence following the Cuban Missile Crisis in 1962 and during the Cold War and the Vietnam War.

Then-US Secretary of Defense Robert McNamara publicly unveiled the program in December 1963, and President Lyndon B. Johnson formally approved the project in August 1965. Though the program was intended to give the US military a reconnaissance vantage point in space, it was portrayed as an operation to find what humans are capable of in space.

"This program will bring us new knowledge about what man is able to do in space," Johnson said at the time. "It will enable us to relate that ability to the defense of America. It will develop technology and equipment which will help advance manned and unmanned space flights. And it will make it possible to perform their new and rewarding experiments."

Operations on the MOL began in the spring of 1964. The MOL sought to obtain high-resolution photographic imagery of foreign adversaries like the Soviet Union. While satellites effectively gathered intelligence, they faced limitations like cloud cover and time delays in retrieval that prevented them from consistently taking useful photographic imagery. An operator onboard the satellite would allow them to circumvent those issues and identify where and when to capture an image in real-time.

"The idea was humans could help pick targets in real time, they could identify cloud cover and save film," Richard Truly, a former MOL crewmember, said in 2022. "The system was resource-limited because it was a film system, not electronic like we have now. But the whole idea was to have a far more capable intelligence capability because you had people there that could think and act and take action in real time during the flight."

The MOL program originally planned to have six launches with a flight duration of two to four weeks — an ambitious feat given that the longest a human had been in space previously was eight days during NASA's Gemini V mission in 1965.

A two-man crew would lift off in a modified Gemini capsule atop a spacecraft that would house the MOL. After the flight duration, the capsule would detach and return to Earth while the MOL would remain in orbit.

The proposed configuration of the MOL was that the front of the spacecraft would house the transfer tunnel and fuel cells, behind that would be the laboratory divided into work and living compartments, and the rear of the spacecraft would be the equipment module and breathing tanks.

Aside from the laboratory where astronauts would conduct experiments, the primary payload of the MOL would be a telescope used for military reconnaissance.

The telescope was designed to have a primary mirror that was 72 inches in diameter, and its imaging system was codenamed Dorian.

After three rounds, the US Air Force selected 17 pilots to participate in the MOL program.

One of the pilots, Robert H. Lawrence, was the first African American selected to be an astronaut by any national space program. Lawrence was among the final selection group completed in June 1967, but he died in an F-104 Starfighter crash in late 1967.

MOL crewmembers had a busy training regiment to prepare for various unexpected events while in space. They were given survival training to prepare for unexpected deorbiting in the case of spacecraft leaks.

Crewmembers also trained in spacecraft simulators and went through underwater training at the Navy dive school in Key West, Florida.

Most importantly, they received training with the National Photographic Interpretation Center to learn more about photographic intelligence and subject recognition — a central part of the MOL's program objective.

The external design for the MOL's spacecraft was similar to that of NASA's Gemini. But the major difference was that a hatch cut into the heat shield allowed astronauts to pass between the capsule at the front of the spacecraft to the laboratory and living quarters in the back without a spacewalk.

Astronauts required a special spacesuit that was flexible enough to allow them to crawl through the narrow passageway between the Gemini capsule and the laboratory on the MOL.

Though the spacesuit never actually made it into space, NASA used the technology behind it in future spacesuit development.

While the existence of the MOL was publicly known, its mission to gather photographic intelligence on foreign adversaries was highly classified. However, press coverage at the time conveyed the MOL as a reconnaissance mission, and the top secret classification of the program prevented officials from denying the claims.

Amid concerns about how other countries would react to the US military operating in space, Louis Mazza, Chief Program Security officer of the NRO, proposed to "admit we have a DOD manned orbital laboratory, and its mission is to determine man's potential usefulness in space."

Thus, MOL operations expanded to include 10 experiments called Project Manifold, which studied cell growth and new technologies aboard the spacecraft.

The first and only launch of the MOL program took place at Cape Canaveral Air Force Station on November 3, 1966, two years after work on the project began.

The launch was only a test, consisting of a Gemini capsule and a mockup of the MOL without the imaging payload atop a Titan-IIIC rocket. The mockup entered Earth's orbit and released three satellites.

The Project Manifold experiments were also aboard the MOL mockup and were intended to operate for 75 days, but the MOL stopped transmitting data after just 30 days before decaying from orbit on January 9, 1967.

Since the program's inception, it was met with criticism and skepticism surrounding the MOL's value. By 1969, the program was years behind schedule and over budget.

Since the MOL was operating under the guise of testing man's "potential usefulness in space," the program publicly seemed all too similar to NASA's Apollo program, so much so that Congress saw it as a duplicate and cut its funding by 60% in 1967.

MOL advocates pushed to combine the USAF efforts with NASA, which was met with pushback as it would damage NASA's image as a peaceful agency.

As budget cuts and delays plagued the MOL, its technology for military reconnaissance was becoming obsolete, rendering the program's original intent virtually useless.

President Richard Nixon canceled the MOL program on June 10, 1969 — just four years after Johnson approved the program.

At the time of cancellation, 192 military personnel, 100 civilians, and 13,187 contractors were working on the MOL program.

Though the MOL never officially made it to space, its legacy inspired future space missions. The MOL's waste management system was used aboard the Skylab, America's first crewed research laboratory in space. The technology intended for the MOL's imaging system helped develop NASA's earth-sensing systems.