 After Gary Powers' U2 was downed on May 1st of 1960, it became impossible for the United States to continue photographing the Soviet Union. But the need for Soviet intelligence didn't change. It remained paramount to American national security to know what was happening beyond the Iron Curtain. Luckily for the United States, there was a new technology ready to take over the job of aerial reconnaissance within months of the Powers incident. The Corona Spy Satellites Hi everyone, I'm Amy. This is The Vintage Space, my little corner of the internet, where we talk about all things mid-century tech and science that, quite frankly, interest me. Like Cold War aerial espionage. Welcome to part four in this series covering the U2, the Corona Satellites, and the A-12 slash Oxcart slash SR-71. So far in the series, we've done the U2 program in depth over three videos. They're all linked in the description. I'd recommend checking those out to get the backstory, as this series is a very deep dive, so there's a lot of context and some major players to get to know. Which also means now is a great time to subscribe so you don't miss the next installment in the story. And a quick reminder before we continue, this series is focused on U.S.-Soviet relations because that's where my interest lies. Alrighty, let's get into it. The Second World War saw rocketry mature as a technology. Mainly with the V2 program in Germany. In the immediate post-war years, both the United States and the Soviet Union imported V2 scientists to harness the new knowledge. Yes, that is an oversimplification. Breaking the chains of gravity has the full story and there's a link below in the description. The United States managed to import some of the German program's foremost minds, including Brunner von Braun, who brought literal train cars full of V2 parts and plans stateside with him. Human engineers were thus able to rebuild the V2 while learning about the technology. And in 1946, a team at the White Sands Proving Ground launched one carrying a camera. That V2 captured the first image of the Earth from space. Photography from above the atmosphere was somewhat literally on the horizon. That same year, the Rand Corporation undertook a feasibility study of orbiting satellites for data collection. Technology became a primary technological focus in the United States in the late 1940s and into the 1950s. And most of the funding came in developing this technology for national defense. The emphasis was on developing intermediate range and intercontinental ballistic missiles capable of carrying nuclear warheads to points around the globe, essentially building up an arsenal against potential aggression from the Soviet Union. This work led to three notable programs. The Redstone IRBM, being developed by Werner von Braun's team now working at the Army Ballistic Missile Agency, the U.S. Air Force's Atlas ICBM, and the Navy's Vanguard Sounding Rocket. While the military branches pursued various missile programs, Rand continued to study and develop the idea of reconnaissance satellites. In 1953, the program was transferred to the U.S. Air Force's Air Research and Development Command, bringing the idea firmly under the military umbrella, which was good timing. Just coincident with the Air Force taking over the satellite program, the Air Force's Scientific Advisory Board gave the Atlas missile a high priority status. The Atlas's development had implications for satellites. If the missile could carry a warhead across the ocean, it would also be powerful enough to carry something smaller into orbit. In essence, the thrust to send a warhead across the Earth could be harnessed for an orbital trajectory with a less massive payload. The same could be said of Redstone and Vanguard as well. Earth could theoretically carry small payloads into space. The link between missiles and spaceflight found various outlets. But the one we're interested in for this story comes in 1955, when General Operational Requirement No. 80 gave the objective of providing continuous surveillance of pre-selected areas of enemy territory. The idea of a satellite surveillance program fell under the Air Force's Ballistic Missile Division. Just two years earlier, in the fall of 1953, the CIA began pursuing a high-altitude reconnaissance plane. The Air Force, officially taking on a satellite program, now marked a shift in overhead reconnaissance in the United States. Traditional forms of espionage using human operatives became impossible after the Iron Curtain came down, shutting off communications with Eastern Europe. What World War II era photography the Americans had was badly outdated. Better intelligence was necessary to manage the mounting Cold War, and the only way to look past the Iron Curtain was to go over top of it. If a plane could fly high enough to avoid radar detection, which would also put it well out of range of intercepting missiles, it could fly into Soviet airspace to photograph missile and bomber sites without being seen. This plane was the U-2. The full origin story is in this video right up here. It was designed by Kelly Johnson and the Lockheed team to be invisible and invincible, but came with a time limit. Even before the plane started flying, CIA program managers knew it was only a matter of time before this cutting-edge technology became obsolete. Including Special Assistant for Planning and Coordination Richard M. Bissell, the CIA's leading advocate of technical over human intelligence gathering, he gave the U-2 two years of overflights before the Soviets would know enough about it to build defenses against it. The U-2 didn't get two years of invisibility. It didn't even get two flights. Herbie Stockman left the base at Wiesbaden on July 4th of 1956 and flew over Poznan, Poland, Belarus, then headed north towards Leningrad before flying over the Baltic states. Carmine Vito followed a similar path the next day, but flew further east, going more than 200 kilometers past Moscow. Soviet radar picked up both flights almost immediately. And though it seemed the Soviet fighters couldn't track the U-2 well enough to intercept it, the plane was no longer a secret. That same month, July of 1956, the Air Force approved a satellite development program called Weapons System 117L, or WS-117L. Four months later, the prime contract was awarded to the Lockheed Missile and Space Company, the same company that built the U-2. WS-117L was originally conceived as a program to explore and implement reconnaissance satellites for national security. The idea was to house various electronic intelligence and imagery intelligence setups within a single system housed in the Lockheed upper stage that eventually became known as the Agena. And unlike the U-2 program that returned film to be developed and analyzed, WS-117L aimed for near real-time data with the E1 and E2 systems. The best available technology at the time was television cameras, but they were too slow to image anything from orbit properly. To bypass the leg of TV cameras, both the E1 and E2 systems used a regular film camera to photograph sites of interest from orbit. That film would be stored and developed on board the Agena. And once processed, scanning cameras would image that film and relay the images back to Earth. Like the U-2 program, WS-117L gave Eisenhower pause. Though he was keen on a technology that would return intelligence without violating Soviet airspace, he was also keen to keep the military out of space. Eisenhower's resolve on this point was strengthened after the Soviets launched Sputnik on October 4th of 1957. The small satellite merely beeped from orbit, but it raised fears among the American people that the Soviets were spying from space. Experts knew the satellite itself was harmless and that the real worry was the R-7 launch vehicle's power. The R-7 that launched 184 pounds into orbit could launch something heavier across the Earth, like a nuclear warhead from Russia to the United States. Sputnik pushed America's nascent space efforts forward and also bred fears over the Soviets' missile powers. The question had been over the bomber gap when the U-2 started flying. Now it was over the missile gap. U-2 overflights were ongoing when the President's Board of Consultants on Foreign Intelligence Activities sent its semi-annual report on October 24th of 1957. It listed two technologies then under development to gather data on Soviet technologies, a new manned high-altitude plane with a smaller radar cross-section than the U-2 and an unmanned reconnaissance satellite system. Eisenhower gravitated to satellites over continued overflights. On October 28th, he asked Secretary of Defense Charles Wilson and Director of Central Intelligence, Alan Dulles, for a status report on this nascent technology. The report ended up being a verbal one to avoid any written records falling into the wrong hands and in the months that followed, more in-person meetings shaped the program. Major players agreed that the WS-117L photographic subsystem represented the best chance of success and should thus be separated into a standalone program called Corona. While early talks were still underway, a new agency joined the discussion. The Advanced Research Projects Agency, or ARPA, which is the predecessor to modern-day DARPA, was established on February 7th, 1958 and was immediately granted authority over military space projects. An ARPA directive on February 28th and the CIA's Assuming Responsibility for Security Arrangements around WS-117L in March finalized Corona's separation. It was now a program to develop a mid-sized satellite that would launch on a Thor-Agenus stack. Thor would be the first stage and a Gena the second stage that would also house the imaging system. Like the U-2, it was officially a joint CIA-ARPA Air Force program, though it developed into more of an ARPA-CIA program with Air Force support. Special Assistant to DCI Alan Dulles for Planning and Development, Richard Bissell and Brigadier General Osmond Ritland were the prominent management voices representing the CIA and Air Force, respectively. From the start, the program was marked by civility. None of the organizations involved wanted credit. They all just wanted to get the job done. WS-117L, as a whole program, meanwhile, did live on under the Air Force umbrella. Corona took shape as it developed into a dedicated standalone program, one of the first things to go was the goal of near real-time imaging. While scanning the photographs was viable, relaying them to Earth was not. The bandwidth for this transfer was beyond the limits of technology at the time, so planners started considering an alternate method. The near real-time goal became a separate project called Samos. Corona took shape as the stop gap while technology caught up and the interim solution was physical film recovery. With this decision made, planners focused on the actual spacecraft in March of 1958. Lockheed presented a spin-stabilized, football-shaped payload design to its counterparts, the CIA, the Air Force, the ballistic missile division, General Electric, and Fairchild, the company building the camera. But the arrangement soon changed. The ITEC company was building a new camera that Bissell was more excited about than the Fairchild design, even though it eschewed spin stabilization for a three-axis stabilization system. Bissell eventually changed Corona's camera system, abandoning Fairchild as a contractor. But to lessen the financial blow, Fairchild was brought on as a subcontractor to ITEC. The camera hardware was designed to be part of the Agena, meaning the stage had to alter its attitude to point the camera at its target. As the film was exposed, it would spool into an onboard bucket, properly called the reentry vehicle or recovery vehicle. Once the full load of film was exposed and spooled, it was time for reentry. The Agena would pitch down through 60 degrees to put the satellite in a retrofire orientation. The retro rockets would fire, then the satellite recovery vehicle would separate from the Agena. Spin stabilization rockets would maintain the recovery vehicle's attitude as it fell through the atmosphere, through the retro rocket thrust cone separation and heat shield and parachute cover deployment phases. Once the recovery vehicle reached thick enough atmosphere, the drogue parachute would deploy, followed by the main chute that would slow its fall in a designated recovery area over the Pacific Ocean near Hawaii. And here's where the decision to recover the film gets really tricky. To avoid the film falling into the wrong hands, the primary recovery method called for a pilot to fly a C-119 or a C-130 over the top of the descending capsule and snag the parachute or its shrouds with a trapeze-like hook suspended below the fuselage. If the pilot missed, the recovery vehicle was designed to float long enough for backup crews to fish it out of the water, but not so long that a foreign ship could find it. The capsules would eventually sink, burying the intelligence with them. In theory, this recovery method was simple, but it proved very difficult in practice. When a test squadron practiced catching descending payloads midair, pilots only recovered 49 of the first 74 drops. A different style of parachutes saw four out of 15 drops recovered. 11 drops with yet another kind of chute saw only five recoveries. Regardless of parachute type, the recovery rate was low, but that wasn't all. On average, it took one and a half passes to snag the chute, which meant even successful recoveries were not smooth. Issues were chalked up to crew inexperience, but the canisters also fell so fast it was hard to gain experience. Still, another kind of chute was eventually developed with a slow enough sink rate for a reasonable chance of air recovery, bringing some reliability to the method. The in-flight and recovery sorted, the final program consideration was getting Corona into orbit. For the Corona Satellites to cover the Soviet Union, they needed to launch into a near-polar orbit, which meant the missions couldn't start at the Air Force's Cape Canaveral Launch Site, which was perfect for equatorial launches. The best launch location for Corona turned out to be near Arguello, California, a site that not only facilitated polar launches, rockets launching southward went safely over the Pacific Ocean. It was great for range safety. The location was perfect, but the site didn't exist. A new facility would have to be built at the Cook Air Force Base, which was renamed Vandenberg Air Force Base in October of 1958. There was only one lingering challenge with the launch location. The Southern Pacific Railroad passed very close to the base. The workaround was setting launch windows around the train schedule, even if it meant a break in rail traffic that was just a few minutes long. These major decisions made Corona's final configuration was sent to the White House Chief of Staff, Andrew Goodpaster, on April 16th of 1958. He passed it to Eisenhower, who approved the program. The official record was a handwritten note on the back of an envelope taken by General Charles Peer Cable, the Deputy Director of Central Intelligence. The last challenge was figuring out the cover story for Corona, since there was no way people wouldn't notice rockets flying over the California coast. The WS-117L program wasn't a public secret. It wasn't openly talked about, but it wasn't highly classified either. Managers knew linking Corona to WS-117L in any way would both draw unwanted attention to the government reconnaissance programs and reveal this satellite's true nature. The solution lay in the nation's very public space program. On December 3rd, 1958, a press release announced the discoverer and sentry programs, which were Corona and Samos respectively. The public was told both programs would be exploring space, environmental conditions, and launching biomedical specimens, and that ARPA would participate by developing radiometric payloads. Corona was thus disassociated from sentry and Samos and protected by discoverer. With all the pieces falling into place, the first Corona design review came on May 14th, 1958, and the design was frozen on July 26th. Already, the first launch tentatively on the books was in mid-1959. As part of the lead-up, the Vandenberg launch site was finished. This Air Force operational missile training site became home to the 672nd Strategic Missile Squadron, working specifically with the Thor missiles. Manufacturing and other program personnel were all moved to the area as they prepared to launch from California and recover the film near Hawaii. The Thor Agena program supporting Corona got off to a rocky start, which was part for the course for rocketry in the late 1950s. But even for the 1950s, Corona had a lot of growing pains. On January 21st, 1959, the first Thor Agena mission and the first launch from Vandenberg was aborted at T-minus 60 minutes. Power was applied to test the Agena's hydraulic system, triggering the explosive bolts connecting it to the Thor booster. The alleged motors fired and the Agena settled into its faring, sustaining significant damage. That was just the first of many problematic attempted launches. By the end of 1959, the program had experienced one misfire, three orbit insertion failures, two high eccentric orbits, one premature ejection, three partial or complete camera failures, one retro rocket malfunction, one temperature failure in the payload bay, and failures of both the camera and the capsule return method. These specific failures were all symptomatic of larger, more serious issues that would continue to affect the program if left unaddressed. A Corona panel finally met to discuss the extensive list of problems. The launch profile explained the orbit insertion problems. The Thor Agena stack demanded the Thor burn all its fuel rather than having the engine cut out at a predetermined point in velocity. This inaccurate profile introduced the potential for trajectory variations that could compound when the Agena fired. A more powerful Agena with lighter instruments would help remedy the problem, but in the meantime, engineers had to literally shave off weight with a file and tin snippers to keep the stacks mass low enough for the correct launch profile. One issue behind the camera failures was the film. It was designed to operate in an unpressurized cabin, a decision made to save weight, but the vacuum caused the acetate-based film to tear, which in turn caused the camera to jam. A new, more durable polyester film solved that problem. Cabin temperature was another cause of camera failure. Again, to keep mass low, the camera's cabin was heated purely through passive thermal control. The sun provided natural heating, but it wasn't stable. Early missions saw a huge variety of in-board temperatures. An interim solution with a minimal weight penalty was adding thermal paint. The spin stabilization rockets explained problems with the capsule's return. They tended to explode rather than fire. Changing to a cold gas system promised to solve the problem. A more challenging problem to solve with the recovery was getting the recovery vehicle to come down in the right zone. A one-second delay in firing the retro rockets translated to a five-mile difference in landing site, and that was a huge error when a pilot had to snag the falling payloads parachute. Adding to the corona team's mounting stresses in solving these problems was the Navy's success with its own satellite program. On June 22nd, 1960, the Navy launched a successful galactic radiation background experiment, GRAB satellite, that carried an electronic intelligence or Elan system that gathered information on Soviet air defense radars. Corona, meanwhile, needed, quote, qualification, requalification, and multiple testing of component parts before more missions could resume, but there was no question of canceling the program. Problems aside, the satellites were getting into orbit, and while GRAB could detect radar, it couldn't photograph airfields or missile locations. To give the corona research and development team time to solve the bevy of issues, a stand-down was in effect from November 20th, 1959 to February 4th, 1960, when the 9th Discoverer mission launched, and it failed to achieve orbit. Discoverer 10 launched on February 19th, 1960, and though it was the first time film was recovered from a mission, it was in a way that made no one happy. The Thor booster fish-tailed and was destroyed by range safety after 52 seconds. The payload was picked up nearby by a crew in a jeep. By April 1960, there had been 11 launches and not a single success, forcing another stand-down to make time for more troubleshooting. The next mission, a diagnostic flight for Discoverer 12, saw the Agena fail to redorb it. The need for viable intelligence increased as the failures piled up. As the Soviets launched increasingly sophisticated and heavy payloads, fear over the nation's missile arsenal increased. The perceived missile gap took center stage in 1960, becoming one of the key points in the presidential race between John Kennedy and Richard Nixon. Meanwhile, President Eisenhower decided to take a decisive step and authorized an audacious and extremely risky U-2 Soviet overflight. That flight took off early in the morning on May 1st and ended with Gary Powers' U-2 being downed deep over Soviet territory. Soviet overflights were officially finished and there was still no information about the nation's true military capability. Grab satellites couldn't image missile installations. The sentry system was still under development and far in the future. Corona had to work. Discoverer 13 launched on August 10th, 1960, a repeat of the diagnostic flight and it all finally worked, almost. The capsule came down outside the recovery area and was fished out of the ocean, but it was nevertheless a tremendous win for the program. The mission was widely celebrated under the Discoverer Cover Story. News photos showed the ocean recovery and Eisenhower displayed the capsule and flag it had carried to the press. Finally, Discoverer 13 was definitive proof that the Corona system worked. Even though this mission had no film on board, it proved orbital espionage was a viable option. On August 17th, the show trial over Gary Powers' flight ended. He was found guilty of espionage and his sentence was 10 years' deprivation of liberty. On August 18th, Discoverer 14 launched on the first complete Corona mission. This mission wasn't without its problems. The Agena had to use a lot of fuel to correct its orientation once in orbit, but once this was done, the full 18 feet of film was exposed. The bucket was ejected and Captain Harold E. Mitchell piloting a C-119 snagged it on his third pass over the falling payload. The film was delivered to the Photographic Interpretation Center for Development and Analysis. The resolution was much lower than photographs returned from U-2 flights and some images had strange artifacts like plus minus density bars related to onboard fluid leaks and some marks caused by actual Corona, electrostatic discharge from the sun. But issues aside, the intelligence was outstanding. This one mission had covered more territory than all the U-2 missions combined. Some 1.5 million square miles of Soviet land, airfields and 26 new surface-to-air missile sites. It even covered areas unreachable by the U-2 with its 24-inch focal length camera that could resolve objects as small as 40 feet across. Analysts could count individual bombers at airfields. It also photographed missile locations. In one mission, Corona had disproved the existence of a missile gap and this was just the beginning. The Discoverer 14 camera was retroactively given the security designation of Keyhole 1 or KH1 and there were other more sophisticated cameras coming out of the WS-117L program for later missions. This raised the issue of managing all the incoming intelligence, not from Corona alone, but from other programs as well, Grab and Samos. To pull together the growing amount of data, the CIA and Department of Defense jointly established the National Reconnaissance Program on September 6th of 1961 as the umbrella organization to manage all military and government espionage program, which also included the still nascent A-12 slash ox cart slash SR-71 spy plane. The office was co-directed by Undersecretary of the Air Force, Dr. Joseph Charek and CIA Deputy Director, Richard Bissell. A very familiar name in this story. The next missions in the Corona series were a mix of partial successes and failures, but saw one major step forward with Discoverer 18. Launched on December 10th, 1960, this mission debuted the larger Agena B stage that was able to support longer missions with more film, in this case 39 pounds, feeding into the updated KH2 camera. The images from this flight resolved objects as small as 35 feet across, confirming results of earlier missions. As the program continued, the camera technology went through upgrades that meant later missions yielded better results. On the heels of the KH2 camera was the KH3, a new model with minor enhancements. This version debuted on August 30th, 1961 as the payload of Discoverer 29, but analysts wanted better imagery, ideally stereoscopic injury to really understand Soviet missile sites. Using the available technology, engineers achieved this goal by combining two KH3 cameras into a single Agena payload. One pointed forwards and the other aft, photographing a swath 15 degrees from vertical in both directions. The resulting images aligned, created a stereo look at that swath of ground. This became the mural variant and this camera system known as KH4. This system also added a new index camera to take small scale photographs to simplify identifying terrain. But before KH3 launched, its numeric successor KH5 flew. It actually even flew before KH3. KH5 was called Argonne. Its first launch on February 17th, 1961 was the first of several failures. There were 12 Argonne missions, only five of which worked. Murrow ultimately became Corona's workhorse with later iterations increasing its yield. The KH4A and KH4B variants doubled the film supply to 160 pounds with a maximum resolution of objects five to six feet across. The upgraded KH4 system also used two buckets, which meant one film reel could be jettisoned and returned while the other remained in orbit working. Doubling the return from one flight was a serious boon to the program. 52 KH4A systems launched, returning 94 buckets between 1963 and 1969. The KH4B system returned 32 buckets over 17 launches between 1967 and 1972. Even as these better cameras found success, analysts wanted more resolution. In June of 1963, a new system called Lanyard launched, also known as KH6, a camera system designed to resolve objects just one foot across. KH6 was a version of the Samos system, one of the original designs under WS117L. KH6 attempted to aim its optics independently rather than maneuvering the whole spacecraft with a dedicated roll joint, covering 192 nautical miles across the length of the spacecraft's flight path. But the camera could only adjust 200 times per mission and it was slow. It took three seconds to move each 15 degree increment and 30 seconds to move from one extreme to the other. Lanyard only launched three times and never yielded the results engineers and analysts had hoped for. The Agena upper stage failed on the Discoverer 37 mission in January of 1962, marking an unceremonious end of the Discoverer program. The cover story had simply run out. The next corona mission launched on April 18th, 1962 and was openly part of the CIA program. Other versions continued flying too, including Mural, which saw 26 missions before its final flight on December 21st, 1963. 20 of them were recovered, all but one by air snatch. Of the six that failed, two were launched failures, one didn't ranter correctly and three sank. Later iterations kept launching with various improvements. In 1963, a cluster of smaller rockets was strapped to the Thor booster increasing its power at launch. The same host system with a longer focal length made for better pictures. Some missions flew low over target areas for the sake of resolving details, necessitating new orbital adjustment systems to compensate for the rapid decay that came with these lower orbits. There were also some new elements to the continued reconnaissance missions. Infrared film limited dependence on daylight, but there remained no way to get around cloud cover. The CIA and Air Force needed better ability to track weather. On June 21st, 1961, the office of the secretary of the Air Force initiated a defense meteorological satellite program to support corona with better weather data. By October 1962, meteorological satellites had paid immense dividends to the program. As the 1960s drew to a close, there was again talk of a new system to replace corona entirely, KH9. KH9, sometimes referred to as Big Bird, was an updated system that also came out of WS-117L, mirroring a mapping camera with high-resolution cameras. Between 1971 and 1986, 19 hexagon missions covered 877 million square miles of land, still using corona-style film return. This program arguably gathered the best ever images of the Earth from space. The year after KH9 first launched, the corona program was officially canceled, coming to an end in 1972. In its 12 years, the program had a pretty outstanding life. What was meant to be a short interim program lasted far longer than anyone had planned, gathering crucial Cold War intelligence that helped multiple presidents shape international politics while navigating the Cold War. In total, the corona family of satellites returned more than 100,000 images and 2.1 million feet of film, over 39,000 separate reels. The system that some have called an assemblage of objects designed to replace the U-2 made immeasurable contributions to U.S. reconnaissance. The only thing corona couldn't do was realize the dream of near-real-time satellite imaging. This was finally achieved in the late 1970s with electronic film optical readout technology developed under the NRO's Project B office. It used a charge-coupled device, the same as modern digital cameras. Of course, satellite imagery from space didn't stop with PH9. Satellites photographing the Earth have become exceptionally commonplace. I hope you guys enjoyed this look at the corona spy satellite program. Up next is the last installment of the Cold War aerial espionage series, the A12 slash oxcart slash SR 71. A quick reminder that my new book, Fighting for Space, is available for pre-order however you like to consume books. Hardcover, audio book, e-book, and you can even pre-order the paperback. My first book, Breaking the Chains of Gravity is also available however you'd like to buy books. I have links for both of those below. A very special shout-out to all my Patreon backers and YouTube members. You guys truly, truly make these videos possible. So thank you so much for your ongoing support. If you would like to help keep the vintage space up and running and get access to my Space Center Discord, I have the link you need in the description. And of course, links to connect across all of my social media as well. Thank you guys so much for hanging out with me today. I hope you enjoyed your time here and I'll see you next time.