After booster problems on the Mercury MR-2 chimp test flight, Von Braun insisted on a further unmanned booster test flight, against the wishes of Shepard and others at NASA. A Mercury boilerplate capsule was launched on a flawless test on 24 March. If NASA had overruled Von Braun, the manned Freedom 7 capsule would have flown instead. Shepard would have been the first man in space (though not in orbit), beating Gagarin's flight by three weeks.

The original Mercury project plan envisioned all of the astronauts making an initial suborbital hop aboard a Redstone booster before making an orbital flight aboard an Atlas. However delays in the program resulted in the Redstone flights coming much closer to the Atlas flights than planned. By the time of the first suborbital Mercury flight, the Russians had already orbited Yuri Gagarin. After Grissom's capsule sunk, it was still planned to fly Glenn on a suborbital flight to prove the capsule. But Gherman Titov was launched on a full-day orbital flight in August 1961, making NASA's suborbital hops look pathetic. Glenn was moved to the first orbital Atlas flight, and further suborbital Mercury flights were cancelled.

Slayton would probably have flown the fourth manned suborbital Mercury. But after the Russians began orbiting cosmonauts, NASA cancelled further suborbital flights. The MR-6 mission was cancelled by NASA administrator James Webb at the beginning of July, 1961.

Astronaut Deke Slayton was to have been the second American in orbit. When Slayton was selected as an astronaut in 1959, it was known he had a minor heart fibrillation. This however did not prevent him from being an Air Force test pilot or being selected as an astronaut. But on January 23, 1962 John Glenn's wife refused to do a television appearance with Vice President Lyndon Johnson after a launch scrub of Glenn's mission. Soon thereafter rumours began in McNamara's Pentagon that Glenn had a secret heart condition. It was not Glenn, and his flight went as planned, but in the process Slayton's heart fibrillation came up. After a series of quick developments, Slayton was told he couldn't fly, and was forced to appear at a press conference making that announcement on March 16. The action was seen by many as a warning to the astronauts who was really in charge, although Slayton didn't think there was a direct cause and effect. Slayton's three orbit flight would have been called Delta 7. Instead Carpenter was selected for the mission, and Schirra, Slayton's backup, was moved to the Mercury 8 flight.

Korolev proposed further manned Vostok flights after Vostok 6. The first was to be a high altitude flight into the lower Van Allen radiation belt for radiological-biological studies. Spacecraft would have been allowed to naturally decay to a re-entry after ten days. A training group for these flights was assigned on 17 September 1963: Belyayev, Gorbatko, Khrunov, Komarov, Leonov, Shonin, Volynov, and Zaikin. By 25 January 1964 this had changed to Belyayev, Beregovoi, Khrunov, Komarov, Leonov, and Volynov. All follow-on Vostok missions were cancelled in spring 1964 when the decision was made to proceed with conversion of Vostok to the multi-crew Voskhod configuration.

Proposed second high altitude manned flight into the lower Van Allen radiation belt for radiological-biological studies. Spacecraft would have been allowed to naturally decay to a re-entry after ten days. All follow-on Vostok missions cancelled in Spring 1964.

Proposed high altitude manned Vostok flight for extended scientific studies. Spacecraft would have been allowed to naturally decay to a re-entry after ten days. Purposes of these flights were to be: geophysical and astronomical research; photography of the solar corona; solar x-ray imagery; medical-biological research; detailed study of the effects of weightlessness on the human organism; dosimetry; and engineering tests of ion flow sensors to be used for orientation of later Soyuz spacecraft. All follow-on Vostok missions cancelled in Spring 1964.

NASA and the Mercury managers had to decide whether to undertake another Mercury after Cooper's planned 22 orbit Mercury 9 flight. Walter Williams, Alan Shepard, and others at MSC pushed for a three-day Mercury 10 endurance mission. A capsule was allocated and Shepard had the name 'Freedom 7 II' painted on the side. But the risk and work pending on Gemini persuaded NASA managers not to undertake another mission unless Mercury 9 failed. By May 11, 1963 Julian Scheer, the new NASA Deputy Assistant Administrator for Public Affairs, announced 'It is absolutely beyond question that if this shot (MA-9) is successful there will be no MA-10.' The massive breakdown of nearly all systems aboard Mercury 9 convinced NASA that this was the right decision. Aerospace writer Martin Caidin used the Mercury 10 scenario as the basis for his novel, Marooned. In the book, the capsule's retrorockets fail, stranding astronaut Pruett in orbit. He is saved by the combined efforts of NASA Gemini and Russian maneuverable Voskhod spacecraft.

Proposed high altitude manned Vostok flight for extended scientific studies. Spacecraft would have been allowed to naturally decay to a re-entry after ten days. Purposes of these flights were to be: geophysical and astronomical research; photography of the solar corona; solar x-ray imagery; medical-biological research; detailed study of the effects of weightlessness on the human organism; dosimetry; and engineering tests of ion flow sensors to be used for orientation of later Soyuz spacecraft. All follow-on Vostok missions cancelled in Spring 1964.

Proposed Vostok flight to conduct extra-vehicular activity tests. The Vostok would be modified by having the ejection seat removed and an airlock built into the spacecraft. A braking rocket carried in the parachute lines would provide a soft landing (as was later used on Voskhod). The single cosmonaut would have conducted the first spacewalk in 1965. All follow-on Vostok missions cancelled in Spring 1964.

Proposed Vostok flight to conduct extra-vehicular activity tests. The Vostok would be modified by having the ejection seat removed and an airlock built into the spacecraft. All follow-on Vostok missions cancelled in Spring 1964.

From September 1962 NASA planned to fly four early manned Apollo spacecraft on Saturn I boosters. A key prerequisite for these flights was complete wringing out of the launch escape system.

NASA originally planned to fly four early manned Apollo spacecraft on Saturn I boosters. The decision was made to conduct all Apollo CSM tests on the more powerful Saturn IB booster. These flights were cancelled in October 1963, before crews were selected. This series of four partial-system lightweight Apollos would have run from fall 1965 to the end of 1966, concurrent with the Gemini program.

Proposed high altitude manned Vostok flight for extended scientific studies. Spacecraft would have been allowed to naturally decay to a re-entry after ten days. Purposes of these flights were to be: geophysical and astronomical research; photography of the solar corona; solar x-ray imagery; medical-biological research; detailed study of the effects of weightlessness on the human organism; dosimetry; and engineering tests of ion flow sensors to be used for orientation of later Soyuz spacecraft. All follow-on Vostok missions cancelled in Spring 1964.

Elliot See and Charlie Bassett were the prime crew for Gemini 9. On February 28, 1966, they were flying in a NASA T-38 trainer to visit the McDonnell plant in St Louis, where their spacecraft was in assembly. See misjudged his landing approach, and in pulling up from the runway hit Building 101 where the spacecraft was being assembled. Both astronauts were killed, and 14 persons on the ground were injured. As a result, the Gemini 9 backup crew became the prime crew, and all subsequent crew assignments were reshuffled. This ended up determining who would be the first man on the moon....

Planned duration 19 days. Biological endurance mission cancelled after near-disaster with Voskhod 2. Initial Orbit was to have been 175 km X 500 km at 65 deg. Follow-on missions with journalist, physician, and all-female crews also cancelled. Original Prime Crew was Katys, Volynov; Backup Crew: Beregovoi, Demin; Support Crew: Artyukhin, Shatalov. These assignments were reshuffled to those shown when Katys had to be dropped from the prime crew.

NASA originally planned to fly four early manned Apollo spacecraft on Saturn I boosters. The decision was made to conduct all Apollo CSM tests on the more powerful Saturn IB booster. These flights were cancelled in October 1963, before crews were selected. This series of four partial-system lightweight Apollos would have run from fall 1965 to the end of 1966, concurrent with the Gemini program.

At the time the Dynasoar project was cancelled, the first manned single-orbit flight was planned for July 1966, atop the sixth Titan 3C. Jim Wood would have flown the first manned Dyna-Soar -- he was the senior test pilot on the project, and Hank Gordon told Michael Cassutt years ago that there was no question he was going to get the first flight. (The Dyna-Soar office was structured like a typical Edwards flight test program, where there really was a lead or senior project pilot). The other five X-20 pilots in active training at the end of the program were Crews, Gordon, Knight, Rogers, and Thompson.

NASA originally planned to fly four early manned Apollo spacecraft on Saturn I boosters. The decision was made to conduct all Apollo CSM tests on the more powerful Saturn IB booster. These flights were cancelled in October 1963, before crews were selected. This series of four partial-system lightweight Apollos would have run from fall 1965 to the end of 1966, concurrent with the Gemini program.

Planned second long-duration 20 day Voskhod flight. Cancelled in spring 1966 after near-disaster with Voskhod 2 and death of Korolev. A follow-on Voskhod 3V s/n 7 mission was also planned that would have conducted an artificial gravity experiment, unreeling a tether between the Voskhod spacecraft and the Block I final rocket stage.

An additional manned Dynasoar single-orbit flight was possible in late 1966, atop the seventh Titan 3C.

Planned all-female ten day long-duration flight. Solovyova would have conducted the first female space walk. Cancelled in spring 1966, after death of Korolev, in order to concentrate on Soyuz and Lunar landing programs.

Planned Voskhod flight that would include EVA with test of the UPMK 'jet belt'. Cancelled in spring 1966.

The first manned flight of the Apollo CSM, the Apollo C category mission, was planned for the last quarter of 1966. Numerous problems with the Apollo Block I spacecraft resulted in a flight delay to February 1967. The crew of Virgil I. Grissom, Edward H. White II, and Roger B. Chaffee, was killed in a fire while testing their capsule on the pad on 27 January 1967, still weeks away from launch. The designation AS-204 was used by NASA for the flight at the time; the designation Apollo 1 was applied retroactively at the request of Grissom's widow.

An additional manned Dynasoar single-orbit flight was possible in early 1967, atop the eighth Titan 3C.

It was originally planned to make a second solo flight test of the Block I Apollo CSM on a Saturn IB. This flight was referred to by everyone outside of the astronaut office as AS-205 or CSM-014. This flight was finally seen as unnecessary; the decision to cancel it came on November 16 and was officially announced on December 22, 1966; the Schirra crew instead became, briefly, the backup crew to Apollo 1 (replacing the original backup crew of McDivitt, Scott, Schweickart). After the Apollo 1 fire on January 27, 1967, the Schirra crew was assigned to Apollo 7, the first manned flight test of the new Block II Apollo CSM-101.

The first manned Soyuz flights were an attempt at an 'all up' manned rendezvous, docking, and crew transfer spectacular (eventually accomplished by Soyuz 4 and Soyuz 5). Komarov was the pilot for the Soyuz 1 active spacecraft, which would be launched first. Soyuz 2, with the crew of Bykovsky, Khrunov, and Yeliseyev would launch the following day, with Khrunov and Yeliseyev space-walking to Soyuz 1 and returning to earth with Komarov. Komarov's spacecraft developed serious problems after launch, including the failure of one of the spacecraft's solar panels to deploy. The Soyuz 2 crew were given the order to rendezvous with Soyuz 1 and to try during the planned EVA to unfold the undeployed solar panel. But the launch of Soyuz 2 was cancelled due to heavy rain at the cosmodrome. Low on power and battery reserves, Komarov made an attempt to land the following day. Parachute failure led to the crash of Soyuz 1 and the death of Komarov. After the disaster the Soyuz 2 spacecraft was checked, and the parachute system had the same technical failure. If Soyuz 2 had launched, the docking may have been successful, but then both spacecraft would have crashed on landing, killing four cosmonauts instead of one.

Before the Apollo 1 fire, it was planned that McDivitt's crew would conduct the Apollo D mission - a first manned test in earth orbit of the Lunar Module. Separate Saturn IB launches would put Apollo Block II CSM 101 / AS-207 and Lunar Module LM-2 / AS-208 into earth orbit. The crew would then rendezvous and dock with the lunar module and put it through its paces. After the fire, it was decided to launch the mission on a single Saturn V as Apollo 9. CSM-101 instead would be used to accomplish the Apollo C mission that Grissom's crew was to have flown.

When Schirra's Apollo 2 / AS-205 mission was cancelled in November 1966, the booster went to McDivitt's mission, and it was called AS (or Apollo) 205/208, or AS-258 (before Schirra's cancellation, McDivitt's was AS-278, because it used Saturn IB boosters 207 and 208).

The first multi-orbit flight of the X-20 was planned for late 1967 atop the ninth Titan 3C at the time the program was cancelled.

The third Apollo flight announced on December 22, 1966, was the Apollo E mission - a test of the Apollo lunar module in high earth orbit. The Borman crew would be launched aboard a Saturn V, and put into a very high earth orbit. In mid-1968 Collins had to leave the crew due to a medical problem, and was replaced by Lovell. By late 1968, Apollo 7 had flown the Apollo C mission, but delays with the lunar module meant that neither the D or E profile missions could be flown. In order to beat the Russians around the moon, it was decided that the E mission would be cancelled and instead Borman's crew would fly an Apollo CSM into lunar orbit. This became Apollo 8.

The planned first flight of the Soyuz VI combat spacecraft was planned for early 1969, beating America's equivalent Manned Orbiting Lab. The project was cancelled in 1968.

Planned first manned circumnavigation of the moon. On 24 September 1968 Bykovskiy/Rukavishnikov were the prime candidates for the first Soviet circumlunar flight. Just three days later, when the crews were named, Leonov was selected as commander of the first mission, with Makarov as the flight engineer. Soviet plans to beat America around the moon were upstaged by the sudden decision to fly Apollo 8 into lunar orbit over Christmas 1968. Given problems with obtaining a trouble-free Soyuz 7K-L1 unmanned flight, it would probably not have been possible to make a Soviet equivalent flight until March 1969. It was decided after the American success to cancel any 'second place' Soviet manned circumlunar flights.

Planned second Soviet circumlunar flight. Cancelled after the success of the American Apollo 8. On 24 September 1968 Bykovskiy/Rukavishnikov were the prime candidates for the first Soviet circumlunar flight. When the crews were named, they had been bumped to the second flight.

Planned third and final Russian circumlunar flight. On 24 September 1968 Popovich/Makarov were the prime candidates for the third Soviet circumlunar flight. When the crews were named, Makarov was moved to the first crew and Sevastyanov was named Popovich's flight engineer.

The Kontakt system designed for the lunar orbit rendezvous and docking of the LOK lunar orbiter and LK lunar lander was to be mounted on two Soyuz spacecraft and tested in earth orbit. The first Kontakt crews were established in February 1969. By April 1969, two separate docking missions were to be executed after the triple Soyuz-6/7/8 mission. The first crew of what would have been Soyuz 10/11 and Soyuz 12/13 would have piloted the active spacecraft, simulating the LOK. The second launch would have launched a passive spacecraft, simulating the LK.

Would have simulated the passive LK lunar lander in an earth-orbit test of the Kontakt docking system.

The active spacecraft in the second planned test of the Kontakt lunar rendezvous/docking system.

The passive spacecraft in the second planned test of the Kontakt lunar rendezvous/docking system. One or two of the crew would have spacewalked to the Soyuz 11 Kontakt and returned in the other spacecraft.

If the Soyuz 11 crew had not perished during return to the earth, a second crew would have been sent to the Salyut 1 space station. Further missions to Salyut 1 were cancelled after the disaster.

By December 1970, there were four crews in training for two pairs of Soyuz spacecraft to be launched to test the Kontakt lunar rendezvous/docking system. The launches at that time were scheduled to occur after the missions to the Salyut 1 space station were completed. Soyuz Kontakt 1 would have been the active spacecraft of the first mission.

Soyuz equipped with the passive Kontakt rendezvous/docking system of the LK lunar lander. Would have docked with Soyuz Kontakt 1.

At the time of the cancellation of the MOL program in June 1969, the first manned mission was planned for early 1972. A crew of two would have spent thirty days in orbit operating sophisticated military reconnaisance equipment and other experiments. Walt Williams told Michael Cassutt that Jim Taylor would have commanded the first MOL flight, and given Williams's background in flight test operations, Mercury. and Gemini, that call was pretty much his at that time. As for the pilot, Al Crews, a holdover from the Dynasoar program, is considered by Cassutt as good a guess as any.

Soyuz equipped with the passive Kontakt rendezvous/docking system of the LK lunar lander. Would have served as a docking target for Soyuz Kontakt 3.

Soyuz Kontakt 3 would have been the active spacecraft of the second dual launch to test the Kontakt lunar orbit rendezvous system.

The Russians were never able to have enough success with the N1 booster to have a serious schedule for the first Soviet lunar landing. In January 1969, before the first N1 launch, it was not expected that a Soviet landing would take place until 1972 at the earliest. In such circumstances only a disaster leading to cancellation of the Apollo program would allow the Russians to be first to the moon. After the explosions of the first two N1 rockets, and the success of Apollo 11, Russian engineering efforts were diverted into crash development of the Salyut space station in order to beat the American Skylab. Cosmonauts trained for L3 lunar landing missions until October 1973, when the last training group was dissolved. By that time actual manned flight of the original single-launch L3 LOK/LK spacecraft to the moon had been abandoned. Instead work was underway on the N1F-L3M, a twin launch scenario that would put the L3M lander on the surface in 1978 for extended operations, and eventually, a lunar base. This in turn was cancelled with the entire N1 program in 1974.

Planned second crew to the first Almaz space station. Cancelled after the loss of control of Almaz OPS 1 (Salyut 2) in orbit.

Planned first crew to the first Almaz space station. Cancelled after the loss of control of Almaz OPS 1 (Salyut 2) in orbit.

Planned first mission to the Salyut DOS 2 space station. Cancelled after it was destroyed during launch.

Planned second mission to the Salyut DOS 2 space station. Cancelled after it was destroyed during launch.

Planned date of second manned MOL mission at time of the program cancellation.

Final crews selected for a dual Soyuz mission in Earth orbit to test the Kontakt docking system to be used on the lunar landing LOK and LK spacecraft. The Kontakt-A Soyuz would have been the active spacecraft, simulating the LOK lunar orbiter.

Final crews selected for a dual Soyuz mission in Earth orbit to test the Kontakt docking system to be used on the lunar landing LOK and LK spacecraft. The Kontakt-P Soyuz would have been the passive spacecraft, simulating the LK lunar lander.

Planned first mission to the Salyut DOS 3 space station (Cosmos 557). Cancelled after it failed in orbit.

Apollo 18 was originally planned in July 1969 to land in the moon's Schroter's Valley, a riverlike channel-way. The original February 1972 landing date was extended when NASA cancelled the Apollo 20 mission in January 1970. Later in the planning process the most likely landing site was the crater Gassendi. Finally NASA cancelled Apollo 18 and 19 on 2 September 1970 because of congressional cuts in FY 1971 NASA appropriations. There was also a feeling after the Apollo 13 emergency that NASA risked having its entire manned space program cancelled if a crew was lost on another Apollo mission. Total savings of cancelling the two missions (since the hardware was already built and the NASA staff had to stay in place for the Skylab program) was only $42.1 million. Before the cancellation, Schmitt was pressing for a more ambitious landing in Tycho or the lunar farside. Pressure from the scientific community resulted in geologist Schmitt flying on Apollo 17, the last lunar mission, bumping Joe Engle from the lunar module pilot slot.

Planned date of third manned MOL mission at time of the program cancellation.

Planned second mission to the Salyut DOS 3 space station (Cosmos 557). Cancelled after it failed in orbit.

Influenced by the stranded Skylab crew portrayed in the book and movie 'Marooned', NASA provided a crew rescue capability for the only time in its history. A kit was developed to fit out an Apollo command module with a total of five crew couches. In the event a Skylab crew developed trouble with its Apollo CSM return craft, a rescue CSM would be prepared and launched to rendezvous with the station. It would dock with the spare second side docking port of the Skylab docking module. During Skylab 3, one of the thruster quads of the Apollo service module developed leaks. When the same problem developed with a second quad, the possibility existed that the spacecraft would not be maneuverable. Preparation work began to fit out a rescue CSM, and astronauts Vance Brand and Don Lind began preparations to rescue astronauts Bean, Garriott, and Lousma aboard the station. However the problem was localized, work arounds were developed, and the first space rescue mission was not necessary. The Skylab 3 crew returned successfully in their own Apollo CSM at the end of their 59 day mission.

Apollo 19 was originally planned to land in the Hyginus Rille region, which would allow study of lunar linear rilles and craters.The original July 1972 landing date was extended when NASA cancelled the Apollo 20 mission in January 1970. Later planning indicated Copernicus as the most likely landing site for Apollo 19. Finally NASA cancelled Apollo 18 and 19 on 2 September 1970 because of congressional cuts in FY 1971 NASA appropriations.

After completion of the three programmed Skylab flights, NASA considered using the remaining backup Saturn IB and Apollo CSM to fly a fourth manned mission to Skylab. It would have been a short 20 day mission - the CSM systems would not have been powered down. Main objective would be to conduct some new scientific experiments and boost Skylab into a higher orbit for later use by the shuttle. The marginal cost of such a mission would have been incredibly low; but NASA was confident that Skylab would stay in orbit until shuttle flights began in 1978 - 1979. But the shuttle was delayed, and faster atmospheric decay than expected resulted in Skylab crashing to earth before the first shuttle mission was flown.

Planned date of fourth manned MOL mission at time of the program cancellation. From the beginning of the project, the Navy had demanded that this be an all-Navy crew, which would limit the crew to Truly, with either Overmeyer or Crippen as co-pilot.

Apollo 20 was originally planned in July 1969 to land in Crater Copernicus, a spectacular large crater impact area. Later Copernicus was assigned to Apollo 19, and the preferred landing site for Apollo 20 was the Marius Hills, or, if the operational constraints were relaxed, the bright crater Tycho. The planned December 1972 flight was cancelled on January 4, 1970, before any crew assignments were made. Work was stopped on LM-14; CSM-115A was studied for use on a second Skylab mission; Saturn V 515 was earmarked for use on Skylab. The remaining Apollo missions were stretched out to six-month intervals, which would have placed the Apollo 20 flight in 1974 had it not been cancelled. No crew was formally selected, but in the normal three-mission-ahead crew rotation, and with the assignments at that time, the Conrad crew would have been named. Instead they were transferred to the Skylab program. At one time it was considered possible that Mitchell would command the crew in place of Conrad. But it has also been stated that since both Conrad and Mitchell had been on the lunar surface, Stuart Roosa would have been commander. Astronaut Lind was considered by Slayton as next in line for a chance to land as lunar module pilot, but not until the never-funded Apollo 21.

Planned but cancelled third mission to the Salyut 3 space station.

NASA realized that after the completion of the Apollo, Skylab, and ASTP programs there would still be significant Apollo surplus hardware. This amounted to two Saturn V and three Saturn IB boosters; one Skylab space station, three Apollo CSM's and two Lunar Modules. After many iterations NASA considered use of these assets for a second Skylab station in May 1973. A range of options were considered. Saturn V SA-515 would boost the backup Skylab station into orbit somewhere between January 1975 and April 1976. It would serve as a space station for Apollo and Soyuz spacecraft in the context of the Apollo ASTP mission. The Advanced or International Skylab variants proposed use of Saturn V SA-514 to launch a second workshop module and international payloads. This station would be serviced first by Apollo and Soyuz, then by the space shuttle. Using the existing hardware, these options would cost anywhere from $ 220 to $ 650 million. But funds were not forthcoming. The decision was taken to mothball surplus hardware in August 1973. In December 1976, the boosters and spacecraft were handed over to museums. The opportunity to launch an International Space Station, at a tenth of the cost and twenty years earlier, was lost.

Planned date of fifth manned MOL mission. This mission was already deleted from the FY 1970 budget request in April 1969, two months before the entire project was cancelled.

A Soyuz 25 mission to the Salyut 5 space station with the crew of Berzovoi and Lisun was to have followed Soyuz 24. However during the four months it took to prepare the Soyuz, Salyut 5 consumed higher than expected fuel in maintaining the station's orientation. As a result, the fuel reserves were 70 kg below those required for the planned 14 day mission and it was cancelled.

Planned mission to Salyut 6 that would make first docking with rear docking port and be the first crew to swap spacecraft and return in the spacecraft that ferried the Soyuz 25 crew. But Soyuz 25 failed to dock with Salyut 6. One result of the investigation of the failure of the mission was that all future crews would have to have at least one cosmonaut with previous space flight experience. Kolodin was replaced by Makarov, and Soyuz 26 as flown had quite a different profile. Kolodin never flew in space.

Dual test of TKS-VA manned capsule. Shutdown of the launch vehicle on the pad triggered the launch escape system, which pulled the top capsule away from the booster. The parachute system failed and the capsule crashed to the ground. The lower capsule remained in the rocket. The top capsule was to have been manned, but the inability to demonstrate two consecutive failure free launches of the Proton/TKS-VA combination made that impossible.

Dual test of TKS-VA manned capsule. One vehicle reentered and landed after two orbits, the other after one orbit. The top capsule was to have been manned, but the inability to demonstrate two consecutive failure free launches of the Proton/TKS-VA combination made that impossible. This launch successfully demonstrated the reusability of the TKS-VA capusle; the same pair had flown as Cosmos 997/998 on 30 March 1978.

In late 1977 shuttle orbital missions were due to start in 1979. The orbiting Skylab space station was not expected to decay until 1983. A plan to save Skylab was developed. In Phase 1a small Skylab Reboost Module would be docked to Skylab on the second Shuttle flight. This would boost the station to a higher orbit for later use, and also provide the capability of deorbiting the station into empty ocean if the decision was taken to abandon it. Astronauts Haise and Lousma were selected for this flight, and development of the reboost module was begun. But it was not to be. Aside from intense resistance from some factions at NASA headquarters, higher solar activity resulted in heavier than predicted drag on Skylab. The shuttle program also was hit with delays. Before the first shuttle flew, Skylab burned up in the atmosphere and crashed into the Australian outback on July 11, 1979.

Planned but cancelled manned flight. Crew dissolved when Lazarev failed physical in early 1981.

Planned first test manned flight of the TKS large ferry craft. Would have docked with the Almaz OPS 4 military space station. Flight cancelled with the rest of the Almaz program in 1981. The spacecraft was instead flown unmanned to Salyut 6 as Cosmos 1267.

Second TKS flight that would have docked with the cancelled Almaz OPS 4 military space station. The spacecraft was instead flown unmanned to Salyut 7 as Cosmos 1443.

Third TKS flight that would have docked with the cancelled Almaz OPS 4 military space station. The spacecraft was instead flown unmanned to Salyut 7 as Cosmos 1686. For that mission the VA reentry capsule was retained but stripped of its heat shield and all recovery equpment. In their place military optical test sensors (infrared telescope and Ozon spectrometer) were installed.

Planned Soyuz flight to a dock with the Almaz OPS 4 space station. The mission was cancelled together with the Almaz program in 1981.

Planned Department of Defense shuttle mission. Cancelled due to payload delays.

Planned TDRS/IUS deployment shuttle mission. Cancelled after Challenger disaster.

Planned Department of Defense shuttle mission. Cancelled due to IUS failure.

Planned shuttle mission for deployment of commercial communications satellites. Cancelled due to payload delays.

Planned Department of Defense or TDRS deployment shuttle mission. Cancelled due to IUS failure.

Planned TDRS/IUS deployment shuttle mission. Cancelled due to IUS failure.

Planned but cancelled manned flight to Salyut 7. Breakdown of Salyut 7 led to cancellation of this flight and its replacement by the Soyuz T-13 repair mission. Savinykh served on the repair mission while Vasyutin and Volkov flew on Soyuz T-14.

Planned shuttle mission. Cancelled due to payload delays.

Planned TDRS/IUS deployment shuttle mission. Cancelled due to IUS failure.

Final expedition to Salyut 7 station was cancelled when control was lost.

Planned Astro-1 shuttle mission. Cancelled after Challenger disaster.

Planned shuttle mission for deployment of Ulysses spacecraft. Cancelled after Challenger disaster.

Planned shuttle mission for deployment of Galileo spacecraft. Cancelled after Challenger disaster.

Planned flight to Salyut 7. Breakdown of Salyut 7, exhaustion of stock of Soyuz T spacecraft led to cancellation of mission.

Planned shuttle mission for deployment of commercial communications satellites. Cancelled after Challenger disaster.

Planned Department of Defense shuttle mission. Cancelled after Challenger disaster. Would have been first launch from the ill-fated SLC-6 launch site at Vandenberg, California.

Planned TDRS/IUS deployment shuttle mission. Cancelled after Challenger disaster.

Planned shuttle mission for deployment of Hubble space telescope. Cancelled after Challenger disaster.

Planned Department of Defense shuttle mission. Cancelled after Challenger disaster.

To have docked with Mir. Cancelled all-female flight to be launched on International Woman's Day. Breakdown of Salyut 7, exhaustion of stock of Soyuz T spacecraft, and official resistance led to cancellation of the mission. Officially cancelled due to birth of Savitskaya's baby. No female cosmonauts would be in training again until a decade later.

Planned shuttle LDEF (Long Duration Exposure Facility) recovery mission. Cancelled after Challenger disaster.

Planned Department of Defense shuttle mission. Cancelled after Challenger disaster.

Planned EOM-1 shuttle mission. Cancelled after Challenger disaster. No crew named, later combined with STS-61K

Planned shuttle mission for deployment of commercial communications satellites. Would have launched the first American journalist in space from Launch Complex 39B. Cancelled after Challenger disaster.

Planned shuttle mission. Cancelled after Challenger disaster.

Planned Astro-2 shuttle mission. Cancelled after Challenger disaster.

Planned shuttle mission for deployment of commercial communications satellites. Cancelled after Challenger disaster.

Planned shuttle mission for deployment of commercial communications satellites. Cancelled after Challenger disaster.

Planned shuttle mission. Cancelled after Challenger disaster.

Planned SLS-1 shuttle mission. Cancelled after Challenger disaster.

Planned Astro-3 shuttle mission. Cancelled after Challenger disaster.

Planned Spacelab-J shuttle mission. Cancelled after Challenger disaster.

Planned SLS-2 shuttle mission. Cancelled after Challenger disaster.

Planned flight to ensure continuous occupation cancelled due to budget cutbacks and delay in launching Kvant 2 and Kristall modules.

Soyuz TM-13 and TM-14 crews were reshuffled extensively due to commercial considerations and necessity of flying a Kazakh cosmonaut. This was the original crew assignment. Kaleri and Avdeyev were replaced by Kazakh researchers in the final crew.

Soyuz TM-13 and TM-14 crews were reshuffled extensively due to commercial seat bookings by Austria and Germany and the necessity of flying a Kazakh-born cosmonaut as part of the Baikonur rental agreement. This was the original crew assignment. The Kazakh researchers were moved to the earlier Soyuz TM-13 flight.

Soyuz TM-13 and TM-14 crews were reshuffled extensively due to commercial seat bookings by Austria and Germany and the necessity of flying a Kazakh-born cosmonaut as part of the Baikonur rental agreement. This was the second crew assignment. The Kazakh researchers were moved to the earlier Soyuz TM-13 flight and paying German researchers took their place in the final crew.

Planned Soyuz flight to Mir. Main purpose was to provide spaceflight experience to Bachurin and Borodai, who had been selected as back-up crew of the first manned Buran flight (the original back-up crew of Levchenko and Shchukin both died in 1988). Cancelled in cut-backs after fall of the Soviet Union.

Buran Flight 5 (3K1) would have been the first flight of the third orbiter. It would be the first manned Buran flight; the third orbiter was the first outfitted with life support systems and ejection seats. Two cosmonauts would deliver the 37KBI module to Mir, using the Buran manipulator arm to dock it to the station's Kristall module. Final crew selection had still not been made at the time the program was cancelled. The original crew was Volk and Stankiavicius, with Levchenko and Shchukin as back-ups. Both Levchenko and Shchukin died in 1988; Bachurin and Borodai were selected as the new back-up crew. By July 1992 the Soviet Air Force and NPO Energia were still arguing about the final crew composition. The Air Force wanted all test pilot crews (those indicated) while Energia wanted to include a flight engineer in each crew. The Buran project was finally cancelled in June 1993 when further funding was deleted from the Russian space budget.