Space missions that never happened

The BBC has an article by Richard Hollingham about space missions the Cold War killed:

Every jaded space nerd has a dream of where they hoped space exploration would take us. By now I imagined the Earth would be circled by gleaming space hotels, flights to the Moon would be routine, and the first settlers would be colonizing the dusty plains of Mars. Yet, despite Richard Branson’s best efforts, our glittering space future remains as elusive as ever. Although, only the other week, a man in a gorilla suit chased a British astronaut through a space station. So it’s not all bad.
For the last forty years, human progress beyond Earth’s orbit has been painfully slow, with space history littered with hundreds of abandoned projects and concepts. But an alternate and very different pattern of space exploration might have become reality had a few Cold War missions been given the final go-ahead: 

Nuclear rocket
On the grey concrete of a small outdoor display area at NASA’s Marshall Space Flight Center in Alabama sits one of the most unusual engines the agency has ever developed. Mounted on a frame alongside a long thin Space Shuttle solid rocket booster (with “empty” reassuringly painted on the side), the funnel-shaped NERVA engine was designed to take astronauts to Mars.
Many rocket engineers still believe that nuclear propulsion has a promising future
Developed in the 1960s, NERVA, or Nuclear Engine for Rocket Vehicle Application, consisted of a cylindrical uranium nuclear fission reactor that heated liquid hydrogen. The gas was then expelled through a rocket nozzle to generate high levels of thrust.
Following Wernher von Braun’s plan, NASA’s first Mars mission was slated for 1979, with astronauts blasting off on a conventional rocket before activating NERVA in orbit to carry them onwards to the Red Planet.
Around twenty nuclear engines were tested successfully, with the results suggesting it was a promising technology for interplanetary travel. The engine on display at Marshall would have been the most powerful, but the project was cancelled in 1973 before anyone could try it out.
Many rocket engineers still believe that nuclear propulsion has a promising future. However, the idea of launching a reactor filled with highly radioactive uranium on the top of a rocket filled with explosive gases also, unsurprisingly, has its detractors. 

Space gunship
One of the scariest spacecraft ever designed emerged from a 1960s Russian program to militarize the Soyuz spacecraft. The aim was to develop a crewed spacecraft to observe enemy territory and destroy enemy satellites.
The plan that emerged was for a manned gunship in space, able to creep up on other spacecraft and fire a projectile to blast them into pieces. The primary target would be American spy satellites as well as any weaponized American spacecraft.
A cosmonaut would aim the weapon by pointing the spacecraft and lining up the target in a gunsight. To ensure that, when they fired, the Soyuz didn’t recoil backwards or start spinning uncontrollably, the gun was mounted on an independent low-friction platform.
Although it seems the technology was developed and cosmonauts trained, the military program was abandoned in favour of a civilian space station program. With the advent of more sophisticated spy satellites, it was also decided that there was no need for a man to snap the pictures. 

Big G
The Gemini program of the mid-1960s featured some of the most audacious missions ever flown. With two astronauts crammed into a cockpit around the size of the front seats of a small family car, Gemini notched up a heap of space firsts: the first American spacewalk, the first long-duration spaceflight, the first orbital rendezvous and docking, the first time a spacecraft was fitted with fuel cells and programmable computers.
It was so good that its maker McDonnell Douglas had big plans for the little spacecraft, deciding to supersize it to carry nine astronauts. The program that emerged was called Big G, described in the promotional brochure as “a truck in space”.
Designed to transport astronauts to and from a planned military space station, Big G had two compartments: a regular two-man Gemini capsule at the front and a larger crew cabin behind. McDonnell Douglas drew up detailed plans for the project and built full-sized mock-ups to show NASA officials how it would all work.
With the space station on hold, Big G was finally dropped in favor of the Space Shuttle in 1971. The idea of a large crewed capsule to transport astronauts to and from orbit, however, is once more back in vogue, with NASA currently funding designs by Boeing and SpaceX. 

Space Station Freedom
The space station that President Ronald Reagan signed off in 1984 was very different to the International Space Station (ISS) that emerged from the political wreckage. Freedom was conceived to be far more than an orbiting laboratory. It would have had a hangar that spacecraft could have been repaired in (Credit: Science Photo Library)
Not only would it be fitted with labs, it would also have a fully-equipped sick bay and recreation facilities. Perhaps most excitingly, the design also featured a hangar where satellites and spacecraft could be brought in for repair before being released back out into the void.
In short, Freedom was far more like the space stations of science fiction than the lumpy collection of cylinders that we have ended up with. Unfortunately, Freedom turned out to be expensive, impractical and, with the end of the Cold War, unnecessary.
Although the ISS has few of the refinements of Freedom, it does bring together the two former Cold War rivals. In fact, it would not have been possible without Russian space station expertise.

Soviet spaceplane
During the 1960s, the two superpowers developed very different-looking spacecraft to solve the same problems. The Americans favoured conical capsules like Apollo, the Russians liked theirs spherical. In the next decade, however, there was rather more, shall we say, ‘borrowing’ of technology.
The Russian Buran spaceplane, for instance, was a straight rip-off of the Space Shuttle. But the Americans too were not immune to copying Soviet space technology. One of the most curious of these borrowed designs was derived from the slipper-shaped MiG-105.
Developed in the mid-1960s, the MiG-105 was Russia’s first attempt at a spaceplane. The idea was to blast the small shuttle into orbit on the top of a conventional rocket. It would then return to Earth on a runway. A few successful atmospheric flights proved this was a sound idea and it wasn’t long before the US ‘acquired’ the technology and developed a version of its own.
This could easily have become just another Cold War concept that was never going to make it into space. Instead, the original design has been adapted into the Dream Chaser spaceplane being developed by the Sierra Nevada Corporation.
With funding from NASA, the first of these spaceplanes is due to fly, unmanned, to resupply the ISS by the end of the decade. With interest from other nations and commercial operators, a crewed version could yet make it into orbit.
Dream Chaser proves that unusual and ambitious ideas developed at the height of the Cold War are sometimes worth revisiting. As we set our sights on Mars, nuclear engines may also make a comeback. As for the space gun, as we reach towards the Final Frontier, we may need all the crazy ideas we can get.

Rico says nothing is crazy if someone's willing to pay for it...