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Reid: There have been plenty of successful space missions over the years, and they’ve accomplished some amazing things. We’ve been to the Moon, we’ve sent rovers to Mars, and we’ve even done a flyby of Pluto. Not to mention the International Space Station orbiting Earth right now.

But there were more missions that could have happened, ones that were researched and developed and could have had a huge impact on the history of space travel. If they hadn’t been cancelled, that is.

Take Mars, for example. Lately, NASA’s been working on plans for the first manned mission to Mars. But what if we’d gone there in the 1980s? Once NASA had sent humans to the Moon, sending people to Mars seemed like the natural next step. But our rockets weren’t really up for the job.

Most of the rockets at the time burned chemicals like kerosene and oxygen. Even though these rockets were great for orbital or lunar missions, they just didn’t have enough power for a trip to Mars, which is more than 50 million kilometers longer than the journey to the moon.

So NASA started Project Rover, to create rockets powered by nuclear reactors. Project Rover would use a reactive fluid like hydrogen — which combines easily with most other elements — and use a reactor to heat it into an ionized gas, aka plasma. The plasma would then be ejected from the rocket, creating thrust to push the rocket forward. Traditional chemical rockets also eject gas for thrust, but with much less force than a nuclear reactor.

In 1961, this nuclear rocket research became part of a new program that came this close to taking us to Mars: the NERVA engine. Early NERVA tests were so successful that a mission to send 12 people to Mars was suggested for 1981. The mission would split crew between two rockets, each powered by three NERVA engines, and would take nine months to reach the planet.

Engine tests continued to go really well, and soon the NERVA engine could meet almost every NASA requirement... but then the project was cancelled. In 1972, Congress decided that a Mars mission would be too expensive and would extend the pricey space race between the United States and the Soviet Union. So, almost 50 years later, we’re still waiting for the first people to land on Mars.

Also during the 1960s, the Soviet Union started working on a huge rocket to send crews to Mars and Venus: the N1. The N1 would launch the TMK, which stands for a Russian phrase that basically means Heavy Interplanetary Spaceship — a very accurate name. The TMK was supposed to take three cosmonauts to fly by each of our next-door neighbor planets.

Besides having crew quarters, the TMK would also have an instrumental module that doubled as a radiation shield. It was even supposed to have artificial gravity caused by the ship’s rotation. It was way ahead of its time! A 2-3 year mission to Mars was planned for 1971, with a Venus mission some time afterward.

Cosmonauts wouldn’t land or anything, but they’d fly by the planets and drop unmanned probes to the surface. But the TMK, and its potential missions were abandoned once NASA became more involved in the Apollo program. Instead of aiming for Mars and Venus, the Soviet Union started using the N1 to try and land on the moon, and plans for TMK were cancelled by 1966.

Unfortunately, the N1 wasn’t too successful either, with four failed launches before the program was cancelled in the 1970s. Now, even though we haven’t sent a crew another planet yet, Americans first started living in space aboard NASA’s Skylab, which launched in the 1970s. Skylab was pretty small and could handle only three astronauts at a time.

So it wasn’t like the International Space Station, which, since 2000, has typically had 3-6 people living on board at a time. But something like the ISS could have existed a lot sooner. In the 1980s, after Skylab, there were plans for a much larger, all-American space station named Space Station Freedom.

Because what else do you call an American space station? The plan was to build the station from 1994 to 1997, with a crew living there and doing scientific research starting in 1995. But when NASA sent their first budget proposal to Congress, the government was pretty upset about the $14. 5 billion price tag.

So the plans were downsized, but the conflicts continued. In 1987, the “all-American” idea was dropped to help lower costs, and the European Space Agency was brought in to add a module to the station. But NASA and the ESA had a hard time agreeing on what Europe’s role was.

On top of that, scientists disliked the new plans for Freedom because the budget cuts had reduced its science capabilities. By 1988, they’d finally seemed to reach an agreement: The U.S., Canada, Europe, and Japan would all share lab space on Freedom, and the station would have a rotating crew of six American and two international astronauts. But more logistics and budgetary problems came up, and despite years of planning and development, Space Station Freedom was cancelled in 1990. The International Space Station was approved just a few years later, though, so we did get a brand-new space station.

The history of space travel could’ve been a lot different if the 1980s Mars mission, TMK, and Freedom had succeeded. But that’s okay. Even without them, we’ve launched hundreds of other amazing missions, explored strange new worlds, and boldly gone where no one has gone before. And we have plenty more missions to look forward to!

Thank you for watching this episode of SciShow Space! And a very special thanks to our patrons on Patreon for helping us make this show possible. If you’d like to help make SciShow Space, just go to Patreon.com/SciShow, and don’t forget to go to YouTube.com/scishowspace and subscribe.