The year of 2013 closed with many interesting stories about the coming age of space exploration. And they came from many fronts, including the frontiers of exploration (Mars and the outer Solar System) as well as right here at home, on the conceptual front. In the case of the latter, it seems that strides made in the field are leading to big plans for sending humans into orbit, and into deep space.

The first bit of news comes from Reaction Engines Limited, where it seems that the Skylon space plane is beginning to move from the conceptual stage to a reality. For some time now, the British company has been talked about, thanks to their plans to create a reusable aerospace jet that would be powered by a series of hypersonic engines.

And after years of research and development, the hypersonic Sabre Engine passed a critical heat tolerance and cooling test. Because of this, Reaction Engines Limited won an important endorsement from the European Space Agency. Far from being a simple milestone, this test may prove to be historic. Or as Skymania‘s Paul Sutherland noted, it’s “the biggest breakthrough in flight technology since the invention of the jet engine.”

Now that Reaction Engines has proven that they can do this, the company will be looking for £250 million (approx $410 million) of investment for the next step in development. This will include the development of the LapCat, a hypersonic jet that will carry 300 passengers around the world in less than four hours; and the Skylon, which will carry astronauts, tourists, satellites and space station components into orbit.

Speaking at the press conference after the test in late November, ESA’s Mark Ford had this to say:

ESA are satisfied that the tests demonstrate the technology required for the Sabre engine development. One of the major obstacles to a reusable vehicle has been removed. The gateway is now open to move beyond the jet age.

The Sabre engine is the crucial piece in the reusable space plane puzzle, hence why this test was so crucial. Once built and operational, Skylon will take off and land like a conventional plane, but still achieve orbit by mixing air-breathing jets for takeoff, and landing with rockets fueled by onboard oxygen once it gets past a certain speed.

The recent breakthrough had to do to the development of a heat exchanger that’s able to cool air sucked into the engine at high speed from 1,000 degrees Celsius to minus 150 degrees in one hundredth of a second. It’s this critical technology that will allow the Sabre engine to surpass the bounds of a traditional jet engine, by as much as twofold.

Alan Bond, the engineering genius behind the invention, had this to say about his brainchild:

These successful tests represent a fundamental breakthrough in propulsion technology. The Sabre engine has the potential to revolutionise our lives in the 21st century in the way the jet engine did in the 20th Century. This is the proudest moment of my life.

And of course, there’s a video of the engine in action. Check it out:

Second, and perhaps in response to these and other developments, the British Interplanetary Society is resurrecting a forty year old idea. This society, which came up with the idea to send a multi-stage rocket and a manned lander to the moon in the 1930’s (eerily reminiscent of the Apollo 11 mission some 30 years later) is now reconsidering plans for giant habitats in space.

To make the plan affordable and feasible, they are turning to a plan devised by Gerard O’Neill back in the 1970s. Commonly known as the O’Neill Cylinder, the plan calls for space-based human habitats consisting of giant rotating spaceships containing landscaped biospheres that can house up to 10 million people. The cylinder would rotate to provide gravity and – combined with the interior ecology – would simulate a real-world environment.

Jerry Stone of BIS’s SPACE (Study Project Advancing Colony Engineering) is trying to show that building a very large space colony is technically feasible. Part of what makes the plan work is the fact that O’Neill deliberately designed the structure using existing 1970s technology, materials and construction techniques, rather than adopting futuristic inventions.

Stone is bringing these plans up to date using today’s technologies. Rather than building the shell from aluminium, for example, Stone argues tougher and lighter carbon composites could be used instead. Advances in solar cell and climate control technologies could also be used to make life easier and more comfortable in human space colonies.

One of the biggest theoretical challenges O’Neill faced in his own time was the effort and cost of construction. That, says Stone, will be solved when a new generation of much cheaper rocket launchers and spaceplanes has been developed (such as the UK-built Skylon). Using robot builders could also help, and other futuristic construction techniques like 3-D printing robots and even nanomachines and bacteria could be used.

And as Stone said, much of the materials could be outsourced, taking advantage of the fact that this would be a truly space-aged construction project:

Ninety per cent of the material to build the colonies would come from the Moon. We know from Apollo there’s silicon for the windows, and aluminium, iron and magnesium for the main structure. There’s even oxygen in the lunar soil.

Fans of Arthur C. Clarke’s Rendezvous with Rama, the series Babylon 5 or the movie Elysium out to instantly recognize this concept. In addition to being a very real scientific concept, it has also informed a great deal of science fiction and speculation. For some time, writers and futurists have been dreaming of a day when humanity might live in space habitats that can simulate terrestrial life.

Well, that day might be coming sooner than expected. And, as O’Neill and his contemporaries theorized at the time, it may be a viable solution to the possibility of humanity’s extinction. Granted, we aren’t exactly living in fear of nuclear holocaust anymore, but ecological collapse is still a threat! And with the Earth’s population set to reach 12 billion by the 22nd century, it might be an elegant solution to getting some of those people offworld.

It’s always an exciting thing when hopes and aspirations begin to become feasible. And though aerospace transit is likely to be coming a lot sooner than O’Neill habitats in orbit, the two are likely to compliment each other. After all, jet planes that can reach orbit, affordably and efficiently, is the first step in making offworld living a reality!

Until next time, keep your eyes to the skies. Chances are, people will be looking back someday soon…

Sources: IO9, skymania, (2), bbc.com