Tuesday, October 16, 2018

There's a lot of bold, visionary thinking coming out of aerospace, just not from the people who are supposed to be the bold visionaries.

Recently, we've been making the point that most of the "futuristic" and "revolutionary" proposals coming from the billionaire Messiah class (dominated by but not limited to the Silicon Valley variety) are usually postwar vintage and, even when you put aside those that probably won't work at all (see the Hyperloop), represent at best incremental advances. This is especially true in the vanity aerospace industry.

In making that point, I may have given the wrong impression about the aerospace industry as a whole. I'll try to post a couple more examples later. For now though, here is one technology that, if it proves viable and it is looking very promising, holds tremendous potential to revolutionize spaceflight.

From Wikipedia:

Like the RB545, the SABRE design is neither a conventional rocket engine nor jet engine, but a hybrid that uses air from the environment at low speeds/altitudes, and stored liquid oxygen (LOX) at higher altitude. The SABRE engine "relies on a heat exchanger capable of cooling incoming air to −150 °C (−238 °F), to provide oxygen for mixing with hydrogen and provide jet thrust during atmospheric flight before switching to tanked liquid oxygen when in space." 

And from the Guardian:

Spaceplanes are what engineers call single-stage-to-orbit (if you really want to geek out, just use the abbreviation: SSTO). They have long been a dream because they would be fully reusable, taking off and landing from a traditional runway.

By building reusable spaceplanes, the cost of reaching orbit could be reduced to a twentieth current levels. That makes spaceplanes a game changer both for taking astronauts into space and for deploying satellites and space probes.

If all goes to plan, the first test flights could happen in 2019, and Skylon – Reaction Engines' spaceplane – could be visiting the International Space Station by 2022. It will carry 15 tonnes of cargo on each trip. That's almost twice the amount of cargo that the European Space Agency's ATV vehicle can carry.

Rockets are cumbersome because not only must they carry fuel, they also need an oxidising agent to make it burn. This is usually oxygen, which is stored as a liquid in separate tanks. Spaceplanes do away with the need for carrying most of the oxidiser by using air from the atmosphere during the initial stages of their flight.

This is how a traditional jet engine works, and making a super-efficient version has been engineer Alan Bond's goal for decades. In 1989, he founded Reaction Engines and has painstakingly developed the Sabre engine, which stands for Synergetic Air-Breathing Rocket Engines.

In late 2012, tests managed by the European Space Agency showed that the key pieces of technology needed for Sabre worked. No one else has managed to successfully develop such a technology.

Spaceplanes should not to be confused with space tourism vehicles such as Virgin Galactic's Space Ship Two. The highest altitude this vehicle will reach is about 110km, giving passengers about six minutes of weightlessness as the craft plummets back to Earth before the controlled landing.

Although there is no fully agreed definition, space starts at around 100km in altitude. To have any hope of staying in orbit, you would have to reach twice that altitude. The International Space Station orbits at 340 kilometres, whereas the Hubble Space Telescope sits at 595 kilometres.

1 comment:

  1. We've had over 50 years since the original space age. In that time there have been revolutions in manufacturing, materials science, combustion and automatic control. In some ways, it reminds me of the 1970s when the US supersonic commercial effort ended and designers started think about all the new materials and what they meant for aviation. There were carbon fibers, strong new synthetic fabrics, improved aluminum fabrication and a new understanding of human physiology. There were all sorts of new flying machines, many human powered. In a way, the 787 was a culmination of a lot of that effort. Now we're seeing its effect on space travel, and about time.