|Above: The rocket stage of a rocket-balloon (called the Bloostar) pulls away from its balloon stage.|
The idea of crossbreeding a balloon with a rocket sounds like madness doomed to end in a fiery explosion on a spectacular youtube video.
But the idea has been around since the 1950's. To get to space a rocket must first punch through the Earth's atmosphere, which eats up a lot of extra fuel. So why not float the rocket to the top of the atmosphere on a balloon?
Well, partly because that makes the rocket incredibly hard to steer, and partly because a rocket big enough to launch a useful satellite would need a balloon that was unfeasibly huge. One snapped cable and someone could be getting a fully fuelled space rocket through the roof of their house.
This, of course, hasn't stopped people doing it: Sub-orbital sounding rockets, carrying simple and lightweight sensor packages, were launched in the 1950's.
And that was as far as the rocket-balloon got, until the turn of the millennium when miniaturisation started to work its way into satellite technology. Today a useful space satellite can be small enough to hold in you hand, and the rocket needed to put it into orbit can be not much bigger than a 1950's sounding rocket. The Spanish company Zerotoinfinity have developed a commercial rocket-balloon launcher for small satellites called the Bloostar, and have just had a successful test firing at altitude - commercial flights could start as soon as next year.
|Above: A rare image of the HARP space cannon firing. Bits of this behemoth gun can be found rusting on the island of Barbados today.|
H.G Wells wrote about a cannon big enough to blast a projectile into space, and all the way to the Moon.
Which is insane, right? I mean, such a cannon would need to be many times the size of the biggest naval cannons, and the shock waves from it would shake buildings apart...
...Enter the US military.
In the 1960s the US army and Canadian ballistics expert Gerald Bull led a project that built, tested, and fired space cannons, sending sensor packages and test payloads well above Earth's atmosphere and into space. Despite their success, the project was scuppered by the space explorer's old nemesis, politics.
From there the story takes a much darker turn: Gerald Bull turned to advanced weapons manufacture to keep funding his research - sort of like a reversed Tony Stark - and ended up facing a professional assassin in a hotel corridor.
You can read the full, tragic, story here.
Ride a laser beam up the rear:
Space travel is fairly risky to start with, so you'd think that shooting a high powered laser at a spaceship while it flew wouldn't be a good idea. I work with industrial cutting lasers professionally, so I can confirm that it's a very bad idea - I've seen how little respect a powerful laser has for solid steel.
It's such a bad idea that it's actually the basis of some novel anti-missile weapons.
But... a rocket, a long tube of highly flammable stuff with an explosion at one end, ain't that safe either hombres. So how do you turn a laser into a rocket?
You attach a curved mirror to the base of your rocket, and fire a powerful laser at it. The mirror focuses the laser light to a point just beneath the rocket, which forces the air there to rapidly expand, producing thrust. If you need it to work in space, you can have the rocket expel material into the laser's focus.
The huge advantage of this is that the rocket is fuel free - the electricity for the laser can be taken from the national grid even. The down side is that you are, as I mentioned, shooting a powerful laser at your spaceship.
Surprising, then, that people have very seriously looked at a laser propelled manned vehicle.
The technology is still a very long way from being mature, but it might do a lot more than just launch satellites. Laser based tractor beams are one of the technologies space agencies are seriously looking at to defend Earth from a major asteroid strike.
Climb a magic rope:
|Above: A car climbing a space elevator cable.|
Rope is wonderful stuff, but most ropes aren't so wonderful that they'll get you into space.
That could change, however: where most people would shrug and go 'eh, rope's just rope' scientists and engineers went 'we shall build a rope all the way into space'!
Because... well, because a great many of us are a wee bit crazy.
Even so, the basic 'climbing rope to space' idea has spawned a host of daringly edge-of-what's-possible high-tech-rope based ways into space.
- Probably the best known is the brain melting space elevator, a cable car into space thousands of kilometres long, anchored at one end to a huge geostationary satellite and to a mega-mega skyscraper on the ground end. But there are other equally zany designs for ropes into space.
- The rotating orbital tether: This is a big, spinning, bit of high strength space rope. As it whirls around the lower end grazes the upper atmosphere, striking just deep enough for a sub orbital spacecraft (like Virgin Galactic's SpaceShipTwo) to hook on to it and be flung into deep space.
- Endo atmospheric tethers: This tether is run behind a high altitude aircraft, and grabs a small, lightweight, launch vehicle. The tether, and the difference in momentum between the big heavy plane and the lightweight launcher propels it to hypersonic speeds.
* Yes there's a condom joke there if you're determined to find it. I'm not, but feel free.