Space elevators, vacuum chutes: What next for big rocket tech? We recently suggested that even the most advanced rocket currently slipping the surly bonds of Earth is nothing more than glorified V2, over 70 years since Hitler's Vergeltungswaffe 2 first lifted off the pad at Peenemünde. Today, we'll have a look at some technologies that may one day allow us to escape V2 designer Wernher …
25% in the long term, compared to the 0% long-term survival probability of the converse that we currently have.
A large asteroid strike is inevitable unless we have the technology to reliably redirect one. That takes routine extra-orbital space travel.
I say our current situation is the converse because over the last decade our politicians have been shoving us into various mapcap schemes to "preserve the planet" that simply don't work anyway because they don't scale anywhere near the size needed for current population, let alone predicted population, and in many cases actually seriously damage the environment!
Large numbers of people will die as a result of those policies - not because climate change is real, but because the methods to "stop" it that the politicians were backing are futile and harmful to people and the environment.
There is some hope - Hinkley C has been given the go-head, which is finally a zero-emissions* generating plant at the scale we need to stop the lights going out and people dying.
It'll be coming on stream too late though.
* Ignoring construction emissions, just like the wind and solar people.
"A large asteroid strike is inevitable unless we have the technology to reliably redirect one"
If by "large" you mean large enough to wipe out the species then the evidence is against you. Our technology already means that we'd be among the most resilient species of large animal and the solar system hasn't whacked the Earth with anything hard enough to knock everything out for many, many millions of years. And even *that* fails to take account of the fact that most of the loose asteroids out there were hoovered up in the first half-billion years, so looking at the surface of the moon is a really bad guide to the current risk level.
It's simply not urgent. At current rates of technological progress, it will be trivial in a thousand years or so whether we prioritise it or not. In fact, since "prioritising" probably means we work less hard in other areas, throwing cash at what might turn out to be the wrong technologies is actually counter-productive.
We know that there aren't any outright planet killers due in the next couple of centuries, and nothing excessively large in the next hundred years.
That's all.
We don't know if something big enough to effectively destroy our civilisation is going to hit in 150 years - and although I suppose I am conflating "species" with "civilisation" here, I think you'd agree that "civilisation falls" is still an apocalypse worth spending some energy avoiding?
We also don't know whether something big enough to wipe out a major city like London, New York, or Washington DC is going to hit tomorrow. That Russian meteor? Imagine if that had airburst directly over a major city at a lower altitude, instead of 'merely' ~25 km up and ~50 km away.
To really avoid those 'civilisation killers', and to even spot the 'citybusters' in time to simply evacuate, interplanetary space travel needs to be routine. Not the "launch a last-ditch heroic attempt to deflect atop quickly thrown-together rocket" we see in films, it has to be "Oh, that one's coming a bit close in fifty years, better start planning to send something to go deal with."
Even simply getting to an asteroid takes a year or two.
We only have around 100 years of clear time to do that - and given our current rate of progress, we won't make it.
I probably won't live to see it. But I want my kids to go to space - for a holiday, or even permanently.
Encounter With Tiber - John Barnes and Buzz Aldrin, had antimatter suspended in an aerogel for thrust, in addition to the laser for larger ships travelling inter-stellar.
Red Mars - Kim Stanley Robinson - had a space elevator but attached to a captured asteroid and harmonised to avoid moons.
Comparing a modern rocket to a V2 is like comparing a Fort T to a modern car: Both run gasoline-burning piston engines with a transmission shaft and mechanical gears. Even modern electric cars are not fundamentally different from those that were designed 100+ years ago.
The reason is that the basic design works well. The same is true for rockets. And that is why viable alternatives are still stuff of the future.
One idea that hasn't been mentioned is using ionised air as the main propellant: The motor is a linear accelerator that ionises the incoming air, accelerates it and expels it at the other end. The energy could come from a nuclear reactor or (for a slower acceleration) solar panels. A solar powered craft could use traditional propellers for a first stage to lift the craft to high altitude, where the next stage (with smaller wings) uses the linear accelerator motor. Eventually, the air would be too thin, at which point you could switch to air you brought along (e.g, liquid nitrogen).
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