View Full Version : How can we propel a starship towards light speed?

03-17-2013, 05:46 PM
Let us imagine a journey to a star 10 light years away. We start from Mars orbit and outside the planet’s gravitational pull and use advanced rocket technology to reach Jupiter. This is a journey of 555 million kilometres [km] taking 7-8 months at 100,000 km per hour. [Approx. estimate of future capability]
We use the immense mass of Jupiter to attract and accelerate our craft onto a collision course [initially] and at the critical moment re-fire the advanced rockets to sling our spaceship around the gas giant and onto its new trajectory and new speed of 1 million km/hour.
Now we start the nuclear reactor, the only power plant capable of sustaining thrust over a 20 year journey [unless we discover something remarkable during the next 100 years]. The heat output from this reactor would be used to power a new type of drive capable of pushing our craft towards light speed. I will describe one concept which has been around for decades, surprisingly – the ion drive.
Here a stream of positively charged hydrogen ions [H+] is ejected at high speed from the rear of the object being propelled. The thrust is small but in the vacuum of space even a large object can be manoeuvred and accelerated provided you have enough thrusters. The ion drive of a starship is likely to be 50-80 metres in diameter and each of the thrusters say 10 cm round. You could get over 500,000 thrusters in this drive [clustered around the advanced rockets] all contributing their power from the emitting stream of hydrogen ions.
By providing constant sufficient acceleration you would design to accelerate from 0.001c to 0.5c in 1 year [c = speed of light – see my previous Blog].
Thus our journey to a star 10 light years away would be approximately 23 years – 2 years to accelerate, 20 to get there and 1 year to slow down to a manageable speed to orbit around a target planet of our destination star.
I’m sure the mathematicians among you can calculate the acceleration required and the typical thrust needed from each tube – can we achieve this in 150 years time?

I think we can and in 2150 my starship leaves Mars for the star Seren, 10 light years away, in search of - The Blue People of Cloud Planet. (http://www.dicepterons.com)

Paul Howard
03-19-2013, 06:07 AM
My guess is that you're all wrong. Einstein's theory of relativity gets in the way of any attempt to reach the speed of light using standard propulsion methods. (Including ion drives.) A way has to be devised that makes it possible to move through space outside of the standard mechanics of space-time as we know it. This is why Star Trek used Time-Warp drive, this method basically short circuits space time by warping it between two points. My guess is that it will also be found to be a non-starter due to the effects it would have on space itself, probably very adverse. Another method suggests using wormholes to get from one place to another, but the physics of wornholes really doesn't support this. Any matter entering a wormhole would be crushed by tremendous gravitational forces, and even if these could be overcome, the thermal properties would be worse than the interior of a star! In my forthcoing novels "The Palindrome Chronicles" the issue is dealt with by skewing the phase of the ships relative to space with magnetic fields. There is no propulsion involved, only polarity. A hyper-magnetic bubble, if you wish. Is it good physics? Who knows? But it doesn't ignore general relativity or the space-time continuum, which is really in the driver's seat anyway, as far as we know. But yes, I believe we will find a way to exceed the speed of light, it probably already happened in the Big Bang and probably also happens to matter ejected from Ultra-Novas, although we have no way of measuring that yet. Sooner or later, we will. Also, if you want to get to Jupiter, teleportation would be much easier and more efficient. I don't think anybody realizes how close that is to becoming feasable. If you have toddlers, they will live see to it. Maybe even sooner than that, if the energy companies don't try to stop it from happening.