Thermal Rockets using Beamed Power?

Terraformer · 2008-02-09 10:21:36

Could we build a rocket system based on using lasers to beam energy to a spacecraft? It would work like an NTR, 'cept without the Nuclear bit. The Atmosphere could be used for the propellent. It would be forced in by the takeoff, compressed, and piped to the heating area where the lasers would be hitting. It would be heated up and forced out the back as in a conventional NTR. When it reaches it's Apogee, it would use Hydrogen as it's propellen to place it on an Orbital tragectory.

If it does work, how much would it cost?

noosfractal · 2008-02-09 11:43:07

There are a lot of interesting concepts based around this idea ...

http://en.wikipedia.org/wiki/Beam-powered_propulsion

http://en.wikipedia.org/wiki/Laser_propulsion

... the main problem is that you can't beam enough energy to launch large payloads. In particular, manned mission sized payloads would be difficult. Also, most designs require high acceleration - another difficulty for manned missions.

Terraformer · 2008-02-10 05:09:13

Can a Mod amend my poll? There was meant to be a 'No' in there as well.

JoshNH4H · 2008-02-10 08:45:32

Firstly, you can, just go to editing your first post, its right where you started it.

Second, I often find that it doesn't show the third option.

Terraformer · 2008-02-10 09:32:31

I can't amend the poll after someone else has posted in the thread.

I forgot about it not showing the third option.

Antius · 2008-02-15 11:01:13

Could we build a rocket system based on using lasers to beam energy to a spacecraft? It would work like an NTR, 'cept without the Nuclear bit. The Atmosphere could be used for the propellent. It would be forced in by the takeoff, compressed, and piped to the heating area where the lasers would be hitting. It would be heated up and forced out the back as in a conventional NTR. When it reaches it's Apogee, it would use Hydrogen as it's propellen to place it on an Orbital tragectory.
If it does work, how much would it cost?

This would actually be very difficult to achieve, at least for ground launch. You are effectively trying to hit a bulls eye on a not just moving, but accelerating target, with perfect accuracy. That target would be as little as 1m in diameter and the beam could not wander by more than a few inches without the vehicle suffering catastrophic power loss. The distance between the laser and target may be over 100km by the time you reach burnout. Any whiff of cloud or stray puff of propellant that comes between the target and the laser would obscure the laser light and cut off power.

cIclops · 2008-02-15 11:22:05

This would actually be very difficult to achieve, at least for ground launch. You are effectively trying to hit a bulls eye on a not just moving, but accelerating target, with perfect accuracy. That target would be as little as 1m in diameter and the beam could not wander by more than a few inches without the vehicle suffering catastrophic power loss. The distance between the laser and target may be over 100km by the time you reach burnout. Any whiff of cloud or stray puff of propellant that comes between the target and the laser would obscure the laser light and cut off power.

Difficult but possible. The Airborne Laser apparently can track and direct a lot of energy to a target that is uncooperative.

Terraformer · 2008-02-15 16:50:13

And once again Military considerations provide the answer!

New Mars Forums

Announcement

#1 2008-02-09 10:21:36

Re: Thermal Rockets using Beamed Power?

#2 2008-02-09 11:43:07

Re: Thermal Rockets using Beamed Power?

#3 2008-02-10 05:09:13

Re: Thermal Rockets using Beamed Power?

#4 2008-02-10 08:45:32

Re: Thermal Rockets using Beamed Power?

#5 2008-02-10 09:32:31

Re: Thermal Rockets using Beamed Power?

#6 2008-02-15 11:01:13

Re: Thermal Rockets using Beamed Power?

#7 2008-02-15 11:22:05

Re: Thermal Rockets using Beamed Power?

#8 2008-02-15 16:50:13

Re: Thermal Rockets using Beamed Power?

Board footer