# What prevents the use of electric engines to assist with spacecraft launches? (Launch Booster Supplement)

Much fuel is used to get rocket off the platform on the initial launch. Could electric turbine engines be used like booster rockets? Could an electric engine like a rail gun work similar in the way they launch planes off an aircraft carrier? The electric turbines would disconnect at the top of the launch platform that could also be made taller. Could either of these save fuel by creating lift for the first 1000 or so assist with the common first stage? It does not have to lift the rocket just make it lighter on the launch pad and would stay with the launch pad.

• Just look up the thrust of an electric turbine, and compare it to the thrust of a rocket. – uhoh Jul 18 '18 at 16:13
• Do you mean electrically driven propellors/fans, or an electromagnetic catapult along the length of the launch tower? – Russell Borogove Jul 18 '18 at 16:14
• @RussellBorogove thanks for the help. updated the question. – Muze the good Troll. Jul 18 '18 at 16:16
• Russian ICBM launch platforms use compressed air to eject the missile from the launch tube and give it initial velocity, before its rocket engine engages. This is done primarily to protect the launcher from the worst of exhaust flames though. I think that's the closest thing to the proposed solution. – SF. Jul 18 '18 at 16:22
• @SF. That is interesting it would be easier to dig a tube and the back pressure from a modified launch like a gun would save fuel. The deeper the hole the more fuel would be saved. Are below ground launches more fuel efficient this way? and would be cleaner. – Muze the good Troll. Jul 18 '18 at 16:27

It would be incredibly difficult to move something as large and minimally structural object to any kind of real speed where it would help anything at all.

One similar proposal is to instead launch from a 20 km high platform, thus being essentially outside of the atmosphere. This proposal is known as the ThothX Tower.

• Oh my gosh, the thing's inflatable! – Don Branson Jul 18 '18 at 21:11
• I wonder what the proposal is to protect giant inflatable kevlar beads from a giant pair of scissors... Hopefully something like automatically aiming turrets. – Magic Octopus Urn Jul 19 '18 at 19:01

The electric turbine wouldn't work because:

 1. A rocket is very heavy and is way heavier than a plane
2. An electric turbine adds more weight
3. An electric turbine uses electricity for fuel and its not like you could
eject batteries onto the launch pad like the way an auto Nerf gun ejects the
clip.


Also, if you managed to do this, it would take more space. Rocket fuel is burned, and once burned it is gone, and the weight goes with it. There was once a project dubbed Project Orion and the idea was to strap a huge amount of nukes to a projectile and launch it into space like that. But then, people realized how dangerous and costly it was so it was cancelled. This could have worked, due to the fact that the nukes blow up which means that they are no longer there. Simply put, the electric turbines wouldn't have enough power to push the rocket up even if the turbines were weightless.

• The electric turbines stay with the pad. Question revised. Thanks – Muze the good Troll. Jul 18 '18 at 21:45
• Do you mean the turbines are underground and they make the rocket lighter by blowing air up? It could work, its is just that it will need tons of electricity. – Leo Pan Jul 20 '18 at 17:27