RC Rock Crawlers

Craft Remote Control

How much thrust / tonne to launch into space?

Theoretically working on a remote control transporter. Taking units to assemble as lunar station. Max payload 500 tonne + transporter. Should it work will be re-usable space craft. A single unit could be entire accommodation block. Would also make a good lunar supply vehicle.

Achieving escape velocity is one of the biggest challenges facing space travel. The vehicle requires an enormous amount of fuel to break through Earth's gravitational pull. All that fuel adds significant weight to the spacecraft, and when an object is heavier, it takes more thrust to lift it. To create more thrust, you need more fuel. It's a cycle that scientists are hoping to resolve by creating lighter vehicles, more efficient fuels and new methods of propulsion that don't require the same ingredients to attain great speeds.

Assume,

Initial velocity = 0
Escape velocity of earth = 11.2 km/s

You need to overcome Earth's gravitational pull, which is 9.82 N/kg, in order to do so. You are constantly being accelerated downward with one G (9.92 m/s^2).

If you would create a force upwards of one G you would hover (0 G).
Let´s say you had a rocket engine that could thrust your spaceship upwards with 2 Gs

How long would it take to reach escape velocity?

You use the equation t=v/a where v is 11200m/s and a is 9.81m/s^2 and get 1141.7s.

You need to accelerate for 19 minutes to reach escape velocity.

But it is a long time to keep an engine running.

Let´s accelerate twice as fast. Put a as 20m/s^2 and you´ll get 560 seconds or 3.3 minutes.

How much thrust do you need to get this kind of acceleration? It´s another simple equation: F=ma. We have a (20m/s^2).

But you also need m that is the mass of the spacecraft. This we can only guess but lets say a tonne (1000 kg).

Then it is pushing downwards onto the launch pad with the force of 1 G wich is 9810 N (9.81x1000).

We need to overcome this by adding another G to our thrust so a is 3Gs or 29.81m/s^2 (20 + 9.81).

Thus we get 29810 N of thrust for 560 seconds to kick that 1 tonne payload into outer space.

You also need fuel to make thrust. The fuel adds weight to the spacecraft which means we need more thrust. Which means the need for more fuel. Also the craft is exposed to alot of drag from the air. More fuel. More weight.

The farther you get from earth the less the value of a G gets but the spacecraft uses up fuel which makes up for the amount of force needed for acceleration. And so on.

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