Question: How many model rockets would it take to launch a real rocket into space?

Edward Taylor answered on 16 Mar 2013:

Tricky one, but I’l give it a go!

Rocket power is measured in something called specific impulse, which is the force from the rocket (in N) multiplied by the time the rocket burns for.

the largest available model rockets produce a force of 8 Newtons (N) on top of the force required to overcome the mass of the rocket itself, for about 10 seconds (s), which gives a specific impulse of 8 x 10 = 80Ns.

The NASA space shuttle produces a force of 3.5 Million Newtons! for 269 seconds, which gives a specific impulse of 3.5million x 269 = 3,362,500,000 Ns.

Dividing 3,362,500,000 by 80 gives about 42 million, which means it would take the force of 42million model rockets to give the same force as a NASA space shuttle and launch it into space.