A rocket that devours itself

IT TAKES a lot of oomph to launch a satellite into space. Typically, the payload represents only about 5% of the mass of a rocket as it leaves the launch pad. The rocket’s motors account for some of the rest, but the bulk of it consists of the propellants (the fuel and oxidant that react to produce the thrust required to reach orbit) and the gubbins needed to handle these propellants (tanks, pumps, valves, piping and the bodywork that contains them). The gubbins are not only expensive in themselves, but their mass also requires extra fuel to lift. Things would be more efficient if the gubbins could be dispensed with and a rocket designed that consists of only payload, motor and propellants.