Self-eating Rockets

• ISRO has been working on a technology wherein the rockets will eat themselves.
• Such satellites and rockets may end up being an inextricable part of future space missions.
• They will also play a critical role in making sure that the space debris problem is not aggravated.

Self-eating rockets

• These are essentially the rockets made of unique materials that burn up in the atmosphere leaving no trace.
• Self vanishing satellites, on the other hand , are those that come down in altitude to burn up in orbit after their lifetime.

Mechanism

• Today, most rockets use tanks to store their propellant as they climb, and the weight of the tanks is usually many times greater than the weight of the useful payload.
• It reduces the efficiency of the launch vehicle, and contributes to the problem of space debris.
• Therefore, a launch vehicle powered by an autophage engine would consume its own structure during ascent, so more cargo capacity could be freed up and less debris would enter the orbit.
• The autophage engine consumes a propellant rod which has solid fuel on the outside and oxidiser on the inside.
• The solid fuel is a strong plastic, such as polyethylene, so the rod is effectively a pipe full of powdered oxidiser.
• By driving the rod into a hot engine, the fuel and oxidiser can be vaporised into gases that flow into the combustion chamber.
• This produces thrust, as well as the heat required to vaporise the next section of propellant.

Projected benefits

• This technology opens the possibility of actually sizing launch vehicles to match small satellites, thereby offering more rapid and more targeted access to space.
• The rockets used presently have metal casings that are dropped into the sea after the launch or they become space debris. To mitigate this problem causing ocean and space pollution, invention of such self killing technology may prove to be a boon.