ACTION-REACTION VEHICLES

All action-reaction vehicles use a simple concept in order to produce "self-propulsion": they all have engines that produce a "thrust" of high speed fluids (gases or water). Action-reaction engines provide an action force that pushes fluids out of an exhaust nozzle; the high speed exhaust fluids then push back with a reaction force, propelling the vehicle in the opposite direction.

Travel through the vacuum of outer space was made possible by the invention of one of the most common action-reaction, self-propelled vehicles: ROCKETS!

Other action-reaction vehicles include military jets and missiles, commercial jet liners, jet-skis, water jet packs, rocket cars, CO2 model racers, model rockets, and NASA jet packs used by astronauts on their "space walks".

Now back to our hypothetical astronaut stranded in space with a wrench in his hand.

Can you guess how he could propel himself back to his space station now?