Rocket Guidance

Rocket Guidance

Navigation of airplanes and rockets has been a challenge met by control and aerospace engineers.

Radio Control

Archibold Low designed both the first airplane and rocket guided by wireless signals during WWI.  His designs require an operator to input commands into the device.  Developing these simple systems was the first step toward more complex systems of guidance.  His airplane didn’t work well but his genius was evident in the fact that the German government attempted to assassinate him more than once!

More on Radio Control Technology >

1930s: Germans develop remote control in the V project.  The first fully functional remote controlled airplanes appear in the 30s as well.

1940s: Control engineers at General Electric used mechanical computers to do complex calculations to allow targeting systems to control weaponry.  These systems were equipped on B-29 bombers and could calculate trajectory of bullets based on airspeed/trajectory of both planes.

In the Korean and Vietnam wars radio controlled missiles used encrypted signals to steer the craft towards a target while video cameras showed operators the missile-eye view.  This allowed for precise navigation as long as atmospheric conditions allowed the optical methods to work.

Inertial Guidance (Inertial Navigation System, INS)

Inertial guidance is the only navigation system not requiring external input.  It involves knowing your starting point, knowing the location of your target, and using Newtonian laws of classical mechanics to launch a trajectory.  This was the system used to guide a rocket or missile before GPS systems.  The V2 Rocket used rudimentary inertial guidance to hit it’s target: (Below our video on the V2 rocket guidance)

After World War 2 the US government contracted with General Electric to design more accurate inertial guidance systems at Malta, NY.  Designing better gyros was needed to advance the field. Gene Wright worked in this effort and describes how these systems worked: (Below video)



After the 1940s inertial guidance became more and more accurate.  In warfare this allowed for smaller weapons which could precisely target areas, reducing collateral damage. The age of ‘carpet bombing’ was coming to an end.

Doppler Radar Guidance, (Microwave) Pre GPS Era:
In 1957 Roy E. Anderson developed the Doppler Direction Finder used to track satellites. Before GPS satellite systems ships, airplanes and rockets could use radar systems (microwave energy) to find their location. Microwave energy was bounced off an object or the ground and distances and speed could be calculated. Anderson and others began to apply their knowledge to develop triangulation methods which could be used by satellites, thus the GPS system was developed.
See our video interview with Roy Anderson >

GPS – Global Positioning System Guidance
GPS allows for the most accurate form of guidance.  Today all airplanes and ships use GPS for some part of their navigation system.  When it comes to missiles, GPS signals can be jammed in a warzone, if this is the case they will revert to inertial guidance to complete their path.



Related Pages:
Gas Turbines
Steam Turbines
Radio
Control and Systems Engineering
Remote/Radio Control
More Stuff
Sources:
Interview with Gene Wright. Edison Tech Center. 2013
Interview with Ted Brown. Edison Tech Center. 2008
Archibald Low. Wikipedia
Time line of Radio Control. StormTheCastle.com
Roy E. Anderson Interview. Edison Tech Center. 2008
Basic Principals of Inertial Navigation. Tampere University of Technology