Editing Project Mercury (section)

===Launch escape system testing===
A {{convert|55|ft|m|adj=mid|-long}} launch vehicle called [[Little Joe (rocket)|Little Joe]] was used for uncrewed tests of the launch escape system, using a Mercury capsule with an escape tower mounted on it.{{sfn|Catchpole|2001|p=197}}{{sfn|Alexander & al.|1966|p=638}} Its main purpose was to test the system at [[max q]], when aerodynamic forces against the spacecraft peaked, making separation of the launch vehicle and spacecraft most difficult.{{sfn|Catchpole|2001|p=223}} It was also the point at which the astronaut was subjected to the heaviest vibrations.{{sfn|Catchpole|2001|p=284}} The Little Joe rocket used [[solid-fuel rocket|solid-fuel]] propellant and was originally designed in 1958 by NACA for suborbital crewed flights, but was redesigned for Project Mercury to simulate an Atlas-D launch.{{sfn|Catchpole|2001|p=196}} It was produced by [[North American Aviation]].{{sfn|Catchpole|2001|p=197}} It was not able to change direction; instead its flight depended on the angle from which it was launched.{{sfn|Catchpole|2001|p=198}} Its maximum altitude was {{convert|100|mi|abbr=on}} fully loaded.{{sfn|Alexander & al.|1966|p=125}} A [[Mercury-Scout 1|Scout launch vehicle]] was used for a single flight intended to evaluate the tracking network; however, it failed and was [[Range safety|destroyed from the ground]] shortly after launch.{{sfn|Alexander & al.|1966|pp=392–397}}