ESRO 4, one in a series of ESRO satellites dedicated to the study of plasma in the Earth's magnetosphere, was launched on a Scout rocket from the Western Test Range, Lompoc, California, USA, in November 1972. John combined supporting his first satellite launch with a walk down, and UP, the Grand Canyon.

Axial boom deployment test at Hawker Siddeley Dynamics

ESRO 4 vibration test at ESTeC

More pre-launch tests