March 1960: Pioneer V

Reporting on the probe’s purpose in the wake of its launch The Engineer wrote that ’the experiments being undertaken while the probe is in orbit include the measurement of high-energy, or “hard” radiation, particularly that proceeding from the sun’.

’These investigations,’ it continued, ’are of particular importance because no previous probe has had an orbit so close to the sun.’

Describing the probe’s key features, the magazine wrote ’the counter consists of six argon gas cylinders ranged about a seventh cylinder. Inbound particles ionise the gas in one or more cylinders according to energy and produce proportional electrical impulses.’

Also described was the development of a micrometeorite device for measuring the number and momentum of meteoric dust particles striking the probe. ’The entire unit weighs less than 1lb and consists of a diaphragm, about twice the size of a playing card, mounted on the skin of the probe, and an internal microphone. The sound of impact is translated into electrical impulses for transmission to earth.’