[5] Solrad 9 was a spin stabilized satellite oriented with its spin axis perpendicular to the sun-satellite line so that the 14 solar X-ray and UV photometers pointing radially outward from its equatorial belt viewed the sun with each revolution.

Data were simultaneously transmitted via FM/AM telemetry and recorded in a core memory that read out its contents on command.

Individual scientists and institutions were invited to receive and use the data transmitted on the 136 MHz telemetry band on the standard IRIG channels three through eight.

Solrad 9 was particularly important among the Solrad series satellites because thanks to the collected data were useful to predict the behavior of the sun during the period of the first crewed missions of the Apollo Program, starting from the first, Apollo 7, it is therefore useful to draw up a mission program to ensure, from this point of view, the safety of astronauts.

The satellite remained active until February 25, 1974, when the gas reserves useful to maintain control of the facility were over.