The Éridan is a two-stage French sounding rocket, which results from the use of the Stromboli engine (also used on the Dragon and Dauphin) for the first and second stages. It belonged to a family of solid-propellant rockets that also encompasses the Belier, the Centaure, the Dragon, and the Dauphin. As the most powerful version of this series it could lift payloads from 120 kg to 250 kg up to altitudes of 220 km to a maximum of 425 km. Its ascent time is between 230 and 350 seconds. Total thrust was 90.00 kN (20,232 lbf) with a gross mass of 2006 kg to 2316 kg depending in payload. The rocket had a height of 9.92 m, a diameter of 0.56 m and a span of 1.773 m. An improved version called Éridan II was planned in 1971 but it never materialized due to the project being cancelled in 1973.

Launches

Éridan was flown fifteen times between 1968 and 1979 from Kourou and the Kerguelen Islands. The first flight from Kourou on 26 September 1968 failed, but was followed by twelve successful launches that took the rocket to altitudes of 196 to 420 km between 12 April 1969 and 14 November 1979. Objectives were ultraviolet astronomy experiments, solar physics and training launches for operators at the Kourou launch base. Two Éridan were launched in January and February 1975 off the Kerguelen Islands for magnetosphere studies.