Ariane 1 was the first rocket in the Ariane family of expendable launch systems. It was developed and operated by the European Space Agency (ESA), which had been formed in 1973, the same year that development of the launch had commenced.
- Type : Medium lift launch vehicle.
- Origin : European Space Agency.
- In service : 24 December 1979 - 22 February 1986
- Mass : 207,200 kg (456,800 lb).
- Length/Height : 50 m (160 ft).
- Diameter : 3.8 m (12 ft).
- Payload to LEO : 4,850 kg (10,690 lb).
- Payload to GEO : 1,850 kg (4,080 lb).
- Propellant: First/Second stage : N2O4 / UDMH. Third stage: LH2 / LOX. Fourth stage : HTPB (solid).
- Engines: First stage : 4 Viking-21 with thrust of 2,771.940 kN (623,157 lbf), Second stage : 1 Viking-4 with thrust of 61.674 kN (13,865 lbf), Third stage : 1 Mage 1 with thrust of 19.397 kN (4,361 lbf).
Ariane 1 was the first launcher to be developed with the primary purpose of sending commercial satellites into geosynchronous orbit. Crucially, it was designed with the ability of sending a pair of satellites into orbit on a single launcher, thus reducing costs. As the size of satellites grew, Ariane 1 quickly gave way to the more powerful Ariane 2 and Ariane 3 launchers, which were heavily based upon the original rocket.The Ariane 4 was the last rocket to heavily draw upon the Ariane 1, as the successive Ariane 5 having been developed using a far greater level of all-new elements.
On 24 December 1979, the first Ariane launch, designated as L-O1, was conducted, which was successful. However, in 1980, the second launch, L-O2 ended in a failure shortly after takeoff, which had been caused by a combustion instability that had occurred in one of the Viking first stage engines. The third launch, L-O3 succeeded, which resulted in the orbiting of three separate satellites; the fourth and last qualification launch, L-04, was also a success. However, during the fifth launch, which was the first commercial mission to be performed by Ariane, designated as L5, the rocket ceased functioning after 7 minutes of flight. This failure was traced back to a single turbopump in the third stage that had stopped functioning, and a significant re-design of elements of the third stage was performed as a result.