The Atmospheric Reentry Demonstrator was an ESA technology mission demonstrating Earth-return technologies which was launched on the third Ariane-5 flight, (V112/503), on 21 October 1998. ARD was ESA’s first Earth-return craft and the first complete spaceflight cycle, from launch to landing, by Europe. It was a major step towards developing space transportation vehicles capable of returning to Earth, carrying payloads or people.

Born out of the ESRO LIIIS project to develop a competitive European satellite launcher, the name Ariane was adopted by delegates at ESRO’s AFC (Administrative and Finance Committee) in September 1973. The success of Ariane’s first launch, on 24 December 1979, paved the way to hundreds of further launches, and to obtaining a significant share of global commercial launch contracts.

Ariane-1 – 1979

Ariane-2/3 – 1984

Ariane-4 – 1988

Ariane-5 heavy-lift satellite launcher –first operational flight 1999

Ariane-6 - first flight in July 2024

Artemis – ESA’s Advanced Relay and Technology Mission Satellite – was the first European data relay mission and demonstrated new telecommunications techniques, primarily for data relay and mobile services. It was launched on 12 July 2001 on Ariane-510 from Kourou. Artemis created the first laser data link between satellites in different orbits and provided data relay for Envisat, the largest Earth observation satellite ever built.

ESA transferred ownership of the satellite to Avanti Communications (UK) in 2014. In November 2017, Artemis was retired and placed in a graveyard orbit.

The British-led Beagle 2 probe was the lander for the Mars Express  mission. It was released on 19 December 2003, but nothing was heard from it after its scheduled touchdown. (It was subsequently located on Mars in 2014, demonstrating its successful landing.)

The mission played a key role in the international exploration programme for Mars, focusing on global coverage and the search for water and life, with the orbiter’s instruments providing remote sensing of the atmosphere, ground and up to 5 km below the surface. 
 

The Huygens Probe was ESA’s element of the joint ASI-ESA-NASA mission to Saturn. It was launched from Cape Canaveral on a Titan IV rocket on 15 October 1997. After a seven-year journey to Saturn, the probe descended to the surface of Titan, Saturn's largest moon on 14 January 2005, and touched down safely on Titan's frozen surface. Huygens provided a stream of data representing a unique treasure trove of in situ measurements from the planet-sized satellite. This was humanity's first successful attempt to land a probe on another world in the outer Solar System.

The Cluster mission investigated plasma processes in the Earth’s magnetosphere using four identical spacecraft simultaneously flying in a pyramid-like formation on an elliptical polar orbit to comprehensive and detailed observations of the magnetosphere and its environment. The four satellites of the original mission (FM1-FM4) were lost in the failure of the Ariane-5 demonstration launch in 1996. The four Cluster spacecraft of the replacement mission, called Rumba, Salsa, Samba and Tango (FM5-FM8), each carrying the same payload of 11 advanced instruments, were launched by Soyuz fregats from Baikonur: the first pair of satellites was launched on 16 July 2000, the second on 9 August 2000.

Despite a nominal lifetime of two years, the Cluster mission spent almost 24 years in orbit. The first of the four satellites, Salsa, underwent a targetted reentry into the Earth’s atmosphere on 8 September 2024, marking the end of the mission.

First satellite to be launched by the newly created ESA, in 1975, and the first European mission to study gamma-ray sources and to be dedicated to a single experiment. Cos-B’s single payload was a gamma-ray telescope which performed the first complete galactic survey in high-energy gamma rays.

The European Communications Satellite (ECS) was the first European regional satellite communications system, operated by Eutelsat, with ESA providing the first-generation space segment.

ECS-1 was launched in June 1983 and handed over to Eutelsat in October. It provided services to Europe and north Africa via three spot beams and a single Eurobeam. ECS-2 was launched in August 1984 and added the Satellite Multiservice System for business users. The ECS-1 mission ended in 1996, ECS-2 in 1993. ECS-3 was launched in September 1985 (but destroyed in a launch failure), ECS-4 in September 1987 and ECS-5 in July 1988. Mission end for ECS-4 and ECS-5 was in December 2002 and May 2000 respectively.

Each one of the ECS satellites (with the exception of ECS-3) served well beyond their 7-year design goals and enabled coverage of the whole European continent for cable television, telephone communications, specialised services and Eurovision transmissions. The ECS system altogether accumulated more than 3 million hours of operation.

Acronym for Ensemble de Lancement Ariane (Ariane Launch Area), the launch pad and associated facilities at the Centre Spatial Guyanais in Kourou, French Guiana, operated by Arianespace.

The first Ariane vehicles were launched from the ELA-1 complex at the Kourou site. ELA-1 was closed in December 1989 and dismantled in 1991, it was replaced by ELA-2 to handle the more powerful Ariane-4 vehicles.

ELA-2 was used for two Ariane-3 launches (V17 in 1986, V25 in 1988), the second Ariane-2 launch in 1987 and all 116 Ariane-4 launches between 1988 and 2003. Following the retirement of the Ariane-4 in favour of the Ariane-5, ELA-2 was deactivated. It was demolished in September 2011.

ELA-3 operates as part of the expendable launch system for Ariane-5 launch vehicles. Over 100 launches have been carried out from it, the first on 4 June 1996. The last Ariane-5 launch was on 5 July 2023.

Envisat was ESA’s second-generation remote-sensing satellite and the largest Earth observation spacecraft ever built. Its package of ten instruments delivered thousands of images and a wealth of data used in the monitoring of the Earth and its environment, including global warming, climate change, ozone depletion and ocean and ice monitoring.

It was launched on an Ariane-5 vehicle from Kourou on 28 February/1 March 2002 and the end of the mission was declared on 9 May 2012.