ESRO’s HEOS programme (Highly Eccentric Orbit Satellite), achieved three ‘firsts’ for European space activities: first probe into cislunar space, first magnetically clean satellite and first highly-eccentric polar orbit. HEOS-1 (launched 1968) studied magnetic fields, radiation and solar wind outside Earth’s magnetosphere. HEOS-2 (launched 1972) investigated northern polar regions.

Hermes was to have been part of a manned spaceflight programme providing independent European manned access to space. The Hermes spaceplane would have been launched using the Ariane-5 rocket.

In the early 1980s, the French space agency CNES started investigating a small spaceplane design to be launched on an Ariane rocket. The Hermes vehicle would have consisted of two parts: a cone-shaped Resource Module attached to the rear of the vehicle, serving as an adaptor to the Ariane 5 launcher and jettisoned before re-entry. Only the 19m long spaceplane would re-enter Earth's atmosphere and land.

In 1985, CNES proposed to proceed with Hermes development under the auspices of the ESA. The project was approved in November 1987, but subject to numerous delays and funding issues, before it was cancelled in 1992.

The High Precision Parallax Collecting Satellite was the first space-based astrometric survey. It had the single goal of producing the most accurate positional survey of more than 100 000 stars, determining their distances, motions and other characteristics.

It was launched in August 1989 from Kourou and its science operations ended in March 1993 (communications ended in August 1993). The Hipparcos Catalogue (118 218 entries) and Tycho Catalogue (a less accurate ‘Tycho’ survey with 1 058 332 entries) were declared final in August 1996 and published by ESA in 1997, fundamentally affected every branch of astronomy, especially on theories of stars and their evolution.

Horizon 2000 was the first long-term plan for the disciplines of space science under the ESA Directorate of Science, covering the period 1984 to 2006. The study, which led to the 20-year plan, was initiated in September 1983 and was coordinated by a Survey Committee composed of scientists from different areas of fundamental science. Horizon 2000 facilitated the development of eight missions between 1985 and 1995 including four cornerstone missions– SOHO and Cluster II, XMM-Newton, Rosetta, and Herschel.

The Hubble Space Telescope mission was a NASA-ESA partnership to operate a 2 m-class astronomical telescope in orbit for at least 15 years as an international observatory. Hubble was launched in April 1990 on Space Shuttle mission STS-31 from Kennedy Space Center and, after five servicing missions, is still operational today.

ESA’s 15% contribution consisted of the Faint Object Camera (FOC, a prime focal plane instrument), the first two solar wings that powered the spacecraft and a team of space scientists and engineers at the Space Telescope Science Institute in Baltimore, USA. Almost 7000 images were recorded with the FOC giving close-up views of almost every type of astronomical object and revolutionising modern astronomy.