European Space Agency (ESA)

Chapter 1 · 1958 – 1974 Two space Europes

Before sending a probe to Mars, Europe had to learn to work together in space. It began by creating not one agency but two, and it would take thirteen years to bring them together.

Two physicists’ idea

In 1958, two physicists, Pierre Auger and Edoardo Amaldi, recommended creating a “purely scientific” European space research organisation, modelled on CERN, the European particle physics laboratory. In 1960 a group of ten countries set up a commission of government representatives to explore this cooperation. In 1961 a preparatory commission defined the future organisation’s scientific programme, an eight-year budget, its administration and the sites of its establishments.

ESRO and ELDO

In 1962 the European nations chose to create two organisations. ELDO, the European Launcher Development Organisation, brought together Belgium, France, Germany, Italy, the Netherlands and the United Kingdom to build a heavy launcher, Europa. ESRO, the European Space Research Organisation, brought together those six countries plus Denmark, Spain, Sweden and Switzerland to build scientific satellites. Their conventions came into force in 1964.

ESRO set up centres that still exist. In 1966 ESRIN was established in Frascati, near Rome. In 1967 ESOC, the operations centre, opened in Darmstadt, Germany. In April 1968 ESTEC, the technical centre, opened in Noordwijk, the Netherlands. That same year ESRO-2B became the organisation’s first successfully launched satellite.

The failure of the shared launcher

ELDO, meanwhile, was struggling: technical problems, cost overruns, political disputes. In 1972 a single European space organisation began to be discussed. In 1973 ESRO agreed with NASA to build Spacelab, a laboratory to fly in the cargo bay of the American Space Shuttle; construction began in 1974. That same year ELDO was downsized and then dismantled.

Sources: ESA, “History of Europe in space” (Auger and Amaldi in 1958, “purely scientific,” the CERN model, the group of ten countries in 1960, the 1961 preparatory commission, the two organisations in 1962, the conventions in force in 1964, ESRIN in 1966, ESOC in 1967, ESTEC in April 1968, ESRO-2B in 1968, the 1972 discussion, ELDO’s difficulties, Spacelab in 1973-1974, ELDO dismantled in 1974); ESA, “History of the ESA Convention 1975” (ELDO’s six countries, the Europa launcher, ESRO’s ten countries).

Chapter 2 · 1975 – 2002 A single agency

On 30 May 1975, in Paris, Europe merged its two space organisations into one. The European Space Agency would take nearly thirty years to send its first probe to Mars.

The Paris Convention

The Convention creating the European Space Agency, ESA, was signed in Paris on 30 May 1975. It merged ESRO and ELDO and widened the new agency’s remit to applications such as telecommunications satellites. Ten states signed it that day, all members of ESRO or ELDO: Belgium, Denmark, France, Germany, Italy, the Netherlands, Spain, Sweden, Switzerland and the United Kingdom. Ireland signed in turn on 31 December 1975. The Convention formally came into force only on 30 October 1980, when France deposited the last instrument of ratification; but the agency worked under its new identity from 1975, with the teams and centres inherited from ESRO.

Ariane and the first missions

In 1975 the Cos-B satellite was launched. In 1978 Canada became a Cooperating State, and the IUE satellite was launched with NASA and the United Kingdom. In 1979 the first Ariane rocket lifted off; in 1980 Arianespace was formed to produce, operate and market it. Europe at last had its own access to space. In 1983 Ulf Merbold became the first ESA astronaut to fly, aboard the American Space Shuttle (mission STS-9). In 1986 the Giotto probe studied comets Halley and Grigg-Skjellerup. In 1996 the first Ariane 5 flight ended in failure.

Sources: ESA, “History of the ESA Convention 1975” (signed in Paris on 30 May 1975, merger of ESRO and ELDO, widening to applications, entry into force on 30 October 1980 after French ratification); ESA, “History of Europe in space” (Ireland in 1975, Cos-B in 1975, Canada and IUE in 1978, Ariane in 1979, Arianespace in 1980, Ulf Merbold in 1983 on STS-9, Giotto in 1986, Ariane 5 in 1996); ESA Historical Archives, “Marking 50 years of ESA: the digitised 1975 ESA Convention” (the ten signatories of 30 May 1975, Ireland’s signature on 31 December 1975).

Chapter 3 · 2003 – 2015 Mars Express

In 2003 Europe sent its first mission to Mars. Built in record time, the spacecraft is still operating more than twenty years later. Its small passenger, however, vanished.

An “express” mission

Mars Express owes its name to the speed of its construction: it was built and launched in record time, at a much lower cost than comparable missions. The savings came from new ways of working among ESA, industry, national agencies and scientists, and from reusing equipment developed for the Rosetta mission. Several instruments inherited designs from the Russian Mars 96 mission.

On 2 June 2003 a Soyuz-Fregat rocket carried it from Baikonur, Kazakhstan. The date was chosen partly because of Mars’s position: on 27 August 2003 the planet made its closest approach to Earth in seventeen years.

Beagle 2

The spacecraft carried a small lander, Beagle 2. It was released on 19 December 2003, six days before arrival. On 25 December Mars Express entered orbit around Mars. But Beagle 2 never made contact. On 6 February 2004 its management board declared it lost. It was found only in 2015, in images from NASA’s Mars Reconnaissance Orbiter.

Twenty years of observations

Science operations began in 2004. Mars Express carries eight instruments: a high-resolution stereo camera, HRSC; a spectrometer that maps minerals, OMEGA; a radar that probes the subsurface, MARSIS; atmospheric spectrometers, PFS and SPICAM; a particle analyser, ASPERA; a small monitoring camera, VMC; and a radio-science experiment, MaRS, which uses the radio link with Earth. The spacecraft found minerals that form only in the presence of water, underground water-ice deposits and evidence that volcanism may have lasted until recent times; it mapped water and ozone in the atmosphere, tracked dust, studied the moon Phobos and relayed communications for NASA’s rovers.

Meanwhile ESA achieved other distant firsts: in 2005 the European Huygens probe landed on Titan, Saturn’s great moon. The experience of Mars Express also gave rise to Venus Express.

Sources: ESA, “Mars Express overview” (“express” and record time, cost, new working relationships, Rosetta equipment, the Mars 96 heritage, 2 June 2003, Soyuz-Fregat, Baikonur, 27 August 2003 and the seventeen years, Beagle 2 released on 19 December, orbit on 25 December 2003, Beagle 2 declared lost on 6 February 2004 and found in 2015 by Mars Reconnaissance Orbiter, the eight instruments, the discoveries, relay for NASA rovers, Venus Express); ESA, “History of Europe in space” (Huygens on Titan in 2005).

Chapter 4 · 2016 – 2022 ExoMars: a success and a crash

With ExoMars, Europe set out to look for traces of life on Mars. The first mission succeeded in orbit and failed on the ground; the second was halted by war.

Two missions

The ExoMars programme, whose name comes from “exobiology,” the study of life beyond Earth, comprises two missions. The first combines an orbiter, the Trace Gas Orbiter, and a landing demonstrator, Schiaparelli. The second is to land a rover, named Rosalind Franklin.

On 14 March 2016 a Proton-M rocket launched the first mission. On 19 October 2016 the orbiter entered orbit around Mars.

Schiaparelli’s fall

That same day Schiaparelli attempted to land. Shortly after the parachute opened, its inertial measurement unit, the instrument that measures its rotations, reached the limit of what it could measure, and this saturation lasted about one second, longer than expected. The guidance software derived a completely wrong orientation from it. It released the parachute and back shell too early, fired the thrusters for only 3 seconds instead of 30, and behaved as if the craft had landed. In reality Schiaparelli fell freely from about 3.7 kilometres and struck the ground at an estimated 540 kilometres per hour.

The inquiry board, chaired by ESA’s Inspector General, named the persistence of the saturation flag in the software as the ultimate cause, and noted a lack of rigorous verification, including testing of failure cases. It also noted that the craft had come very close to landing successfully at the planned site, and that a very important part of the demonstration objectives had been achieved. Its descent instruments returned valuable data.

The orbiter at work

The Trace Gas Orbiter, for its part, braked in Mars’s upper atmosphere from March 2017 to March 2018 to adjust its orbit, then began its science mission in March 2018. It searches for methane and other trace gases in the atmosphere that could betray biological or geological activity. It is also to serve as a relay for the future rover.

The break with Moscow

The second mission, conducted with the Russian agency Roscosmos, was to launch in September 2022. On 17 March 2022, after Russia’s invasion of Ukraine, ESA’s Council acknowledged “the present impossibility of carrying out the ongoing cooperation with Roscosmos,” unanimously suspended the mission with Roscosmos and authorised a fast-track industrial study to find other options. In April 2022 the spacecraft, ready to leave for Baikonur, stayed on the ground. In July 2022 the Council cancelled the cooperation with Roscosmos on the mission.

Sources: ESA, “ExoMars Factsheet” (the two missions, exobiology, launch on 14 March 2016 on Proton-M/Breeze-M, arrival on 19 October 2016, aerobraking from March 2017 to March 2018, science from March 2018, methane, relay, data from AMELIA and COMARS+); ESA, “Schiaparelli landing investigation completed” and inquiry report DG-I/2017/546/TTN (IMU saturation for about one second, attitude error, premature release, 3 seconds instead of 30, free fall from about 3.7 km, 540 km/h, ultimate cause, lack of verification, very close to success); ESA, “ExoMars suspended,” 17 March 2022 (“the present impossibility,” unanimous suspension, industrial study); ESA, “FAQ: The rebirth of ESA’s ExoMars Rosalind Franklin mission” (launch planned for September 2022, April 2022, cancellation in July 2022).

Chapter 5 · 2022 – 2030 Rosalind Franklin and today’s ESA

Deprived of its Russian partner, Europe decided to build for itself what it lacked to land on Mars, with NASA’s help. The rover is to drill two metres below the surface.

Rebuilding the lander

In November 2022, meeting at ministerial level, the Member States committed to fund the new ExoMars Rosalind Franklin mission. Europe is building a new lander itself, reusing some hardware built for the Russian descent module: the onboard computer, the radar Doppler altimeter and the parachute system. Building and qualifying such a lander takes at least three to four years. Thales Alenia Space, in Turin, Italy, is the prime contractor.

On 16 May 2024, at ESA headquarters in Paris, ESA and NASA signed a memorandum of understanding: NASA will provide the launch, elements of the landing propulsion system and radioisotope heater units for the rover. Its mass spectrometer, part of the MOMA instrument, is already on board.

Drilling two metres down

The rover has a launch mass of 310 kilograms; it stands about two metres high and two and a half metres wide. Its drill is to collect samples two metres below the surface, deeper than any other mission in development. It will be able to cover fifty to a hundred metres per Martian day and cross difficult terrain by “wheel-walking.” The first launch opportunity is the October 2028 window, for a landing in 2030 after a two-year journey; the first data are expected at the Rover Operations Control Centre in Turin in October 2030.

Thinking ahead

ESA has also long been preparing what it will take to live far from Earth. Its MELiSSA project aims at a closed-loop life support system, needing almost no resupply, that recycles waste, water and air using microbial bioreactors and plant growth chambers. A pilot plant was inaugurated in June 2009 at the Autonomous University of Barcelona; it uses animals as its “crew.”

The agency in 2025

In 2025 ESA has twenty-three Member States, a budget of 7.68 billion euros and around three thousand staff. Its headquarters are in Paris; its main centres are in Noordwijk, Darmstadt, Frascati, Cologne, near Madrid, at Harwell in the United Kingdom and at Redu in Belgium, and it has a launch base in French Guiana. Its Director General is Josef Aschbacher.

Sources: ESA, “FAQ: The rebirth of ESA’s ExoMars Rosalind Franklin mission” (the November 2022 funding, the new lander and reused hardware, three to four years, Thales Alenia Space in Turin, the 16 May 2024 memorandum, NASA’s contributions, MOMA, the two-metre drill, October 2028, two-year transit, landing in 2030, Turin in October 2030); ESA, “ExoMars Factsheet” (310 kg, two metres by two and a half, 50 to 100 m per sol, wheel-walking); ESA, “MELiSSA life support project” (closed loop, compartments, bioreactors and plants, Barcelona pilot plant inaugurated in June 2009, animals); ESA, “ESA facts” (twenty-three Member States, 7.68 billion euros in 2025, around three thousand staff, the establishments, Josef Aschbacher). The ExoMars factsheet speaks of a surface mission in 2028 and a Falcon Heavy launch; the more recent FAQ of a launch in 2028 and a landing in 2030 (see the “Sources and method” appendix).