The Science Programme

ESA's Science Programme has three primary features that single it out among the Agency's activities:

Development of the Programme

Given the always limited means that have been available, ESA's Science Programme has consistently focussed on missions with a strong innovative content.

Spacecraft launched/about to be launched

A total of 17 missions have been launched by the Science Programme of ESRO and ESA, four of them being collaborative ventures with NASA. All of these missions were selected in the traditional way, in that a Call for Ideas was issued, a number of proposals were received, and a competitive selection of the mission and payload was made using a procedure that has become more and more refined over time and involves successive peer reviews.

Five scientific spacecraft are presently in orbit:IUE, Giotto, Hipparcos, Hubble Space Telescope and Ulysses, although all five are not currently operational:

Giotto
Giotto

Hipparcos
Hipparcos

The three spacecraft currently being operated, IUE, HST and Ulysses, are cooperative programmes with NASA:

IUE
IUE

HST
HST

Ulysses
Ulysses

1995 will be a watershed year because it will see the launch of ISO, the last 'Pre-Horizon 2000' mission, and the first Horizon 2000 mission, STSP.

ISO
ISO

Horizon 2000

1985 was an important milestone in the history of ESA's Science Programme. It saw the approval of a long-term programme of scientific research in space, designed to ensure that Europe would continue to play a key role in this field up to, and indeed beyond, the early years of the next century.

The programme objectives are to:

Carrying out Horizon 2000 required a special financial effort from the Member States, amounting to a progressive budgetary increase of 7% per year from 1985 to a steady state in 1992. The Council meeting at Ministerial Level in Rome authorised a slower progression of 5% a year until 1989, thus affording about 50% of the requested increase. The realisation of the entire Horizon 2000 plan became dependent on such a progression of 5% a year being maintained until 1994. This progression was granted by the ESA Council in December 1990, thereby opening the way to full implementation of Horizon 2000.

The Cornerstones

The main elements of the programme are the four 'Cornerstone' missions: The Solar-Terrestrial Science Programme (STSP): Soho and Cluster

The Solar-Terrestrial Science Programme is the first Cornerstone of Horizon 2000. It combines two missions: Soho, the Solar and Heliospheric Observatory, designed to investigate the Sun's interior structure and dynamics; and Cluster, consisting of four spacecraft, designed to study the turbulence and small- scale structures in the Earth's plasma environment in three dimensions.

The primary STSP objective is to address outstanding scientific problems in solar, heliospheric, and space-plasma physics using a unified and co-ordinated approach.

The main scientific aims of Soho are investigation of the structure of the solar interior by observing velocity oscillations and irradiance variations, and investigation of the physical processes that form and heat the solar corona and give rise to the solar wind, by imaging and making spectroscopic plasma diagnostics of the Sun's external regions, as well as by in-situ solar-wind measurements.

SOHO
Soho

Soho's launch is planned for late 1995, when it will be injected into a 'halo orbit' around the L1 Sun/Earth Lagrangian point, located about 1.5 million kilometres sunwards from the Earth. The mission has a design lifetime of two years, but will be equipped with sufficient on-board consumables for an extra four years.

The Cluster mission has been primarily designed to study the three-dimensional shape and dynamic behaviour of small-scale structures (from a few hundred to a few thousand kilometres in extent) in the Earth's plasma environment. The main topics of investigation will be:

The key concept is that of making simultaneous observations from four identical spacecraft, each carrying identical sets of ten instruments.

Cluster will be launched into polar orbit by the first Ariane-5 flight in early 1996. The mission will be supported by the Cluster Science Data System (CSDS), a mission-wide, coordinated ground data-handling system. X-Ray Multi-Mirror Mission (XMM)

The scientific objectives of this High-Throughput X-Ray Spectroscopy Cornerstone require a powerful imaging instrument with the largest possible collecting area for making high-quality spectral measurements on faint sources, i.e. down to 2x10 -15 erg/cm2/s, and fast, low- and medium-resolution spectroscopy on the brighter objects.

It is intended to place the Observatory in a highly eccentric, 24 h period orbit in 1998. The mission will operate as a general-purpose astronomical observatory with a design lifetime of two years, and a target lifetime of ten years.

The investigations will have as their principal targets:

Cluster
Cluster

XMM
XMM

Rosetta

Rosetta will be launched in 2003 and after eight years will approach a comet (P/Wirtanen) and stay with it for several years, operations being planned to last until 2013. Partly remotely and partly by landing instrumentation on the comet, it will perform in-situ analysis of cometary material.

The mission is named after the 'Rosetta Stone', an ancient Egyptian tablet of black basalt bearing a tri-lingual inscription, the deciphering of which led to the understanding of hieroglyphics. Analogously, it is believed that the Rosetta mission will establish the correspondence bet-ween interstellar matter, cometary material and primitive meteorites, thereby providing an experimental approach for establishing the chemical and physical processes that marked the beginning of the Solar System, about 4.6 billion years ago.

Rosetta
Rosetta

First - The Far InfraRed and Submillimetre Telescope mission

The purpose of this mission is to make observations in the virtually unexplored 100 micron to 1 mm wavelength region of the electromagnetic spectrum. The main scientific objectives relate to:

When launched in early 2006, First is expected to be put in a 24 h, highly eccentric orbit, where it will have a lifetime of about three years.

First
First

The medium-size missions

Within the framework provided by the four Cornerstones of Horizon 2000, selected at the outset of the Programme, flexibility is provided via a number of medium- and small-size projects, selected competitively one by one.

So far, two medium-size missions have been selected, namely the joint ESA/NASA Cassini mission and Integral (also known as M1 and M2, respectively):

The Call for Proposals for the third medium-size mission (M3) was issued in November 1992 with a deadline of the end of May 1993. A total of fifty-three proposals were received and evaluated during the summer of 1993. Two successive selection rounds reduced the number of candidates to five:

Horizon 2000+
Horizon 2000 and Horizon 2000 Plus

Huygens
Huygens

Integral
Integral

Cobras/Samba, Intermarsnet, Moro and STEP are undergoing an industrial Phase-A study, while Stars, the only mission that could use an XMM/Integral common bus, is being studied in house.

The M3 mission will be selected in late spring 1996 and, according to current planning, will be launched in 2003.

Horizon 2000 also considers low-cost projects, of which the Giotto Extended Mission (GEM) to Comet Grigg-Skjellerup was a typical example.

Also, the Science Programme is striving to secure access to the International Space Station and related platforms to fly scientific payloads.

Moro
Moro

Intermarsnet
Intermarsnet

Achievements of the Programme

The Science Programme, through the timely implementation of the Horizon 2000 Long-Term Plan, is successfully and efficiently achieving all of its objectives, namely:

Areas where ESA's Space Science Programme can already claim leadership include:

The Science Programme is also a partner in the two most successful ultraviolet and optical astronomy missions, namely IUE and the Hubble Space Telescope, respectively. With the forthcoming missions in the forefront of space science, one can reasonably expect that European leadership will soon extend to:

This scientific leadership is being achieved with a budget that has varied in recent years between one seventh and one fifth of the corresponding budget of NASA.

Another less visible success should also be highlighted here, namely the fact that the ESA Science Programme, through a continuous striving for greater efficiency, has been able to:

It has been possible to assume these extra tasks only because of a progressive improvement in efficiency. This improvement has allowed the Science Programme to develop and deliver larger and more ambitious missions, in terms of both objectives and the number of scientists involved, without a commensurate increase in Programme funding.

Objectives for the Future Programme

The Horizon 2000 Plus Long-Term Plan

At its Ministerial Meeting in Granada in 1992, the ESA Council invited the Director General to submit a plan in 1995 taking account of scientific, technical and political developments and after consultation with the scientific community for the continuing implementation of European space-science policy. Work on the plan started immediately, and culminated in a meeting in Rome in September 1994 bringing together the ESA Executive and a Survey Committee, composed of European Scientists and chaired by Prof. L. Woltjer. More than seven hundred European space scientists were involved in this exercise at all levels.

The programme, called Horizon 2000 Plus, covers some ten years and is concerned with missions beyond 2006. It is designed as a rolling programme, thereby ensuring continuity and coherence with the objectives of Horizon 2000, whilst at the same time maintaining the necessary realism.

Horizon 2000 Plus includes three new Cornerstones, characterised by aims of reaching the extremes of knowledge, instrumentation and technology. They are:

A number of other objectives have also been indicated as priorities, such as participation in a Mars mission, a solar-science mission, and a high-energy astrophysics mission, the latter to be preceded by extensive system and instrument tests making use, if possible, of the Space Station.

Current Programme Elements and Proposals

The conclusions of the Survey Committee and Executive are that the bulk of the activity aimed at ensuring continuity from Horizon 2000 in areas where Europe has achieved recognised internationa leadership, can be carried out at the 1994 level of funding, even though the aims to be pursued are recognised as being massively more ambitious. The preparatory activities for Horizon 2000 Plus can also be carried out within this budget.

However, entry into the field of fundamental physics, which will be an entirely new departure for ESA, together with the pressing need to engage in the development of new technologies, will call for an extra financial effort to be granted at a later date. So compelling are these studies, however, and so important for our ultimate understanding of the Universe and the forces that bind it together, that the Survey Committee is convinced that the extra effort is worthwhile. The Committee is therefore proposing that the ESA science budget be held at the 1994 level until 2000 and then increased by 5% per year for the subsequent five years.

With the level of resources requested, the Executive will be able to:

On the other hand, a decision to reduce the Science Programme's budget would put into question the efforts made so far by the Member States, by the scientific community and by the Executive of the Scientific Programme. A failure to maintain a constant budget would induce delays in the remaining Horizon 2000 missions XMM, Integral and Rosetta, as well as in the third and fourth medium-size missions and First. It would also require the Science Programme Committee to establish priorities and make choices regarding future support to the scientific community, in terms of the extra loads on the scientific programme (ISSI, ESIS); archiving; mission extensions; support to non-ESA missions (such as HST); support to Member States, in payloads and national missions; Horizon 2000 Plus preparation.

Ultimately, the Executive might have to cancel missions if they come too late in the implementation of Horizon 2000.

Conclusion

Europe is progressively becoming the world leader in many areas of fundamental research. CERN is the focus of elementary-particle research, and many non-European Countries are planning to participate more actively in its programmes. ESA's Science Programme is already recognised as a leader in most areas of space research, through a close collaboration with both the Member States and the European scientific community, and through careful scientific and financial management of the programme. Its position can be strengthened still further.

Full success, however, can only be assured if the Ministerial Conference support's the Executive's request to maintain the Science Programme's level of resources at least constant, in terms of purchasing power, until the year 2000.


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Right Left Up Home The ESA Programmes (BR-114).
Published August 1995.
Developed by ESA-ESRIN ID/D.