A little more money and a lot more challenge for ESA's Science Programme
21 May 1999ESA's Scientific Programme Committee (SPC), which met in Bern on 19-20 May, took an optimistic view of the decisions taken at Ministerial level in Brussels on 11-12 May. The SPC judged that the level of resources was sufficient to proceed with the approved projects of the Science Programme. After review of the available means and of the Council's assumptions, the SPC confirmed in particular Mars Express, scheduled for launch in 2003. "Following the conditional approval of Mars Express in November 1998, and given the Executive's assessment that the conditions are fulfilled up to the end of 2001, the SPC confirms that Mars Express can proceed", the text of the Resolution states.
Intended to give Europe a substantial role in the exploration of the Red Planet, Mars Express brings together senior scientists representing ESA's 14 Member States. A stipulation was that there should be sufficient resources and no adverse effect on other projects already approved. Figures available at that time suggested that Mars Express might be affordable only with a delay to the FIRST and Planck astronomical missions. The Council of Ministers addressed this potential conflict in making a small adjustment to the budget for space science, which allowed the SPC to give the go-ahead to the mission.
Discussions about the Science Programme implementation plan led to unanimous agreement and reconfirmation of the future targets in the medium term plan. In particular it was agreed that a constant purchasing power of 370 MEUROS was a reasonable objective to be obtained in 2001 for the following years, and a figure on which planning could be based. A new appointment was fixed for September to discuss carefully the whole medium-term implementation plan.
The schedule of expected launches of major science missions is now as follows:
1999 XMM for X-ray astronomy
2000 Cluster II for solar-terrestrial physics
2001 Integral for gamma-ray astronomy
2003 Rosetta for close inspection of Comet Wirtanen
2003 Mars Express for an orbiter and lander on Mars
2007 FIRST for far-infrared astronomy
2007 Planck for microwave astronomy and cosmology
The launch date of FIRST and Planck was of particular concern to both the Council and the SPC and the budget adjustment was made on the understanding that both Mars Express and FIRST/Planck are preserved as planned. Clearly, the precise date for FIRST/Planck will critically depend on the decision that will be taken at the next ESA Council meeting at Ministerial level, in 2001. As the budget increase granted by Council barely covers one third of Mars Express cost, the challenge to ESA planners is now much greater. However, the SPC re-asserted its confidence in ESA's managers to find solutions to the problem.
Uncertainty surrounds smaller missions during the 2001-2007 period, and major missions beyond FIRST and Planck. The smaller projects include a series of SMART missions, with SMART-1 in preparation for a proposed launch in 2001 to test solar-electric propulsion. Nevertheless, the technical need of the Agency for SMART-1 is fully endorsed by the SPC: the question will be revised at the next meeting in September 1999.
STEP, with a possible launch date in 2004, would be a joint project with NASA to test severely a fundamental principle of the law of gravity.
Looming too are ESA's participation in the Next Generation Space Telescope (2007) and possible new Flexi missions on the scale of Mars Express. ESA's science planners and Europe's space scientists also wish to see a major Cornerstone mission, comparable with XMM or Rosetta, before the end of the next decade. The outlook for these projects, within the overall science programme Horizons 2000, will depend on decisions about long-term funding due to be made by the Council of Ministers in two years' time.
The present state of affairs arises from a ruling by the Council of Ministers in 1995, that ESA's annual space science budget should be fixed in cash terms. That led to a steady decline in the budget in real terms, because of inflation. ESA responded with wide-ranging economies and new methods of managing scientific projects. Classes of smaller and cheaper missions, Flexi and SMART, were introduced to prevent a loss of flexibility and innovation that could result from the budgetary squeeze.
Mars Express is the first Flexi mission. Its future is now secured by small cash additions that, in effect, reduce the rate of decline in the science budget. Other major missions (those listed above) are also provided for in current budgetary planning. It will be for Ministers to reconsider in 2001 how the future science budget should be set. That will determine what further space science will be affordable up to 2010.