How the European Space Agency plans more science with less money
Tim Furniss/LONDON
As the European Space Agency (ESA) prepares to see its penultimate large-scale, high-budget, planetary mission, the Huygens, take off with NASA's Cassini en route for Saturn on about 13 October (Flight International, 7-13 August, 1996), it says that it has drawn up a "table d'hôte" of future science missions in its Horizons 2000 programme.
ESA has a developed a "balanced menu of research opportunities in solar-system exploration and astronomy". That the menu is not à la carte is because, behind the scenes, budget cuts have forced ESA's "-frustrated scientists to make drastic decisions to amend the science programme", according its science chief, Roger Bonnet. He has been forced "-to do more for less".
It has happened to NASA and, more recently, to Japan. It is now happening to ESA. In 1995, it was agreed by ESA member states to freeze the science budget until 1999 at a level of about $390 million a year. This means that the actual budget is dropping year by year and, unless the freeze is lifted, the table d'hôte could be reduced to the equivalent of a school dinner.
Exciting missions
Other factors contributing to Bonnet's dilemma were the Ariane 5 failure in June 1996, which killed off four Cluster satellites (now resurrected as the Cluster 2 mission), and the loss of the Russian Mars '96 mission in November 1996, which held some ESA experiments.
Even when squeezed, the ESA science programme is "first class", says the agency, citing the Hipparcos, the Infrared Space Observatory (ISO), the Solar and Heliospheric Observatory (SOHO) and the Ulysses as classic examples of ESA "sticking to its promises" (see box).
Despite the cuts, and the cancellation of some long-term mission plans, however, the programme still retains some "-exciting missions and has even introduced new ones, including the Mars Express, which could be launched in 2003", says Bonnet, putting on a brave face. He has been forced to be a convert to NASA's "smaller , faster, better, cheaper" approach.
This Mars mission has been made possible by combining two astronomy missions: the former Cobras-Samba, now the Planck Surveyor, for cosmic-ray observations, and the Far Infrared Space Telescope (FIRST), saving about $350 million. The Mars Express - for which ESA will budget $170 million - will orbit and land a small craft on the Red Planet to analyse the soil.
Other, longer-term, missions include a spacecraft to orbit the planet Mercury, and an astronomical interferometric mission, using two or more telescopes in combination to observe the stars in the visible and infra-red wavelengths. Astronomers and engineers from the UK have made a proposal for this mission, called the Darwin.
A programme innovation - which is taken from NASA's New Millennium programme to demonstrate new technologies - is the Small Advanced Research and Technology (Smart) project, a series of small spacecraft to prepare for future missions, starting with the Smart 1, which will be used to test ion-propulsion technologies.
Ion-propulsion demonstrator
The Smart 1 would use the Moon as its target, demonstrating how ion propulsion could propel a future craft to orbit the planet Mercury, the largely unexplored inner planet of the Solar System. The Smart 2 mission could be dedicated to testing Einstein's theory of relativity. The ambitious gravitational-wave mission will detect radiation predicted by Einstein's theory of gravity, which, he postulated, stretches and squeezes itself.
The Smarts would be launched piggyback on commercial Arianespace flights, saving more money. In a way, this is the first time that ESA has supported overtly a programme which will produce technology which could be commercialised. Another innovation - which seems obvious now - is the use of similar spacecraft buses for different missions, as illustrated by the Integral gamma-ray observatory, using the bus designed for the X-Ray Multi Mirror (XMM) telescope. The use of common, off-the-shelf, technologies will be encouraged, too.
ESA may be contributing some funds to the new instrument to be flown on the NASA Hubble Space Telescope, which will be fixed on the fourth Shuttle servicing mission in 2002. It will also contribute $200 million to an instrument to be flown on NASA's Next Generation Space telescope, due to be launched around 2007 (Flight International, 4-10 June).
The final large-scale planetary mission, the Rosetta comet rendezvous craft, which has been under development for many years, is still scheduled to be launched in 2003. It is scheduled to fly in close orbit around the comet Wirtanen in 2011.
Future missions:
XMM
When it enters orbit on 2 August, 1999, after an Ariane 506 launch, the $800 million, 56-mirror XMM will make in a matter of seconds observations of objects in the Universe which took hours with previous X-ray astronomy missions.
The 3,900kg, 10m-long, craft is equipped with three highly sensitive X-ray-imaging cameras, two high-resolution X-ray spectrometers and a 300mm-diameter optical-monitoring telescope, which, for the first time, will enable simultaneous observations in the visible and near-infra-red wavelengths.
The XMM will provide images of unparallelled sensitivity of the hottest objects in the Universe, with temperatures exceeding 10,000íC. These are produced by extreme forces, powered by intense gravitation and include quasars and black holes in the hearts of distant galaxies. The XMM will be placed into an eccentric, 100,000 x 7,000km orbit, with an orbital period of 48h. Prime contractor Daimler-Benz Aerospace Munich has just completed the first development flight model for testing.
CLUSTER 2
These four satellites, to be launched in pairs on two Russian Soyuz boosters in 2000, will explore the Earth's environment more thoroughly than before. The Clusters replace the four lost in the Ariane 5 failure in June 1996. They will study the physical interaction between the Sun and the Earth, specifically the effect of the solar wind on the Earth's magnetic field. The $248 million mission will use the original Cluster ground-spare satellite and three new craft.
INTEGRAL
The Integral will be orbited in 2001, and will renew ESA's role in gamma-ray astronomy pioneered by its COS-B mission more than 20 years ago. Gamma rays reveal the most violent events in the Universe. The primary mission will be to observe the plane of the centre of the galaxy for the most energetic objects.
ROSETTA
A successor to the highly successful Giotto, which explored Halley's Comet in 1986 and the Grigg-Skjellerup in 1992, the Rosetta will be launched in January 2003, to fly in close orbit around the comet Wirtanen in August 2011. It will fly an extraordinary path around the solar system to reach the final destination.
The Rosetta will use the gravity of Mars during a fly-by in August 2005, to divert it to the Earth again in November 2005, for another "gravity-assist" fly-by towards a brief rendezvous with the asteroid Mimistrobell in September 2006. Another Earth gravity-assist will be made in November 2007, taking the Rosetta for another brief fly-by of the asteroid Rodari in October 2008.
MARS EXPRESS
This high-level, low-cost mission could set off for the planet in 2003, giving Europe an important stake in the exploration of Mars by remote sensing from an orbiter and by experiments on a microlander, or several small landers. The orbiter would make a detailed survey of the planet.
A Mars Express lander has been proposed by the UK's Open University's Planetary Sciences Research Consortium, in conjunction with the University of Leicester Space Science Centre, with co-operation from Austria, Finland, France, Germany, Holland, Italy and Russia.
The Open University's Professor Colin Pillinger has called the lander the Beagle 2. It will be dedicated to exiobiology, with an integrated package of experiments to look for evidence of past life on the Red Planet. The instrument suite will include a drill, to provide core samples from the depths of Mars not exposed to the harsh oxidising conditions on the surface. Samples would be investigated for the presence of organic molecules indicative of life processes and other tell-tale signs of biological activity. There will also possibly be other microlanders dedicated to other scientific disciplines, especially geochemical analysis of the upper surface. This mission will ensure that the Mars Express is not another "all eggs in one basket" space mission, says Pillinger.
FIRST/PLANCK
A combined mission to be launched in 2005, the FIRST and Planck Surveyors will extend the scope of infra-red astronomy to wavelengths longer than those of the ISOs. The Planck Surveyor will chart cosmic microwaves and the First the far-infra-red spectrum.
DARWIN
The first step in the "search for extra-solar life", could be the Darwin Space Infrared Interferometer, a space-telescope system capable of finding Earth-like planets around nearby stars. The Darwin - which could be launched in 2015 - will also study the atmospheres of these planets.
Major successes:
Hipparcos
Results from the star-mapping satellite, launched in 1989 aboard an Ariane 4, were released in mid-1997 and give the positions and motions of 118,000 stars in our night sky 100 times more accurately than before.
ISO
Every day, the Infrared Space Laboratory examines 45 cosmic objects at different wavelengths, never observable before, giving fresh insights into the history of the Universe and its chemistry. The satellite was launched aboard an Ariane 4 in 1995.
SOHO
Invaluable new knowledge of the Sun has come from the SOHO, which is the first spacecraft able to observe the Sun's deep interior, as well as its active, stormy, surface and atmosphere. The SOHO was launched aboard an Atlas in 1995.
Ulysses
Deployed from the Space Shuttle in 1990. This craft was the first to enter an orbit around the poles of the Sun in 1994-5. It will return for a second period of observation in 200-01.
Source: Flight International
