This, in turn, would allow it to use cameras and spectrometers to map features and activities much closer to the Sun's polar regions than Earth-based telescopes or any previous solar astronomy spacecraft can -- as well as undergoing a period during the inner part of each orbit when it would be swinging around the Sun at almost the same rate that the Sun rotates, allowing it to observe how individual solar features change over unprecedentedly long periods.

Although Solar Orbiter by itself would be too expensive to be classed a Flexi mission, the spacecraft will be closely based on the heat-resistant design being developed for Bepi Colombo's main "MPO" Mercury orbiter, and its ion drive would be based on the ion-drive module which Bepi Colombo must use to spiral in to reach Mercury. As such, it must fly after Bepi Colombo -- around 2012.

While this is quite an impressive schedule for ESA, NASA, --with its much larger space science budget -- could in theory achieve it easily if its resources were not going into the Space Station. And, not surprisingly, ESA's space science managers would also like more.

At its next Ministerial Conference this November, they will put pressure on the Ministers to return to the days of five percent yearly real increases in ESA's science budget for the next five years, instead of merely keeping it at a steady level as is currently planned. As ESA Science Program's new director David Southwood has pointed out, since the Toulouse Conference the total GNP of ESA's member states has grown by 18 percent, and is now more than America's GNP.

If the science directors succeed in this effort, they will be able to increase space science spending enough to launch all the planned independent ESA missions by 2011.

Moreover, they have one major new program in mind: Aurora, which would combine a major search for extraterrestrial life with research work on possible future human travel into deep space.

Europe, like the US, seems to have decided that the search for life elsewhere is one of the most generally popular goals a space program could possibly have -- and that this can be linked to research into possible techniques for future manned expeditions to the Moon, Mars and near-Earth asteroids.

"If we decide it is right in 20 years' time to send people to Mars or an asteroid, we must find out now what knowledge and supporting technology we would need,", according to Didier Schmidt, the head of ESA's Pace research and Technology Centre in the Netherlands. Aurora would thus combine aspects of the work done by ESA's Science Program and its Manned Spaceflight and Microgravity Program.

Although it would be officially separate from the Science Division, it would involve a large number of unmanned space missions focusing on astrobiology research on Mars and Europa -- with the first perhaps being launched before 2010.

ESA's manned Spaceflight Directorate is already designing a life-detection package that could be flown on future Mars landers larger than the little 30-kg Beagle 2, carrying more sophisticated biochemical experiments and a 1.5-meter drill.

ESA is also interested in studying concepts for a possible purely European Mars sample return mission at some point in the future, despite such a mission's high expense and the possible huge hurdles European Greens might erect against any European-led Mars sample return missions.

Unquestionably, Aurora would be expensive -- the request before its Ministers in November would involve $30 million a year in 2002-04, rising to about $130 million per year thereafter, and the Science Division insists that this would be in addition to ESA's current science program. However, there is now some speculation that Aurora may eventually turn into the umbrella program under which all of ESA's Solar System focused missions are launched, on the grounds that this would make it easier to fund such missions and to coordinate them with the planetary exploration missions of the US and other nations.

That, however, is assuming that Aurora is approved at all, and that the Ministers can be persuaded to provide ESA's total scientific spending with that five percent per year boost that ESA's science directors hope for.

Even if they fail in this effort, though, it seems likely that ESA's Space Science Division is about to gain a fair amount more money than was believed last year.

The reason is that -- while NASA spends fully eight times more on science than ESA -- the majority of that money goes into the Space Station, and its ever-increasing cost overruns are now eating away at the budget for the rest of NASA's science programs.

Those victims now include both NGST and LISA, with NGST now officially delayed until 2009, as well as having the size of its mirror cut to only 6 or 7 meters.

Moreover, last week the House Appropriations Committee ordered a further cut of $20 million in its development funds for this year, which (unless reversed by the Senate) will delay its launch another six months.

The American part of the LISA project is also undergoing delays which seem likely to delay its launch at least one or two years. The result is that Europe is now almost certainly in a position to be able to safely delay some of its own spending on its parts of those missions (although its "SMART-2" test flight for LISA is still set for 2006). Thus, ESA is now likely to have enough spare cash to fly one, or perhaps even two, additional independent missions this decade.

What would these missions be?

At the time ESA picked the three Flexi missions last October, it also picked another Flexi mission as a possible near-term addition to its schedule in the event of such delays on the part of its American partner.

That fourth Flexi mission is "Eddington" -- a spacecraft which (like NGST and GAIA) would be put into solar orbit permanently hovering near the "L-2" point 1.5 million km beyond the Earth's night-side (a good location for future astronomy spacecraft).

Eddington would try to achieve another astronomical milestone: the first detection of Earth-sized planets around other stars.

These are too small for their gravitational tuggings at their central stars to be detectable from Earth, even using devices as sensitive as GAIA. And they're too small to be detected optically, until a later, more ambitious NASA-ESA collaborative project is launched: "TPF-Darwin", which would use three to six fairly large space telescopes -- hovering in super-precise formation, like the spacecraft of LISA -- to form an incredibly high-resolution optical interferometer which could not only clearly photograph Earth-sized inner planets of other stars, but take spectra of their atmospheres to look for ozone and other gases which could indicate that they actually hold life.

However, Eddington would look for such planets, not by observing them directly, but by detecting their transits across the disks of their suns as seen from Earth -- by using a 1.2-meter telescope hooked up to a very large CCD array to stare continuously at a field of fully tens of thousands of stars for 3 years while precisely monitoring the brightness of each of them, to try to identify those brief periods when the star's brightness dips slightly as a planet moves in front of it as seen from Earth.

If three or more such dips in the star's brightness occurred at identical time intervals and for the same short period of time, it would be safe to assume that they were due to transits by a planet, rather than to the star's own natural fluctuations in brilliance.

Thus Eddington could detect planets with orbital periods of as much as 1 1/2 Earth years -- as well as determining their distance from the star and their diameter. And these inner planets are those likely to be in their stars' "Habitable Zones" (the range of distances from a star in which its planets can possess liquid water and thus life).

The odds that any planet circling another star will have an orbit tilted as just the right angle to allow such transits to ever be seen from Earth is only about 0.5 percent -- so the odds that Eddington could locate any small planet circling a nearby star (and thus one close enough to be later observed by TPF) are miniscule.

But, by observing so many stars at distances of up to several thousand light-years, it would at least allow us to get that first "census" data on how many such planets there are, and what kind of stars they're likely to be found near.

Moreover, Eddington would spend its first two years measuring tiny brightness fluctuations in 50,000 other stars, slewing from one group of interesting stars to another and observing each for periods of 1 or 2 months -- allowing "astroseismological" studies of them.

That is, the resonant natural shock waves constantly vibrating through them because of their nuclear burning could be precisely measured; allowing detailed new understanding of their internal structure and how it changes with time as different types of stars evolve. This technique has already been very useful to provide new insight into the internal structure of our own Sun.

While ESA has not yet firmly put Eddington on its schedule -- it's still waiting for NASA to officially drop the other shoe and admit that there will be some further delays in NGST and LISA -- it seems increasingly likely that it will indeed be launched in 2008.

This is despite the fact that NASA has listed "Kepler" -- another extrasolar-planet transit satellite -- as one of the three finalists for the next low-cost "Discovery" planetary mission, since Discovery missions can be aimed either at targets in our own Solar System, or at the detection of extrasolar planets.

It's by no means certain Kepler will be picked for launch. It must compete against the "INSIDE Jupiter" orbiter to study Jupiter's internal structure, and the "Dawn" mission that would use ion drive to orbit the big asteroids Ceres and Vesta for close-up study.

If it is picked, though, the two missions would by no means be redundant -- for Kepler's main goal is planet detection, while Eddington was designed primarily for astroseismology.

Eddington has a relatively narrow view-field, which can be used for accurate short-term seismic observations of a whole series of carefully selected clusters of interesting types of stars -- but this also limits the number of stars it can then observe simultaneously for planetary transits during that later three-year period.

Kepler, on the other hand, is designed to spend its entire lifetime engaged in planet detection. It will stare at a single field of stars for 4 straight years; and its view-field has 15 times the area of Eddington's, which means its count of detected planets would be 15 times greater.

Moreover, the fact that its viewing period is a year longer than Eddington's would allow it to detect planets with orbital periods between 18 months and two years, which Eddington cannot detect -- and many of the planets in the outer halves of their stars' Habitable Zones fall into that category.

Kepler, however, will be able to gather astroseismic data only on those types of stars which happen to be in that same view-field. So it's quite possible that both missions will end up being selected.