PARIS--Faced with the need to save $460 million over the next decade, the European Space Agency (ESA) has announced a revised list of upcoming missions that includes more science for less money. The trick, says ESA science director David Southwood, is linking the development of related missions and squeezing launch schedules.
Last November, Europe's space scientists faced a grim future. Ministers meeting in Edinburgh had capped the ESA science budget over 3 years. It seemed certain that one large mission would have to be scrapped, most likely a galaxy-charting satellite called Gaia. Southwood called it "a rather dismal picture." But on 27 May, Southwood and his team unveiled a plan for 16 launches in 10 years rather than the original schedule of 12 launches in 11 years. They even managed to save Gaia and introduce a new mission into the $3.4 billion mix.
Southwood's "cosmic vision" program calls for spacecraft to land on Mars, Mercury, Saturn's moon Titan, and a comet. Its instruments also would observe the birth, evolution, and death of stars and galaxies at gamma ray and infrared wavelengths; study the afterglow of the big bang; and map the positions and motions of nearly every star in the Milky Way. ESA will also join NASA in building Hubble's successor, the Next Generation Space Telescope, and LISA, a gravitational wave observatory in space.
The savings are based on one-time economies, such as saving $140 million by shrinking Gaia and placing it on a smaller launch vehicle. The belt-tightening has allowed Southwood to resurrect a former backup mission, Eddington, to study the composition and structure of stars by measuring seismic vibrations at their surfaces, a technique known as asteroseismology. It will also look for small extrasolar planets moving across the disks of parent stars. Eddington is a step toward a 2015 mission that would study the atmospheres of extrasolar planets and search for life. "I can't imagine a human being not interested in this," Southwood says.
The drastic pruning of the program budget did nip one bud, however--a planned mission to Venus. Even so, "the final result is the best of the possible solutions," says Bo Andersen of the Norwegian Space Centre in Oslo, chair of ESA's Science Program Committee.