For all the anxiety and discord surrounding civil space programs everywhere – much of it rooted in the never-ending competition for limited resources – there are occasions when everyone associated with this enterprise, regardless of sector or scientific discipline, cannot help but stand and applaud. Mid-May brought two such occasions: the launch of ‘s Herschel and Planck astronomy satellites and the successful completion of the final servicing mission to NASA’s venerable Hubble Space Telescope.
Herschel is the largest infrared observatory launched to date, with a telescope mirror measuring 3.5 meters in diameter. Cooled to within a few degrees of absolute zero, the spacecraft will look for clues into the early evolution of galaxies in unexplored infrared wavelengths. Launched along with Herschel aboard an Ariane 5 rocket was the smaller Planck satellite, which will map cosmic microwave background radiation in unprecedented detail, answering questions about the early universe and shedding light on the current universe’s ubiquitous yet mysterious dark matter.
Together the Herschel and Planck spacecraft, costing a combined 1.8 billion euros ($2.4 billion) including launch and operations, represent the European Space Agency’s biggest-ever investment in space science. They are now making their way to the Lagrange 2 orbital location – about 1.5 million kilometers from Earth, where gravitational forces of the sun and Earth cancel each other out – for missions expected to last at least three years.
As the European satellites lifted off, NASA astronauts were conducting the first of five long-duration spacewalks outside Space Shuttle Atlantis to give the 19-year old Hubble Space Telescope its fourth and final in-orbit makeover. Working in pairs, the astronauts overcame several challenges to install two new instruments, repair two others, and change out power and pointing components, adding at least five more years to Hubble’s already groundbreaking mission and enabling it to peer deeper into the heavens than ever before.
Significantly, this was a mission that almost never happened: It was canceled due to safety concerns in the wake of the February 2003 Space Shuttle Columbia disaster but reinstated after NASA came up with a plan to rescue Atlantis’ crew in the event that their orbiter suffered the kind of damage that would render it unsafe for re-entry.
Hubble launched in 1990 with an optics flaw that was not corrected until three years later with the first servicing mission. Since then it has gone from laughingstock to one of the most productive scientific instruments ever. Though costly – investment in the observatory by some accounts has topped $10 billion – Hubble has made unique and indispensable contributions to astronomy. Perhaps equally as important, Hubble’s spectacular pictures have introduced and drawn an otherwise largely disinterested general public to the field.
Between Hubble and several other spacecraft on orbit, including the Chandra X-ray Observatory, Spitzer Space Telescope and others, scientists have been on the receiving end of a data bonanza for several years. With the addition of Herschel, Planck and the newly refurbished Hubble, astronomers will now have the universe covered across the entire electromagnetic spectrum, according to Jon Morse, director of NASA’s Astrophysics Division. Although Spitzer, after more than five and a half years on orbit, has run out of the coolant necessary for its infrared instruments to work, astronomers will soon have the biggest and most capable set of data collection assets ever in space, Morse said.
Assuming all continues to go well with Hubble, Herschel and Planck, the next several years should yield new discoveries that improve scientists’ understanding of the fundamental nature of the universe and how it has evolved over the eons since the Big Bang.
Meanwhile, more missions are in the pipeline, the biggest being the U.S.-German Stratospheric Observatory for Infrared Astronomy, a telescope-carrying 747 aircraft slated to begin limited science operations in 2010; and NASA’s Hubble successor, the James Webb Space Telescope, which is scheduled for launch in 2014. With steady funding, good engineering and perhaps a little bit of luck, these platforms, along with several others in development or on the drawing boards, will help keep astronomers awash in data and discovery for years to come.