Peering deep into space is like seeing back in time since light has a limited speed. This means the light that is detectable can be millions, even billions of years old. In this way, a telescope like SPIRIT will be able to watch how stars and planets formed millions of years ago.
The Spitzer Space Telescope, now in orbit, has begun making similar observations with its infrared telescope. But, as planned, SPIRIT's dual-telescope gazing power should be about 100 times stronger than Spitzer.
Besides SPIRIT, one other NASA mission is now in the making to use the dual visibility of two joined telescopes. The Space Interferometry Mission is scheduled for launch in about five years and will fly up to four interferometers with two telescopes each, mounted on a single 33-foot bar. The telescopes won't be able to glide around as in the SPIRIT telescope design, but the entire unit will be able to rotate. SIM's main mission is to identify and study distant habitable planets as well as analyze the motion of galaxies.
"SIM is a very precise instrument," said Andrew Gould, an Ohio State University astronomer who is part of the SIM team. "If you placed a dime on its side on the moon, SIM could see it from as far away as Earth."
From 1990, the Hubble Space Telescope has wowed scientists and the public alike with its spectacular pictures of the deep universe. But the future of the famous space telescope is now uncertain since NASA chief Sean O'Keefe scrapped a manned mission to service the telescope in January. NASA may send a robot to do the repair work, but, in the meantime, projects like SPIRIT and SIM show that scientists are eager to take the next generation of space telescopes to a new level.
If approved, SPIRIT could be ready for launch by 2016 while SIM is slated to blast to orbit by the end of 2009. While scientists have an inkling of what these kinds of telescopes could reveal, the most exciting data could be the unexpected.
"Every time we send out a new instrument, we find new things," says Leisawitz. "I'm sure we will discover things we haven't really dreamed of yet."