NEW YORK — After 19 years orbiting hundreds of kilometers above Earth’s surface, the Hubble Space Telescope is getting its fifth and final makeover, with a slate of new instruments and repairs scheduled that will restore and expand some of the iconic telescope’s capabilities.

At press time, the astronaut crew that will give Hubble its tune-up was slated to launch aboard the Space Shuttle Atlantis May 11 for an 11-day mission. The excitement over the mission and Hubble’s capabilities afterward is palpable among NASA scientists.

“If we are successful, [Hubble] will be more powerful and robust than ever before and it will continue to enable world-class science for at least another five years,” said Ed Weiler, associate administrator of NASA’s Science Mission Directorate in

With those added five years, “we’ll be entering our second quarter century on Hubble – that’s not bad for a mission we hoped would last 10 to 15 years,” Weiler added.

In those five extra years, scientists will use Hubble to peer back closer to the beginning of the universe, look for more exoplanets and try to help solve the mysteries of dark matter and dark energy.

“It’s been seven years since we’ve serviced the Hubble Space Telescope,” said David Leckrone, Hubble project scientist at NASA’s Goddard Space Flight Center in
That’s “twice as long as we should go in terms of servicing intervals. As a consequence of that, over the last few years, we’ve seen significant deterioration within the set of scientific instruments that we provide to the astronomical community.”

One of the instruments the astronauts will try to fix is Hubble’s Advanced Camera for Surveys (ACS), which has been hobbled in recent years. It has three so-called channels, which each act as separate instruments with different capabilities: the wide-field channel, the high-resolution channel, and the solar blind channel.

Scientists can choose which they want to use based on the kind of science they want to do. But currently only the solar blind channel is working.

The Space Telescope Imaging Spectrograph (STIS) also has three channels, none of which are currently working. If time allows, the astronauts will try to revive its three channels.

The planned STIS and ACS repairs involve complicated circuitry work not designed to be done in space, so mission scientists cannot be sure how the repairs will turn out, though they are optimistic about the chances.

If the team cannot complete the ACS repairs, then the instrument will still be left with the solar blind channel, “so we should be no worse off there than we were before,” said Hubble project manager Preston Burch of NASA Goddard.

Meanwhile, the brand new Cosmic Origins Spectrograph will augment STIS’s capabilities with two channels, one for near-ultraviolet observations and one for far ultraviolet. It can also substitute for STIS if that sensor cannot be repaired. Also slated for installation is the Wide Field Camera 3, which will replace the Wide Field Planetary Camera 2 and complement ACS’s observing capabilities.

Wide Field Planetary Camera 2 “has been operating like a champ for about 15 years now, but it is getting a little bit long in the tooth and will be replaced on this mission,” Leckrone said.

All of these instruments are “tremendously important tools to be used for a broad variety of astronomical investigations,” Leckrone said.

When this servicing mission is complete, assuming all goes according to plan, “Hubble will be at the apex of its capabilities,” Leckrone said. “It will never have been better before than it will be at that point.”

In the nearly two decades it has been operational, Hubble has contributed considerably to scientists’ understanding of the universe.

In an essay in the Jan. 1 issue of the journal Nature, astronomer Julianne Dalcanton of the University of Washington discussed some of the contributions Hubble has made, including: refined distance scales in the universe; the life cycle of stars; the first observations of proto-planetary disks around stars; a better understanding of black holes and their role in the formation of galaxies; the formation of the first galaxies; and the general age, composition and size of the universe.

“We have reformulated so many different areas of astronomy,” Leckrone said. “There is no area of modern astronomical research that hasn’t been profoundly affected and changed by Hubble.”

With its new components, Hubble will continue to do science in many of these areas, with the hopes of shedding even more light on the dark spots of space.