NASA to Select New Space Telescope

Aeroworld NET ^ | September 3, 2002 | UPI

[vannrox]

NASA to Select New Space Telescope

United Press International - September 3, 2002

CAPE CANAVERAL, Fla., Sep 03, 2002

(United Press International via COMTEX) -- Hoping to peer much farther than ever into space and back in time, NASA this week is expected to choose the design and builder of its Next Generation Space Telescope.

The two competitors for the project are Lockheed Martin Aeronautics Company of Fort Worth, Texas, and the tandem of TRW's Space Systems division, of Redondo Beach, Calif., and Ball Aerospace & Technologies Corp. of Boulder, Colo.

NASA plans to build and launch the successor to the Hubble Space Telescope for about $1.5 billion, project manager Bernard Seery, with the agency's Goddard Space Flight Center in Greenbelt, Md., told United Press International.

Unlike Hubble, the new observatory will not be placed in low-Earth orbit and serviced by teams of space shuttle astronauts. Instead, it will be launched on an expendable rocket out to an orbit about 940,000 miles from Earth. From that locale, the telescope's infrared sensors can be kept cold enough to detect light from extremely distant galaxies -- radiation that has been shifted into infrared wavelengths due to the universe's expansion.

The NGST will need a much larger light-collecting surface to pick up the faint emissions of far-away galaxies. Its primary mirror is expected to be at least six meters -- or 20 feet -- in diameter, compared to Hubble's 2.4- meter -- 7.8-foot -- mirror.

NASA and its contractors turned to the military to figure out how to launch a mirror that size on a rocket with a payload container measuring just five meters in diameter. The container also must hold a sun shield roughly the size of a tennis court when fully extended.

"All the deployables have heritage in the (Department of Defense) world," said Seery. "We've had to push the state-of-the-art."

Borrowing from de-classified spy satellite technology, Lockheed and TRW both are proposing fold-up mirrors that would unfurl in space after the telescope reaches its intended orbit. Lockheed's design is for a glass mirror with its panels folded alternatively up and down like a fan. TRW's mirror design has two hinges so its panels can fold like a table with drop-down leaves.

"At first blush, the designs seem similar," Seery said. "The purpose is the same, but in the fine details there are differences."

NASA has paid both Lockheed and TRW for initial design work, some details of which remain proprietary. In addition to a deployable mirror, the telescope needs a shield to prevent sunlight and reflected light from Earth from reaching its mirror. The shield also must be resistant to micro-meteoroid impact.

"They based their designs on what they've done for the DoD for deploying antennas and other large structures," Seery said.

The military contributions also include mathematical algorithms and computer programming techniques to coordinate the individual segments of the mirror into a single large reflective surface.

NGST will have three science instruments: a near-infrared camera, to be built by the University of Arizona in Tucson in partnership with scientists sponsored by the Canadian Space Agency; a near-infrared spectrometer, provided by the European Space Agency using detectors and a micro-shutter provided by NASA; and a mid-infrared camera/spectrometer to be built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., in partnership with a consortium of European institutions overseen by the European Space Agency.

The Canadian Space Agency has agreed to provide the telescope's fine guidance sensor.

NASA hopes to launch NGST in 2010, the same year the Hubble Space Telescope is scheduled to be taken out of service, said NASA's space sciences chief Ed Weiler.

[vannrox]

THis is exciting. But Eight years in the future is a long time, and with normal cost overruns, a possible democrat in office, and other uncertainities, it may never happen.

[taxcontrol]

I remember a concept paper long ago that talked about the possibility of deploying hundreds of smaller mirrors on a lattis structure. The idea would be that each smaller mirror would be a small (say 2") parabolic mirror that would then focus on the main reflector of only a meter or so.

Each small mirror would require constant micro modifications to compensate for stresses in the lattis structure. This was to be accomplished by piezo (sp?) motors and lasers for measurements.

The idea was that you could pre-assemble the lattis components with the mirrors and assemble in space. The back side of the lattis would provide shielding and a place to mount solar pannels, batteries, electronics, etc.

I wonder if such a design would work here?

[RonF]

Actually, such designs are already in use on Earth. There are scopes with multiple small mirrors on movable mounts, and scopes where one large mirror is supported by movable supports that distort the mirror to adjust for atmospheric conditions. The systems use lasers that are shot up through the atmosphere to measure aberrations in viewing.

[Lokibob]

This is the lead contractor on the Hubble.

Suppose he will bid on the new one?

 

 

[T. P. Pole]

Here's my concern with this. How many trips have they made to Hubble to fix things? Can they even get to this orbit?

[john in missouri]

Its primary mirror is expected to be at least six meters -- or 20 feet -- in diameter, compared to Hubble's 2.4- meter -- 7.8-foot -- mirror.

Whoa! That's one hell of a piece of glass!