SPACE.com -- Chandra's Cousin: Telescope Sees X-Rays from Space Balloon

An image of the Crab Nebula and pulsar is one of the first two focused high-energy X-ray images of any astronomical object. The two historic images were captured by a team from NASA's Marshall Space Flight Center in Alabama, on May 23, 2001, using a telescope containing X-ray mirrors. Click to enlarge.

This image of the Cygnus X-1 binary star system is one of the first two focused high-energy X-ray images of any astronomical object. It was captured by a team from NASA's Marshall Space Flight Center in Alabama, on May 23, 2001, using a telescope containing X-ray mirrors. Click to enlarge.

The National Scientific Balloon Facility in New Mexico launched an experimental telescope for the High Energy Replicated Optics (HERO) team on May 23, 2001.The 40 million cubic-foot (1.1 million cubic-meter) balloon carried its payload to an altitude of 128,000 feet (39,000 meters). Click to enlarge.

Dr. Brian Ramsey, lead scientist for the High Energy Replicated Optics (HERO) program, at NASA's Marshall Space Flight Center in Alabama, installs the mirrors of the world's first focused high-energy X-ray telescope. The telescope uses six nested X-ray reflecting mirrors - three in each of the two assemblies. Click to enlarge.

Black Holes Less Voracious, Chandra Shows

Chandra Telescope Sees Skeleton of Crab Nebula

Powerful X-Ray Telescope Will Peer Into Distant Black Holes

Mysterious X-Ray Objects Revealed in Andromeda Galaxy


	Chandra's Cousin: Telescope Sees X-Rays from Space Balloon By Heather Sparks Staff Writer posted: 07:00 am ET 14 June 2001

xray_telescope_rl_revise

Nearly two years ago, the Chandra X-Ray Observatory nearly knocked astronomers out of their chairs with the telescope's low-energy X-ray images of the universe's most violent events.

From Earth orbit, well beyond our planet's blinding atmosphere, Chandra has detected heated beams licking at black holes and supernova remnants.

Now, a new, experimental telescope is offering a high-energy X-ray view of the universe from the low-cost perch of a balloon floating above Earth, a view that fills in the blank left by Chandra's detectors.

"In some ways, it's a different sky we're looking at," said Brian Ramsey, HERO project's lead scientist.

A different sky already and this scope's only a demo. The real deal, 50 times more sensitive than the test telescope and 1,000 times less costly than Chandra, will be launched in 2003.

The tester scope, developed by the High Energy Replicated Optics (HERO) team at NASA's Marshall Space Flight Center in Alabama, was launched last month and already has returned detailed pictures of the Crab Nebula and the Cygnus X-1binary star system. Ramsey says the final version will yield snapshots of thousands of high-energy X-ray sources, bringing to life objects that are 10 to 100 times dimmer than Cygnus and the Crab Nebula.

In the realm of high-energy X-rays, these formations are the brightest objects in the sky, yet they had never been seen like this before.

Complementing Chandra

The HERO project telescope and Chandra each have their uses in astronomy because they read different regions of the X-ray spectrum.

But unlike Chandra, the new scope doesn't have to exit the atmosphere completely to get a clear view of its subject. High energy X-rays penetrate the upper part of Earth's atmosphere, making the HERO project inherently simpler and cheaper. Ramsey is quick to point out that his telescope was built in three years for $1.2 million total.

"Chandra is a billion dollar observatory, and this is just a balloon," Ramsey said. "This is cheaper, inexpensive exploration."

The tester telescope was launched at Fort Sumner, New Mexico, on May 23 with the help of the 40 million cubic-foot (1.1 million cubic-meter) balloon. The scope was lofted to an altitude of 128,000 feet (39,000 meters), above 99.7 percent of the Earth's atmosphere, where high energy X-rays exist.

During the maiden 24-hour float, the HERO team demonstrated its mirrors were focused correctly, that the telescope could be remotely pointed with accuracy, and that the balloon's unique carbon-fiber platform was stable enough too hold the telescope steady for hours while a series of images were taken.

How it works

Along with saving launch dollars, the HERO project cut costs with its telescope's X-ray mirrors as they are relatively inexpensive to make due to a process called replication. The process starts with an aluminum master cylinder, polished very smooth and electroplated with shiny nickel. When the rod cools, the nickel pops off as an extremely thin, perfectly smooth, mirror shell.

The current eye-in-the-sky has two sets of three nested mirrors, but 240 mirrors will nest on the final version. Their extremely smooth inner surfaces reflect X-rays at shallow angles and focus the rays onto a teeny detector. This beam-concentrating ability makes for infinitely better images because background noise can't hit the detector. The result: the most focused high-energy X-ray images ever.

X-ray promises

As has been the case with the Chandra telescope, HERO project scientists are excited about the possible unknowns that the new approach will turn up.

"Chandra revolutionized low-energy X-ray observation, and we're trying to do that in the high energy region," said Ramsey.

X-ray images are the key to probing the universe's major cosmological births and deaths which often occur at the sites of quasars, black holes and supernova remnants. When galaxies collide, black holes devour matter or aging stars dance together, energetic jets are emitted as hot gases are whacked with intense energy fluxes and heat that can only be seen in the X-ray spectrum.