Thursday, January 17, 2013

Shuttles, Turning Sedentary, Leave Pieces Behind for Science and Safety

As the agency gets its space shuttles ready to be shipped out to museums, it will not be sending them off lock, stock and barrel. The crews doing the prep work have been flooded with requests to squirrel away parts of the spacecraft for analysis. Valves, flight-control instruments, even the tires and windows — little is safe from the clutches of NASA engineers.

“I’ve got a list of hundreds of items that have to come off the ship,” said Stephanie S. Stilson, who is directing the preparation of the shuttle Discovery for delivery to the Smithsonian Institution next year in what NASA calls its “transition and retirement” program.

In April, NASA named the permanent old-age homes for its shuttles, which have been escorting astronauts to space for 30 years. The Endeavour, which completed its last mission early Wednesday with a pinpoint landing after 16 days in orbit, will bask in glory only briefly before it is groomed for delivery to the California Science Center in Los Angeles. The Atlantis, which will make its final flight next month, is destined to live at the visitors’ center here at the space center.

The Discovery made its last flight in March and now sits in a maintenance bay, enclosed by platforms that would normally be crawling with workers inspecting and maintaining its many systems — including the thousands of thermal tiles that cover its skin — to be ready for its next liftoff. These days, as the shuttle program winds down and the staff has been winnowed by layoffs, technicians work on the Discovery only when there are no more pressing tasks. And rather than sprucing it up for another trip to space, likely as not they are taking something out of it.

“We in engineering, we want to hold on to things that we could potentially use, or we want to study them, which is a smart thing to do,” Ms. Stilson said. The shuttles are the only spacecraft that have been launched into orbit multiple times — the Discovery is the most-traveled, with 39 missions — and a better understanding of how the materials and equipment have fared could help future aerospace designers.

Ms. Stilson spoke near one of the Discovery’s main landing gears, where the tires used on the last flight had been removed in favor of what NASA calls “roll-around tires” — basically a bunch of old spares. On a higher platform, workers were putting the finishing touches on replacement windows for the spacecraft, the originals having been taken out so engineers could study what effect the microdebris encountered in so many trips in space had on the glass.

While those who are to receive the shuttles say they understand the need for research, they are a little surprised by how much will be missing.

“We’re considered to be the nation’s official repository of our past,” said Valerie Neal, curator for contemporary human spaceflight at the Smithsonian, which will display the Discovery at the National Air and Space Museum’s annex near Dulles Airport. “Our point of view would be to receive an orbiter in as intact a state as possible.”

Ms. Neal said that when she first started discussing the fate of the shuttle with NASA several years ago, “I rather naïvely thought it would be intact.”

Some of the removal work is dictated by safety concerns. There are small explosive charges all around the shuttle, including one designed to blow a latch and deploy the front landing gear should the normal systems fail. Although the firing mechanism has been disabled, “We don’t want to take a chance that if it’s sitting in the Smithsonian it could somehow detonate,” Ms. Stilson said.

The thrusters near the shuttle’s nose and the podlike maneuvering engines in the rear both contain propellants that are highly toxic and corrosive, even in tiny amounts. So these components have been removed and sent to a special facility where workers in hazardous materials suits will “cut and gut” them, removing much of the insides before shipping them back. “We’ll reinstall them, and from the outside they’ll look exactly the same,” Ms. Stilson said.


View the original article here