What If NASA Came Up With A Band-Aid To Repair Hull
Even before the
Columbia Accident Investigation Board (CAIB) released its
highly critical final report this week, NASA Administrator Sean
O'Keefe promised to buy into its recommendations hook, line and
sinker. He promised to leave no stone unturned in making the space
shuttle program more safe. Stung by suggestions that, contrary to
what Shuttle Program Manager Ron Dittemore said February 2nd, the
day after Columbia disintegrated upon re-entry,
Columbia could have been saved, O'Keefe now has to figure
out a way to repair shuttle debris damage in orbit.
The answer could be to slap a band-aid on hull breaches.
Literally. A band-aid.
"That's something that NASA is really working [on] very
intensely," said CAIB member Sheila Widnall, an expert on flight
aerodynamics who teaches at the Massachusetts Institute of
Technology in an interview with Discovery News. "There are
very few materials that can withstand those kinds of temperatures.
It's a tremendous problem."
Those temperatures can reach 3000F. This will have to be one
tough band-aid. That goes not only for the patch's surface
material, but for the glue that holds it to the shuttle's
Enter The Gecko. Yeah, The Lizard
So what would a shuttle patch have in common with the little
green gecko? Have you ever seen one crawl up a wall? The little
critters can do that because their feet are covered, not with glue,
but with ultra-thin fibers called spatulea. Those fibers create a
weak molecular field called the van der Waals force. But it's the
geometry of the spatulea that gives the gecko his grip. It's not
unlike velcro, really, but much stronger. Here's the trick: If NASA
can formulate these precicely-placed fibers out of a heat-resistant
material as hefty as reinforced carbon (carbon-carbon), O'Keefe
might just be able to keep his promise to implement the
repair-in-orbit mandate from the CAIB.
"Using very small carbon fibers you could create the capability
to take a piece of carbon and push it on and have it stay on
there," CAIB member Scott Hubbard told Discovery.
Already, NASA has pledged to greatly reduce or do away
altogether with the foam insulation blamed for punching a hole in
the leading edge of Columbia's left wing and ultimately
causing a massive, fatal structural failure. Still, repairing the
shuttle's thin skin in orbit could become necessary if it were hit
by a meteorite or some other space debris, hail or a host of other
possibly damaging substances. The space agency wants to return
space shuttles to flight by March. But NASA has also promised it
won't be bound by schedules so tight they create safety problems.
The idea of creating a heat-resistant skin patch made out of gecko
glue seems almost easy in comparison.