A team of university
students is counting down toward the ultimate science ride, a weightless flight
aboard a modified NASA jet to see just how certain fires burn in zero gravity.
The experiment, led by
engineering undergraduate Sam Avery of the University of California, San Diego,
is aimed at testing how biofuels burn in weightless conditions. And with a
target flight date of Thursday (July 18), Avery and his crew are getting
pumped.
"The team is
really excited about this experiment," Avery said just two weeks ahead of
takeoff. "We've been working hard to get the equipment ready and tested
for the parabolic flights with NASA in a couple of weeks."
Avery and his team are
flying with NASA under the space agency's Microgravity University Program, which
offers university students the chance to perform experiments under weightless
and reduced-gravity conditions using a modified aircraft. The "Vomit
Comet" flights, as they've been nicknamed, fly about 30 parabolas, moving
up and down like a roller coaster, to produce short periods of weightlessness
that are followed by brief stints of "hypergravity" that can reach
2Gs, twice the normal pull of Earth's gravity.
The flights are based
at Ellington Field near NASA's Johnson Space Center, which oversees the
Microgravity University project. The space center is also home to NASA's
astronaut training and Mission Control for the International Space Station.
The UCSD team's
biofuels in space project is being conducted under the supervision of UCSD
professor Forman Williams. SPACE.com managing editor Tariq Malik will serve as
the team's journalist member. After the flight, the results will be written up
by the team and submitted to the university and NASA for evaluation.
When asked how his team
might best prepare for the ordeal, Avery said: "We might take a few runs
on roller coasters or drop towers at theme parks to feel the effect of
free-fall."
Before each weightless
dive, Avery's team must electronically trigger two small hypodermic needles to
inject a droplet of biofuel onto a thin fibrous crosshair that holds the
droplet in place until the environment reaches a weightless condition. Then a
small spark ignites the drop and twin video cameras record the burning process
for later evaluation.
"We have had some
great success rates with our ground tests of the fuel ejection and ignition
systems, and we have programmed each system so that we can repeat its process
multiple times during each parabola," Avery said. "I am 80 percent
confident that it will work on the first parabola and 95 percent confident that
it will work by the end of the flights."
As it turns out, not
all parabolas are created equal.
"There will be
around 28 parabolas, with around 25 microgravity parabolas, two lunar-gravity
parabolas, and one Mars-gravity parabola," Avery said. "There will
also be periods of level flight occasionally between parabolas."Lunar gravity
is about one-sixth that of Earth, and Mars gravity is about one-third that of
our planet.
Avery's team also
recently completed testing of software they have written that automates the
fuel-drop delivery to the crosshairs.
"We recently fixed
our code for our automated syringe ejection system so that every time we press
a button the syringes will move toward the cross fiber and eject another
droplet," he said.
One big hurdle still
looms large for the team.
"JSC would like us
to do more analysis of our rig to validate our load testing. They will review
it at the beginning of the flight week, which is coming up soon," Avery
said. "But with most of the team members working full time [over the
summer break], it's difficult to get everything to work."
Avery himself is
interning for the summer at a San Diego-based company that works on the Orion
capsule's abort system. His team is one of 14 different groups flying on NASA's
microgravity aircraft between today (July 12) and July 20. The groups include
seven student teams flying under the Microgravity University program, as well
as seven teacher groups as part of NASA's Teaching from Space program.
Source: Yahoo news
No comments:
Post a Comment