January 18, 2003 - The bright sun dissects the airglow above Earth's horizon in this digital still camera's view photographed from the Space Shuttle Columbia during the STS-107 mission. (NASA/JSC). Original sun image from NASA.
POSTED 6 FEB 2003
The crew of the Columbia (L. to R.): David Brown, Rick Husband, Laurel Clark, Kalpan Chawla, Michael Anderson, William McCool, Ilan Ramon. Photo: NASA.
These tiny flame balls, which form only in low gravity conditions, are hard to see. They were filmed in the dark by a low-light video camera onboard the Columbia. Photo: NASA.
A candle flame on Earth (top) and onboard the space shuttle (bottom). Photo: NASA.
This miniature rose, dubbed "Overnight Scentsation," was cultivated for experiments in space. Photo: NASA.
Dust plumes, like this one over the Red Sea, were studied on the Columbia to help scientists understand global weather patterns. Photo: NASA.
The
seven astronauts aboard NASA's Columbia left behind more than memories
when the shuttle went sadly down: Even though much valuable data was lost
amid the ruins, 16 days of vigorous research had already imparted some
dazzling news to scientists on the ground.
STS-107 was the first shuttle mission in three years devoted entirely to onboard science. The Columbia's 3.4-ton Research Double Module held 88 different experiments from institutions around the world. The shuttle's crew was split into two teams that performed around-the-clock experiments in the microgravity conditions of space.
A substantial portion of the stuff on board - including the astronauts themselves - was poked or prodded or otherwise examined for the sake of science. By all accounts, the crew was tireless, working through lunch breaks and reporting back to colleagues with much exhilaration.
Introducing: Howard and the flame balls!
Mohamed Abid is grateful that some of the work done by the STS-107 crew
on his project was preserved. Abid, a professor of aerospace engineering
at University of Southern California, studies the efficiency of combustion
engines. Space-based experiments, he says, provide an opportunity to see
combustion in its most elegant state: the flame ball.
These golf ball-sized flames are the weakest known fires and are famed among physicists for their leanness. One flame ball typically produces 1 watt of thermal power, compared to the powerhouse 50-watt birthday candle. They are also remarkably efficient, bouncing around zero-gravity chambers to gobble up every last drop of fuel available.
"Microgravity is crucial for flame balls to exist, because if you don't have it, the heat goes up and the cold goes down," Abid says. That's why flames on Earth typically form teardrops rather than spheres.
The kind of burning possible in space mixes in more air and less fuel. In theory, learning from space-based combustion could help scientists develop more efficient engines that require less fuel and are less polluting. Onboard Columbia, the astronauts sparked flame balls inside a small chamber filled with combustible gases - just enough, Abid says, to feed a few flame balls.
The astronauts were so taken with the burning orbs that Israeli astronaut Ilan Ramon began to give them names. First there was Howard the suicide ball, who headed unexpectedly for a fuel-poor part of the chamber just before winking out. There was the biggest flame ball ever seen, Zeldovich, named after the Russian physicist who predicted flame balls in 1944. And there was Kelly, who burned for 81 minutes, the longest-lasting flame ball ever recorded.
Fun, indeed. But the experiments gave way to more than anecdotes for Abid. "We lost some of our data, but the astronauts left behind enough answers to our questions to give us more questions...I'm so grateful for their work."
Something smells in spaceflight
Essential oils. They aren't the kind of thing you'd
imagine would take high priority at NASA. But in fact, STS-107 supported
a number of commercial ventures through NASA's Space Product Development
Office. And for companies like International Flavors & Fragrances in New
York - one of the world's largest perfume companies - space science means
big business.
The
Columbia was equipped with a special chamber designed to allow astronauts
to watch and record how plants change in a weightless environment. Flowers,
are sensitive to a number of environmental conditions - including gravity.
Columbia astronauts collected scent molecules from a miniature American
hybrid rose and an Asian rice flower. Had they returned safely, the fragrances
would have been analyzed, and possibly recreated synthetically, back on
Earth.
Dust in the wind
But
the STS-107 mission wasn't only about the behaviors of objects in space.
It was also about what can be seen from space. The vantage point allowed
the crew to gather crucial new information on the clouds of dust and other
aerosol particles blown from deserts by storms for the Mediterranean Israeli
Dust Experiment.
Particles from dust plumes affect the way clouds produce rain and scatter the rays of light that affect global warming. Understanding how these particles affect the atmosphere may someday help scientists offset the climate warming induced by increases in atmospheric greenhouse gases. That's one goal of the project.
The kind of remote sensing used to watch and measure these aerosols as they travel across deserts is only possible from space.
A twin-camera instrument scanned desert plumes during the day and snapped images of the tops of thunderstorms at night to study the particles. The Columbia crew transmitted stunning, clear images of cloud-to-space lightning and the first pictures from space ever to show the doughnut-shaped electrical glow that forms above thunderstorms.
And that's just the tip of the iceberg...
88 experiments, remember? Here are some highlights:
The Columbia's astronauts were being monitored to measure the effects of spaceflight on the human respiratory system.
Columbia's final mission was as international as it was interdisciplinary, Abid points out. "Flame balls, for example... were first predicted by a Russian, discovered by an American, researched in a California lab by a Tunisian, and investigated in space by an Israeli...I think that says something."
And of the astronauts who risked it all for the work they loved, he speaks for us all: "They did an amazing job."
-- Sarah Goforth
A quarter moon graces this view of Earth's
horizon, recorded with a digital still camera aboard the Space Shuttle
Columbia during the STS-107 mission. Photo:
NASA.
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