Genesis set for stellar return from space
By Michael Coren
An artist's image of the midair retrieval of the Genesis sample return capsule.
Days of spaceflight
Days of Solar Wind Collection
Sample material collected
approx. 0.4 milligrams
August 8, 2001 Halo Orbit Insertion
November 16, 2001Start of Sample Collection
December 3, 2001Complete Sample Collection
April 2, 2004Earth "Flyby" on way to L2
May 2, 2004 Capsule Return to Earth
September 8, 2004 Samples to JSC
September 11, 2004
(CNN) -- A daring trip to study the solar wind will end on Wednesday with the midair retrieval of extraterrestrial samples above the Utah desert. However, the scientific journey is only beginning.
"We are bringing a piece of the sun down to Earth," said Charles Elachi, the director of the Jet Propulsion Laboratory in Pasadena, California. "That's going to give us some fundamental understanding of our origins."
Scientists say the data will not only reveal the composition of the sun, but illuminate how our planet could have formed from clouds of stellar dust.
"Four and a half billion years ago, all of the matter of the solar system, including us, was part of a giant molecular cloud," said Don Burnett, principal investigator for the Genesis mission. "Genesis is providing the chemical composition of that solar nebula. ...The material is still stored for us in the surface of the sun."
Two helicopters will be poised above a Utah Air Force base to snag the Genesis spacecraft's return capsule. The sturdy container contains atomic isotopes collected as particles streaming off the sun, known as the solar wind.
The unorthodox midair retrieval will snag the first extraterrestrial samples since the Apollo missions in the 1970s.
Genesis collected the particles over the last two years on special tiles made from silicon, diamond, gold, sapphire and other materials. The solar particles, embedded in the collector tiles, were ejected at about 280 miles per second (450 km/s) from the sun's scorching corona or outer atmosphere.
Genesis will fill in an astronomical blank spot about its makeup.
"What we've been missing is a starting point," says Burnett. "These samples allow precise measurements of the abundance of elements and isotopes in the sun."
Our star accounts for 99 percent of the mass in the solar system. It is composed mostly of isotopes of hydrogen and helium and includes 60 other elements including neon, argon carbon, nitrogen, oxygen and iron.
In all, Genesis has collected the equivalent of a few grains of the material. Scientists say that is enough to keep researchers busy for decades.
"We'll have a reservoir of solar matter," said Burnett. "We can meet the requirements for (studying ) the solar composition through the 21st century."
Launched in 2001 from Cape Canaveral, the Genesis spacecraft traveled beyond the protective cloak of Earth's magnetosphere for two years before heading home. Because of Earth's electromagnetic field, much of the sun's deadly radiation and material never reaches the planet's surface.
In April, the craft ejected a 500-pound return capsule for return to Earth.
It has been approaching the planet at a leisurely 600 mph. By the time it reaches Earth's atmosphere, the craft will be racing toward the planet at more than 25,000 mph. It will use a series of parachutes to slow its descent.
On Wednesday, it is expected to enter the atmosphere at 11:55 am ET above Oregon and, just two minutes later, glide down over the Utah desert. The main parachute, a wing-like parafoil, will deploy during its decent and a helicopter will snatch the Genesis capsule when it is still about a mile off the ground.
This daring retrieval method will protect the samples and sensitive instruments during reentry. A crash landing, even at the capsule's relatively slow speed of 9 mph, could ruin some of the data collected during the mission.
The prospects for success look good according to NASA's retrieval partner in the mission, the aerospace firm Vertigo.
"If they can find it, the success rate is very high," said Vertigo official Roy Haggard.
A modified helicopter -- with a winch, hydraulic capture pole and hundreds of feet of line -- will follow the capsule by radar until it moves in and snags the parafoil. Because the Genesis capsule must repressurize in the upper atmosphere, scientists want to minimize the sample's exposure to air and possible contamination.
Once it is secured at a NASA facility, scientists can breathe easier, said Burnett.
"After that we can take our time, and we will see what we have," he said.