Genesis capsule crashes in Utah
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 8, 2004
A small spacecraft carrying priceless samples of the sun crashed into the Utah desert today when its stabilizing parachute failed to deploy, bringing an innovative $264 million mission, NASA's first sample return flight since the Apollo moonshots, to a disappointing end.
The Genesis sample return canister was to have been plucked out of mid air by a helicopter flown by a Hollywood stunt pilot over the Utah Test and Training Range. But a drogue chute needed to stabilize the craft before deployment of its large parafoil never fired and the craft slammed into the ground at about 100 mph.
Video showed the canister half buried in the Utah desert, largely intact. But the mid-air recovery had been planned because the system used to capture particles from the sun was exceptionally fragile and it was believed a ground landing, even under a parachute, would have caused extensive breakage.
"Whether or not we can recover any of the science from this remains to be seen," said Chris Jones, a senior manager at the Jet Propulsion Laboratory in Pasadena, Calif. "Clearly, we're going to do all we can to recover science from the capsule. But the capsule obviously wasn't designed to withstand this kind of impact."
Hitting the atmosphere at 24,700 mph, the 450-pound sample canister's energy of motion was equivalent to that of a 4.5-million-pound freight train moving at 80 mph. In seconds, most of that energy was converted into heat, subjecting the probe's heat shield to temperatures up to 4,700 degrees and slowing the craft with a braking force of 30 times Earth's gravity.
Two minutes after entry began, at an altitude of about 21 miles, the small drogue parachute was to have unfurled to stabilize the craft and four minutes after that, at an altitude of about 22,000 feet, a wing-like parafoil was to deploy, slowing the craft's descent to a gentle 10 to 12 miles per hour.
Down below, two helicopters piloted by Hollywood stunt pilots were waiting, flying a criss-cross pattern along the spacecraft's ground track across the Utah Test and Training Range, an isolated military reservation where munitions and unpiloted aircraft are tested.
Using radio beacons and radar tracking, one of the helicopters, piloted by Cliff Fleming of South Coast Helicopters in Santa Ana, Calif., was to have moved in for a mid-air recovery, snaring the parafoil with a large hook on the end of a pole mounted to one of the chopper's landing skids.
After attaching a nitrogen purge to protect the solar particles from earthly contamination, the sample canister was to have been trucked to the Johnson Space Center in Houston and moved into an ultra-clean laboratory for detailed scientific analysis.
But it was not to be. Instead, engineers will pour over what data they have to figure out what might have gone wrong.
Why did NASA spend more than $264 million to capture a few wisps of the solar wind? Because those traces are expected to serve as a sort of cosmic Rosetta stone, providing critical insights into the birth and evolution of our solar system.
The streaming solar wind originates in the sun's outer atmosphere. It is made up of electrons, protons and trace amounts of various atomic nuclei that are unchanged since the birth of the solar system.
In that sense, the solar wind is nothing less than a sample of the original cloud of gas and dust that coalesced to form the sun and its retinue of planet some 4.6 billion years ago. Capturing a sample of this raw material is the goal of NASA's innovative Genesis mission.
"The composition of the solar wind is a clue to the composition of the outer layers of the surface of the sun, which in turn is the composition of the solar nebula from which all the planets formed," Donald Burnett, principal investigator of the Genesis mission, said before launch in 2001. "That's the connection."
Scientists believe the sun and other stars in this neighborhood of the Milky Way galaxy formed inside a vast molecular cloud that has since thinned out and dissipated. The stars formed when areas of slightly higher density contracted under their own gravity to form flattened, rotating solar nebulae.
As gravitational contraction continued in a given cloud, densities in the inner region eventually reached levels high enough to trigger nuclear fusion and a star was born. Material circling the infant sun clumped together to form planets, moons, asteroids and comets.
So far so good. But the details of this complex process - how the solar system evolved from a fairly homogenous cloud of dusty debris to the myriad objects we see today - are poorly understood. By determining the initial composition of the solar nebula, scientists had hoped to fill in the blanks.
"Most of our models and how we understand the formation and evolution of the solar system, processes that formed our planets, asteroids, comets and ... planetary atmospheres, all of that requires an assumption of an initial starting composition of our solar system," Meenakshi Wadhwa, a cosmochemist with the Field Museum in Chicago, said before launch.
Knowing the actual starting composition would "have a tremendous impacting of these on our understand areas."
"The sun has basically more than 99 percent of the mass of the solar system in it," Wadhwa said. "So if we know the composition very well of the sun, we basically understand the starting composition of the initial solar nebula."
The 1,400-pound Genesis probe was launched Aug. 8, 2001, from the Cape Canaveral Air Force Station atop a Boeing Delta 2 rocket.
To collect pristine samples of the solar wind, the spacecraft was fired on a long, looping trajectory that carried it to a point about a million miles toward the sun where the gravity of Earth and its star essentially cancel each other out.
Three months later, Genesis slipped into a so-called halo orbit around the Lagrange 1, or L1, point where it remained for 27 months, exposing its collectors to the passing solar wind, before beginning the trip home in late April. Earlier today, the sample container separated from the main body of the spacecraft and made a pinpoint re-entry. And then, something went wrong.
The collectors measured about one yard square and were each made up of 55 hexagonal tiles about four inches across. The tiles, in turn, were made up of various materials, ranging from silicon and germanium to artificial diamond. The materials were selected because of their ability to capture specific elements in the solar wind.
A key goal of the Genesis mission was to precisely measure the abundances of three isotopes of oxygen: Oxygen-16, the most common form, with eight protons and eight neutrons; oxygen-17, with nine neutrons; and oxygen-18, which has 10 neutrons.
Scientists already understand the relative abundances of these isotopes in asteroids, Earth, the moon and Mars. But the ratio of the isotopes in the sun, and hence the original solar nebula, is not well understood.