Hollywood stunt pilots hired by Nasa to catch a capsule carrying samples of the sun were gearing up for a blockbuster ending to their mission on Wednesday over Utah in the western United States.
When the Genesis spacecraft re-enters Earth’s atmosphere at 3.55pm GMT on Wednesday, the helicopter pilots are to intercept a capsule from the vessel in midair.
Genesis has travelled three years and 32-million kilometres to capture atomic bits of solar wind that Nasa hopes will help scientists understand what the sun is made of and how the solar system began.
The two helicopters will try to catch the returning Genesis capsule before it hits the ground, which scientists fear could disrupt the solar particles.
”We are bringing a piece of the sun down to Earth,” said Charles Elachi, director of Nasa’s Jet Propulsion Laboratory in Pasadena, California, which is overseeing the $264-million mission.
When the capsule is 33km above ground, a drogue parachute will open to slow it down. The main parachute will open six minutes later at an altitude of 6,1km.
Then the two helicopters, each with a team of three people, will scramble to catch the capsule in mid-air.
The lead helicopter will deploy a 6m pole with a giant, high-tech hook to catch the capsule by its parachute as it falls.
If the first chopper misses, the second will trail 300m behind and make another attempt. The helicopters will have five chances to intercept the capsule, according to flight operations director Roy Haggard, who heads the US firm Vertigo.
”These guys fly in some of Hollywood’s biggest movies. But this time the Genesis capsule will be the star,” Genesis project manager Don Sweetnam said.
The Genesis spacecraft was launched in August 2001 and sent to a precise point between the Earth and the sun to collect bits of solar dust that could offer clues to how the planets were formed.
The probe was positioned at a spot called Lagrange Point 1, where the gravitational pulls of the sun and Earth balance each other perfectly, and where Genesis had an uninterrupted view of the sun away from Earth’s magnetic field, which disrupts the solar winds.
The 494kg spacecraft used hexagonal wafers of silicon, gold, sapphire and diamond to capture 10 to 20 micrograms of the invisible bits of solar wind. The samples will be the first returned to Earth from outside the moon’s orbit, and they will be the first samples of any kind returned to Earth since the final Apollo mission to the moon in 1972.
The wafers will be sent to the Johnson Space Centre in Houston, Texas, for study. — Sapa-AFP