Much of the science from NASA鈥檚 Genesis space capsule, which crashed in Utah on 8 September, will probably be salvaged, mission scientists say.
Initial inspections of the ruptured capsule at an airbase near the crash site suggest many, if not all, of the capsule鈥檚 hexagonal particle collectors are broken. But contamination from dirt and moisture may not be as widespread or damaging as originally thought, Genesis team members said Friday.
The capsule spent 27 months in space, collecting charged particles blown on the solar wind from the Sun鈥檚 outermost layer. That layer is thought to be nearly unchanged from the cloud of gas and dust from which the solar system formed about 4.5 billion years ago.
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Genesis was designed to improve estimates of the cloud鈥檚 composition by at least threefold in order to test theories of how the solar system evolved. Its most important target was oxygen, which exists on different planets in different ratios of its three most common isotopes.
鈥淚f we understand what we start with and what we end up with, we can try to understand what kind of thermal environments the planets went through,鈥� Benton Clark, a Genesis team member at Lockheed Martin Space Systems, told 快猫短视频.
Oxygen trap
The solar wind is 99% ions of hydrogen and helium. So mission planners designed an instrument to trap oxygen at concentrations at least 20 times greater than normally found in the solar wind.
On Friday, mission scientists said they could see two of the four wedges housing these oxygen ions when they peeked inside the cracked science canister with a flashlight and a mirror on a stick.
鈥淲e鈥檙e really quite confident we can achieve a high degree of success from a science point of view,鈥� said team member Roger Wiens of Los Alamos National Laboratory in New Mexico.
Genesis scientists described a mixed outlook on the mission鈥檚 other top targets, nitrogen and carbon. Gold foil used to collect isotopes of nitrogen, which could lend insight into the evolution of planetary atmospheres, was found intact.
But Don Burnett, the mission鈥檚 principal investigator at the California Institute of Technology in Pasadena, California, said an experiment using some of the mission鈥檚 silicon wafers to study carbon isotopes was 鈥渧ery challenged鈥�. This is because of carbon contamination 鈥� 鈥渢he dirt is full of it and the atmosphere is full of it,鈥� he said.
Sapphire and diamond
Genesis used five arrays of coaster-sized hexagonal wafers to collect solar wind ions. These were made of ultra-pure materials 鈥� including silicon, germanium, sapphire, and diamond 鈥� to make studying particular elements easier in labs back on Earth.
The ions probably embedded themselves a few hundred atomic lengths (50 nanometres) into these wafers. 鈥淭hat is very close to the surface,鈥� says Wiens. Cleaning techniques would affect the surface by a few nanometres, he says, 鈥渟o we have to be extremely careful鈥�.
Clark said ultra-pure water, brushes, or air currents might be used to get rid of the dirt, which was 鈥渁 little sticky and hard to get off鈥� because the capsule had landed in Utah鈥檚 salt flats.
Burnett said the team might also consult with experts in the semiconductor industry. Gabor Somorjai, a chemist at the University of California, Berkeley, says a commonplace technique used to etch microelectronic circuits on computer chips could easily remove the debris with an accuracy of 1 nanometre. Called sputtering, it involves firing high-energy ions of an inert gas, such as argon or xenon, to remove a material鈥檚 surface.
Somorjai also said contamination from oxygen in the air was probably not a problem, as some of the wafer materials react with oxygen only at high temperatures, and the few minutes the capsule spent blazing into the atmosphere was probably not long enough to affect them.
NASA also announced Friday that Michael Ryschkewitsch, director of the Applied Engineering and Technology Directorate at the agency鈥檚 Goddard Space Flight Center in Maryland, would lead the investigation into the crash.