A Near-Earth Object Survey spacecraft planned by Ball Aerospace & Technologies Corporation. Placed in a Venus-like orbit, its mission would be to on the prowl for space rocks near Earth. Credit: Ball Aerospace
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One concept that has already been fleshed out is dubbed the NEO Survey mission, a detailed appraisal done by Ball Aerospace & Technologies Corporation in Boulder, Colo.
Results of a study by Ball Aerospace highlighted how best to meet the George E. Brown objectives for detecting NEOs.
As explained in a Ball Aerospace white paper review provided to SPACE.com, in only 1.6 years, a spacecraft could locate all of the roughly 165 feet (50 meter) diameter, and larger, nearby space rocks that are potentially accessible for human spaceflight, and within 7.5 years could catalogue 90 percent of all NEOs greater than 459 feet (140 meters) in diameter.
"We have more work to do, but what we've created is a very high-quality existence proof. We have a point design based on real engineering with real parts," said Robert Arentz, a Ball Aerospace Advanced Systems Manager.
Arentz told SPACE.com that the NEO survey spacecraft draws upon the firm's heritage of working on NASA's space-based observatories – from the Hubble Space Telescope and the Kepler exo-planet hunter to the Spitzer infrared telescope and the Wide-field Infrared Survey Explorer, along with the company's comet-smacking Deep Impact spacecraft.
The internally funded Ball Aerospace concept has not yet been given a green light by NASA, noted Kevin Miller, a Ball Advanced Systems Manager, but the point design does showcase proven capabilities and an affordable approach, he said. The work uses a recipe "to establish confidence that, yes, this really is a very tractable problem," Miller said.
In order to meet the George E. Brown requirements to find 90 percent of all NEOs larger than some 460 feet (140 meters) within 7 years, the NEO Survey mission would cost roughly $638 million. The catalog it would yield is a superset of the targets that NASA human spaceflight planners would find of interest for piloted excursions to selected space rocks.
Given a go, the NEO hunter from start to launch should take around 42 months to develop, Arentz added.
But there are technological challenges in building the NEO survey spacecraft.
Dealing with solar radiation is one. The heat load from a location so near the sun means the spacecraft would need a large thermal shield and cryocooler hardware. Also, the telescope's photon-gathering array requires highly advanced engineering.
The key is to prevent the intense solar radiation at Venus from reaching the telescope. This is done by careful design of the spacecraft's solar array and use of two thermal shields between the main array and the telescope.
The spacecraft design, Arentz said, is based largely on the Kepler planet-hunting spacecraft design to reduce cost and risk.
And, if two NEO-hunting spacecraft were placed in roughly opposite locales in a Venus-like orbit, this would allow a binocular view of space rocks, and scientists could chart them with an even greater degree of tracking accuracy.
Link: Article ("Experts Push for a NASA Asteroid-Hunting Spacecraft")