NASA chooses 3 finalists for future space missions

NASA has selected three proposals as final candidates for the agency's next space venture to another celestial body in our solar system, namely, Venus, an asteroid, or the Moon.

The final project selected in mid-2011 may provide a better understanding of Earth's formation or perhaps the origin of life on our planet.

The proposed missions would probe the atmosphere and crust of Venus; return a piece of a near-Earth asteroid for analysis; or drop a robotic lander into a basin at the Moon's south pole to return lunar rocks back to Earth for study.

NASA will select one proposal for full development after detailed mission concept studies are completed and reviewed.

The studies begin during 2010, and the selected mission must be ready for launch no later than December 30, 2018. Mission cost, excluding the launch vehicle, is limited to $650 million.

The selected proposals include the Surface and Atmosphere Geochemical Explorer, or SAGE, mission to Venus that would release a probe to descend through the planet's atmosphere.

During descent, instruments would conduct extensive measurements of the atmosphere's composition and obtain meteorological data.

The probe then would land on the surface of Venus, where its abrading tool would expose both a weathered and a pristine surface area to measure its composition and mineralogy.

Through this mission, scientists hope to understand the origin of Venus and why it is so different from Earth.

Secondly, the Origins Spectral Interpretation Resource Identification Security Regolith Explorer spacecraft, called Osiris-Rex, would rendezvous and orbit a primitive asteroid.

After extensive measurements, instruments would collect more than two ounces of material from the asteroid's surface for return to Earth.

The returned samples would help scientists better understand and answer long-held questions about the formation of our solar system and the origin of complex molecules necessary for life.

The third proposal is the launch of the Lunar South Pole-Aitken Basin Sample Return Mission, which would place a lander in a broad basin near the Moon's south pole and return approximately two pounds of lunar materials for study.

This region of the lunar surface is believed to harbor rocks excavated from the Moon's mantle.

The samples would provide new insight into the early history of the Earth-Moon system.

The proposals were submitted to NASA on July 31, 2009, in response to the New Frontiers Program 2009 Announcement of Opportunity.

The final selection will become the third mission in the program.