NASA selected three finalists on Tuesday to be the agency’s next cheap, robotic exploration mission. Depending on which wins, a probe will head for Venus, the moon, or a near-Earth object no later than 2018.

The latter two missions would include the return of samples, while the Venusian lander would test the planet’s composition much like the Phoenix Lander did on Mars. The NASA anointing means that the teams proposing the excursions will have some money to make more detailed plans.

The winning mission will be the next in a series of explorations under the New Frontiers program. New Frontiers missions have to run under $650 million and be ready to launch relatively quickly. In this case, the final pick will be made in 2011 and will launch just seven years later.

While NASA personnel will be digging into the proposals to come up with the official decision, we’d like to know which proposal you like. Read up on the contenders, and vote in the poll afterwards.

Name: The Surface and Atmosphere Geochemical Explorer (SAGE)

Destination: Venus

Principal Investigator: Larry Esposito of the University of Colorado in Boulder

Plan: The SAGE mission would release a probe that would descend through Venus’ thick atmosphere to its surface. There, it would dig into the crust and measure its composition, not unlike what the Phoenix Lander did on Mars.

Why: “Venus is like a twin sister of the Earth, and it’s gone terribly bad,” Esposito told Colorado Daily. Scientists want to know what happened.

Name: Origins Spectral Interpretation Resource Identification Security Regolith Explorer (Osiris-Rex)

Destination: A “primitive asteroid”

Principal Investigator: Michael Drake, of the University of Arizona in Tucson

Plan: Osiris-Rex would fly to a primitive asteroid, orbit it, and then land on it. After collecting 2 ounces of material, it would fly the samples back to Earth. It’s a bit like Russia’s planned Phobos-Grunt mission, which would return samples from a Martian moon. (Osiris is pictured above.)

Why: “A primary motivation for an asteroid sample return mission is the desire to both acquire samples with known geologic context and to return materials that are either unlikely to survive passage to Earth (e.g., friable, volatile-rich material) or would be compromised by terrestrial contamination upon their fall (e.g., extraterrestrial organics).” — according to a description of the mission plan [pdf]

Name: MoonRise

Destination: Aitken Basin, at the Moon’s south pole

Principal Investigator: Bradley Jolliff, of Washington University in St. Louis

Plan: The mission would place a lander in a south polar lunar basin, where it would excavate about two pounds of lunar material. The samples would be returned to Earth.

Why: The area where MoonRise would dig is believed to be composed of rocks from the moon’s mantle conveniently exposed by a massive meteorite strike. Understanding the interior of the moon could help explain a lot about the formation of the solar system.

Image: Osiris-Rex.

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