An extremely rare complete American spacesuit from the Gemini space program is expected to sell for up to $150,000 at auction this week.

The main body of the suit was worn by Air Force chief warrant officer Mitchell Kanowski during high-altitude tests of the Gemini emergency launch escape system. Kanowski jumped from a NASA training aircraft at high altitude to test the suit in the event of a takeoff failure during launch.

“What makes it significant is that it’s the only known complete American spacesuit to come to market,” Sotheby’s Vice-president and Senior Specialist for Books and Manuscripts Cassandra Hatton told Fox News. “To see something like this is very, very rare indeed.”

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The Gemini program, which ran from 1961 to 1966, was an important stepping stone for the subsequent Apollo missions.

The suit is a Gemini G2-C, which is the earliest of the white space suits to be developed, according to Sotheby’s. It is also a precursor of the A7L suit used by the Apollo 11 astronauts to walk on the Moon.

The spacesuit, which has a pre-sale estimate of $100,000 to $150,000, will be auctioned on Nov.29.

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“The suits for Mercury and Gemini, those missions were meant to lead towards Apollo 11,” Hatton told Fox News. “So everything that they did, from the hardware on the spacecraft to the spacesuits, were there just to develop towards landing on the Moon.”

A host of space artifacts will be auctioned by Sotheby’s this week. Three tiny Moon rocks brought back from space by the Soviet Luna-16 mission, for example, are expected to sell for up to $1 million when they go up for sale on Nov. 29.

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