BELLEVUE, Wash. — The job description and title, “Chief Asteroid Miner,” are not what you are likely to come across on a job-search Web site. Besides, the position is taken. Chris Lewicki, the president of Planetary Resources, a company based in this city just east of Seattle, has it on his business cards.

“It’s certainly an audacious thing that we’re after,” said Mr. Lewicki, 38.

Lots of small start-up companies have stars in their eyes, captivated by entrepreneurial dreams — some half-baked, some brilliant, often a bit of both — of global success and riches. Here, at least the part about the stars is literal.

In an otherwise unremarkable low-rise office park, with the Bread of Life Christian Church and a gym as neighbors, Mr. Lewicki and about 30 employees are aiming beyond Earth for the next great gold rush. (They are actually after the platinum group of metals, which dwarf gold in value and rarity.)