A team from the U.S. state of Washington has won $900,000 from NASA for building a miniature space elevator.
The competition asked entrants to build a prototype of a machine that could one day shuttle people from the Earth's surface into outer space along a cable tethered to an orbiting satellite.
The idea has existed in science fiction for decades but so far has been impossible to achieve.
A team from a new company, LaserMotive, sent a climbing robot nearly a kilometer into the air along a cable suspended from a helicopter. The team aimed a land-based laser beam at photovoltaic cells on the bottom of the machine to power it to the top.
The fastest attempt, on Thursday, took three minutes and 48 seconds, fast enough to qualify for the prize.
It was the fourth year of the NASA-sponsored competition, and the first year with a winner.
No one has yet won the top prize, worth $1.1 million, which requires an entrant to reach the top in less than three minutes
LaserMotive says it is still a long way away from being able to build a full-size space elevator.
But the team says its "power-beaming" technology has many earth-based commercial applications, such as powering drone aircraft.