US astronauts prepare station for commercial space taxis

Two NASA astronauts left the International Space Station on Friday for a 6-1/2-hour spacewalk to install a parking spot for upcoming commercial space taxis, which will end U.S. reliance on Russia for rides to the orbiting outpost.

Station commander Jeff Williams and flight engineer Kate Rubins floated outside the station's airlock at about 8:15 a.m. EDT (1215 GMT) and headed toward the berthing slip once used by NASA's now-retired space shuttles, a NASA TV broadcast showed.

"Great view," said Rubins, who is making her first spacewalk.

Since grounding the shuttle fleet in 2011, the United States has been dependent on Russia to ferry astronauts to and from the space station, at a cost of more than $70 million per person.

During Friday's spacewalk, Williams and Rubins plan to attach an adapter onto the shuttle's docking port that will allow commercial space taxis under development by Space Exploration Technologies and Boeing to park at the station, a $100 billion research laboratory that flies about 250 miles (400 km) above Earth.

California-based SpaceX, owned and operated by technology entrepreneur Elon Musk, plans to begin test flights of its new passenger Dragon capsule to the station in 2017.

Boeing's debut flight of its CST-100 Starliner capsule is expected in 2018.

NASA had hoped to have the first of two new docking ports installed last year, but the equipment was destroyed during a SpaceX cargo ship launch accident in June 2015.

A replacement docking port is under construction and expected to be delivered to the station in early 2018.

(Reporting by Irene Klotz in Cairns, Australia; Editing by Colleen Jenkins and Paul Simao)