The SpaceX Dragon commercial cargo spacecraft is grappled to Canadarm2 at the International Space Station in this NASA picture taken April 20, 2014
The supply capsule brought nearly two-and-a-half tons of supplies and scientific payloads to the station, according to NASA. Reuters

More spacewalks await American astronauts Barry “Butch” Wilmore and Terry Virts after they did their third space walk on Sunday for seven hours. The station commander and flight engineer, respectively, temporarily left the International Space Station (ISS) to install communications and navigation aides for new commercial space taxis.

It’s part of the ISS preparing the berthing slips for spaceships that Boeing and Space Exploration Technologies or SpaceX are developing as demand for space tourism grows. The advance work involves almost 800 feet of cable in three spacewalks, reports AP.

The spacewalk of Wilmore and Virts, which began after 7 am/EST, is their third space walk in eight days to install 400 feet of power and date cable.

In the next few days, the space duo will hold more space walks to install over 122 metres of cables and a pair of antennae for use of the new space vehicles that will approach and dock at the ISS, Reuters reports.

Last week, Wilmore and Virts rigged 364 feet of power and data cables for two docking port adopters slated to arrive at the $100-billion ISS in the later part of 2015. The first adapter would be installed at the berthing slip for use by NASA space shuttles that were retired in 2011 and the second at an adjacent hatch on the Harmony connecting node.

With the NASA space shuttle retirement, Russia sends crew to the ISS, but by 2017, NASA will use tap Boeing and SpaceX as alternative ride providers.

The successive spacewalks come at a time that the world is celebrating this March the 50th anniversary of the first spacewalk in March 18, 1965 by Soviet cosmonaut Alexei Leonov.

To contact the writer, email: v.hernandez@ibtimes.com.au