CAPE CANAVERAL, Fla. -- A 59-year-old Russian cosmonaut became the world's oldest spacewalker Friday, joining a much younger cosmonaut's son for a little maintenance work outside the International Space Station.

Pavel Vinogradov, a cosmonaut for two decades, claimed the honour as he emerged from the hatch with Roman Romanenko. The pair installed new science equipment, and worked at gathering old experiments and replacing a navigation device.

Until Friday, the oldest spacewalker was retired NASA astronaut Story Musgrave, who was 58 when he helped fix the Hubble Space Telescope in 1993.

Romanenko, 41, is a second-generation spaceman who's following in his father's bootsteps. Retired cosmonaut Yuri Romanenko performed spacewalks back in the 1970s and 1980s. This is the son's first experience out in the vacuum of space.

Vinogradov is making his seventh spacewalk; he ventured into a dark, ruptured chamber at Russia's old Mir space station in 1997 following a cargo ship collision. He will turn 60 aboard the space station this summer. He arrived for a six-month stay at the end of March.

The spacewalkers joked as they toiled 260 miles above the planet.

"I'm afraid of the darkness," one of them said in Russian as the space station passed over the night side of Earth.

"Oh, you're such a joker," replied his partner.

"I don't like going to work at nighttime. Who likes it?" the first cosmonaut said.

This is the first of eight spacewalks to be conducted this year, most of them Russian. Two will be led by NASA this summer.

Russian flight controllers outside Moscow oversaw Friday's action. The four other space station residents monitored the activity from inside; Canadian commander Chris Hadfield drew the short straw and had to work on a balky toilet.