Oldest EVA Spacewalker: Russian cosmonaut Pavel Vinogradov (59)

Russian cosmonaut Pavel Vinogradov floats outside the International Space Station near the end of a 6.5-hour spacewalk on April 19, 2013. 

Vinogradov, 59, became the world's oldest spacewalker during a spacewalk that was only marred by the last-minute loss of an experiment. 

CREDIT: NASA TV

Pavel Vinogradov, a veteran cosmonaut, took his seventh cosmic excursion in 16 years during Friday's spacewalk.

He donned a bulky Russian Orlan-MK spacesuit and left the confines of the International Space Station just after 10 a.m. EDT (1400 GMT) to upgrade the orbiting lab with new experiments.

Vinogradov paired up with 41-year-old fellow cosmonaut Roman Romanenko, a first-time spacewalker but second-generation cosmonaut.

Romanenko's father, former cosmonaut Yuri Romanenko, logged more than 10 spacewalking hours in his career, including long stay durations in the Soyuz MIR Spacestation, a predecessor of the ISS.

The spacewalkers were at times lighthearted during the more-than-six-hour job.

"Nobody took a photo of me," Romanenko jokingly protested after heaing they used a camera to take pictures outside the lab. "How can it be like that? Please take a photo of me, Pavel."

In the last task of the spacewalk, Vinogradov was attempting to retrieve a panel from the Russian materials exposure experiment called Vinoslivost, but the panel flew out of his grasp before he had a chance to tether it. The cosmonauts were unable to recover the piece.

Flight controllers do not believe the 6.5-pound (3-kg) panel, which measured 18 inches by 12 inches (45 cm by 30 cm), hit any part of the space station.

NASA announcers noted that there is another Vinoslivost panel still attached to the space station that will be retrieved in a future spacewalk, so all is not lost from the experiment.

Vinogradov and Romanenko's primary objective was to install a new Russian experiment called Obstanovka, which will measure charged particles interact with a variety of materials kept outside of the space station.

Obstanovka could offer scientists new insights about how space weather affects the ionosphere, an active region of the Earth's atmosphere, NASA officials explained in a spacewalk description.

The pair also successfully retrieved a Biorisk canister, an experiment that measures the effects of bacteria and fungus on spacecraft materials, and prepared the outpost for the arrival of a robotic cargo ship later this year.

The spacewalkers are two members of the six-man Expedition 35 crew currently living aboard the International Space Station.

The others are Canadian astronaut Chris Hadfield, Russian cosmonaut Alexander Misurkin, and NASA astronauts Thomas Marshburn and Chris Cassidy.

This was the 167th spacewalk dedicated to the construction and upkeep of the International Space Station, which was built by five different space agencies representing 15 countries.