Spacewalking cosmonauts set free the world's first satellite made almost entirely with a 3D printer on Thursday.
In total, Russians Fyodor Yurchikhin and Sergey Ryazanskiy ended up releasing five nanosatellites by hand. One by one, the tiny craft — no more than 1 to 2 feet in size — tumbled safely away from the International Space Station.
The exterior casing of the first one tossed overboard was made with a 3D printer. So were the battery packs inside. Researchers want to see how 3D-made parts weather the space environment.
The 3D satellite contains regular electronics. It also holds greetings to planet Earth in a variety of languages, courtesy of students at Siberia's Tomsk Polytechnic University, where the satellite was made.
The other satellites deployed Thursday have traditional spacecraft parts.
Each weighs just 10 to 24 pounds (4.5 - 10 kg). They're expected to orbit for five to six months.
One commemorates the 60th anniversary of the world's first satellite, Sputnik 1, launched Oct. 4, 1957, by the Soviet Union. Another pays tribute to Russia's father of rocketry, Konstantin Tsiolkovsky. He was born 160 years ago next month.
The remaining two small satellites involve navigation and other experiments.
Yurchikhin and Ryazanskiy completed the satellite releases within an hour of venturing outside. Barely a minute passed between a few of the launches. The rest of their work took longer than expected, however, and Russia's Mission Control outside Moscow sent the planned six-hour spacewalk into overtime. It ended up lasting 7 1/2 hours, and the cosmonauts said their hands were tired. All but one task got done.
"We will have actually some grounds to get drunk today, I think," one of the cosmonauts joked in Russian. A flight controller replied that he'd do it for them.
The cosmonauts collected science experiments from outside their 250-mile-high home, and wiped thruster residue from various surfaces for analysis. Three Americans and one Italian also live on the space station.