NASA is seeking friends for a new game the US space agency launched on Facebook.
The online game, Space Race Blastoff, tests a player's knowledge of the space program with multiple-choice questions. Players can compete against others or play solo.
It features questions such as "Who was the first American to walk in space?" and "Who launched the first liquid-fuelled rocket?"
Players who answer questions correctly earn virtual badges depicting NASA astronauts, spacecraft and celestial objects.
"Space Race Blastoff opens NASA's history and research to a wide new audience of people accustomed to using social media," David Weaver, a NASA spokesman, said in a statement.
"Space experts and novices will learn new things about how exploration continues to impact our world," Weaver said.
NASA has been quick to adopt Facebook, Twitter and other social networking tools and offers Foursquare badges to visitors to a number of NASA facilities, including the Kennedy Space Center in Florida and mission control in Houston.
The Space Race Blastoff game is available here.