Reid Wiseman is having a blast in space. And thanks to his disarmingly wide-eyed tweets from orbit, that enthusiasm has quickly become contagious back on Earth. In fact, the object of Wiseman's awe so far hasn't really been space itself, but the beauty of the planet he recently left for the first time.

The Baltimore native embarked May 28 on his rookie spaceflight, a six-month tour aboard the International Space Station. He had previously spent a decade as a U.S. Navy pilot, including service in Iraq and Afghanistan that earned military honors for valor in combat. But he also developed an "unabashed enthusiasm" for flying even higher, according to his hometown newspaper, a quality that helped him rise from NASA's Astronaut Candidate Program in May 2011 to the ISS in May 2014.

"When I saw my first space shuttle launch from the side of a road in Cocoa Beach in 2001, my ambition was sealed," he told NASA in 2009, the year he was picked as an astronaut candidate.

And as seen on his Twitter feed, Wiseman's distinctive zeal also thrives in zero gravity:

Along with his photography skills, Wiseman's excitement and sense of wonder have endeared him to the Internet. He may not be near the Chris Hadfield level of astronaut stardom yet, but he is finding a niche with earnest, exuberant updates from space — including the occasional selfie with a stuffed giraffe, named "Giraffiti," that was a pre-launch gift from his two daughters:

Wiseman, 38, will serve as flight engineer on the ISS, and is expected to get at least two spacewalks during his mission. If he can maintain this kind of vigor for six months — and don't bet against it — he could help inspire lots people on Earth to get similarly excited about space. And that's especially important in the U.S., where the recent end of NASA's space shuttle era has left a generation of Americans feeling detached from the heavens. Whether it's for the ISS, new NASA missions or the fledgling private space industry, America still really needs astronauts like Reid Wiseman.

To see why, check out some of Wiseman's best tweets from his first week aboard the ISS:

And in light of a new National Research Council report that focuses on the pitfalls of NASA's long-term plans for manned spaceflight, the perspective of an astronaut like Wiseman illustrates the intangible value of letting lively, likable humans explore the final frontier. "Why do we bother sending humans to space when robots are so much more efficient?" asked space journalist Mika McKinnon in a recent io9 post about Wiseman. "Because this type of enthusiasm is inspiring and contagious."

But if you're still not on the Wiseman bandwagon, watch the video below. It shows a pre-launch press conference on May 27, where Wiseman displayed a heartwarming reaction to a reporter's question about how political tensions might affect American and Russian crewmates aboard the ISS:

Russell McLendon is science editor at MNN. Follow him on Twitter and Google+.

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Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

See Earth through the eyes of a first-time astronaut
Reid Wiseman has only been in space a week, but his infectious enthusiasm has already made him a rising star on Twitter.