Letters reveal what it's really like to travel to space or the Arctic

“From orbit: Launch was awesome!! I am feeling great, working hard, & enjoying the magnificent views, the adventure of a lifetime has begun!”

NASA astronaut Mike Massimino typed those words on May 12, 2009, the first tweet ever sent from space. He’d even asked his pal and fellow astronaut Neil Armstrong, who knew something about making grand statements from the lunar surface, for pre-tweet advice.

“I didn’t really think much about it,” Armstrong told him about crafting his legendary “one small step” speech, as Jeff Wilser recounts in the new book “ The Explorers Club Presents: Letters from the Edge: Stories of Curiosity, Bravery, and Discovery ” (Crown, out now). So Massimino kept his focus on the mission and then posted whatever came naturally.

That off-the-cuff tone became the point