Prosecutors in the attempted kidnapping case against jealous astronaut Lisa Nowak released a set of e-mail messages between her colleague William Oefelein and his new love interest. The first of these e-mails was sent to Oefelein while he was in orbit. How do astronauts get e-mail in space?
NASA delivers it via satellite. The space agency exchanges data files with astronauts throughout the day using the Ku band of microwave frequencies. This works only when there is an unobstructed path between the antenna on the space shuttle and a relay satellite in contact with Mission Control. The astronauts use the Ku band antenna to pick up and drop off e-mail two or three times a day, for about half an hour. They're each allowed to transfer up to 30 megabytes' worth of data in a session.
Astronauts get special NASA.gov addresses just for space missions—one for work and the other for personal matters. To check their e-mail, they do what a lot of mobile workers do—open Microsoft Outlook on their laptops. The space-bound messages are treated like any other message in NASA's system, except they're scrubbed one extra time for viruses. Oefelein kept a space blog by e-mailing posts to mission control. Two astronauts have also voted from space. (Typing can be a bit tricky; in zero gravity, a few clicks at the keyboard can send you floating toward the ceiling. That's why astronauts wear foot straps when they're using their computers.)
There isn't much time for e-mail onboard the shuttle. Astronauts keep in touch during "pre-sleep" and "post-sleep"—the hours at the beginning and end of the day allotted for hygiene, communications, and personal time. Check e-mail for more than 15 or 30 minutes, and an astronaut ends up losing time for sleep.
Since time is so precious in space, NASA makes sure its crew members don't get spam. That's why you can't communicate with an astronaut unless you're on his or her VIP list of approved e-mail addresses. Those spending months in space typically place 100 to 300 names on this list.
Astronauts can also surf the Web, at least in a way. NASA builds static Web pages for each crew member, with news from their hometown papers, for instance, or sports scores. (The links don't connect to the Internet, of course.) Then they beam up the pages four times a week.
Bonus Explainer: Can astronauts make phone calls? No. But they can dial friends and family using an Internet protocol phone; signals go over the Ku band. Conversations usually don't last longer than 45 minutes, at which point the satellite moves out of range. Astronauts also stay in touch via weekly video conferences.
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Explainer thanks Scott Curtis of NASA and Greg Olsen of GHO Ventures.