Fourth of July in Space: How Astronauts Celebrate

For Americans, the Fourth of July is an iconic summer holiday, even in space.

While people across the United States celebrate Independence Day with cookouts, swimming and fireworks, NASA astronauts Karen Nyberg and Chris Cassidy the two Americans on the International Space Station — will join in on the fun in a different way.

"It's one of the selected holidays for the whole crew, so they are off duty," NASA spokesman Josh Byerly wrote in an email. "Nothing else special planned."

They may have the day off from work, but Nyberg and Cassidy can certainly spend some quality time with their families if they choose for the July Fourth holiday. The astronauts have access to an Internet Protocol phone to call friends and family on Earth, and they can set up video conferences and log on to the Internet from orbit as well. [Holidays in Space: A Photo Album]

Even if the astronauts onboard the space station won't celebrate the holiday in the usual way, they still might have a chance to see Fourth of July fireworks all the same. In the past, some astronauts have reported seeing fireworks shot from the ground from their posts in space, Byerly told SPACE.com.

Spaceflyers have also seen flashes of lightning in clouds from space, and plenty of manmade structures are visible from low-Earth orbit. Astronauts have captured amazing photos of Earth from space, featuring dazzling views of city lights, eye-popping landscapes and other details.

While astronauts Earth-watch from space, stargazers can be treated to a naked eye view of the space station if they know when and where to look. The International Space Station is one of the brightest objects in the night sky, and looks like a quick moving, luminous star as it flies by about 220 miles (354 kilometers) overhead.

By entering your city, state or country into any of the following satellite-tracking websites, skywatchers around the globe can see when the space station is due to pass overhead: Chris Peat's Heavens Above, NASA's SkyWatch and N2YO.com, which tracks more than 8,000 satellites in real time..

A handful of space apps for smartphones can also tell an observer where and when the space station is expected to flyby on any given day.

Nyberg and Cassidy are joined by their four fellow space station crewmembers: Russian cosmonauts Fyodor Yurchikhin, Pavel Vinogradov, Alexander Misurkin and European Space Agency astronaut Luca Parmitano.

The $100 billion space station is the product of an international collaboration by 15 different countries represented by five space agencies. The space laboratory has been staffed continuously by rotating crews of three or six astronauts since 2000.

Follow Miriam Kramer on Twitter and Google+. Follow us on Twitter, Facebook and Google+. Original article on SPACE.com.