Due to the federal government shutdown, 97 percent of NASA employees will have to celebrate the space agency's 55th birthday from home on unpaid leave, CBS News reported.

NASA will not answer the phone, messages on their Facebook or Twitter pages and has shut down its website. The Curiosity Mars rover will sit inactive, as only 549 of the space agency's 18,250 employees reported to work Tuesday morning because of the halt caused by the federal government's budget remaining unapproved.

In a memo released ahead of the shutdown, which is no longer viewable because the website is completely inaccessible, NASA CFO Elizabeth Robinson said current missions will be the only operation undertaken.

"First NASA currently is operating the ISS with a crew of 6 astronauts/cosmonauts, which has been in continuous operation since 1998," she wrote. "To protect the life of the crew as well as the assets themselves, we would continue to support planned operations of the ISS during any funding hiatus.

"Second, if a satellite mission is in the operations phase, we will maintain operations that are essential to ensure the safety of that satellite and the data received from it," she wrote. "However if a satellite mission has not yet been launched, work will generally cease on that project."

NASA was the first space agency to put a man on the moon. That first moon mission included, the U.S. space agency has landed 12 astronauts on the lunar surface. Four landers and four rovers have explored Mars and the Voyager satellite recently entered interstellar space, leaving our solar system.

NASA helped build the International Space Station (ISS) where astronauts from all over the world have been continuously working and living in since 2000. In another two decades, NASA has plans to put humans on Mars and, by then, also to allow tourists to take commercial flights to Earth's low-orbit atmosphere.

In one last update before shutting down the website, NASA posted a graphic with two columns. One column read "Things Done" and the other read "Things to Come."