NASA Spaceflight believes NROL-37 is carrying an Orion spy satellite that the agency uses to intercept signals in space as part of its intelligence-gathering efforts. Whatever the mission's details are, you'll be able to watch the rocket take off. ULA will stream the launch online starting at 1:31 PM Eastern time today from the launchpad at Cape Canaveral in Florida. You may want to grab some snacks, a book or a game to play while waiting, though. Universe Today warns that ULA is keeping the rocket's exact launch time a secret. It could be shortly after the livestream begins -- the company did say that blastoff is planned for 1:51 PM -- but it could be hours later, as well.