See how NASA's soon-to-launch SLS rocket compares to Starship, Soyuz - Business Insider

NASA built a new mega-rocket for the next lunar astronaut era, and it's about to launch for the first time as soon as Tuesday.

It's designed to fly astronauts to the moon for the first time since 1972, when astronauts conducted the last moonwalk of the Apollo era.

Now NASA is kicking off a new program, called Artemis, to build a space station orbiting the moon and set up a permanent human presence on the surface of the lunar south pole.

This first mission, called Artemis I, is a test flight that will carry no astronauts.

If Artemis I goes well, the next SLS mission will send an Orion spaceship around the moon with astronauts on board.

It's unclear when they will launch to orbit for the first time — a critical test flight before the rocket can fly humans or land on the moon.