No, seriously, NASA’s Space Launch System is ready to take flight

It's actually happening. NASA is finally set to launch its massive Space Launch System rocket, and barring catastrophe, the Orion spacecraft is going to fly to the Moon and back.

The space agency's final pre-launch preparations for this Artemis I mission are going so well, in fact, that NASA now plans to roll the rocket to Launch Pad 39B as soon as Tuesday, August 16, at 9 pm ET (01:00 UTC Wednesday). This is two days ahead of the previously announced rollout schedule.

This earlier date for the rocket's rollout follows completion of a flight termination system test over the weekend. This was the final major test of the launch system and spacecraft prior to rollout and marks the completion of all major pre-launch activities. NASA continues to target three dates to attempt the Artemis I launch: August 29, September 2, and September 5.

The flight termination system is an isolated component of the rocket. In the event of a problem during liftoff, ground-based controllers can send a signal to the flight termination system to destroy the rocket before it flies off course and threatens a populated area.

Because this termination system is separate from the rocket, it has an independent power supply that is rated only for about three weeks. This limit is determined by the US Space Force, which operates the Eastern Range, including Kennedy Space Center. The problem for NASA is that one of its proposed launch dates, September 5, fell outside this prescribed limit.

However, NASA said it has received an extension from the Space Launch Delta 45 on the validation of the flight termination system from 20 to 25 days before it would need to be retested. The waiver will be valid throughout the Artemis I launch attempts, NASA said. However, if the mission fails to launch on one of these three attempts due to weather, a technical issue, or other reasons for a scrub, the rocket will need to be rolled back to the Vehicle Assembly Building for work on the flight termination system.

Each of the three upcoming launch opportunities would allow for a "long-class" mission for the Orion spacecraft, which will be uncrewed and fly into lunar orbit for several weeks before returning to Earth and splashing down in the Pacific Ocean. The missions would range in length from 39 to 42 days.

The Artemis I mission represents a significant step forward for NASA and its ambitions for a deep space human exploration program. The rocket's next launch will carry four astronauts around the Moon, and its third launch is scheduled to enable a human landing there, possibly in the mid-2020s.

The SLS rocket program has been oft criticized for its extensive delays and price tag in excess of $20 billion. But with a successful launch in a few weeks the space agency will be able to put at least one of these criticisms to bed by proving the massive rocket works as intended.