NASA has spent years and billions of dollars developing a giant rocket known as the Space Launch System, which is supposed to take astronauts to the moon and perhaps one day further into the solar system. The rocket’s first launch – an unscrewed test flight that leads to the moon and beyond – won’t take off from the ground until November.

This Saturday, however, NASA will be putting on a fiery show as it is conducting a crucial test: all four booster-stage engines will be ignited for up to eight minutes to simulate what would happen during an actual launch into orbit. However, the booster is securely held on a test stand in NASA’s Stennis Space Center in Mississippi.

The test fire is scheduled for Saturday at 5 p.m. Eastern Time. NASA television will report on the test from 4:20 p.m. A press conference should follow about two hours after the test.

The Space Launch System is the equivalent of the 21st century Saturn V that took NASA astronauts to the moon in the 1960s and 1970s. Although there are many other rockets out there today, they’re too small to launch spaceships that can carry people to the moon. (One possible exception is SpaceX’s Falcon Heavy, but a human moon mission would require two separate launches that carry parts that then dock together in space or fly separately to the moon.)

The Falcon Heavy can lift up to 64 tons into low earth orbit. The original version of the SLS is a bit more powerful and can lift 70 tons. Future versions of the rocket can throw up to 130 tons, more than the rockets that the Apollo astronauts transported to the moon.

Although the space launch system will be expensive – up to $ 2 billion per launch for a single-use missile – Congress has so far provided unwavering financial support for it. Supporters claim it is important for the government to own and operate its own powerful space rocket, and parts of the system are being built by companies across the country, spreading the economic benefits to many states and congressional districts.

The Space Launch System is a key component of Artemis, the program designed to bring NASA astronauts back to the moon in the years to come. Although President Trump promised to make the trip by the end of 2024, few expected NASA to actually stick to that schedule even before President-elect Joseph R. Biden Jr. was elected.

When NASA announced its plans for the space launch system in 2011, the first launch was scheduled for 2016. As is typical of new missile designs, the development encountered technical difficulties, such as the need to develop methods of welding metal parts together, large as those in the missile. NASA suspended work on the rocket for some time last year in the early stages of the coronavirus outbreak.

When the first launch date slipped several times, the price rose. NASA has so far spent more than $ 10 billion on the rocket and more than $ 16 billion on the Orion capsule that the astronauts will sit in.

The test fire is part of what NASA calls the Green Run, a series of tests of the fully assembled booster stage. The same booster will be used for the first flight into space, so engineers want to make sure it works as planned before it is launched.

Just like a real start, technical glitches occur. Almost everything went well in an earlier test known as the wet dress rehearsal, which simulated the entire countdown except for the ignition of the engines. In the last few seconds, one of the propellant valves did not close as quickly as expected. It turned out that the temperature was a little lower than predicted, which made the valve a little harder to turn. The software has since been adapted.

A worst case scenario would be if a malfunction led to the destruction of the booster. This would delay the program for years and again ask NASA to consider alternatives.