The reason to blow up methalox, other than “because it’s fun,” is because it’s just possible that a space rocket might explode accidentally. If one were to do so on the launch pad, it turns out that could be very bad for the people nearby! Who knew? But what NASA, alongside the Federal Aviation Administration and the U.S. Space Force, need to know is just how bad that would be. Blast radius, concussive force, shrapnel distance, that sort of thing. So as the space agency blows stuff up, it will take careful measurements of exactly how it blew up. For science! And also safety.
The tests are cut up into three series. The first series, already completed in February, involved using the plastic explosive C-4 to blow up a mock thruster with the methane and liquid oxygen still separate. This sounds like fun, as you can see from the pictures, but was it fun enough? Obviously not, because later in March, the second series will up the ante from a measly 100 pounds of fuel to a full 2,000 pounds. And this time, the liquids will be mixed. Now we’re cooking with methalox!
Still not enough boom for you? Don’t worry: in June, the third series will test a worst-case scenario, simulating a full bulkhead breach and detonating an entire 20,000 pounds of fuel. For that one, NASA will literally move the control room from 1.6 miles away to 4 miles, just to give you a sense of how big that explosion will be.
SpaceX, as usual, has an opinion. It’s done its own methalox testing, apparently, which it believes indicates that everything’s fine and there’s no reason for anybody else to test it for themselves. Therefore, its methalox-fueled Starship rocket is perfectly safe and should be able to launch from anywhere just fine, thank you. For some reason, NASA went ahead with its own tests anyway. Possibly, it wasn’t willing to take SpaceX’s word for it. Or just maybe, it just wanted to blow stuff up. In Florida. Obviously.