SLS verifies a basic test to return to the moon

Despite a leak that raised fears of a new failure, the return of humans to the moon has begun to take shape.

Better late than never! On Monday, June 20, NASA’s Space Launch System (SLS), the massive launcher on which the next Artemis I lunar mission will be based, finally passed successfully. Wet Dress Exercise (WDR). This is a decisive test to keep the operation going, and engineers can finally sleep in their two ears after several failures.

This is a test and training sequence for engineers and ground crews. The purpose is to get as close to the real situation of the launch as possible. Or, more precisely, the sequence of events that led to it.

The most important step in WDR is Tank filling test. This involves charging 2.6 million liters of very low temperature liquid hydrogen and oxygen. These two components will be evaporated and then combined at launch time and throughout the ascent so that the craft is driven. The word wet (“wet” in English) derives its name from the presence of these liquids.

The Wet dress rehearsal Finally valid after three failures

NASA made its first attempt on April 1 (see our article). But the agency failed to properly press a connector that was supposed to connect to the tank. The teams therefore could not fill the tanks, or go as far as the famous fictional countdown that could end the test.

This multi-billion dollar device and its makers had to be patient. A delay that was not particularly surprising; Since WDRs rarely go as planned on the first try. But there; Since then, NASA’s controversial mega-rocket quirks have continued.

The technicians faced two additional setbacks in early April before deciding to return to the workshop for the next SLS test. For two months, NASA was so busy solving all the problems during these three efforts.

Thus they repaired several important components, including the valve responsible for the first failure. They had to update a significant portion of the software side. Okay it took them, since the machine is back in much better condition. “This was absolutely the best thing to do to solve the problem we encountered on the launch pad”, Claims NASA through Administrator Jim Free.

The Orion capsule sat on the SLS, itself on a huge transit platform. The set is so huge that it is difficult to take a complete picture without facing vision problems, as can be seen in the corner! NASA, Aubrey Gemignani

SLS (almost) has a ticket to the moon

But despite all these warnings, WDR’s 4th attempt is almost over … Another hydrogen leak. Fortunately, this time it was not a damaged item. The incident was simply caused by an incorrectly locked connection where the two phases of the rocket had to be separated. The leak was quickly brought under control and the connection was restored.

After this event, the test may finally be completed; The launch was therefore successfully mimicked completely – That is, until the countdown reaches T-30 seconds. This is finally the first big win Controversial mega rocketTroubled by delays, budget bursts, and long struggles with a solid collaboration with Boeing (see our article).

“It’s a big day for our team,” said Charlie Blackwell-Thompson, program launch director. And the expression deserves better. After postponing the launch scheduled for June for the last time since its failure in April, NASA has repeatedly confirmed its ambition to launch the Artemis 1 mission in August 2022.

© Boeing

A launch is planned for the fall

And that launch window seems very close now. NASA will now carefully analyze the data collected during WDR, and if everything conforms to its expectations, it may officially lock in the launch date.

The next window will be on August 23rd. In contrast, in NASA’s schedule, it has been designated as a “short” mission window. So it probably won’t be consistent with the mission. There is such a window, you have to wait until August 29, otherwise until September 2.

On this date, SLS will depart for the famous mission Artemis d. An Orion capsule will be carried into orbit around the moon in this inaugural adventure. Test all tools in real life. In this way it will be able to lay the foundation for the Artemis 2 mission. This will bring astronauts back to lunar orbit. We will then arrive at Artemis 3, which was planned for 2026; It was during this last mission of the Artemis program that astronauts In 1972, Apollo 17 will land on our satellite for the first time.

The return to the moon is becoming clearer, but the future of SLS remains uncertain

A rendering of the base camp Artemis conceived by NASA. NASA

The SLS project has come a long way, but it will eventually be able to try to justify consuming billions of dollars through development. And the move promises to be more complex Wet dress rehearsalI

As a reminder, we talk a lot more about SLS for the same reason as the European Ariane 6; It is a vehicle that has not yet flown once, but technically it is already lagging behind, which many observers call “static birth” (see our article).

In fact, SLS is a single-use launcher; Much of the structure will return to wreck in the middle of the ocean … a vision that raises eyebrows for many when SpaceX’s reusable launchers have completely redefined the industry to change the roadmap for each of the sector’s key players.

So there are reasons to be skeptical about the future of SLS, especially since the current NASA program plans to use this launcher, which was already behind schedule before launch, until 30 2030.

But nonetheless, the passage of the wet dress exercise remains an exciting step for all space lovers; The return to the moon is fast approaching, and with some luck, this possibility will evoke a great collective thrill that will force people to forget the galleys of SLS for a while. So we are giving you an appointment in autumn so that this mission is not missed under any circumstances.

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