After several unsuccessful attempts, the American space agency will try again this Wednesday, November 16 to launch its new rocket, the SLS. This is the first mission of the Artemis program aimed at returning humans to the Moon.
From our special correspondent in Florida,
” It’s a wonderful opportunity to be here. This is history: this is the new Apollo program. It’s still a few days away from the launch, but Ryan’s eyes are already shining. Sunglasses on his nose, a NASA T-shirt on his shoulders, this 30-year-old spends his Sunday with his feet in the water of the Atlantic Ocean, in Cocoa Beach, not far from the Kennedy Space Center. Here it is, in what is called ” space coast Florida, that he came from as far away as Colorado to attend the launch of the Space Launch System (SLS), NASA’s new lunar rocket. Like him, more than a hundred thousand Americans traveled at the end of August in the first attempt to launch. Another, equally unsuccessful, took place at the end of September. This is the third campaign, and despite the previous failures, the Americans still continue in numbers: all the hotels in the region are sold despite the stratospheric prices.
It must be said that the performance is promising. Standing proudly on the Space Center’s 98.3-meter-tall launch pad 39-B, the SLS is impressive, in keeping with its status as the most powerful rocket ever built. ” SLS is simply Artémis’ programming operating system “, explains with a smile Chris Cinciola, deputy program manager of NASA. In Greek mythology, Artemis is the twin sister of Apollo. She is also associated with the Moon.
A perfect name for the ambitious American program that aims to put astronauts back on our satellite in 2025. And for that, you need a powerful rocket: ” We go a thousand times more than the low Earth orbit where the International Space Station (ISS), and we have to take everything on board: the ship and everything the astronauts need. “, Chris Cianciola details.
A story of machines
Here is SLS, one of NASA’s most ambitious programs, whose relationship with Saturn 5 in the Apollo missions and the space shuttle is clear. ” The teams that built the Saturn 5 understood that well. Besides, they went to the moon! The program manager laughed. This can be seen in the overall design of the two machines, whose similarities are striking.
But in its very principle, the SLS should be more powerful than its predecessor: “ They went to the moon, but only for a few days. We want to be true pioneers. We want to stay there. So you need to bring extra things. In space, it’s a deterrent to an engineer: more things mean it’s heavier, therefore more powerful at take-off. This is why there are also borrowings on the side of the space shuttle. ” That was one of the challenges of designing the SLS: we needed the best engines, the best thrusters and we knew we already had them, the RS-25. »
These engines, among the most powerful ever made, Doug Bradley knows it very well, because he was one of the people who designed it at the industrial Aerojet Rocketdyne. ” The principle is simple, it is a rocket engine, it uses hydrogen and oxygen and mixes them in the combustion chamber to get the thrust. The RS-25 happened to do this well, and that’s why NASA used it to power its space shuttle. ” When defining the needs of SLS, we asked ourselves: “What is needed for this mission”. This tells us about the capacity of the engine. In this case, the most logical thing is to see if it already exists rather than creating a new one. The RS-25 is perfect. »
Another advantage, the shuttle was reusable at that time, everyone had already flown. One of them completed twelve space stays before docking at the SLS base. So engineers know them like the back of their hand and know how they behave. The adaptations to be made to mount it in their new car are also minimal, except for the on-board computers that need to be upgraded. ” It would be foolish not to consider the past when designing this new moon rocket continued Doug Bradley. ” What Saturn 5 did helped us build the shuttle. What the shuttle has done will help us for SLS. These are the foundations that allow us to move forward. »
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Most people think that without good engines, a rocket is just a bunch of metal sheets without much of a purpose. That is why it is important for NASA to have reliable machines with known behavior. However, the stacking of metal sheets on top is also not random, and it should also be tested. ” We test the ground, we do simulations, we test the central body, the thrusters, we do all the tests we can “, explained Chris Cianciola. ” But at some point, to fully test the rocket before putting astronauts on board, it must be launched. This is precisely the purpose of this Artemis 1 mission.
Unfortunately, flying the SLS turned out to be more complicated than expected. NASA tried to launch it for almost three months without success. It’s not so much the rocket itself that causes concern, but the so-called ground segment, the facilities at the launch base. In this case, it is the systems that allow filling the tanks that have experienced some failures, canceling the take-off scheduled at the end of August and the beginning of September. Three weeks later, when everything seemed to allow the engines to fire, hurricane Ian forced NASA to return the engine to the VAB, the assembly building. Now in the middle of November, a third opportunity came, the rocket was reinstalled on its launch pad, and it was the storm Nicole that appeared. This time, the teams did not have time to transport the launcher, which had to face the strong wind outside, but there was no damage according to the engineers of the American space agency. A few hours before the scheduled launch, all lights were green for Artemis 1.
The mission is simple: conduct a dress rehearsal to qualify all systems. So the SLS will fire up its engines at 1:04 a.m. this Wednesday in Florida. After two minutes and 12 seconds, his powder boosters are exhausted and ejected. The launcher will then be at an altitude of 50 kilometers. After the 8 minute 30 flight, it is the main stage that separates after fulfilling its function. The SLS will then be in space at an altitude of 167 kilometers, accelerating at a speed of 28,000 kilometers per hour. Finally, after a two-hour mission, at an altitude of 4,000 kilometers, the Orion spacecraft will be released and driven towards its lunar trajectory. It will take six days to reach our satellite, where it will orbit for two weeks, before returning to Earth.
A new spaceship
Orion is the spacecraft that will carry the astronauts of the Artemis program, the successor to the Apollo capsule. It is designed to reach unprecedented distances while protecting its crew, which can include up to four people, and return them safely to Earth. The car has been tested. It is placed atop a Delta IV Heavy rocket, which propels it into orbit. After two Earth orbits, its ability to withstand the shock of atmospheric re-entry and the proper deployment of its parachutes have been proven. But now, the return of our planet from the Moon will be faster. Its ability to enter orbit and return is one of the major challenges of this mission.
The behavior of another element of Orion will also be closely analyzed: its service module. Developed by the European Space Agency (ESA) in collaboration with NASA, it plays an important role for the spacecraft. ” It’s like the engine of a car: Orion is the car, the service module provides its functionality. It also provides all the regulatory systems that allow the capsule to travel in space by providing a suitable atmosphere for the astronauts. explained Philippe Deloo, program manager of ESA. Here again, the goal is to check everything: ” We must ensure that all the systems we develop work as we expect, without surprises or anomalies. The next flight will be with astronauts and obviously we don’t want to risk their lives. »
In fact, after this mission, Artemis 2 will arrive in 2023 if all goes well. The first crew will live at the top of the 98 meters of the SLS for a copy of Artemis 1 or Apollo 8 at the time: several trips to the moon to check all the systems again, but with astronauts on board that time. Next Artemis 3 will arrive in 2025 for the first time, or for the first time since Apollo 17 in 1972, two people will set foot on the lunar surface. The names of the two astronauts are not yet known, but NASA has announced its intention to have a woman and an African-American make up the crew. ” We’re going back to the moon, and that’s cool Doug Bradley smiled. ” It reminds me of the end of Apollo 13, the movie with Tom Hanks. He reflects on the end of the Apollo program, and wonders when we will return to the Moon and by whom. We have it, our rocket is on the launch pad! »
For many, Artemis is a legacy story. Through its technologies and methods, but also through the imagination it brings: the Apollo program of a new generation. Chris Cianciola agrees: “ I was a kid when we launched Apollo 11 in 1969. My family and I parked in Titusville, three miles from the space center, and watched the launch from the road. Afterwards, we went home and saw the first steps on the Moon. It will always be in my memory. Now, I work on a team that does the same. And when it launches on Wednesday, there’s sure to be a kid watching from the street, like I did. In 40 years, this child will take the torch. This is what you need if you want to go further into space and explore! »
@NASA_SLS was at launching pad 39-B, where he weathered the last storm without much of a shake. Engine ignition at 1:04 am here, 7:04 am Paris, 6:04 am UT. To follow live commented by yours truly on @rfi . The launch window lasts two hours. pic.twitter.com/lnJGIPcflU
— Simon Roze (@simonroze) November 15, 2022
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