NASA's Artemis 1 mission was delayed due to a malfunctioning engine. (Image credit: NASA / Screenshot) NASA will attempt for a second time to launch the Artemis 1 on Saturday, September 3, reported Reuters. The Moon mission had been postponed due to a malfunctioning RS-25 engine on the Space Launch System (SLS) rocket.
Artemis 1 ran into trouble as team engineers noticed that one of the engines had an issue with the liquid hydrogen. The launch director had signed off on a plan to troubleshoot one of the RS-25 engines which was malfunctioning. But the troubleshooting plan did not work. The countdown clock was put on hold at T-40 minutes as the hydrogen team discussed options with the launch director. Here is a full recap of what went wrong during the mission.
Artemis I is an uncrewed mission that will be the first in a series of increasingly complex missions to the Moon, eventually taking humans back to Earth’s lone satellite. During the mission, NASA will demonstrate the performance and capabilities of its most powerful launch vehicle ever, the Space Launch System (SLS), and the Orion crew capsule. During the approximately six-week-long mission, SLS and Orion will travel a distance of around 65,000 kilometres to the Moon and back.
Do you know why NASA's Moon mission is named after an ancient Greek goddess? After Apollo, the space shuttled program shunned mythological monikers in favour of names that represented a spirit of innovation, like Columbia, Challenger, Discovery, Atlantis and Endeavour. But after 50 years, Artemis will pick up where her twin left off.
NASA will attempt for a second time to launch the Artemis 1 on Saturday, September 3, reported Reuters. The Moon mission had been postponed due to a malfunctioning RS-25 engine on the Space Launch System (SLS) rocket.
Read this Explained article to get a full recap of the Artemis 1 mission, what happened during the first launch attempt and NASA's long-term objectives with the program.
While the scrubbing of the Artemis 1 mission launch is a setback, it might look like nothing but a small speed bump in the rearview mirror if NASA goes on to achieve the ambitious objectives of the Artemis mission, which includes the assembly of the Gateway Space Station orbiting the Moon.
The next launch window for the Artemis 1 mission is between 10.18 PM IST on September 2 and 12.18 AM IST on September 3. There is another launch window between 2.42 AM and 3.54 AM IST on September 5. Even though NASA is yet to confirm whether it will attempt another launch during these windows, Artemis mission manager Mike Sarafin hinted that the launch could still happen this week during the post-scrub press conference. “Friday is definitely in play. We just need a little bit of time to look at the data. But the team is setting up for a 96-hour recycle,” said Sarafin during the conference.
The RS-25 engine that malfunctioned is not new. NASA began developing the engine model in 1970 and the it had its first launch in 1981.
NASA has not yet announced when it will next attempt launch with the SLS rocket. Here is what we can expect the space agency to do.
NASA will hold a media teleconference at 6 pm EDT later today. For India, this translates to 3.30 am at night by August 31. The conference will discuss the flight test of the agency’s mega Moon rocket and uncrewed Orion spacecraft.
According to NASA's Artemis blog, the four RS-25 engines need to be "thermally conditioned before super cold propellant begins flowing through them for liftoff." This take place by increasing pressure on the "core stage liquid hydrogen tank to route," which is called a 'bleed'. But engine number 3 did not bleed as expected. According to NASA, managers suspect the reason for this is likely a problem with the engine itself.
While NASA has not set "a precise time frame for retrying a launch of the mission," according to Reuters, senior NASA officials said a second attempt could be made on Friday depending on what data analysis results reveal. Engineers will still need to fix the issue of the engine bleed. "Friday is definitely in play," Michael Sarafin, NASA's Artemis mission manager told reporters, according to Reuters.
NASA Administrator Bill Nelson has explained why the mission was scrubbed. "They've got a problem with the gases going on the engine bleed on one engine. You can't go, you there are certain guidelines. And I think it's just illustrative, that this is a very complicated machine, a very complicated system, and all those things have to work," he said in a short statement. Watch full video below:
NASA has officially scrubbed its first attempt at launching the Artemis 1 mission to the moon due to a malfunctioning core stage RS-25 engine. From what appeared to be a "crack" in the inner tank to a hydrogen leak when the core stage was being fuelled to the RS-25 bleeding issue, here is our recap of everything that went wrong during this attempt.
The launch director has announced that the mission will be postponed since the issue with the RS-25 engine has not yet been resolved. The next available launch window is on September 2.
Engineers are working with data models to come up with a troubleshooting plan for the malfunctioning RS-25 engine, and the launch director is waiting to hear from them. The countdown clock is still on hold at T minus 40 minutes and that will not change till the launch team has come up with a solution to troubleshoot the malfunctioning engine.
Engineers have looked at the line of ice that built up on the inner tank on the exterior of the core stage near the flange and have concluded that the ice was formed by frozen air that was chilled by the tank and trapped inside a crack in the foam. This should mean that there is no crack in the actual tank. NASA spokesperson added that there has been a history of this phenomenon going back to the space shuttle days. In the meanwhile, the hydrogen team is still working on plans to troubleshoot the malfunctioning RS-25 engine.
The countdown clock was put on hold at T-40 minutes. The hydrogen team will now discuss plans with the launch director before deciding on how to proceed
The launch director had signed off on another troubleshooting plan. One of the four RS-25 engines is not getting the right amount of engine bleed to condition it for launch. The latest plan was to close the pre-valves on engines 1,2 and 4 and let the tank vent through the third engine. Even after going through with the plan, the teams didn’t see the engine bleed that they were looking for on engine number 3.
There appears to be a crack in the inner tank flange of the upper stage. There is frost build-up and there is a trail of vapour from it as can be seen from the image below. Artemis launch control is currently monitoring the situation. Another issue is what appears to be a line of frost on the inner tank seal on the exterior part of the core stage. We don’t yet have an image of that. All of this could mean that the launch will be delayed.
The RS-25 engines are bleeding but the liquid hydrogen team reports that they are not getting enough bleed from one of the four (engine number 3). The liquid hydrogen tank of the core stage is now closed. The upper stage is currently being loaded. The RS-25 engines are pictured in the screenshot below. The launch team is working on the engine bleed, trying to get engine number 3 to work in the right configuration.
Both the liquid oxygen and liquid hydrogen cryogenic tanks are filled up. NASA is currently filling up the ICPS liquid hydrogen tank and will start filling its liquid oxygen tank as well. The mission was delayed by close to an hour due to the potential of lightning storms and the teams had to wait till all storm clouds were outside a 5-kilometre radius from Launch Complex 39B.
“As that leak showed itself, the team went into a configuration called “revert,” which means we took the pressure off the tank so that the leak is no longer fed with pressure. Once they did that, we did some discussion and troubleshooting to understand where that leak was coming from and during this, we got back into slow fill. The leak then flattened out below our limits and we have not had an increase in that leak throughout that fill. Now we are in great shape,” said Jeremy Graeber, assistant launch director.
Now, the NASA team will evaluate all the work that happened and establish a new “T-0” or launch time. Graeber said the team is still working on finding an optimum launch time and can’t yet say when the launch will happen during the window.
The Artemis team has been given a go to kickstart liquid hydrogen bleed. This will give a first look at the repair of the liquid hydrogen bleed line. This was the line that leaked during the fourth wet dress rehearsal. The rocket is also “in replenish” for core stage liquid oxygen.
Currently, both the liquid hydrogen and liquid oxygen tank are currently in topping, which means they are both at 100 per cent, cycling between venting and topping to make up for what’s lost in the form of vapours.
Both the liquid hydrogen and liquid oxygen cryogenic tanks on the SLS tank are close to being full. This is despite the leak detection equipment going off and stopping the fill. This graphic shows the status of fuelling. Liquid oxygen is in blue and liquid hydrogen is in red.
In a positive turn of events, the NASA test director gave teams the go-ahead for filling the upper stage rocket with liquid hydrogen. The liquid hydrogen will fill faster than the liquid oxygen in terms of flow rate. The team is preparing to load the upper stage of the liquid hydrogen tank.
“During the transition from slow fill to fast fill of liquid hydrogen, launch controllers saw a leak in the amount of hydrogen that was allowed to leak into the purge can. Engineers looked at the percentage, which exceeded 4 per cent. They examined the situation, looked at all the data, slowly chilling down the lines and getting back into fast fill. So far, that is holding as we get nearly 40 per cent filled,” said NASA spokesperson Derrol Nail.
Nail added that the agency is behind on the timeline because of the weather issues as well as the potential hydrogen. But since there is a two-hour window, the mission could still launch within it.
This handy graphic from NASA shows the current status of tanking operations. This handy graphic from NASA shows the current status of tanking operations. The fuelling teams are currently assessing whether there is a liquid hydrogen leak.
The SLS rocket will continue to evolve along with the Artemis missions as they get more complex. The SLS Block 1 configuration will launch an uncrewed Orion space capsule for the Artemis I mission and two more missions in the program. After that, the SLS will evolve into a more powerful Block 1B configuration where a new Exploration Upper Stage will replace the ICPS. The final variant, Block 2, will be the most powerful and will increase the payload mass to over 46 tonnes.
The SLS rocket is being fuelled up for launch. Currently, Artemis I is in the tanking operations stage.
NASA’s Orion crew capsule is designed to take humans much farther in space than they have ever been taken before. This includes missions to the Moon and the vicinity of Mars, and maybe even further. The spacecraft will carry a crew into space, provide emergency abort capabilities, sustain astronauts during their mission and is designed to provide safe re-entry into Earth’s atmosphere from deep space return velocities.
It is around 3.3 metres tall and will weigh around 9,344 kilograms at launch for the Artemis I mission. It consists of a crew module, which is the pressurised module where the crew will live and work during missions; a service module that provides propulsion, thermal control, solar energy and life support systems; and a spacecraft adapter that attaches to the SLS rocket. Of course, the Artemis I mission will be uncrewed but it will carry all these systems for testing.
The Artemis I mission will also carry a host of secondary payloads to Earth orbit, lunar orbit and beyond. Here are the various secondary payloads that will be hitching a ride on the SLS rocket.
EQUULEUS
Developed by researchers at the University of Tokyo and JAXA (Japanese Aerospace Exploration Agency), EQUULEUS will image Earth’s plasmasphere for a better understanding of our planet’s radiation environment from Lagrange Point 2.
CuSP
Developed by the Southwest Research Institute in Texas, CuSP will act as a “space weather station,” measuring particles and magnetic fields.
NEA Scout
The NEA Scout will travel to a near-Earth asteroid to take pictures and observe characteristics of its surface. It is developed by NASA’s Marshall Space Flight Center in Alabama.
Lunar IceCube
The Lunar IceCube is developed by the Morehead State University in Kentucky and will look for water in all forms and other volatile compounds using an infrared spectrometer.
LunaH-Map
LunaH-Map, developed by researchers at Arizona State University, will create high-fidelity maps of near-surface hydrogen craters and other permanently shadowed regions of the Moon’s South Pole with neutron spectrometers
OMOTENASHI
Developed by JAXA, OMOTENASHI is the smallest lunar lander ever and will study the Moon’s environment
LunIR
LunIR was developed by Lockheed Martin and as the name suggests, will perform advanced infrared imaging of the Moon’s surface.
BioSentinel
BioSentinel, developed by NASA’s Ames Research Center, will carry a cargo of yeast to space to stuffy the effects of deep space radiation on living cells.
ArgoMoon
ArgoMoon will observe the SLS rocket’s ICPS (Interim Cryogenic Propulsion Stage) with advanced optics and software imaging systems. It was developed by the European Space Agency and Italian aerospace company ArgoTec
The Space Launch System (SLS) represents a new generation of space exploitation and will make crewed missions to the Moon possible. The rocket has propulsion systems that consist of solid rocket boosters and liquid-fuel RS-25 engines paired with a new central core stage. It uses larger solid sprocket boosters than the space shuttles and the RS-25 engines, fueled by a mixture of liquid hydrogen and oxygen, operates at a higher thrust level with new controllers.
SLS is 98.3 metres tall and weighs up to 2,600 metric tons. At launch, it will produce a thrust of 36,786 kN. It will produce a maximum thrust of 39,144 kN at the time of trans-lunar injection. The SLS rocket is capable of a maximum speed of 36,484 kilometres per hour, also happening at trans-lunar injection when the ICPS (Interim Cryogenic Propulsion Stage) kicks in.