Artemis 1 science prepares for departure
We’ve been highlighting several Artemis 1 science investigations in recent stories as the mission prepares for a departure to the moon no earlier than Aug. 29.
Radiation experiments will feature on the mission as it will be taking the Orion spacecraft, rated for humans, deeper in space than any vehicle like it. Mannequins and biological experiments will fly aboard the spacecraft and on cubesats to assess the environment of the moon and deep space for astronaut safety.
Also, a Japanese experiment called OMOTENASHI will serve as a lunar lander. While other investigations are in orbit, this cubesat will be the only of the secondary payloads to conduct a controlled landing on the moon.
Elizabeth Howell, Ph.D., is a staff writer in the spaceflight channel since 2022. She was contributing writer for Space.com (opens in new tab) for 10 years before that, since 2012. Elizabeth’s on-site reporting includes two human spaceflight launches from Kazakhstan, three space shuttle missions in Florida, and embedded reporting from a simulated Mars mission in Utah.
Back at the pad!
Artemis 1 has reached the pad!
The stack, consisting of the Space Launch System (SLS) megarocket topped by the Orion capsule, arrived at Launch Pad 39B on Wednesday (Aug. 17) around 7:30 a.m. EDT (1130 GMT), according to a NASA statement (opens in new tab).
The rocket is targeting launch on Aug. 29 for an uncrewed test flight around the moon.
Artemis 1 rocket rollout begins!
NASA’s Artemis 1 Space Launch System megarocket has begun its hourslong trek back to Launch Pad 39B tonight for its planned Aug. 29 launch to the moon.
“Rollout has begun,” officials with NASA’s Kennedy Space Center in Florida wrote as the the SLS rocket began the slow trip to the launch pad atop its massive crawler carrier vehicle and mobile launch platform. It should take up to 12 hours for the 322-foot rocket to complete the trip.
Roll has begun #Artemis I pic.twitter.com/51WSRipiAqAugust 17, 2022
Artemis 1 rollout delayed by storms
The start of NASA’s Artemis 1 moon rocket rollout has been delayed by about an hour, to no earlier than 10 p.m. EDT (0200 GMT), due to stormy weather at its Kennedy Space Center, Florida, launch site, according to Spaceflight Now (opens in new tab).
Artemis 1’s Space Launch System rocket was scheduled to begin at 9 p.m. EDT, but lightning and stormy weather appears to have delayed the rollout. Spaceflight Now reports NASA has a Phase 2 lightning warning in effect currently.
NASA’s Artemis 1 launch pad roll out webcast begins
NASA’s live webcast of today’s Artemis 1 Space Launch System rollout to the pad has begun. You can watch the Artemis 1 moon rocket rollout live on Space.com, or directly from NASA’s Kennedy Space Center Newsroom YouTube page.
While NASA’s webcast began at 3 p.m. EDT (1900 GMT), the SLS rocket itself is expected to begin rolling out at 9 p.m. EDT (0100 GMT on Aug. 17). It could take up to 12 hours for the SLS rocket to reach the launch pad.
NASA is providing two views of the rollout. A closeup of the Vehicle Assembly Building, where the SLS is currently located, and of Pad 39B (opens in new tab) where it will settle in for a planned Aug. 29 launch.
Artemis 1 moon rocket rollout moved up to Aug. 16
NASA has moved up the launch pad rollout of its Artemis 1 moon rocket, the first Space Launch System, by two days. The rocket will now roll out its Launch Pad 39B site on Tueday, Aug. 16, (two days earlier than planned) to begin final preparations for its Aug. 29 launch to the moon.
Officials with NASA’s Ground Systems team announced the schedule change on Twitter.
“ARTEMIS I UPDATE: The rollout of @NASA_SLS & @NASA_Orion to Launch Pad 39B has now moved up to tomorrow, the evening of Aug. 16, ahead of the targeted Aug. 29 launch. Stay tuned for more information as well as ongoing coverage,” NASA wrote in the update (opens in new tab).
The rollout of Artemis 1’s SLS will be webcast live on NASA TV. It will come amid a series of teleconferences this week to discuss the Artemis 1 moon mission. Here’s a schedule of events for the week, which you’ll be able to watch for free on this page.
- Monday, Aug. 15, at 5 p.m. EDT: Artemis 1 lunar science payloads teleconference.
- Tuesday, Aug. 16, at 12 p.m. EDT: Artemis 1 technology & solar system science teleconference.
- Tuesday, Aug. 16, evening: Artemis 1 moon rocket rollout.
- Wednesday, Aug. 17, at 12 p.m. EDT: Artemis 1 radiation science teleconference.
ARTEMIS I UPDATE: The rollout of @NASA_SLS & @NASA_Orion to Launch Pad 39B has now moved up to tomorrow, the evening of Aug. 16, ahead of the targeted Aug. 29 launch. Stay tuned for more information as well as ongoing coverage. pic.twitter.com/28kRuwB4pNAugust 15, 2022
Artemis 1 cleared for launch; Space.com on site
The Artemis 1 moon megarocket is cleared for launch for its debut mission, no earlier than Aug. 29. The European Space Agency released a video (visible above) celebrating the milestone for the mission, which is led by NASA.
Space.com is on site at NASA’s Johnson Space Center in Houston talking to officials about the progress of Artemis 1, which aims to circle the moon and come back to Earth uncrewed on a mission lasting more than a month. We’ll keep you tuned into our coverage as the briefings progress.
On Aug. 3, NASA officials said the rocket is on track for launch preparations following a “wet dress rehearsal” fueling test in June that revealed a few issues. The agency also framed this mission as critical to get the Space Launch System rocket and Orion spacecraft ready for future human missions as the system collects science on the moon and on human effects on spaceflight.
Artemis 1 NASA preview today (Wednesday) at 11 a.m. EDT
NASA’s will hold a press conference Wednesday (Aug. 3) at 11 a.m. EDT (1500 GMT) to give a general overview of the Artemis 1 lunar mission, which you can watch for free in the YouTube stream above.
The briefing is expected to last an hour and will feature the following speakers:
- NASA Administrator Bill Nelson;
- Bhavya Lal, associate administrator for technology, policy, and strategy at NASA’s headquarters;
- Mike Sarafin, Artemis 1 mission manager with NASA HQ;
- Charlie Blackwell-Thompson, Artemis 1 launch director at NASA’s Kennedy Space Center (KSC) in Florida (the mission’s launch site);
- John Honeycutt, Space Launch System program manager with NASA’s Marshall Space Flight Center in Huntsville, Ala.;
- Howard Hu, Orion program manager, with NASA’s Johnson Space Center (JSC) in Houston.
After Wednesday’s briefing, NASA will host an in-person media day concerning Artemis 1 at its Johnson Space Center, where astronaut training takes place.
Artemis 1 will send an Orion spacecraft to the moon atop a Space Launch System megabooster, in an uncrewed mission meant to prepare for future human excursions. The mission will also launch 10 cubesats targeting several off-Earth science missions.
The exact duration of Artemis 1 will depend on orbital dynamics at the time of launch; an Aug. 29 launch (the nominal date so far) would see a 42-day flight, for example, but a Sept. 2 liftoff would kick off a 39-day mission.
Artemis 1 targets Aug. 29 launch date
NASA’s moon megarocket is scheduled to fly its first mission as soon as late August, pending testing and reviews of all the components of Artemis 1.
The agency announced today (July 20) that it has three “placeholder” launch dates for the uncrewed test flight around the moon: Aug. 29, Sept. 2 and Sept. 5.
“It’s not an agency commitment,” Jim Free, NASA’s associate administrator of exploration systems, said of the interim launch dates during a teleconference with reporters. The agency, he said, will make a commitment closer to the launch date pending work on several outstanding items from Artemis 1’s wet dress rehearsal that concluded June 20.
Learn more at Space.com here.
Artemis 1 reaches end of terminal count
NASA’s Artemis 1 moon mission has reached the end of terminal count, effectively wrapping up its two-day-long wet dress rehearsal. The milestone came today (June 20) at 7:37 p.m. EDT (2337 GMT), after which the mission team began safing Artemis 1’s huge Space Launch System rocket.
Terminal count ended at T-29 seconds before (simulated) engine ignition rather than T-9 seconds, as originally planned. That change resulted because the mission team “masked” three issues that cropped up today during the test, including a leak of liquid-hydrogen fuel, agency officials said. Masking allowed the countdown to proceed despite the issues, which would have raised red flags on the day of an actual launch.
Artemis 1 begins wet dress rehearsal’s terminal count
NASA’s Artemis 1 moon mission has begun terminal count in its wet dress rehearsal,. The countdown clock began ticking down from T-10 minutes at 7:33 p.m. EDT (2333 GMT).
Artemis 1 ‘go’ for T-10 countdown
The Artemis 1 team has decided to proceed with a simulated launch countdown that will end at T-10 seconds, NASA officials announced this evening (opens in new tab) (June 20). That countdown will be performed in a modified configuration, one that masks a hydrogen leak discovered earlier today.
Artemis 1 moon rocket fully fueled
NASA has fully fueled its Space Launch System (SLS) megarocket, notching a huge milestone in the “wet dress rehearsal” for its Artemis 1 moon mission, agency officials announced via Twitter this evening (opens in new tab) (June 20).
Some issues have cropped up during the wet dress, however; for example, the Artemis 1 team noticed a hydrogen leak in one of the SLS “quick disconnect” lines. But the wet dress may proceed to its conclusion today even if that leak is not fixed.
“The team may decide to continue terminal count with certain issues masked in order to get further into the testing for today’s wet dress rehearsal,” NASA officials said in another tweet this evening (opens in new tab).
Artemis 1 team diagnoses hydrogen leak problem
The Artemis 1 team has determined that the hydrogen leak in one of the Space Launch System (SLS) rocket’s “quick disconnect” lines resulted from a faulty seal on the rocket side of the cable, NASA officials said during an update this afternoon (June 20). The team is still working through its next steps and has not yet set a T-0 time that would mark the end of the “wet dress rehearsal” test of the Artemis 1 SLS and Orion capsule.
NASA recalibrating new T-0 for Artemis 1 wet dress rehearsal
NASA is recalibrating the T-0 for its Artemis 1 wet dress rehearsal after failing in an attempt to fix a hydrogen leak in a “quick disconnect” line in the Space Launch System rocket’s core stage, agency officials said in an update this afternoon (June 20).
Technicians tried warming up and then cooling down the quick disconnect, hoping that would reseat the hardware and seal the leak. But it didn’t work, so Artemis 1 team members are “putting their heads together and seeing if they can come up with any other options to seal that leak,” NASA spokesperson Derrol Nail said this afternoon during the agency’s webcast of the wet dress rehearsal.
Nail added that the team is also trying to come up with a new T-0 , the milestone that will wrap up the wet dress rehearsal. The current T-0 is 4:38 p.m. EDT (2038 GMT), but it’s been apparent for some time now that Artemis 1 would not hit that mark.
Three of four SLS propellant tanks now filled
Three of the four propellant tanks on the Artemis 1 Space Launch System rocket are now filled, and the fourth could be tanked up soon, NASA officials in a Twitter update this afternoon (opens in new tab) (June 20).
“Liquid oxygen is currently at fast fill for upper stage. Team is working a plan to reseal at the hydrogen leak,” the tweet reads, in part. That leak was spotted earlier today at a “quick disconnect” on the SLS core stage.
Teams at NASA’s Kennedy Space Center in Florida continue troubleshooting the hydrogen leak at the core stage quick disconnect of the Space Launch System rocket, which stopped the fueling operation of the Artemis 1 wet dress rehearsal test earlier today.
Teams from Boeing as well as NASA are on site trying to seal the leak, hoping to be able to continue with the test, although it’s unlikely that T-0 will occur at 4:38 p.m. EDT (2038 GMT) as still officially planned.
“Team is working to manually adjust the LOX pressure in upper stage to get back into tanking,” NASA said on Twitter (opens in new tab).
The fueling of the rocket’s upper stage has been completed.
Hydrogen leak troubleshooting ongoing during Artemis 1 tanking
Artemis 1 teams are currently troubleshooting the leak at the core stage quick disconnect.
“This includes manually configuring valves to reduce the pressure on the upper stage,” spokesperson Derrol Nail said on NASA Television.
Whilst troubleshooting continues, there is no plan to intervene with the small grass fire that is burning near the hydrogen flare stack, according to Nail.
As the grass is burning towards a dirt road the belief by the launch team is that it will burn out once it gets to the road.
“It would be more risky to send a team out there to put it out,” Nail said.
It is still unclear what impacts these issues would have, if any, on the planned T-0 during the wet dress rehearsal, currently set for 4:38 p.m. EDT (2038 GMT).
Hydrogen leak, grass fire discovered during Artemis 1 tanking
NASA says Artemis 1 teams are “working on an issue with the liquid hydrogen” during tanking operations of the core stage, among other issues.
“They are getting some data that says there’s a leak, a liquid hydrogen leak, in the quick disconnect that takes the bleed for the engines,” spokesperson Derrol Nail said on NASA Television around 2:07 p.m. EDT (1807 GMT).
“The team is currently evaluating that situation,” Nail said. “Of course, any leak of liquid hydrogen is something … to be concerned about for the launch team. This is a hazardous gas. They want to understand the situation fully before they take any action.”
Nail added there are more issues forthcoming: there appears to have been a pressure limit exceeded during fueling in the liquid oxygen for the upper stage, and a small grass fire has emerged nearby the launch pad.
It is unclear what the grass fire was caused by, and agency officials have their cameras on the area to monitor the smoke coming out of the grass.
It is unclear what impacts these issues would have, if any, to the planned T-0 during the wet dress rehearsal, currently set for 4:38 p.m. EDT (2038 GMT).
Tanking graphic during Artemis 1 tanking
The above graphic was released on NASA Television at 1:15 p.m. EDT (1715 GMT) showing the progress of tanking operations in the Space Launch System’s core stage. The rocket is being fueled during the wet dress rehearsal of Artemis 1, which is expected to wrap up later on Monday afternoon (June 20).
Update, 1:32 p.m. EDT / 1732 GMT: While saying the core stage is fully filled, NASA added that the graphic showed the incorrect temperature for the liquid hydrogen. The correct temperature should have read -423 degrees Fahrenheit (-253 degrees Celsius).
Core stage almost completed on tanking; upper stage ‘a little behind’
The core stage of the Space Launch System is almost completed tanking. Liquid hydrogen is fully tanked, while liquid oxygen is at 90%, NASA spokesperson Derrol Nail said during a Monday (June 20) update at 1 p.m. EDT (1700 GMT) on NASA Television.
The upper stage entered chilldown of its gas lines at 1:03 p.m. EDT (1703 GMT) to prepare it for entry of the cryogenic gas, Nail added.
“We’re running a little behind on the tanking for the upper stage, probably about a half hour or so,” Nail added. “Tweaking of an upper stage skid took a little longer than expected.”
So far, the T-0 in the wet dress rehearsal countdown remains at 4:38 p.m. EDT (2038 GMT) following now-resolved delays from early in the morning EDT. Preparations for the test have been running for nearly two days since a call to stations at 5 p.m. EDT (2100 GMT) on Saturday (June 18).
Liquid hydrogen reaches ‘topping’ stage
With the core stage hydrogen tank at 98% full, the tank is now in “topping” procedures to make sure the liquid gas is fully ready for the wet dress rehearsal in the coming hours, NASA Television said in an update at 12:35 p.m. EDT (1635 GMT).
The liquid oxygen tank in the core stage is at 76% full, and all operations are still proceeding to a T-0 in the wet dress rehearsal test at 4:38 p.m. EDT (2038 GMT).
Liquid oxygen and hydrogen beyond 50% filled
Liquid hydrogen and liquid oxygen levels are beyond half filled, NASA said in an update around 12:15 p.m. EDT (1715 GMT). Liquid hydrogen in the Space Launch System megabooster core stage is at 67% full, while liquid hydrogen at 63%.
Engineers are also preparing the upper stage of the rocket for fueling, which will go much faster than the core stage, according to NASA Television spokesperson Derrol Nail.
T-0 on the simulated countdown is still expected at 4:38 p.m. EDT (2038 GMT), following now resolved delays from early in the morning EDT. You can listen in live on NASA’s website (opens in new tab).
Artemis 1 ‘go’ in prep for liquid hydrogen tanking
Engineers just received the “go” to prepare the upper stage of the Space Launch System (SLS) for liquid hydrogen tanking, beginning with a helium purge, according to NASA Television.
Liquid hydrogen enters ‘fast fill’
Liquid hydrogen tanking is now entering a ‘fast fill’ phase as engineering teams work to get the Space Launch System megarocket tanked for the wet dress rehearsal of Artemis 1 later today, NASA officials said in an update around 11:30 a.m. EDT (1530 GMT).
Liquid oxygen and liquid hydrogen are being tanked at the same time, but the flows on each gas are being adjusted. Hydrogen is flowing a bit faster and oxygen is flowing a bit slower, explained spokesperson Derrol Nail in the update on NASA Television.
The aim is to avoid an “aft strut constraint”, Nail said. Aft struts are horizontal attachment points between the solid rocket boosters on either side of the core stage of SLS.
“The vehicle moves during fueling. It’s very much alive. As the super-chilled propellants go into that tank, it [the vehicle] becomes heavier,” Nail said.
The metal on the tanks also shrinks slightly due to the cryogenic temperatures of the hydrogen and oxygen, he added. “For that reason, the propellants are put in in proportion to each other.”
The liquid hydrogen tank, at 537,000 gallons (2.4 million liters), is expected to finish before the liquid oxygen tank at 196,000 gallons (roughly 740,000 liters), Nail said. Liquid hydrogen is much less dense than liquid oxygen.
The oxygen tank is roughly 38% filled as of the update time, while the hydrogen tank stands at less than 5%; the oxygen tank is not allowed to exceed 49% filled until the hydrogen tank gets to at least 5%, according to NASA.
Artemis 1 teams adjust liquid oxygen and hydrogen flow
Liquid hydrogen is now flowing during the Artemis 1 wet dress rehearsal, NASA officials said around 11:10 a.m. EDT (1500 GMT) on Monday (June 20), confirming that announcement in an agency tweet (opens in new tab).
As liquid hydrogen tanking proceeds in the Space Launch System megarocket, the hydrogen’s flow rate will be slightly accelerated in light of liquid oxygen tanking operations, which have been ongoing for about an hour.
The liquid hydrogen team anticipates they will slightly accelerate their flow of gas, while the liquid oxygen team plans to slow down their rate, NASA spokesperson Derrol Nail said during a NASA Television update.
That’s because liquid hydrogen must be filled up to at least 5% in the SLS tank before liquid oxygen loading is authorized beyond 49% levels, Nail said. (Current levels are at 15% for liquid oxygen, he noted, so slowing down the oxygen flow is a precaution.)
Teams appear to be carefully adjusting these oxygen-hydrogen flows to reduce loads on the SLS during tanking, although NASA Television did not directly confirm that. The procedure is called an “aft strut constraint.” The SLS has four struts securing the core stage to the boosters when the megarocket is stacked on the mobile launcher, according to NASA documentation (opens in new tab).
Artemis 1 begins slow fill of hydrogen
NASA has given the go for Artemis 1 to begin “slow fill” of liquid hydrogen in preparation for the wet dress rehearsal, the agency said on NASA Television Monday (June 20) around 10:42 a.m. EDT (1442 GMT).
Liquid hydrogen will then be authorized for a “fast fill”, providing that tanking operations proceed as planned. The milestone was confirmed on the agency’s Exploration Ground Systems Twitter account in a brief tweet (opens in new tab).
“The reason for that [slow fill] is to properly condition the vehicle,” spokesperson Derrol Nail said on NASA Television. “The engineers are trying to prevent thermal shock to the system by flowing too much super-chilled propellant too fast.”
NASA gives ‘go’ for liquid hydrogen tank filling
Engineers have a “go” to proceed for liquid hydrogen tank filling, NASA Television said in an update Monday (June 20) around 10:30 a.m. EDT (1430 GMT).
The milestone was confirmed on the agency’s Exploration Ground Systems Twitter account (opens in new tab) at 10:33 a.m. EDT (1433 GMT).
“This is a major milestone,” spokesperson Derrol Nail said on NASA TV. “As you may recall from previous wet dress rehearsals, there was a leak …the umbilical leak was fixed, so this is a big moment for the team.”
NASA had made multiple attempts to perform the wet dress rehearsal in April, but ultimately pulled the Space Launch System and Orion spacecraft stack back to NASA’s Kennedy Space Center’s Vehicle Assembly Building to address the hydrogen leak issue.
Tanking operations are ongoing. Liquid oxygen entered a “fast fill” phase earlier in the hour, and liquid hydrogen lines are now being pre-chilled in preparation for tanking.
UPDATE: We have now entered chilldown of the @NASA_SLS liquid hydrogen transfer line.🚀 Check out our clickable rocket to explore it’s tanks here: https://t.co/EVroYXvGoWJune 20, 2022
Core stage liquid oxygen enters ‘fast fill’
Liquid oxygen is now proceeding at a fast fill in preparation for Artemis 1 wet dress rehearsal operations, according to a NASA Television update and a brief tweet (opens in new tab) from the agency’s Exploration Ground Systems account.
Core stage liquid oxygen enters ‘slow fill’
The liquid oxygen for the Space Launch System’s core stage has entered the “slow fill” part of the tanking process after chilling of the oxygen to cryogenic temperatures completed, according to an announcement from NASA Television.
“Core stage LOX [liquid oxygen] chilldown … is complete and the team has now begun slow fill of liquid oxygen into the tank,” NASA’s Exploration Ground Systems account confirmed (opens in new tab) on Twitter at 10:08 a.m. EDT (1408 GMT).
The slow fill will take about two hours and 40 minutes to complete, which will be the longest process during wet dress rehearsal operations. Chilling for liquid hydrogen will begin in less than 10 minutes, spokesperson Derrol Nail said on NASA Television at 10:12 a.m. EDT (1412 GMT).
UPDATE: Core stage LOX chilldown of @NASA_SLS is complete and the team has now begun slow fill of liquid oxygen into the tank.June 20, 2022
Tanking ongoing for Artemis 1 wet dress rehearsal
NASA has confirmed tanking is ongoing during the Artemis 1 wet dress rehearsal on NASA Television, its Artemis blog and a tweet from the Exploration Ground Systems account, embedded below.
“The process for filling the core stage tank begins with the chill down, or cooling, of the propellant lines to load the liquid oxygen and liquid hydrogen in preparation for tanking,” NASA officials said in the blog post, published Monday (June 20) at 9:38 a.m. EDT (1338 GMT).
“The team will slowly fill liquid oxygen into the core stage tank with the fast fill beginning soon after,” the post added. “Teams will then proceed to slowly fill the core stage’s liquid hydrogen tank, followed by fast fill.”
Tanking has begun with chilling down the liquid oxygen propellant lines for core stage. In sequential fashion, liquid oxygen and liquid hydrogen will flow into the rocket’s core stage and interim cryogenic propulsion stage tanks and be topped off as some propellant boils off.June 20, 2022
New eight-minute delay in exiting the hold
NASA expects to exit the lengthened test hold eight minutes later than expected. The new exit time will be 9:28 a.m. EDT (1328 GMT), allowing Artemis 1 wet dress rehearsal operations to proceed, agency officials said during an update on NASA Television.
“The team is configuring the launch vehicle to get ready for cryogenic tanking,” agency spokesperson Derrol Nail said during the update, delivered around 9:20 a.m. EDT (1320 GMT).
The hold was lengthened about two hours beyond its expected conclusion at 7:30 a.m. EDT (1130 GMT) due to issues with a backup gaseous nitrogen line, issues which all appear to be resolved now. The nitrogen is required to purge harmful gases during tanking, among other uses.
Should the tanking proceed to plan after this point, the new T-0 (simulated liftoff) would be at 4:38 p.m. EDT (2038 GMT), Nail added during the update.
Launch director gives ‘go’ for cryogenic tanking
NASA launch director Charlie Blackwell-Thompson gave the “go” for cryogenic tanking to begin on the Artemis 1 wet dress rehearsal, according to a livestreamed update on NASA Television shortly before 9 a.m. EDT (1300 GMT).
The cryogenic cooling was expected to begin at 9:05 a.m. EDT (1305 GMT) as NASA officials proceed with the test, which is a key milestone in assessing the Space Launch System megarocket and Orion spacecraft for their readiness to perform a round-the-moon mission.
Jeremy Graeber, assistant launch director, told listeners on NASA Television that the gaseous nitrogen issue holding up tanking operations earlier in the morning EDT has been resolved. Both the gaseous nitrogen valve and the controller, which had been troublesome, are now working properly following previously disclosed engineering fixes.
“The team did a great job identifying the problem and resolving it, and so we’re in really good shape,” Graeber said. “That problem has been cleared and we’re at a good configuration to pick up with cryo loading [and] no longer constrained.”
Engineers have also picked up an issue with the left solid rocket booster, showing that the resistance was lower than expected, Graeber said. But given the consistent history of the booster’s performance, the teams decided to proceed and not to declare it a constraint to the wet dress rehearsal.
The resistance test was showing a value of 22.4, compared to a nominal reading of between 24.4 and 37.4, Graeber said.
“The value we’re seeing now is consistent with what we’ve been seeing over the last several weeks,” he added. “So although it is outside of our nominal range, we understand that it’s consistently here. So we believe that’s a valid number.”
Weather is predicted to remain good for tanking operations despite T-0 (the simulated liftoff) being pushed back about two hours to 4:30 p.m. EDT (2030 GMT), Graeber added.
We are “GO” to begin tanking of the @NASA_SLS rocket as part of the #Artemis I wet dress rehearsal test.Watch our live feed for updates throughout the day: https://t.co/1XQVlkaW6V pic.twitter.com/7ZEKqt6vYqJune 20, 2022
NASA resets terminal countdown to 4:20 p.m. EDT
NASA expects to bring Artemis 1s wet dress rehearsal out of its extended hold at 9:20 a.m. EDT (1320 GMT) after engineers successfully addressed issues with a valve and automatic controller on a backup gaseous nitrogen system.
As planned, the backup gaseous nitrogen system will now be swapped with the primary, meaning the backup will be used as the source to purge harmful gases throughout the tests, NASA’s Derrol Nail said during a livestreamed update at 8:30 a.m. EDT (1230 GMT) on NASA Television.
Should the countdown go to plan, the terminal countdown will start at 4:20 p.m. EDT (2020 GMT) and conclude at 4:30 p.m. EDT, roughly two hours later than scheduled.
Weather is expected to hold into that period, Nail said. “Some showers could develop around the pad in the early afternoon, but they’re expected to move west. Tanking, therefore, in the weather forecasts for taking is go,” he added.
Backup gaseous nitrogen line troubleshooting continues
Artemis 1 wet dress rehearsal teams have successfully replaced a gaseous nitrogen valve on a backup line that forced an extension of a launch hold past 7:30 a.m. EDT (1130 GMT), NASA officials said during a live update at 8:00 a.m. EDT (1200 GMT).
“It would not close,” NASA’s Derrol Nail, a communications representative, said during a broadcast on NASA Television. “Not sure about what caused the failure at this time, but the teams have been working on it and have replaced the valve. The manual retest of that valve is working well, according to the team that’s out there.”
Teams are now focused on an automatic controller for the backup gaseous nitrogen line, performing tests to see if that will work properly, Nail said. Provided they get the controller working, engineers have also decided to move the troublesome gaseous nitrogen as the primary source for the rocket’s test. (There are two sources; it was the redundant one causing issues, but the prime one was working just fine.)
“The launch team, meanwhile, has been moving forward configuring the launch vehicle for tanking,” Nail continued. “They have cycled the valves for liquid oxygen tank in the upper stage, and then began proceeding with cycling the valves on the liquid oxygen stage.”
NASA is providing updates approximately every half hour on its live broadcast (opens in new tab) as tanking operations continue for the wet dress rehearsal, which may take place later today (Monday) if all goes to plan. Exact rescheduled timing for testing procedures have not been released yet, as the troubleshooting is ongoing; the nominal plan had put the first expected terminal countdown at 2:30 p.m. EDT (1830 GMT).
NASA repairs backup valve for gaseous nitrogen
Engineers have repaired a valve for the backup gaseous nitrogen line, NASA’s Exploration Ground Systems stated on Twitter at 7:45 a.m. EDT (1145 GMT).
“The launch team is assessing next steps and continue to be in an extended hold,” agency officials tweeted.
A planned hold during the wet dress rehearsal was supposed to conclude at 7:30 a.m. EDT (1130 GMT), but the backup supply issue forced a pause in returning to the countdown.
The primary supply of gaseous nitrogen, required to purge harmful gases from the Space Launch System megarocket during tanking, remains operational.
UPDATE: A valve for the redundant gaseous nitrogen (GN2) line has now been repaired. The launch team is assessing next steps and continue to be in an extended hold. Stay tuned to https://t.co/6CWuCVIE53 for ongoing updates.June 20, 2022
NASA proceeds with tanking while working backup issue
NASA officials have decided to “press” towards tanking operations while attempting to address a backup supply issue of gaseous nitrogen in parallel, a live broadcast for the Artemis 1 wet dress rehearsal stated around 7:40 a.m. EDT (1140 GMT).
The primary supply for gaseous nitrogen is working well, but the backup remains at issue.
An update from engineering teams is expected in about 45 minutes on how operations are going, NASA communications official Derrol Nail said during the broadcast. He noted nitrogen is used to prevent buildup of gases, along with keeping avionics and electronics in the engine section dry, among other purposes.
“Gaseous nitrogen is critical to get started with tanking,” Nail said.
NASA extends hold to examine backup nitrogen issue
NASA has extended its hold of the Artemis 1 tanking operations, which was supposed to conclude at 7:30 a.m. EDT (1130 GMT), due to an issue with a backup supply of gaseous nitrogen, the agency said on its broadcast.
“The primary supply is good. It’s the backup supply issue for the controller for the supply valve, and so the launch team is currently working on that issue,” Derrol Nail of NASA communications said during the live broadcast a few minutes ago.
“Until they do until find a resolution, the launch team has decided to hold off on cryo loading until they have a better understanding of what is required for that repair.”
Problems with gaseous nitrogen supply, used to support activities at the pad, had delayed previous countdown rehearsals, although it was liquid hydrogen and liquid oxygen issues that ended up being the main issue during past tests.
NASA recently upgraded its infrastructure at Pad 39B at the agency’s Kennedy Space Center to increase storage facilities for gaseous nitrogen. Engineers performed this work ahead of schedule after Artemis 1 was rolled back to the Vehicle Assembly Building in April to address its tanking issues during previous rehearsals.
Nitrogen is used during testing, along with hydrogen, helium and air, in test stands provided by NASA’s High Pressure Gas Facility, according to agency materials (opens in new tab). Gaseous nitrogen is used to purge oxygen from the SLS prior to fueling operations, for safety purposes, during wet dress and launch, NASA said during previous tests.
Under the nominal schedule (opens in new tab), the terminal countdown is supposed to proceed at 2:30 p.m. EDT (1830 GMT), but Nail said it is likely that countdown will be delayed due to the issue.
NASA begins Artemis 1 tanking livestream
NASA has just begun the livestream of the Artemis 1 tanking operations, in anticipation that the wet dress rehearsal will start later today (Monday, June 20). You can watch the livestream above, on NASA’s YouTube channel and on NASA’s website.
“We are good to go for tanking, in terms of the weather,” the broadcast said (opens in new tab) at 7:12 a.m. EDT (1112 GMT). For example, the weather officer says probability of precipitation is 20%, and lightning is 10%. This forecast is valid until about 2:40 p.m. EDT (1840 GMT), agency officials said on the broadcast.
Updates will be provided every half-hour at the least during the broadcast, which will extend through much of Monday if operations go to plan. The agency said the launch team is working a “few issues”, but provided no further detail as of 7:15 a.m. EDT (1115 GMT).
“The team powered up ICPS [interim cryogenic propulsion system] overnight, and just finished their morning prep meeting before we proceed with the test,” said Jim Free, associate administrator for NASA’s exploration systems development mission directorate, on Twitter (opens in new tab) at 6:52 a.m. EDT (1052 GMT).
Artemis 1 ‘go’ for tanking operations Monday
The countdown would allow the stacked Space Launch System rocket and Orion spacecraft to practice a launch on the ground prior to doing it for real, during a planned uncrewed round-the-moon test.
“Teams are performing a pre-launch walkdown of the rocket to ensure the Space Launch System is prepared for the upcoming propellant loading operations,” the blog post stated at 4:57 p.m. EDT (2157 GMT) on Sunday (June 19).
“Later today, they [teams] will configure mobile launcher and pad facility systems and structures, and power up the interim cryogenic propulsion stage,” added the blog post, which was published following a routine mission management team meeting earlier in the afternoon EDT.
Favorable weather conditions are expected for the countdown, NASA noted. For tanking to proceed, there must be less than a 20% chance of lightning within 5 nautical miles (5.8 miles or 9.3 km) of Launch Pad 39B at NASA’s Kennedy Space Center in Florida, where the rehearsal is taking place.
Additionally, winds must be lower than 37.5 knots (43.1 mph or 69.5 km/h) and the temperature must be above 41 degrees Fahrenheit (5 degrees Celsius), the agency stated.
Another mission management team meeting is expected Monday at 6 a.m. EDT (1000 GMT) “to assess operations and determine whether to proceed with tanking operations,” NASA said. That milestone will be L-8 hours, 40 minutes in the countdown and the meeting will take place at the start of a planned 90-minute hold.
After today’s mission management team meeting progress continues ahead towards terminal count. Weather is still a go for #Artemis I wet dress rehearsal. Meteorologists predict favorable weather for tanking on June 20. Read more here: https://t.co/zgoL2CnoXa pic.twitter.com/nmBkAPSA24June 19, 2022
Wet dress rehearsal ‘on track’ as second day of test approaches
NASA says all Artemis 1 wet dress rehearsal operations are “on track” as the test approaches its second day of work later today, at 5 p.m. EDT (2200 GMT) Sunday.
NASA plans a routine mission management team meeting this afternoon EDT to review the status of rehearsal, the agency said in a blog post (opens in new tab) Sunday (June 19) at 10:48 a.m. EDT (1448 GMT). The wet dress rehearsal is a key step in getting Artemis 1 ready for its uncrewed round-the-moon test, which may launch later in 2022.
“Overnight, engineers powered up the Orion spacecraft and the Space Launch System’s core stage,” the agency stated in the blog post. “Teams also configured several systems on the ground, rocket, and spacecraft and performed activities to prepare umbilicals that connect the rocket and spacecraft to the mobile launcher and are used to provide power, communications, coolant, and propellant.”
The Twitter feed for NASA’s Kennedy Space Center, where the test is taking place at Launch Pad 39B, confirmed (opens in new tab) at 11:26 a.m. EDT (1526 GMT) that tanking operations remain scheduled for tomorrow (Monday, June 20).
The agency plans to provide live commentary Monday during tanking operations. In the meantime, NASA is streaming live video (opens in new tab) of the rocket and spacecraft.