Post-Artemis-1 report: heat shield ablated more than expected; power system issued unexpected commands; damage to launchpad

In a March 7, 2023 briefing, NASA officials provided an overall report of what happened during the first SLS launch, noting that there were some minor engineering issues but none that appeared to them significant.

The biggest issue of note was the Orion heat shield.

Howard Hu, Orion program manager at NASA, said that material on the heat shield had ablated differently than what engineers expected from ground tests and computer models. “We had more liberation of the charred material during reentry than we had expected,” he said. Engineers are just beginning detailed analysis of the heat shield to determine why it behaved differently than expected.

The amount ablated was well within safety margins, but engineers still do not understand why the material behaved differently than expected.

Engineers are also trying to understand why the power system of the Orion service module issued unplanned commands, several times opening what officials called a “latching current limiter.” This action caused no problems to the capsule’s operations, but it is concerning it occurred.

The launch also did more damage to the mobile launcher tower than expected.

According to NASA officials, none of these issues will delay the planned November 2024 launch date for the Artemis-2 mission, the first intended to carry humans.

Update on the ten cubesats launched by SLS

Link here.

At this moment six of the ten cubesats either accomplished their mission successfully or are still operating, while four cubesats failed entirely.

Of those still working, two will go into lunar orbit and try to find evidence of both hydrogen and ice on the Moon. A third is testing “solid iodine” thrusters, while a fourth will observe how yeast samples react to a long exposure in deep space. A fifth cubesat is a joint NASA-JAXA mission, and is testing how to fly a smallsat in the low gravity of a Lagrangian point.

Finally, an Italian cubesat was used to successfully take images of the Moon and Orion, and has completed its mission.

Orion successfully splashes down in the Pacific

NASA’s Orion capsule today successfully returned from a three week trip around the Moon, splashing down in the Pacific where it was successfully recovered.

The next Artemis flight will be a manned one, using SLS and Orion to fly around the Moon. It will also be the first time Orion will use its full environmental system, with humans on board. Though presently scheduled for May 2024, it is almost certainly not going to fly before 2025.

The actual Artemis manned lunar landing will follow, no sooner than two years after that. As presently designed, that mission requires the establishment of the Lunar Gateway station — astronauts can be transferred from Orion to Starship and back again, and that station is likely not going to be ready in this time frame.

As I said yesterday, I predict the two already purchased private Starship missions around the Moon, paid for by Yusaku Maezawa and Jared Isaacman, will happen first. Both will certainly beat NASA’s planned landing on the Moon. I also expect both to beat that Orion manned fly-around in ’24-’25. And each will cost pennies compared to the entire SLS/Orion program, while actually making a profit that will be used to further development and more manned private flights.

Orion completes burn to send spacecraft back to Earth

NASA’s Orion capsule yesterday successfully fired its engines as it zipped past the Moon to send it on a trajectory back to Earth, with splashdown in the Pacific off the coast of California scheduled for December 11, 2022.

Not all was hunky-dory, however. Prior to the burn a power unit shut down unexpectedly.

A power unit on board the Orion spacecraft turned off four devices “responsible for downstream power” that connect to the Artemis 1 vehicle’s propulsion and heating subsystems, NASA officials wrote in a statement. But mission personnel swiftly put a fix in place and the mission is carrying on, the statement emphasized. “Teams confirmed the system was healthy and successfully repowered the downstream components,” agency officials wrote in the statement, released late on Sunday. “There was no interruption of power to any critical systems, and there were no adverse effects to Orion’s navigation or communication.”

Engineers think the shut down was related to a test performed in connection with an earlier incident.

Regardless, all now appears well for that December 11nd splashdown.

Orion fires engine, leaves lunar orbit

After firing its engines yesterday, NASA’s Orion spacecraft has left lunar orbit and begun a long looping route that will zip past the Moon and then head back to Earth.

The burn changed Orion’s velocity by about 454 feet per second and was performed using the Orion main engine on the European Service Module. The engine is an orbital maneuvering system engine modified for use on Orion and built by Aerojet Rocketdyne. The engine has the ability to provide 6,000 pounds of thrust. The proven engine flying on Artemis I flew on 19 space shuttle flights, beginning with STS-41G in October 1984 and ending with STS-112 in October 2002.

The burn is one of two maneuvers required ahead of Orion’s splashdown in the Pacific Ocean on Dec. 11. The second will occur on Monday, Dec. 5, when the spacecraft will fly 79.2 miles above the lunar surface and perform the return powered flyby burn, which will commit Orion on its course toward Earth.

The spacecraft will splashdown on December 11, 2022, if all goes right.

Orion enters retrograde lunar orbit

Engineers today successfully completed an engine burn that put Orion into the retrograde lunar orbit in which it will remain for the next week.

Due to the distance of the orbit, it will take Orion nearly a week to complete half an orbit around the Moon, where it will exit the orbit for the return journey home. About four days later, the spacecraft will harness the Moon’s gravitational force once again, combined with a precisely timed lunar flyby burn to slingshot Orion onto its return course to Earth ahead of splashdown in the Pacific Ocean on Sunday, Dec. 11.

As of now all systems seem to be working as intended.

Controllers lose contact with Orion for almost an hour

NASA engineers unexpectedly lost all contact with Orion for 47 minutes just after midnight last night.

NASA’s Mission Control Center at the agency’s Johnson Space Center in Houston unexpectedly lost data to and from the spacecraft at 12:09 a.m. CST for 47 minutes while reconfiguring the communication link between Orion and Deep Space Network overnight. The reconfiguration has been conducted successfully several times in the last few days, and the team is investigating the cause of the loss of signal. The team resolved the issue with a reconfiguration on the ground side.

At present the loss of signal caused no issues with the spacecraft. However, its cause has not yet been pinpointed.

Six of the ten cubesats launched toward the Moon by SLS still working

The Moon as seen by ArgoMoon
Click for full image.

Of the ten cubesats launched toward the Moon by SLS last week, six are still working while four have problems that are likely killing their missions.

The photo to the right, cropped, reduced, and sharpened to post here, was taken by ArgoMoon, an Italian cubesat that is working perfectly. The large impact basin visible is Orientale Basin, located just on the edge of the visible face of the Moon but partly hidden on the far side.

A summary of the status of all ten can be found here. Of the other five still functioning properly, all have been able to maintain proper communications.

Possibly the biggest disappointment however is the failure of Japan’s Omotenashi lander, which was going to attempt a lunar soft landing. Shortly after launch it began tumbling, and engineers were never able to regain full control or communications. The landing attempt has now been abandoned.

Side note: Orion itself also captured some images as it zipped past the Moon yesterday, but they do not appear as high quality as ArgoMoon’s pictures.

Ten cubesats released by SLS on way to Moon; one has problems

Shortly after SLS’s upper stage completed its engine burn to send Orion to the Moon, it separated and then successfully released ten cubesats on their own deep space missions.

These CubeSats will fly to various destinations including the Moon, asteroids, and interplanetary space. They will study various facets of the Moon and interplanetary travel, ranging from navigation techniques to radiation and biology. One of them is even planned to conduct a soft landing on the lunar surface.

Because of SLS’s numerous delays, there was a chance that many of these cubesats would lose the charges on their batteries and not function after launch. According to the article at the link, communications with six of these cubesats has been established.

The last cubesat above, from Japan and dubbed Omotenashi, was designed as a demonstration test. According to Japan’s space agency, JAXA, however, communications with the spacecraft are “unstable.”

Japan’s space agency said Thursday it has been unable to establish stable communication with the country’s mini moon lander launched on a U.S. rocket the previous day along with a mini satellite. The Japan Aerospace Exploration Agency said it is now trying to control the position of the Omotenashi lander, adding its system of automatically turning to the Sun to gain solar power appears to be not functioning.

Before launch JAXA had rated the mission’s chances of success at 60%, but that mostly referred to the lunar landing. Though intended as a demo mission, it will be unfortunate if it fails for these reasons this early in the mission.

NASA’s SLS rocket successfully launches Orion toward the Moon

After almost eighteen years of development and almost sixty billion dollars, NASA tonight finally completed the first unmanned test launch of its Space Launch System (SLS) rocket, lifting off at 1:41 am (Eastern).

The two solid rocket boosters functioned as planned, separating from the core stage with no problem. Then core stage and its four former shuttle engines completed its burn, putting the capsule and its upper stage into Earth orbit, and then separated cleanly. At about 30 minutes after launch the service module’s solar arrays completed their deployment. At 53 minutes after launch a 30 second burn circularized the orbit in preparation for the trans-lunar-injection (TLI) burn that will send Orion to the Moon. TLI occurred about 90 minutes after launch, after a period of check-out in orbit.

Orion will spend 26 days in space, about a week of which will be in a wide lunar orbit, testing its systems. If all goes right it will splashdown on around December 11th.

As this was the first U.S. government launch in more than a decade, since 2011 when the space shuttle was retired, the leader board for the 2022 launch race remains unchanged:

The leaders in the 2022 launch race:

52 SpaceX
51 China
19 Russia
9 Rocket Lab

The U.S. now leads China 76 to 51 in the national rankings, and trails the rest of the world combined 79 to 76.

Watching the first SLS launch tonight

At this moment, with weather 90% favorable and the countdown underway, the first launch of NASA’s SLS rocket appears go for a 1:04 AM (Eastern) launch tonight.

You can watch the live stream on NASA TV here, which will begin at 3:30 pm today and mostly be NASA propaganda intermixed with descriptions of the rocket, its payloads, its full mission, and updates on the launch countdown.

NASA’s live stream is now embedded below, beginning at 10:30 PM (Eastern) when actual coverage of the final countdown begins. I would still suggest that you wait until at least 12:30 AM (Eastern) before watching, as those first two hours will still be filled with a lot of NASA propaganda blather.
» Read more

NASA managers okay SLS launch attempt November 16th

NASA managers have given the go-ahead to the scheduled launch of the agency’s SLS rocket for 1:04 am (Eastern) on November 16, 2022, despite the existence of some detached caulking that Hurricane Nicole had pulled free.

Engineers examined detailed analysis of caulk on a seam between an ogive on Orion’s launch abort system and the crew module adapter and potential risks if it were to detach during launch. The mission management team determined there is a low likelihood that if additional material tears off it would pose a critical risk to the flight.

Technicians also completed replacing a component of an electrical connector on the hydrogen tail service mast umbilical. While swapping the component did not fully fix the issue, engineers have redundant sources of information supplied through the connector.

The launch window is two hours long. As this is a night launch, it will be quite spectacular, no matter what happens. I will embed the live stream tomorrow in the early evening, for those who wish to watch NASA’s multi-hour propaganda stream. My suggestion would be to find a better use of your time until around 12:50 am (Eastern). Then would be a good time to tune in.

SLS launch early on November 16th remains uncertain

Despite repeated assurances that the November 16, 2022 1:04 am (Eastern) launch of NASA’s SLS rocket remains on target, managers have also noted that damage to a small piece of caulking at the base of the shroud protecting the Orion capsule remains an issue that could cause a scrub.

But high winds from Nicole caused a thin strip of caulk-like material known as RTV to delaminate and pull away from the base of the Orion crew capsule’s protective nose cone at the top of the rocket. The material is used to fill in a slight indentation where the fairing attaches to the capsule, minimizing aerodynamic heating during ascent. The fairing fits over the Orion capsule and is jettisoned once the rocket is out of the dense lower atmosphere. “It was an area that was about 10 feet in length (on the) windward side where the storm blew through,” said mission manager Mike Sarafin. “It is a very, very thin layer of RTV, it’s about .2 inches or less … in thickness.”

Engineers do not have access for repairs at the pad and must develop “flight rationale,” that is, a justification for flying despite the delaminated RTV, in order to proceed with the launch. Managers want to make sure any additional material that pulls away in flight will not impact and damage downstream components.

In plain language, NASA managers would either have to issue a waiver that says this small piece of caulking poses no risk, or scrub and roll the rocket back to the assembly building to fix it. The second option would delay the launch another month, at a minimum.

A waiver however would continue NASA’s pattern with the shuttle (and continuing with SLS) to dismiss potential engineering problems simply to avoid schedule delays. With the shuttle, this pattern twice caused the loss of a shuttle and crew. With SLS, NASA has already waived by more than a year its rules concerning the stacked life of the rocket’s solid-fueled boosters. Agency managers have also waived the full test requirements from the dress rehearsal countdown, so that this test did not test everything it should.

It is expected that NASA managers will announce the waiver today on this problem. Whether it matters when the rocket goes through maximum dynamic pressure shortly after lift-off will likely determine the future of SLS.

SLS rides out hurricane; engineers now assessing damage

NASA’s SLS rocket has apparently successfully survived on the launchpad the hurricane-force winds from Nicole, though engineers will need to inspect the rocket to see if there is any less obvious damage that might delay the now scheduled November 16th launch.

With blastoff on a long-delayed maiden flight on tap next week, sensors at pad 39B recorded gusts as high as 100 mph atop a 467-foot-tall lightning tower near the rocket. But winds at the 60-foot-level, which are part of the booster’s structural certification, peaked at 82 mph, just below the 85 mph limit.

The observed winds were “within the rocket’s capability,” said Jim Free, manager of exploration systems at NASA headquarters. “We anticipate clearing the vehicle for those conditions shortly.”

“Our team is conducting initial visual check outs of the rocket, spacecraft and ground system equipment with the cameras at the launch pad,” he tweeted. “Camera inspections show very minor damage such as loose caulk and tears in weather coverings. The team will conduct additional on-site walk down inspections of the vehicle soon.”

If no issues are found, the countdown will begin on November 14th.

SLS launch delayed until November 16

In order to give them time to make sure all is right after the coming tropical storm, NASA managers have decided to delay the first test flight of SLS two days until November 16.

A launch during a two-hour window that opens at 1:04 a.m. EST on Nov. 16 would result in a splashdown on Friday, Dec. 11. If needed, NASA has a back-up launch opportunity on Saturday, Nov. 19, and will coordinate with the U.S. Space Force for additional launch opportunities.

At the moment they have decided to keep the rocket on the launchpad, as they expect it will be able to withstand the predicted storm. If the predictions change however they still have the option to roll it back into the assembly building.

Hurricane threatens SLS on launchpad

A storm, now rated subtropical, that is expected to cross the east coast of Florida on November 10th with the possibility that it could strengthen into a hurricane now threatens NASA’s SLS rocket that is on its Florida launchpad preparing for its first test flight on November 14, 2022.

A map of the storm’s presently predicted track can be seen here.

NASA’s Kennedy Space Center in Florida is currently in a HURCON (Hurricane Condition) IV status, which includes implementing checklists and preparations for the storm as the agency continues to prioritize its employees in the Kennedy area. Based on current forecast data, managers have determined the Space Launch System rocket and Orion will remain at Launch Pad 39B. Teams at Kennedy will continue to monitor the weather, make sure all personnel are safe, and will evaluate the status of the Monday, Nov. 14, launch attempt for the Artemis I mission as we proceed and receive updated predictions about the weather.

Depending on the storm’s track in the next 24 hours, as well as its strength, NASA managers have the option of returning the rocket to the assembly building to protect it. If they do so, however, it is certain the November 14th launch date will be scrubbed. As they have a window of a number of additional dates [pdf] through November 27th, I suspect they will then aim for one of those dates.

NASA sets November 14th as next SLS launch date

NASA today announced that it will make its next attempt to launch its SLS rocket just past midnight on November 14, 2022.

NASA is targeting the next launch attempt of the Artemis I mission for Monday, Nov. 14 with liftoff of the Space Launch System (SLS) rocket carrying the Orion spacecraft planned during a 69-minute launch window that opens at 12:07 a.m. EST. Artemis I is an uncrewed flight test to launch SLS and send Orion around the Moon and back to Earth to thoroughly test its system before flights with astronauts.

This is the second launch opportunity in the November launch window, as shown in this graph [pdf]. It will result in a 26-day mission for the Orion capsule to and from lunar orbit, returning on December 9th.

NASA now aiming for SLS launch in November

In finding that Hurricane Ian caused little damage at its vehicle assembly building at Kennedy, NASA managers have decided to target the the November 12 to 27 launch window for the first launch of its SLS rocket.

According to this graph [pdf], November 27th is the only date that will provide NASA with the longest mission for Orion (38 to 42 days). Furthermore, the mission precludes launches on November 13, 20-21, and 26.

Expect them to aim for November 12th, even though that will result in an Orion mission only 26 to 28 days long.

NASA managers decide finally to roll SLS back to assembly building

NASA managers this morning finally gave up on launching their SLS rocket in an early October launch window and scheduled rolling back the rocket to the assembly building tonight.

NASA will roll the Artemis I Space Launch System rocket and Orion spacecraft back to the Vehicle Assembly Building on Monday, Sept. 26. First motion is targeted for 11 p.m. EDT.

Managers met Monday morning and made the decision based on the latest weather predictions associated with Hurricane Ian, after additional data gathered overnight did not show improving expected conditions for the Kennedy Space Center area. The decision allows time for employees to address the needs of their families and protect the integrated rocket and spacecraft system. The time of first motion also is based on the best predicted conditions for rollback to meet weather criteria for the move.

Based on this graph [pdf] provided by NASA earlier this year, the next launch window is from October 17 to October 31, followed by another from November 12 to November 27. It is unclear whether they can meet that first window, even if all engineers do is check and recharge the flight termination system batteries.

The question of the rocket’s two solid-fueled boosters however looms. Both are now one year past NASA’s use-by date, and it appears somewhat unknown what the risks are using them. Replacing them however will entail a significant delay, from three to six months.

As I said this weekend, NASA managers face no good choice, because of the impractical and inefficient design of this rocket.

NASA managers might forego SLS rollback and aim for Oct 2nd launch

Based on the present hurricane track, NASA managers are considering the possibility of leaving SLS on the launchpad so that they can go for a launch on October 2, 2022.

NASA managers will meet this evening to evaluate whether to roll back or remain at the launch pad to preserve an opportunity for a launch attempt on Oct. 2. The exact time of a potential rollback will depend on future weather predictions throughout the day and could occur Monday or very early Tuesday morning.

If they stay on the launchpad, it means the flight termination system is questionable at launch. If the rocket goes out of control during its first test launch — a not-unreasonable possibility for a new rocket — there is a chance the range officer will not be able to destroy it.

If they roll back to the assembly building, it means the rocket’s two solid strap-on boosters will either have to be replaced, delaying the launch months more, or the rocket will launch with two boosters that are questionable.

Every choice they face is a bad one, simply because this rocket is really not well designed for practical use.

NASA managers scrub September 27th SLS launch

NASA managers today decided that they had to scrub their attempt to launch SLS on September 27, 2022 due to a hurricane threatening Florida, and are instead preparing to roll the rocket back to the assembly building to protect it.

During a meeting Saturday morning, teams decided to stand down on preparing for the Tuesday launch date to allow them to configure systems for rolling back the Space Launch System rocket and Orion spacecraft to the Vehicle Assembly Building. Engineers deferred a final decision about the roll to Sunday, Sept. 25, to allow for additional data gathering and analysis. If Artemis I managers elect to roll back, it would begin late Sunday night or early Monday morning.

This will likely delay the launch until the late October launch window, or the mid-November window, as shown in this graph [pdf]. During this time engineers will certainly test and recharge the batteries that run the rocket’s flight termination system so that there will be no question they will work should the Space Force safety range officer need to destroy the rocket during launch.

NASA however now faces another quandary it has been avoiding for the past year. The stacking of the five segments of SLS’s two solid rocket strap-on boosters began in November 2020, two years ago. During the shuttle era and until last year, NASA had a rule that said a booster must launch within a year of stacking. The fear was that the weight of the solid rocket fuel could distort it over time, and possibly cause it to burn improperly once ignited. As these boosters are the equivalent of firecrackers — once you light them you can’t turn them off — NASA had chosen, until last year, to have a use-by date of one year for the boosters.

Now however NASA has abandoned that rule. The boosters have been stacked for twice that time, and the agency has to ask if it will be safe to use them. To change them out however will take at least three months, if not longer. The present set of boosters would have to be removed, and a new set stacked and installed.

I fully expect NASA to stay with these boosters, despite their age, once again violating its own safety rules, as it did routinely during the shuttle era (resulting in the loss of two shuttles and the death of fourteen astronauts). Though no humans will be on this test flight, this sloppy engineering culture clearly threatens the lives of the astronauts who will fly on the second Artemis SLS mission, around the Moon.

Range gives NASA waiver to launch SLS on September 27th, despite a questionable flight termination system

In a briefing today, NASA officials confirmed that they are proceeding with their September 27, 2022 first launch of the SLS rocket, having obtained a waiver from the Space Force’s range office on testing the batteries for the flight termination system that would destroy the rocket should it begin flying out of control.

During a Sept. 23 teleconference, NASA announced an extension for the flight termination system battery certification, which expired after 25 days on Sept. 6. Now the Space Force’s Eastern Range has granted a waiver to allow the rocket to launch as late as Oct. 2 before needing to be returned to the Vehicle Assembly building to recertify the batteries.

The flight termination system is only used in the event the rocket veers off course during a launch anomaly.

Note that the 25 day use-by limit was actually an extension itself, as these batteries had been previously required testing every 20 days. Now the range is willing to let them go for as long about 50 days without testing, a two and half times increase.

If the rules before — based on engineering — said the batteries were not reliable after 20 days, why are those batteries now considered reliable up to 50 days? What facts or data does NASA or the Space Force have to allow this waiver? And if they have no data, it seems almost criminal to allow the go-ahead of this launch of a giant untested rocket on its first lift-off. Should something go seriously wrong — which is not that unlikely — and the flight termination system fails to work, we could see a very big rocket careening out-of-control into populated areas.

We all hope SLS launches with no problem on September 27th. We now have a really serious reason for that desire.

Regardless, the launch is now scheduled for a 70-minute launch window that opens at 11:37 am (Eastern) on September 27th, with a back-up launch window on October 2nd of 102 minutes beginning at 2:52 pm (Eastern).

Meanwhile, a developing tropical storm could put a kabosh on all these plans, forcing NASA to roll SLS back to the assembly building anyway. NASA managers plan to meet again before launch to make a decision.

SLS fueling test completed

NASA engineers today successfully completed the tanking test of the agency’s SLS rocket, completing all objectives after successfully dealing with a hydrogen fuel leak at the beginning of fueling.

The four main objectives for the demonstration included assessing the repair to address the hydrogen leak identified on the previous launch attempt, loading propellants into the rocket’s tanks using new procedures, conducting the kick-start bleed, and performing a pre-pressurization test. The new cryogenic loading procedures and ground automation were designed to transition temperature and pressures slowly during tanking to reduce the likelihood of leaks that could be caused by rapid changes in temperature or pressure. After encountering the leak early in the operation, teams further reduced loading pressures to troubleshoot the issue and proceed with the demonstration test. The pre-pressurization test enabled engineers to calibrate the settings used for conditioning the engines during the terminal count and validate timelines before launch day to reduce schedule risk during the countdown on launch day.

Teams will evaluate the data from the test, along with weather and other factors, before confirming readiness to proceed into the next launch opportunity. The rocket remains in a safe configuration as teams assess next steps. [emphasis mine]

The highlighted words are key. NASA has proposed a September 27, 2022 launch date. For that launch to occur, the rocket must remain on the launchpad, where it is impossible to check the batteries for operating the flight termination system used by the military range office to destroy the rocket should it go wildly out of control during launch. To check the batteries they need to roll it back to the assembly building, and one week is simply not enough time.

The vagueness of the highlighted language suggests that NASA has not yet gotten a waiver from the range for that date. Nor should it. Those batteries normally have a 20-day limit. On September 27th they will been unchecked for about 42 days, well past their use-by date.

This will be the first test launch of this rocket. Such first launches very frequently go wrong, and if SLS goes wrong, it would go wrong in a very big way, considering the size of the rocket. To do such a risky launch with a questionable flight termination system would not simply be improper it would be downright criminal.

Hydrogen leak detected during today’s SLS tank test

Though engineers have apparently overcome the issue so that today’s tank test of NASA’s SLS rocket can continue, a hydrogen leak was nonetheless detected during fueling.

The fueling tank test is not yet complete.

At this moment I cannot imagine the military’s range office will allow NASA to launch on September 27th, as the agency has requested. To do so will require the range to ignore the possibility that the flight termination is inoperable, as its batteries are past their use-by date by almost a month. Combined with these ongoing leak issues, it would be irresponsible to do otherwise.

NASA revises its SLS launch schedule, pending approval of the range’s safety office

NASA today announced that it is now targeting September 27, 2022 for the first test launch of its SLS rocket and Orion capsule.

Engineers have — on the launchpad — completed the repair work on the hydrogen leak that caused the previous launch scrubs. The plan now is to do a test fueling on September 21st to see if the repair worked.

If all is then well, the agency wants to launch on September 27th. To do so however NASA needs to get the approval of the safety range office to waive the use-by date of the batteries used to terminate the flight after launch, should something go seriously wrong. The rules require those batteries to be checked every 20 days, and as of today they have been in use for 31 days. The range had already given NASA a five day waiver so it could try to launch on September 5. To launch on September 27th will require the range to allow those batteries to remain unchecked for 46 days, more than double their accepted use-by date.

For the range to allow such a waiver would be I think entirely unprecedented, especially for the very first launch of a new rocket. Such test launches are exceedingly risky. A lot can go wrong, and often does when a rocket tries to fly for the first time. To allow such a lift-off with a questionable flight termination system seems completely insane and irrational.

NASA is also proposing an October 2nd launch date. I suspect this date is based on the range safety office refusing to give this waiver. If so, NASA would then do its September 21st fueling test on the launchpad, quickly roll the rocket back to the assembly building to check the batteries, and then try to get it back to the launch pad in time for that October 2nd date.

NASA wants to launch SLS in September; needs range safety office waiver to do it

In outlining the status of the repair work on the hydrogen leak on SLS on the launchpad yesterday, NASA officials indicated that they are targeting a September 23rd launch date that will require the Space Force range safety office to okay the use of a flight abort system with batteries that are significantly past their use-by date.

NASA has submitted a request to the Eastern Range for an extension of the current testing requirement for the flight termination system. NASA is respecting the range’s processes for review of the request, and the agency continues to provide detailed information to support a range decision.

The range office had required that the batteries for that flight termination system be checked every 20 days, a process that requires the rocket to be rolled back to the assembly building. It had already given NASA a five day extension to 25 days, but even that was insufficient to get the rocket launched in its previous launch window, expiring on September 6th. Though NASA has not said how long an extension it is requesting, to do a September 23rd launch would require another extension of 17 days, making for a total 23-day waiver for those batteries. Thus, instead of limiting the life of those batteries to 20 days, NASA is requesting the range to allow the batteries to go unchecked for 43 days, at a minimum.

For the range to give that first waiver I think is somewhat unprecedented. To do it again, for that much time, seems foolish, especially as this will the rocket’s first launch, and a lot can go wrong.

NASA officials also hinted during yesterday’s press conference — in their bureaucrat way — that human error might have caused the hydrogen leak.

NASA has not confirmed if an “inadvertent” manual command that briefly overpressurized the hydrogen fuel line caused the leak, but the agency is investigating the incident. Bolger said new manual processes replaced automated ones during the second attempt and the launch team could have used more time to practice them. “So we didn’t, as a leadership team, put our our operators in the best place we could have,” Bolger said. During the Sept. 17 fueling test, NASA will try out a slower, “kinder and gentler” process that should avoid such events.

If the Space Force and the Biden administration demand the range officer allow this rocket, with this team, to be launched with a questionable flight termination system, we should expect public resignations from several range officers. Whether anyone in our present government however has the ethics to do such a thing appears very doubtful.

NASA to roll SLS back to assembly building, delaying launch by weeks at minimum

NASA managers today decided they will not attempt another launch of SLS during the present launch window that closes on September 6, 2022, and will bring the rocket back to assembly building for more detailed trouble-shooting.

Engineers not only need to solve the hydrogen fuel leak in a fuel line connection that caused today’s launch scrub, they will also have to replace the flight termination batteries needed in case the rocket has to be destroyed during liftoff because it is flying out of control. These batteries only have a few weeks life, and the launch delays this week caused them to reach their limit.

The next launch windows are either from September 19 to October 4, excluding September 29-30, or October 17 to October 31, excluding October 24, 25, 26, and 28.

At that point SLS’s two solid rocket strap-on boosters will have been stacked for about two years, one full year past what NASA once considered their safe lifespan. The agency has waived that rule for SLS, but waiving it for more than a full year might simply be too risky. If the boosters need to be replaced, that will delay the launch by at least another three months, at the minimum.

Right now the odds remain high this launch will not occur in 2022.

SLS test launch scrubbed again

NASA engineers once again were forced to scrub the launch of the SLS rocket today due to another hydrogen leak during fueling.

The launch director waived off today’s Artemis I launch attempt at approximately 11:17 a.m. EDT. Teams encountered a liquid hydrogen leak while loading the propellant into the core stage of the Space Launch System rocket. Multiple troubleshooting efforts to address the area of the leak by reseating a seal in the quick disconnect where liquid hydrogen is fed into the rocket did not fix the issue.

NASA has one more chance, on September 5th, to launch this rocket before it must return it to the assembly building to replace the flight termination batteries, used to abort the launch after liftoff should something go seriously wrong during flight. As I understand it, their use-by date is September 6th, and it would require a major safety waiver by the military range officer, who is entirely independent from NASA and under no obligation to it, to allow for a launch after that date with those batteries.

NASA thinks engine issue on SLS launch caused by misreading sensor

NASA engineers have now concluded that the improper temperatures in one engine in SLS’s core stage that forced the August 29, 2022 launch to be scrubbed were caused by a faulty sensor, and that the actual temperatures in the engine were correct.

During a news conference on Tuesday evening, NASA’s program manager for the SLS rocket, John Honeycutt, said his engineering team believed the engine had actually cooled down from ambient temperature to near the required level but that it was not properly measured by a faulty temperature sensor. “The way the sensor is behaving does not line up with the physics of the situation,” Honeycutt said.

The problem for NASA is that the sensor cannot be easily replaced and would likely necessitate a rollback to the Vehicle Assembly Building at Kennedy Space Center in Florida, a few kilometers from the launch pad. This would delay the launch of the rocket at least into October, and the space agency is starting to get concerned about wear and tear on a rocket that has now been stacked for nearly a full year.

With this SLS rocket, NASA management is now trapped between a rock and a hard place. The rocket’s solid rocket boosters has been stacked for just short of two years, almost a full year beyond their use-by date. Moreover, there are batteries on the rocket that only function for about a month before they must be replaced. Their replacement date is September 6th, which means if NASA cannot get the rocket launched by that date it will have to return it to the assembly building, delaying the launch to at least October. If it has to replace the solid rocket boosters the launch will likely then be delayed until next year, which will seriously impact the second SLS launch, set to send astronauts around the Moon and back.

At the moment the launch is scheduled for a two hour launch window beginning at 2:17 pm (Eastern) on Saturday, September 3, 2022. The countdown will be live streamed here. At the moment the weather for Saturday has improved, with s 60% chance the launch can proceed.

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