Friday, September 16, 2022

Next Big Artemis Test Wednesday Sept. 21

It has been an agonizingly slow week for space news.  We had three consecutive scrubs of a SpaceX Starlink launch due to weather.  Starbase Boca Chica has done some more in their test campaign for the booster 7 static fire that we've been anticipating for months, but nothing as dramatic as the static fire/brush fire last week.  

There are two noteworthy items care of NASA's Artemis blog: first that the Artemis team has replaced seals on the vehicle associated with the hydrogen leak that scrubbed the mission attempts; and second, that the CAPSTONE vehicle, on its long, circuitous voyage to the moon put itself in "safe mode" after a recent midcourse maneuver and is currently still being recovered. 

Starting with the first, work began immediately after the final scrub on September 3rd. By Thursday the 8th, the blog posted:

Technicians constructed a tent-like enclosure around the work area to protect the hardware and teams from weather and other environmental conditions at Launch Pad 39B. They have disconnected the ground- and rocket-side plates on the interface, called a quick disconnect, for the liquid hydrogen fuel feed line, performed initial inspections, and began replacing two seals – one surrounding the 8-inch line used to fill and drain liquid hydrogen from the core stage, and another surrounding the 4-inch bleed line used to redirect some of the propellant during tanking operations.

The repairs were made and the next step - to test this repair - was originally set for Saturday the 17th (when most of you will be reading this).  Since then, the test has been rescheduled for No Earlier Than Wednesday the 21st.  NASA has requested a launch opportunity Sept. 27, with a potential backup opportunity of Oct. 2 under review.  Just how busy the Space Center is affects this.  NASA is planning the launch of Crew-5 to the space station NET October 3rd at 12:45 p.m. EDT; this will be from Pad 39A, now SpaceX's property under a long term agreement.  The pads are a little over 1-1/2 miles from each other.  They won't interfere with each other as long as everything goes normally.  

Artemis is requesting:

  • Sept 27: 70-minute launch window opens at 11:37 a.m. EDT; landing on Nov. 5
  • Under review – Oct. 2: 109-minute launch window opens at 2:52 p.m.; landing on Nov. 11

Don't forget that under the Space Force requirements for the Flight Termination System and the battery issue we've discussed, Artemis is supposed to be rolled back to the VAB and that would absolutely scuttle those two dates.  Artemis program has requested an extension on those batteries from the range and is working with them, providing additional information and data as required by Space Force.  Considering the batteries were supposed to be replaced originally before the September 3rd window and were given an extension, adding about a month to that original extension seems iffy - if the original date meant anything.  

Artemis core stage with the "service tent" in front of it.  NASA photo.

On September 10th, the following was reported:

The CAPSTONE spacecraft executed a planned trajectory correction maneuver on Thursday evening, Sept. 8, and CAPSTONE mission controllers have since obtained telemetry confirming that an issue put the spacecraft in safe mode near the end of the maneuver.

Following that update, the mission operator Advanced Space provided an update that was more complete.   Either during or shortly after the midcourse maneuver, the spacecraft started tumbling, and tumbling faster than its reaction control wheels could counteract. 

CAPSTONE was attempting to communicate with the ground for approximately 24 hours before any telemetry was recovered. After data was received, mission controllers found that the spacecraft was tumbling, the onboard computer systems were periodically resetting, and the spacecraft was using more power than it was generating from its solar panels.

Using the Deep Space Network, the mission team was able to contact the spacecraft and reconfigured the spacecraft’s systems to stabilize the situation while recovery plans are evaluated.  While still tumbling, the spacecraft was able to recover some position stability, and gets enough power from its solar panels to keep itself running properly.  The current update from Advanced Space, dated September 15th, says the emphasis is on heating the engine system on the spacecraft to above its minimum operational temperature (+5C or 41F) for at least 12 hours.  They believe they're getting enough power from the solar panels to do that.  

When the spacecraft propulsion system temps are at +5C for 12+ hours the system will be further evaluated for use in the recovery operation. Information on the cause of the anomaly has been obtained and is being evaluated, and recovery plans that mitigate risk of further anomalous behavior are being developed. We do not have a timeline for a recovery attempt, but the team is working hard to make progress guided by what we are learning from the data with an explicit goal to minimize further risk to the mission.

If this sounds scary to you - welcome to the club.  Advanced Space was honest enough to say they almost lost the spacecraft and they're still not completely out of the woods.  

We are effusively grateful to the teams at the Deep Space Network, NASA, Terran Orbital, and Advanced Space who have supported this ongoing effort continuously over the past 5 days. Without the quick action and dedicated attention of all of these exceptional individuals, the CAPSTONE mission would likely have been lost due to this anomaly. As it stands today, the vehicle is stable, and the combined mission operations team is working towards attempting a recovery operation.

This remains a dynamic and changing situation. We are focused on working the technical situation with an emphasis on disciplined analysis supporting a well thought out recovery attempt. The success of the CAPSTONE mission remains our primary focus. As we are able to, we will continue to share information on progress.




  1. Best wishes to the CAPSTONE Team. I've sweated things similar, and they can be nail-biters. Hope it ends well for us. I've seen the pain of losing "your" spacecraft, and it's real...

    1. Yeah, the first satellite I worked on was in service much less time than expected, and then unexpectedly died. I think it hit some space junk although it was kind of high (~400-ish miles, IIRC). We seem to get an attachment to something we've worked on a long time.

  2. Let me comment on the battery: "Artemis program has requested an extension on those batteries from the range..." The batteries that power the Flight Termination System (FTS) have a 90 day life, and are good until mid-October. The issue with the Range is the expiration of the FTS Verification test, which verifies that the entire FTS is connected and works correctly. The test is valid for a limited time, and due to Artemis' "Clean Pad" design, can only be performed in the VAB. Artemis has requested this time-after-test Requirement to be more than doubled what Artemis originally signed up for.

  3. Thanks very much for that info. Having worked in other hi-rel applications, I assume that if they say the batteries have 90 day life, that there's margin in that number and they're expected to be useful beyond 90 days. I just have no idea how much margin is in there. Likewise for the tests.

    With the exception of damage to the system, say wires inadvertently getting broken or cut while something else is being worked on, I don't see how the test can be invalid while the batteries (and other parts) are still considered good.

    The (what's a good word?) irony of the program asking for more than twice what was asked for originally is hard to get past, though. It just looks like no one ever thought this sort of situation would come up.

  4. I was just musing on a line in your post:

    (2022) “ It has been an agonizingly slow week for space news.”

    We are so spoiled, and yet, maybe …

    (2032) It has been an agonizingly slow DAY for space news.

    (2042) It has been an agonizingly slow HOUR for space news.

    (2052) It has been an agonizingly slow MINUTE for space news.

    1. Yeah, I admit to being spoiled by it. With the pace SpaceX works at and the rate news typically rolls in, it's easy to get used to having a constant flow of new stuff to read. A regular highlight of my week is the Ars Technica Rocket Report, but that didn't get issued this week for some reason, and that's a place where I tend to get a lot of my information on other companies.