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Artemis 1 carries ten cubesats as secondary payloads. One of the concerns prior to the last rollback, in September, was that the batteries were almost out of charge and that there was no way to recharge them while they were onboard the SLS. Flat batteries would mean the cubesats are useless.

Are those batteries now flat? Did NASA find a way to recharge them while the vehicle was stacked?

I've hunted around but can't find a statement from NASA about this.

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TL;DR: (22/11/22 updated edit added at bottom)

Are those batteries now flat?

For some (definitely for one) it could be too late. For the lucky few, they had a recharge.

Did NASA find a way to recharge them while the vehicle was stacked?

For some that could be, yes, for others, no.

I've hunted around but can't find a statement from NASA about this.

Probably because NASA was not focused on their wellbeing, and they do say that failure 'is the nature of cubesats'.

Partial:

Back in august this came up in the news, some good, some not so good:

https://spaceflightnow.com/2022/08/23/cubesats-on-artemis-1-to-pursue-bold-missions-in

CubeSats on Artemis 1 to pursue bold missions in deep space, if they overcome battery concerns

The 10 CubeSats hitching a ride to deep space on NASA’s Space Launch System moon rocket promise new discoveries about the moon, space weather, and asteroids. But some of the small spacecraft will launch with their batteries only partially charged after sitting inside the rocket for more than a year.

Five of the 10 secondary payloads had their batteries recharged, while the others were not topped off due to design and access constraints. In at least one case, mission officials chose not to recharge a CubeSat’s battery.

“There were several that had the capability of being recharged, and then there were several that simply did not have that capability once we are stacked,” Bleacher said. “At this point, it’s difficult to apply any more charge to those CubeSats. So we’re trying to work through preparations and get the SLS ready to fly. That’s the best thing that we can do at this point.

“The remainder of those CubeSats, based on analyses we believe have sufficient charge to conduct a mission. Some may actually need to recharge after they’re deployed, after they gain some solar power through their solar arrays. But we believe each of these have a mission.

“That said, the CubeSats are relatively low cost,” Sarafin (NASA’s Artemis 1 mission manager) said. “They have relatively low levels of redundancy and a relatively high failure rate, so we do anticipate one or more of these CubeSats to not be successful in its mission just due to the nature of the CubeSats themselves.”

Of the 10, the following were not recharged as of August:

  • Lunar
  • IceCube
  • LunaH-Map
  • CuSP
  • LunIR
  • Team Miles

Further, in September:

https://nasawatch.com/artemis/what-about-those-fading-batteries-on-sls-cubesats/

What About Those Fading Batteries On SLS CubeSats?

Based on media briefing comments NASA doesn’t seem to be especially interested in making sure that these payloads have good batteries.

Comments:

From the AAAS Journal SCIENCE: "BioSentinel, NEA Scout, and three other CubeSats were allowed to recharge their batteries during their long wait aboard the SLS. But five others were out of luck, including both LunaH Map and Lunar IceCube. Some could not be recharged without removing them from the rocket; in other cases NASA engineers feared the process might spark discharges that could harm the rest of the rocket. “We have to be very cognizant of the risk to the primary mission when we interface with these CubeSats,” says Jacob Bleacher, NASA’s chief exploration scientist."

Not all dispensers have a connector for charging the cubesat externally, nor does the host spacecraft or launch vehicle have it cabled up to be accessible. And the typical "install before flight" IBF plug (which is how a lot of cubesats are charged) is only accessible if the cubesat is removed from the dispenser. Or, if you're lucky, through an access panel in the dispenser. So you have to remove: a) the panel in the dispenser b) the cover over the IBF plug c) the IBF plug

enter image description here

Added NASA Secondary Payloads brochure Nov 2021

FLY WITH SLS!

https://www.nasa.gov/sites/default/files/atoms/files/0364_secondary_payloads_brochure_07282020_508_single_pages_for_web.pdf

Spaceflight-Mission-Planning-Guide-Rev-G

https://spaceflight.com/wp-content/uploads/2019/02/Spaceflight-Mission-Planning-Guide-Rev-G.pdf

Added this link for the comments in the article:

NASA seeking proposals for cubesats on second SLS launch

https://spacenews.com/nasa-seeking-proposals-for-cubesats-on-second-sls-launch/

The following is a twitter thread, from the Professor of one of the cubesat programs, after the September press conference that mentioned the cubesats situation:

enter image description here

https://twitter.com/hardgrove/status/1566408247350894592?lang=en

Excerpt:

Without access to the spacecraft, each cubesat program is doing their best to assess the risks to their mission based on the possible charge states after over 1 year in storage.

Five of the cubesats on Artemis-1 are unable to charge their batteries. The reasons why vary across the missions. Some did not design that capability, some decided not to, and others were not allowed to due to SLS safety concerns. @lunahmap is one of those that can not.

Upon deployment, all the cubesats use solar panels to charge their batteries and/or power their subsystems. In the case of @lunahmap and CuSP, they were designed so that if sunlight hits their solar arrays the batteries will charge even if the spacecraft has not booted up

SLS launch delays do NOT mean that the cubesat missions are dead, as long as they were designed to charge after deployment when their solar arrays are exposed to the Sun.

So while there is increased risk to the cubesats who can not charge, at worst they will deploy into a “dormant” state and spring to life after some Sun hits their solar arrays. The biggest risk to the missions then is lost time.

(and a thread update in October)

My understanding is that the cubesats which can have their batteries charged by SLS did/will receive a charge prior to the next rollout. For @lunahmap, the risk to lost mission time increases a bit but likely not too high if the rate of self discharge has remained low (~few %/mo)

This thread is specifically regarding the Lunar Polar Hydrogen Mapper (LunaH-Map) which is a NASA 6U CubeSat mission from Arizona State University and School of Earth and Space Exploration to map water on the moon.

.

.

enter image description here

These cubesats are really small!

.

(Edit, updated 20th November)

https://www.nasaspaceflight.com/2022/11/artemis-i-cubesats/

After the installation of the CubeSats in the ICPS upper stage, concerns arose about the effect delays could have on the satellite missions.

The satellites’ onboard batteries were charged before payload installation on the upper stage, but some of them could not be recharged due to a lack of access. After the SLS was rolled back to the VAB in September, some satellites – those that could be accessed – were recharged.

The BioSentinel satellite’s yeast payload was cooled before installation to preserve the viability of the experiment. The effect of the mission’s cumulative delays on BioSentinel’s experiments remains to be seen, as does the effect on the other CubeSats.

After Artemis I’s successful launch and trans-lunar injection burn, the 10 CubeSats were deployed starting four hours after launch and finished the process after eight hours.

Six CubeSats have been heard from as of publication: EQUULEUS, LunIR, CuSP, LunaH-Map, ArgoMoon, and BioSentinel. It is hoped that if a CubeSat had lost its electrical charge during the mission delays, the spacecraft’s solar arrays would eventually catch sunlight and recharge the craft’s batteries themselves.

https://gizmodo.com/nasa-sls-artemis-cubesats-jaxa-malfunction-1849796055

ESA’s ArgoMoon has already done its part, as it observed the cryogenic propulsion stage that set Orion on its course towards the Moon.

Unfortunately, JAXA’s OMOTENASHI seems to be experiencing an issue. The space agency put out a short statement earlier today saying EQUULEUS is a-okay, but that OMOTENASHI “has not completed sun acquisition,” meaning the tiny probe hasn’t referenced its position relative to the Sun, which is needed for stabilization. What’s more, “communication is not stable,” JAXA added.

The space agency is “continuing operations to stablise attitude, secure power and establish communication,” the space agency wrote. OMOTENASHI is designed to land on the Moon and explore its surface as the world’s smallest lunar lander

During a pre-launch press conference on November 14, NASA officials said ground crews were able to recharge 4 out of 10 cubesats while SLS took shelter inside the Vehicle Assembly Building on account of Hurricane Ian.

The officials did admit that one unnamed cubesat had a low state of charge that would impact its ability to achieve its mission, and that the other cubesats were sufficiently charged.

From comments:

According to rumour, at least two more of the cubesats are in trouble - one’s not responding at all.

https://global.jaxa.jp/press/2022/11/20221117-1_e.html

enter image description here

JAXA update:

https://news.mynavi.jp/techplus/article/20221119-2517553/

After the spacecraft separated from the rocket, trouble occurred. It turned out that it was rotating at an unexpected speed and could not generate electricity.

When the transmitter is put into high power mode, communication becomes possible and telemetry is received from the spacecraft. As a result of confirming this data, it became clear that the solar cells were rotating at high speed while facing away from the sun. The rotation speed is about 80°/s, a speed that would normally be unthinkable. Moreover, since it is stable like a spinning top, it cannot generate electricity at all.

for some unknown reason, OMOTENASHI was rotating at a high speed at this time. It was in sun capture mode, but the sun was not captured. If this continues, the power will be exhausted, so the operation team hastily sent a command to inject a gas jet to try to stop the rotation (rate dump control).

At this rate, it was predicted that the power would run out before the rotation stopped, so the rate dump control was suspended.

However, the voltage drop continued, and finally the transmitter turned off. if the transmitter remains off all the time, the situation is completely unknown.

enter image description here

Given that they were able to recharge these, JAXA's current problem with the second of its two cubesats is unrelated to the battery problem anticipated with the delayed SLS launch.

LunaH-Map cubesat update:

https://twitter.com/NASAMoon/status/1592910168035102721

batteries are charging, and it is sending & receiving signals on its journey to the Moon

https://parabolicarc.com/2022/11/17/status-report-on-artemis-i-secondary-cubesat-payloads/

enter image description here

Update: 22/11/22

https://news.mynavi.jp/techplus/article/20221122-2519850/

JAXA have confirmed that OMOTENASHI is lost. Unable to re establish communications, the cubesat is set for a crash landing on the Lunar surface.

https://mobile.twitter.com/EDVEGA8823/status/1593247062300053504

enter image description here

https://gizmodo.com/cubesats-secondary-payloads-failure-sls-launch-artemis-1849808636

OMOTENASHI ran into trouble early on, with JAXA stating that communication with the satellite was not stable.

Two other cubesats that launched with Artemis 1 have not made contact:

NASA’s Near-Earth Asteroid Scout (NEA Scout) and Miles Space’s Team Miles, while Lockheed Martin’s LunIR cubesat sent out a weak signal.

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    $\begingroup$ I cannot imagine how angry I'd be if I was part of a university cubesat project (haven't actually checked the provenance of these), signed up for a launch on SLS, and after the satellite died on the ground because NASA decided to do wet-dress rehearsals as launch attempts a NASA spokesperson said welp that's cubesats for ya $\endgroup$
    – Erin Anne
    Nov 16, 2022 at 20:28
  • $\begingroup$ Great answer, thanks very much! $\endgroup$ Nov 17, 2022 at 10:36
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    $\begingroup$ @ErinAnne I imagine all teams involved knew the risks, not only of prolonged storage but also of launching on what is effectively a maiden flight. "Failure is the nature of CubeSats" sounds harsh but is exactly what it is - they are usually not designed with redundancy and failure prevention in mind, not to mention that qualification is extremely expensive as well. Of course, you want your mission to succeed, but in the CubeSat world you need to realize there is a high chance it does not. $\endgroup$
    – Mu3
    Nov 17, 2022 at 15:47
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    $\begingroup$ @Mu3 I admittedly worked on a (much too large) nanosat stack, not a CubeSat, but I was sort of prepared for it not to work at all, or for the launch vehicle to fail, etc. I still would've been furious if the payloads had been integrated too early and just failed on the pad or in the bay because of it. I actually have lost spaceflight hardware in a launch accident before (the targets on IDA 1) and mostly experienced fright (could it have been the targets that failed somehow?) and relief later when it wasn't our fault. ...and the explosion was rad. too bad dragon couldn't do launch escape. $\endgroup$
    – Erin Anne
    Nov 18, 2022 at 1:04
  • $\begingroup$ "failure 'is the nature of cubesats'" I mean, I guess, but that's just cold. Especially when the payloads fail not for some technical reason, but out of essentially negligence. Also, personally, I found the cubesat investigations some of the most interesting parts of Artemis 1... providing lasting lunar science and more small lunar orbiters is far cooler than re-demonstrating capabilities that I assumed NASA already had (flying Orion). $\endgroup$
    – Dragongeek
    Nov 22, 2022 at 16:24

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