A couple of weeks back we featured a story (third item) about a chunk of space jetsam that tried to peacefully return to Earth, only to find a Florida family’s roof rudely in the way. The 700-gram cylinder of Inconel was all that was left of a 2,360-kg battery pack that was tossed overboard from the ISS back in 2021, the rest presumably turning into air pollution just as NASA had planned. But the surviving bit was a “Golden BB” that managed to slam through the roof and do a fair amount of damage. At the time it happened, the Otero family was just looking for NASA to cover the cost of repairs, but now they’re looking for a little more consideration. A lawsuit filed by their attorney seeks $80,000 to cover the cost of repairs as well as compensation for the “stress and impact” of the event. This also seems to be about setting a precedent, since the Space Liability Convention, an agreement to which the USA is party, would require the space agency to cover damages if the debris had done damage in another country. The Oteros think the SLC should apply to US properties as well, and while we can see their point, we’d advise them not to hold their breath. We suppose something like this had to happen eventually, and somehow we’re not surprised to see “Florida Man” in the headlines.

There was a little hubbub this week around the release of a study regarding the safety of autonomous vehicles relative to their meat-piloted counterparts. The headlines for the articles covering this varied widely and hilariously, ranging from autonomous vehicles only being able to drive in straight lines to AVs being safer than human-driven cars, full-stop. As always, one has to read past the headlines to get an idea of what’s really going on, or perhaps even brave reading the primary literature. From our reading of the abstract, it seems like the story is more nuanced. According to an analysis of crashes involving 35,000 human-driven vehicles and 2,100 vehicles with some level of automation, AVs with SAE Level 4 automation suffered fewer accidents across the board than those without any automation. Importantly, the accidents that Level 4 vehicles do suffer are more likely to occur when the vehicle is turning just before the accident, or during low-visibility conditions such as dawn or dusk. The study also compares Level 4 automation to Level 2, which has driver assistance features like lane-keeping and adaptive cruise control, and found that Level 2 actually beats Level 4 in clear driving conditions, but loses in rainy conditions and pretty much every other driving situation.

There’s a strange story coming out of New York regarding a Federal Communications Commission (FCC) enforcement action that seems a little shady. It regards a General Mobile Radio Service (GMRS) repeater system used by the New York State GMRS Alliance. GMRS is sort of a “ham radio lite” system — there’s no testing required for a license, you just pay a fee — that uses the UHF band. Repeaters are allowed, but only under specific rules, and that appears to be where things have gone wrong for the club. The repeater system they used was a linked system, which connected geographically remote repeaters stretching from the far western part of the state near Buffalo all the way to Utica. It’s the linking that seems to have raised the FCC’s hackles, and understandably so because it seems to run counter to the GMRS rules in section 95. But it’s the method of notification that seems hinky here, as the repeater custodian was contacted by email. That’s not typical behavior for the FCC, who generally send enforcement notices by certified snail mail, or just dispense with the paper altogether and knock on your door. People seem to think this is all fake news, and it may well be, but then again, the email could just have been an informal heads-up preceding a formal notice. Either way, it’s bad news for the GMRS fans in upstate New York who used this system to keep in touch along Interstate 90, a long and lonely stretch of road that we know all too well.

Third time’s a charm? We’ll see when sunspot region AR3723 (née AR3697 née AR3664) makes a historic third pass around the Sun and potentially puts Earth in its crosshairs yet again. The region kicked up quite a ruckus on its first pass across the solar disk back in May with a series of X-class flares that produced stunning aurorae across almost all of North America. Pass number two saw the renamed region pass more or less quietly by, although it did launch an M-class flare on June 23 that caused radio blackouts in most of the North Atlantic basin. When AR3723 does peek out from behind the eastern limb of the Sun it’ll be a much-diminished version of its former Carrington-level glory, and will likely be given multiple designations thanks to fragmentation while it was hanging out on the backside. But it could still pack a punch, and even if this particular region doesn’t have much juice left, it sure seems like the Sun has plenty of surprises in store for the balance of Solar Cycle 25.

Somebody made a version of Conway’s Game of Life using nothing but checkboxes, which is very cool and you should check it out.

And finally, we’ve been doing an unexpected amount of automotive DIY repairs these days, meaning we spend a lot of time trolling around for parts. Here’s something we didn’t expect to see offered by a national retailer, but that we’d love to find a use for. If it ever comes back in stock we just might pick one up.

A little while ago, we talked about the concept of timezones and the Moon. It’s a complicated issue, because on Earth, time is all about the Sun and our local relationship with it. The Moon and the Sun have their own weird thing going on, so time there doesn’t really line up well with our terrestrial conception of it.

Nevertheless, as humanity gets serious about doing Moon things again, the issue needs to be solved. To that end, NASA has now officially been tasked with setting up Moon time – just a few short weeks after we last talked about it! (Does the President read Hackaday?) Only problem is, physics is going to make it a damn sight more complicated!

Relatively Speaking

The problem is all down to general and special relativity. The Moon is in motion relative to Erath, and it also has a lower gravitational pull. We won’t get into the physics here, but it basically means that time literally moves at a different pace up there. Time on the Moon passes on average 58.7 microseconds faster over a 24 hour Earth day. It’s not constant, either—there is a certain degree of periodic variation involved.

It’s a tiny difference, but it’s cumulative over time. Plus, as it is, many space and navigational applications need the utmost in precise timing to function, so it’s not something NASA can ignore. Even if the agency just wanted to just use UTC and call it good, the relativity problem would prevent that from being a workable solution.

Without a reliable and stable timebase, space agencies like NASA would struggle to establish useful infrastructure on the Moon. Things like lunar satellite navigation wouldn’t work accurately without taking into account the time slip, for example. GPS is highly sensitive to relativistic time effects, and indeed relies upon them to function. Replicating it on the Moon is only possible if these factors are accounted for. Looking even further ahead, things like lunar commerce or secure communication would be difficult to manage reliably without stable timebases for equipment involved.

Still, the order to find a solution has come down from the top. A memo from the Executive Office of the President charged NASA with its task to deliver a standard solution for lunar timing by December 31, 2026.  Coordinated Lunar Time (LTC) must be established and in a way that is traceable to Coordinated Universal Time (UTC). That will enable operators on Earth to synchronize operations with crews or unmanned systems on the Moon itself. LTC is required to be accurate enough for scientific and navigational purposes, and it must be resilient to any loss of contact with systems back on Earth.

It’s also desired that the future LTC standard will be extensible and scalable to space environments we may explore in future beyond the Earth-Moon system itself. In time, NASA may find it necessary to establish time standards for other celestial bodies, due to their own unique differences in relative velocity and gravitational field.

The deadline means there’s time for NASA to come up with a plan to tackle the problem. However, for a federal agency, less than two years is not exactly a lengthy time frame. It’s likely that whatever NASA comes up with will involve some kind of timekeeping equipment deployed on the Moon itself. This equipment would thus be subject to the time shift relative to Earth, making it easier to track differences in time between the lunar and terrestrial time-realities.

Great minds are already working on the problem, like Kevin Coggins, NASA’s space communications and navigation chief. “Think of the atomic clocks at the U.S. Naval Observatory—they’re the heartbeat of the nation, synchronizing everything,” he said in an interview. “You’re going to want a heartbeat on the moon.”

For now, establishing CLT remains a project for the American space agency. It will work on the project in partnership with the Departments of Commerce, Defense, State and Transportation. One fears for the public servants required to coordinate meetings amongst all those departments.

Establishing new time standards isn’t cheap. It requires smart minds, plenty of research and development, and some serious equipment. Space-rated atomic clocks don’t come cheap, either. Regardless, the U.S. government hopes that NASA will lead the way for all spacefaring nations in this regard, setting a lunar time standard that can serve future operations well.