Earth-Sun L4 and L5 Lagrange points

I understand these are at 60 degrees ahead of, and behind, Earth (respectively). Does anyone know how much harder it is to keep satellites at other 'offsets' from Earth? Could we realistically also have one at 30 degrees, one at 90 degrees, one at 120 degrees, and one at 150 degrees?

And could it be beneficial to send data via that route? Could they play a role analogous to something like this?:
https://en.m.wikipedia.org/wiki/Optical_communications_repeater
Or would it just be a pointless increase in latency for no benefit?

My uneducated guesses:

1. Starlink's existing provision for Earth could be achieved for Mars too, using a very similar system
2. In some ways, Mars will be easier.
   1. Much thinner atmosphere
   2. Far fewer of the constraints needed to 'play nice' with an existing high-tech civilization, like minimizing reflections of sunlight to the ground, or avoiding radio interference.
3. But the first generation system for Mars will be different in an important way: significantly higher altitude
   1. Thus higher ping times
   2. And fewer satellites than would otherwise be needed for continuous coverage, which in turn means lower total bandwidth capability, and less redundancy, but much cheaper & quicker to set up and maintain.
4. None of the above covers the actual NASA requirement/aspiration for new interplanetary comms (which seems to be referred to as "DRM 4").
   1. For one thing, an in-space laser link that can cover 100s of miles efficiently, is qualitatively different from one that can cover 100s of millions of miles.
   2. But as NASA has already achieved over 6 Mbps across 240 million miles, SpaceX will also be able to create a usable interplanetary link
5. SpaceX will equip some of their Earth-orbiting Starlink satellites, and all of their Marslink satellites, with this qualitatively different, and outward-facing, laser comms tech.
   1. Having, as your endpoints, devices that are orbiting around planets, is disadvantageous in some ways, such as the fact they spend about half the time on the wrong side.
   2. But SpaceX will find a way to make it into an advantage. (Multiple simultaneous connections?)

Any thoughts?

Also, you need a relay capability when the sun is in the way. But are such relays expected to be beneficial even at other times? Will SpaceX find a way to make them beneficial?

P.S. It's interesting that Spaceflight Now did a tweet thread on this NASA presentation, but didn't consider it worth an article. Yet PC Mag made a whole article primarily out of 1/3 of a slide from one of those tweets by Spaceflight Now! (And I'm glad they did!)

Elon may have given them the info

No need. Spaceflight fans (like me!) are supporting and funding what may be the biggest aerospace espionage operation in history by a factor of 10, down in South Texas. With crowdsourced tracking and analysis. Must be beyond the CPC's wildest dreams!

E.g.:
https://www.youtube.com/live/mhJRzQsLZGg
https://ringwatchers.com/
https://sh.itjust.works/post/27492397

And we ain't gonna stop!

starlink availability in Russia

I remember a story coming out about Russians using Starlink but it seemed a bit vague to me. Has anyone reliable actually asserted that SpaceX are significantly underperforming in the job of blocking captured terminals (once notified), or other aspects of the day-to-day operations that the Ukrainians would do if they controlled it themselves?

FWIW, SpaceX seems to deny it. https://x.com/SpaceX/status/1849956344691912873

" … As has been repeatedly confirmed by the Department of Defense, SpaceX has worked (and continues to work) in close partnership with the U.S. Government regarding Ukraine and denial of service to bad actors. …"

Also onboard is the ARTEMOSS experiment, which is pronounced similarly to “Artemis” in a nod to NASA’s Moon-bound program. The acronym stands for “From Antarctica to Space: Molecular Response and Physiological Adaptation of Moss to Simulated Deep Space Cosmic Ionizing Radiation and Spaceflight Microgravity.”

Shouldn't that be FATS:MRPAMSDSCIRSM?

Nestled inside the trunk of the Dragon is a device called CODEX (COronal Diagnostic EXperiment), ... the device will be unpacked and installed using the Canadarm-2 robotic arm.

I've been wondering why this mission couldn't just dock to the zenith port. Could this be why? Is there better access for the arm at the forward facing port? (For those who didn't know, Crew-9 had to relocate Dragon Freedom to the zenith port a couple of days ago, to free up the forward port for CRS-31.)

Just saw this https://x.com/SpaceX/status/1849956344691912873

... As has been repeatedly confirmed by the Department of Defense, SpaceX has worked (and continues to work) in close partnership with the U.S. Government regarding Ukraine and denial of service to bad actors. ...

Yeah. One possibility is that SpaceX were indeed underperforming, and the story was placed to put public pressure on them to improve. (A bit like the 2019-09-27 Bridenstine tweet.)

(And just to be clear, I have many problems and potential concerns about Musk. I'm just saying I'd choose him over, say, a Maoist, or a Stalinist, and over "Burn_The_Right".)

How do we remove this cancerous cyst?

I think your username gives us a clue what you would do to Musk and others if you ever gained any power.

I would entrust the wellbeing of humanity to him, over you, without hesitation. We had enough of your type in the 20th Century, thanks.

I’m sure he could block the Starlink terminals Russian army is using, if he wanted to try, for example.

I remember a story coming out about Russians using Starlink but it seemed a bit vague to me. Has anyone reliable actually asserted that SpaceX are significantly underperforming in the job of blocking captured terminals (once notified), or other aspects of the day-to-day operations that the Ukrainians would do if they controlled it themselves?

Though at least they've already proved they can relight during a belly flop.

I would not have thought it could float in a different orientation

Me either. But they call that orientation "Stable 1", possibly implying they've accounted for other stable orientations, and some non-stable situations.

Here was the first time I heard that term (with Bob & Doug): https://www.youtube.com/live/tSJIQftoxeU?t=6h29m34s

The commentator then gives some explanation.

Post-splashdown news conference: https://youtu.be/gOUoI-UYi2Y

They mentioned that Cargo Dragon sometimes reuses parachutes, which I didn't know.

Watched some of the official coverage: https://www.youtube.com/live/5CRB3FHV9Dw

Things that were new to me:

• 1:40:50 Drone footage of the capsule lift
• 34:42 Jones explains that the same set of 12 hooks secures Dragon to either its nosecone or to the ISS. Makes perfect sense; I'd just never thought about it before.
• 1:35:57 "There are multiple options so if Dragon were to splash down in a different orientation they could egress from the top hatch as well."
  • Would this be a last resort after they'd tried & failed to correct the orientation?
  • Would it only be used when Dragon was still in the sea or would they ever lift Dragon onto the boat in an orientation that necessitated top hatch egress?

And all this talk of Dragon orientation, combined with the extensive weather delays in Crew-8's departure, got me wondering ... How would Dragon fare if it was left in very rough seas for an extended period? (Imagine the recovery vessel broke down a minute after splash-down and then a big multi-day storm blew in, or something.)

Plausible. It's not how I imagine them engaging with their defence contractors but I don't actually have a clue how it works. One supporting point might be if there were any other companies treated similarly, like if Lockheed Martin was ordered to immediately ramp up production of relevant types of military hardware, and told that the details (contracts / payment / etc.) would be sorted out later.

An opposing point would be the fact that the US and its allies knew an invasion was likely well in advance. Yet the initial Starlink 'roll out' seemed pretty ad hoc, with SpaceX organizing its own logistics. But then maybe the allies didn't expect Russia to be so effective in disrupting the existing military comms infrastructure.

that the engines relight multiple times in orbit

Should they do an orbital test next? Or continue with the previously used 'almost orbit' trajectory that ensures the second stage re-enters safely with no need for a relight?

The SpaceX officials in the audio said they were “trying to focus on booster risk reduction versus ship envelope expansion” for the next flight.

For the "ship envelope expansion", do you think they will/should do an in-space engine relight test? Or are the seemingly successful flip-landing maneuvers on flights 4 and 5 sufficient? (Has this been covered elsewhere?)

Interesting! They're talking about unnecessary aborts, and how they want to do as much analysis as possible of the abort criteria, to prevent them.

This will remain an issue for Flight 6 which, it seems, will happen the moment SpaceX decides it's sufficiently ready. Unlike previous flights ...

"Given this is the first launch in a long time ... well really ever ... that we've not been FAA driven ..."

This would be a nuclear option and, in reality, probably would do more harm than good to SpaceX,

It would probably set back their more ambitious targets by decades. But even Starship is now far enough along to no longer really need Musk's stewardship, and the US government would be happy enough just with control of the Falcon programme. They don't care much / at all about Making Life Multi-Planetary.

So I consider a move like this pretty plausible.

If so, why would SpaceX have so rapidly & aggressively moved to restore Ukraine's communications capabilities in the early days and weeks of the current war, and maintained them ever since?

I find the defendant not guilty! I think the NSF guy's idea involved replacing the woman & her arms and the daughter with the tower & "chopstick" arms, and a Super Heavy rocket booster (which is in the process of being caught by the arms). Something like that?

The closest I've seen is this. Not great!

So I tried getting Chat GPT to do a better one for me. This did not go well 😂 But surely someone with experience should be able to cajole a suitable generative AI tool to do a good job of it?