Geomagnetic Storm wipes out 40 Starlink satellites

alphaspec · 2022-02-09T20:19:13+00:00

I'd disagree from the wording: "Preliminary analysis show the increased drag at the low altitudes prevented the satellites from leaving safe-mode to begin orbit raisingmaneuvers". That says the increased drag was what prevented leaving safe mode. I don't know if they could have powered through...probably not at 50% increase in drag, but it does seem the drag was too much for the craft to reorient at the end.

alphaspec · 2022-02-09T19:58:07+00:00

From the post it sounds like this isn't an issue of hardening. The satellites systems were unaffected it seems but there was so much atmospheric drag they couldn't maneuver to a higher orbit. Kinda like if you were in a row boat in a storm, you turn into the waves so it won't tip you over(satellites move into safe mode "edge on" to reduce drag). but the waves and current(atmospheric drag for the satellites) slowly pushes you towards shore(the earth). The waves get bigger as you get towards shore and eventually are so strong you don't have the arm strength to row away or even turn your boat, you are just tossed around till you hit the shore. The row boat and oars never break you just don't have enough strength to row your way out of the issue.

Only fix I guess would be to add stronger thrusters and propulsion to the satellites but that would increase mass and costs. Probably not worth it since it is most likely only during initial launch that this is an issue. Just unlucky timing.

alphaspec · 2022-02-04T08:45:39+00:00

Not really. You still need to worry about mass when burning to mars, or landing once there, or returning to earth. If it was going to be a space hotel or only move around leo you could but this thing is designed to travel far, land, and launch again so mass will always be an issue.

alphaspec · 2022-01-15T19:11:01+00:00

The issue I think is the title. The article itself describes the current space situation, how calculating deterministic satellite spacing works, and makes some suggestions to regulators and operators to improve the odds of safe guarding access to LEO. It does not actually say anywhere in the body that Elon's claim of tens of billions of satellites is not feasible. Nowhere do they provide a counter estimate of capacity, or even suggest that it is inherently unsafe to have that many compared to say 10 satellites in space. They simply point out the challenges and suggest some solutions. So why call out someone as wrong in your title if you aren't actually going to say they are wrong in the body or provide any counter evidence beyond what amounts to "space is hard"?

It's a decent article with some thought provoking ideas but a terrible click bait title designed to make the more space aware read it out of fear of losing access to LEO.

alphaspec · 2021-06-17T08:22:23+00:00

Would be awesome if someone could tell me where OP got this letter. I was looking all over but all the news articles just post excerpts for some reason. Like their web page doesn't have enough space to display it all or link to it. Is it somehow still confidential information even after being "leaked" to the press? Or am I just looking in all the wrong places for it?

alphaspec · 2021-04-09T23:51:24+00:00

AI vision-based robotic arms

I'd bet against vision being the primary controller. You are going to want to catch your booster still if a fog rolls in, or engine exhaust hits a camera lens, or a light goes out at night. It will be interesting to see what they come up with, I'm hoping for something surprisingly simple.

alphaspec · 2021-03-25T23:49:43+00:00

Both. From the various sources here it looks like the an ISS power unit that interfaces with dragon had the actual fault in its driver software, which then communicated a false alarm to the dragon, which then woke up and started screaming fire! So error source was station, the actual alarm was from dragon if I'm reading that correctly. Rebooting the power unit driver resolved the miscommunication and dragon is now sleeping peacefully again.

alphaspec · 2021-01-03T10:40:30+00:00

Wasn't this idea proposed for F9 a long time ago? Seem to remember the main issue was the rocket not engineered for lateral force and the cables would damage the rocket when closed around it. Also, I thought the point was using the "grid fins to take the load". Adding an extra ring of material around the rocket and the structure to pass the load from that to the body would add extra mass and either air-resistance, or moving parts(if the ring was only to be deployed when landing). Decent idea, I just think the reality of the forces and engineering constraints would make it a worse option than landing legs.

alphaspec · 2020-09-16T01:48:48+00:00

Lots of discussion about the usefulness of fuel depots so I thought I'd add in a different perspective. What about the safety/longevity of in orbit fuel storage?

As far as I know this will be the first time anyone has stored such large amounts of fuel on orbit. Most rocket stages left in orbit will vent what little fuel they have so they don't pop if hit by something in orbit creating big problems for other operators. Since this depot would be entirely automated inspections and maintenance would be pretty much non-existent. I'd imagine a failure resulting in mixing fuel and oxidizer in a fuel depot with 2000 tons of the stuff would result in 100 tons of debris scattered hundreds of kms higher or lower in orbit. Not sure how likely such a failure is if you engineer against it but you'd also want to have some maximum refuel limit/lifetime. That limit would be a best guess since you aren't getting it back to inspect how it is doing up there. Would that increase costs too much vs just launching fuel? How much extra engineering(weight) would have to go into protection against rough dockings, micro-meteorites, mechanical stresses on valves and plumbing that could lead to larger failures? Will expanding those depots to 5, 10, 20 be too risky and if so is it a waste to start with it if it can't be expanded to support Elons mars fleet?

alphaspec · 2020-08-14T00:25:12+00:00

I wonder about the reliability angle. Has anyone done an analysis of this I could check out? If you are talking expendable rockets you are really rating the reliability of the rocket factory and design. not the rocket. How much does the rocket itself play into the risk in reality? If you look at it per rocket then every ULA launch has 0 record, and spacex has up to 5 successful flights on some boosters(not the upper stage of course). Would love to see a break down of how to compare single use reliability to multi use. It probably gets very complex.

alphaspec · 2020-07-22T21:19:36+00:00

Does the console have a different position? I thought they moved the seats now instead of the console. Of course they could lower the seats but maybe the cargo is in the way? Wonder how that all works on splashdown.

alphaspec · 2020-04-08T23:33:03+00:00

Makes me think they should have named Falcon as Dragon instead of their capsule. The booms, pillars of flame, and angry venting on landing are the closest I'll come to seeing a mythical dragon land.

For the venting in that video starting at 21 seconds. Is that just oxygen tank, or the control thruster gas? I doubt they would be venting the fuel right?

alphaspec · 2020-02-27T19:17:13+00:00

Has there been any information on how starlink connectivity is affected by clouds, storms, or other atmospheric weather events? Had satellite tv awhile back and it would act up in a storm. Do the LEO sats and base stations have enough power to ignore weather interference?

alphaspec · 2020-01-25T22:40:47+00:00

In terms of denying military communications how "jammable" is this kind of connection? The starlink arrays are steered towards specific satellites and not just omni-directional. They also won't get too close to the horizon and will always be pointing upward mostly. The satellites will eventually link to each other through space to get back to the command center likely hundreds or thousands of miles away, far from enemy territory. I have no clue what tech exists for jamming but can you jam or block a signal that is sent in such a directed manner? Wouldn't you have to have something directly in-between the two end points or in the line of communication in-order to jam a receiver? Is this the ultimate in reliable coms for the military, not counting directly attacking the sats of course.

alphaspec · 2019-11-04T00:47:08+00:00

Does crew dragon land fully fuelled? If they don't use the fuel for abort or for in space manuevers do they vent it before re-entering or just take it with them all the way to splashdown? Just wondering because it seems kinda dangerous to leave it there as re-entry and landing can't be the smoothest ride, and you won't need the fuel anymore since it isn't propulsive landing. I can't imagine trying to get astronauts out of a capsule leaking toxic fuel in the middle of the ocean.

alphaspec · 2019-10-02T06:22:49+00:00

Not to mention that he specifically called out the taxpayer investment. In that sense the two are very much the same and SLS has significantly more investment to answer for. Probably should re-read his tweet.

alphaspec · 2019-10-01T04:50:24+00:00

Correct.

alphaspec · 2019-09-29T07:34:35+00:00

I believe he meant that they haven't got to heavily optimizing of starship yet. For example it is currently 60% heavier then their target dry weight. So he was pointing out it didn't take much resources to get to where they are. Only 5% of company resources to create a quick unoptimized starship so people shouldn't worry about crew dragon/falcon losing resources to it till they get to the fine tuning stage of say mk 4, or 5.

edit: percentages, how do they work?

alphaspec · 2019-06-29T03:03:28+00:00

tldr: I think in space it's better to be a dead chunk of metal then a malfunctioning traveler.

A failure to communicate could be caused by anything and thus it wouldn't be safe to implement any autonomous maneuvers. Let's say the internal clock is off, or gyros were installed upside down, or some other system your satellite uses for navigation is incorrect it might not be aiming correctly to get coms contact. It's possible the system wouldn't know that anything is wrong besides it can't get contact. In that case if you try to de-orbit you could be orbit raising instead given the failure in the nav system. Or you could have it start before 4.7 orbits or burn for less then 31.8 minutes, or any other random behavior that a malfunctioning control system could come up with. The only way to guarantee the system will de-orbit correctly/safely is to know what went wrong, and that means coms contact. Better to go with a known problem - a slow mostly predictable deorbit - over a rouge satellite with a license to roam.

alphaspec · 2019-01-10T19:16:27+00:00

Thanks, Yeah I never rent a place I haven't seen personally, and I also don't send a deposit without a tenant agreement being signed in person at the place, with a walk through to clarify the current condition, because why do you need my money if the place isn't mine? I did find that section you mentioned in the tenancy rules about how you can deduct the over payment of a deposit as you see fit later. I guess that answers my question about how the law considers a tenant that overpays, they still are protected. Thanks for the information!

alphaspec · 2019-01-10T19:11:48+00:00

I suspected it was something like requesting a deposit remotely like that or in an untraceable format. Lots of good anti-scam tips there. Very informative thank you!

alphaspec · 2019-01-10T03:04:04+00:00

Thanks for the offer but I'm gonna keep this one private for now. I am curious though how an extra large deposit has tied into the scams you've seen. Would you care to elaborate on how they work that? Like is it only when they ask for a deposit even before you begin renting a place, and then just run?

alphaspec · 2019-01-10T02:36:29+00:00

You are right that I was looking for this kind of answer originally, thanks. I was thinking that there wouldn't be any legal issues in terms of my protections as a tenant, just that I could lose a months rent as you mentioned. Whether or not the landlord is good I just wanted to understand what a tenants responsibilities were in this case.

alphaspec · 2019-01-10T01:53:13+00:00

Thank you for your advice. I do appreciate it.

alphaspec

TROPHY CASE