orbital maintence tools? a threat? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: December 21, 2023, 08:28:16 pm
content: I saw some news article about the threats posed by Chinese orbital maintenance tools that can be misused.Am I the only one that thinks that its a great idea to develop the tech to refuel and repair satellites? I wanted this tech for years, it seems like what the beginning of the space age actually looks like, that you can sustain small infrastructure in space on maintenance contracts from contractor companies and stuff, instead of basically being tied to a 'trucking company (heavy launch)' for the entire product life cycle.IMO even something as simple as a satellite being able to have its card swapped in space by a robot means that the cost of sat development went way down, much like computers. You can put more ram, a new monitor, better sensors... extends the life of a computer drastically.... and eventually when the repairs get good enough (space soldering) you could even get away with doing less tests on issues that can likely be fixed in orbit by repair/upgrade/maintenance bots.I hope the DoD does not stunt development of this technology but some how works to improve warning satellite security and stuff so it can coexist.Because IMO, its really starting to feel like its the begining of the real space age where there is potential for cheap applicability to space projects.I am imagining essentially floating PC's in space with generic inputs that can be retrofitted with various hardware, even possibly on a space rental basis, developed at a later time. Then you only have 1 heavy launch for the power system and then just robots or possibly space workers to plug in cards. And you don't have power constraints of things like cube sats, its more like you get access to a large power source on board for your card.and it seems like there will be less space debris this way, since project life is extended, and the 'chassis' can be reused. Space Milkshake comes to mind

author: u666sa
author_rank: Frequent Contributor
timestamp: December 21, 2023, 08:33:00 pm
content: Nah. Because tech in 5 years, gets old. We talking about space age tech. Spy images and stuff. So it's pointless to sustain it, really. In 5 years your new satellite is old, in 10 years it is obsolete. Space trash really.

author: coppercone2
author_rank: Super Contributor
timestamp: December 21, 2023, 08:33:47 pm
content: why. You could put a different low power card on it to use degraded solar panels. Efficiency improves. I think its a total game changerits literary repurposing a self powered mainframe (in the sense of a HP modular system) that has communication and power generation + chassis, just floating around in space. if its built right

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 21, 2023, 08:52:40 pm
content: I like the old quote, usually attributed to the American baseball player Yogi Bera. "Predictions are hard, especially about the future."Old technology makes sense in space for a couple of reasons. First, since it is really expensive to put something up there, it takes a lot of functionality improvement to make the cost of replacement worth it. Second, the environment favors older technology. As gate sizes get smaller sensitivity to radiation goes up. A lot.But the cost of putting stuff in space is coming down. If Musk succeeds with his Starship, it will come down a lot. Changing the calculations in many ways.Doing in orbit maintenance may make sense for economic reasons, but as with any technology can be applied for good or evil. Two groups want to limit this technology - those who think they have a big lead, and those who think they are far behind. Those seeking the economic opportunity will be for, and certainly there is overlap in those categories. I certainly can't predict how this will play out.All of this plays into the background of limiting how much stuff is randomly floating around out there. If we can't control the collisions the whole point will be moot.

author: u666sa
author_rank: Frequent Contributor
timestamp: December 21, 2023, 08:56:33 pm
content: Tech goes like this.Space -> Military -> ConsumerIt's a time process. Thing that are in space right now will soon be mainstream military, and then later mainstream consumer.You talking about changing modules, most likely fuel and some other low stuff upgrades. I guess okay for consumer grade single purpose satellites. But for spy or weapon, like nuclear or kinetic weapon, no. I don't think this is useful for dual use satellites. That's my unprofessional opinion.I will go further. Elon Musk right now doing reusable self landing boosters. Well, Soviet Union did those in 70s and deemed them too expensive and not useful. It is old tech. What Elon Musk doing now in consumer segment is 20 + 30 = 50 years old. Soviet Union pioneered this tech and scrapped it. Just think about the technology in terms of time. You have to feel it and breath it in. What we have there up there now is 40+ years ahead of what we will have in consumer segment down here. It makes absolutely no sense to keep old crap in orbit.

author: Kim Christensen
author_rank: Super Contributor
timestamp: December 21, 2023, 09:13:41 pm
content: The problem with launching a repair mission from Earth's surface is that it takes a lot of deltaV (Fuel) to reach orbit and rendezvous with the target satellite to be repaired. So much so, that for small satellites, it's just as efficient to send a new one because the robot + parts payload mass would be comparable. It can work for fixing large expensive/massive sats, like the Hubble repair missions.It could possibly work if you had a large number of expensive satellites that all used the same universal parts. Then you could park a "parts depot" and repair robot in a similar orbit with a bunch of spares. But that would have problems of it's own due to the difficulty in keeping propellant from slowly leaking away and the limited number of orbital changes. (Costing DeltaV/Fuel every time you rendezvous with a different sat) Plus, space is a harsh environment and the spares would slowly degrade from radiation, etc.

author: coppercone2
author_rank: Super Contributor
timestamp: December 21, 2023, 09:43:47 pm
content: well the point is the chinese are looking into it right now and the US goverment is scared. So it must be feasible to launch cheap maintenance missions.

author: u666sa
author_rank: Frequent Contributor
timestamp: December 21, 2023, 10:06:03 pm
content: Quote from: coppercone2 on December 21, 2023, 09:43:47 pmThe U.S. has this tech. There is the narrative yea. But it's all political. The distance between political talk and what actually is feasible or been done is far, far in between.

author: abeyer
author_rank: Frequent Contributor
timestamp: December 21, 2023, 10:07:57 pm
content: Quote from: coppercone2 on December 21, 2023, 09:43:47 pmThe US government was terrified of the "Bomber Gap" and then the "Missle Gap" too... (or at least it benefited them to act like they were) so it's not clear that public statements to that effect have any real reflection on the underlying truth/feasibility of the issue.

author: tszaboo
author_rank: Super Contributor
timestamp: December 21, 2023, 10:56:51 pm
content: Quote from: Kim Christensen on December 21, 2023, 09:13:41 pmI tried doing this in KSP, and it wasn't feasible there. And it was with theoretical nuclear engines. Inclination change is too expensive, it was just more economical to launch a maintenance mission. Or to scrap the craft and launch a new one.

author: coppercone2
author_rank: Super Contributor
timestamp: December 21, 2023, 11:09:43 pm
content: I assume it would be a scheudled rocket with lots of maintenance bots (low cost) that go to different sats and work on themlike the bus, drops people off at different locations.

author: Kim Christensen
author_rank: Super Contributor
timestamp: December 22, 2023, 12:20:05 am
content: Quote from: tszaboo on December 21, 2023, 10:56:51 pmHello fellow kerbonaut!Yes, inclination changes are expensive fuel wise. It could work if the repair craft was servicing multiple sats in geostationary orbit all at around the same time. Then there'd be no inclination changes required, the repair craft's orbit wouldn't need to change much to move from one sat to another, and it wouldn't spend years waiting in space for the next repair mission. The sats would still have to be designed to have modules easily swapped and things could still go irreparably wrong (pun intended).

author: coppercone2
author_rank: Super Contributor
timestamp: December 22, 2023, 01:35:42 am
content: hmm thats when you send the panel beaters into space on a special mission, when the chassis is dented

author: Dan123456
author_rank: Regular Contributor
timestamp: December 22, 2023, 05:05:58 am
content: I personally like the idea of space maintenance robotsThe longer we can keep things up there alive, the less rockets we need to launch, meaning less space junkSure some satellites will need to be replaced with new, better systems, but I would imagine a lot of others work perfectly fine with their current hardwareQuote from: wraper on December 21, 2023, 09:13:34 pmYou might be correct about the USSR. I dunno. But the US was looking at / using reusable stuff decades ago. One similar to what u666sa is talking about was called the DC-X and it got abandoned only for Musk to take his inspiration from it years later. There was also the space shuttle which has put the most people into orbit to date.Also, have they really reused boosters 10+ times? Or is are they just the space age version of the ship of Theseus?I do not know the answer to that (and doubt anyone outside of the company does) but am just weary to take SpaceX’s word due to the copious amounts of bullshit Musk spews constantly. I.e. weren’t we meant to be living on Mars last year?Again, I have nothing against SpaceX, just Musk.

author: coppercone2
author_rank: Super Contributor
timestamp: December 22, 2023, 05:08:38 am
content: there is also probobly a global warming effect of launching rockets. its greener to repair with smaller payloads then to keep sending giant payloads and its smarter then trying to miniaturize things and limit potentialI wonder how many short term experiments and systems are stunted by power requirements. its like getting a 3 phase hookup in space to use a bigger sat for a rental.

author: fourfathom
author_rank: Super Contributor
timestamp: December 22, 2023, 05:17:24 am
content: Well, we did send a five repair missions to the Hubble Space Telescope. And it was cheaper than sending up a new Hubble. And the ISS regularly gets repaired and updated. These are high-priced and critical assets where it makes sense to repair rather than replace.

author: Simon
author_rank: Unknown
timestamp: December 22, 2023, 07:23:52 am
content: Quote from: u666sa on December 21, 2023, 08:56:33 pmPerhaps you could provide some evidence.

author: wraper
author_rank: Unknown
timestamp: December 23, 2023, 02:36:57 am
content: Quote from: Dan123456 on December 22, 2023, 05:05:58 amUS may have looked into it but never tried actually building a reusable rocket booster. Calling Space Shuttle SRB reusable would be a big stretch, those were just empty shells splashing into the sea and which would be cheaper to discard rather than take apart, heavily refurbish and use for assembly of new SRB. DC-X was a tiny suborbital single stage rocket (huge difference between orbital and suborbital). Last time I checked the most reused F9 booster had flown 18 times and a few others 2-3 times less.EDIT: Actually 3 other boosters have reached 17 launces already. Most reused booster today should fly for 19th time. Fastest reuse they achieved was 21 day.

author: Dan123456
author_rank: Regular Contributor
timestamp: December 23, 2023, 05:09:29 am
content: Quote from: wraper on December 23, 2023, 02:36:57 amNa, the space shuttle boosters were reusable. Just the external tank was not.“Once they were returned to Cape Canaveral, they were cleaned and disassembled. The rocket motor, igniter, and nozzle were then shipped to Thiokol to be refurbished and reused on subsequent flights.: 124 ”https://en.m.wikipedia.org/wiki/Space_ShuttleI think you miss my point on SpaceX’s boosters. The question is are they really the same booster that first launched? Or do they just replace every single part after each launch and slap the same number on it and just call it the same booster?I do not know the answer to that. I would like to believe that they can reuse them with minor repairs, but due to Musks track record of massive overstating capabilities / straight up lying, I can not trust anything that his companies say. Especially in regards to marketing.

author: wraper
author_rank: Unknown
timestamp: December 23, 2023, 01:01:10 pm
content: Quote from: Dan123456 on December 23, 2023, 05:09:29 amDo you understand that in SRB engine and propellant is the same thing? All that is left afterwards is an empty husk. They could not even reuse that without taking them apart into pieces, stripping all paint, etc, and from what I've read it the process spending 1.5 times more than it would take to just using brand new.

author: Dan123456
author_rank: Regular Contributor
timestamp: December 23, 2023, 02:01:00 pm
content: Quote from: wraper on December 23, 2023, 01:01:10 pmYes, I am aware how solid rocket boosters work. That is why they had to take them apart to refuel them.Anyways, we are derailing this thread but you stated:Quote from: wraper on December 23, 2023, 02:36:57 amSo I just wanted to point out that is not quite true.

author: wraper
author_rank: Unknown
timestamp: December 23, 2023, 02:21:10 pm
content: Quote from: Dan123456 on December 23, 2023, 02:01:00 pmAnd I said it's a stretch to call them reusable. When you take maybe 20% of what takes to build the thing, take apart, heavily refurbish it and then use to build a new booster, it's very far from being reusable booster. Call it refurbishable booster shell, not reusable booster. Also it's way more complicated than refueling.

author: BrokenYugo
author_rank: Super Contributor
timestamp: December 23, 2023, 02:42:13 pm
content: As I recall from Feynman's autobio he gave a pretty detailed account of his visit to the shuttle SRB refurb facility.Basically the empty tube would hit the water and, as one would expect, get all tweaked and twisted from the impact. Then once returned to land people would clean and straighten the sections out with hydraulics and hammers, and they'd by refilled and reassembled for flight. They were about as reusable in practice as a cardboard tube model rocket engine. A great case of just because you can doesn't mean you should.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 23, 2023, 06:27:11 pm
content: Quote from: Dan123456 on December 23, 2023, 05:09:29 amThere is quite a bit of reason to believe they are reusable. For starters the externals aren't repainted and show the evidence of prior use. But sure, that could be a smoke screen for complete replacement of the internals. But doing a complete replacement of the internals in 21 days buggers my imagination and should give you a little pause. Most important, NASA and the military customers who are buying many of the launches are watching very closely and they seem to agree. And over time have changed their policy from requiring a new booster for their flights to accepting what are now called "flight proven" boosters. I also find the fact that they are able to price launches at 50-75% of what other vendors can provide evidence. Either they have found a way to manufacture these things far more cheaply than others, or they are re-using with relatively low refurbishment costs. None of this may meet your standard for re-usable. If you require that the only thing that happens upon a booster return is to stand it up, fuel it and light the fire, I doubt that it meets that standard. But if you can re-launch $50 million dollar booster with a few million dollars of inspection and repair I think it counts. It is also my guess that the inspection and repair costs have been dropping as they have learned and made adjustments based on the prior flights. That database is rapidly growing, and will soon be larger than for any other space vehicle.Caution with respect to Musk's statements is wisdom. Assuming that everything his companies do is a lie is not. Tesla cars aren't as good as Musk claims. But they are generally serviceable vehicles with more on road mileage than all other vendors combined. The Tesla powerwall is expensive but works. Starlink works.Find a way to hold Musk accountable for the falsehoods without throwing out the successes.

author: Dan123456
author_rank: Regular Contributor
timestamp: December 24, 2023, 03:41:46 am
content: Quote from: CatalinaWOW on December 23, 2023, 06:27:11 pmYou make some good points and you are correct. I was being a bit hyperbolic in saying that they maybe they could replace every part after every flight.My point is that Musk could be massively overstating the reusability. While it may not be every part after every launch, they could require major repairs each time (similar, although different, to the space shuttles boosters).As they have only achieved the 21 day turn around once, it could have very well been a publicity stunt with large teams working multiple shifts 24 hours a day, 7 days a week to repair and replace a significant proportions of the ship. If you have all the replacements parts sitting next to you, and teams of people working around the clock, you can replace a lot of parts in ~500 hours.As for customers using flight proven boosters rather than new, that could be more due to the terms in the contract rather than their faith in the booster. If SpaceX has a clause offering insurance covering damages of their cargo, government agencies would pretty much be forced to take that option as financial legislation (at least here in Aus - so I would assume the US would be similar) says they must take the best value for money option. Even if it isn’t the “best” option.Again, I am not saying SpaceX’s boosters aren’t reusable or that they are bad, just that I don’t know how reusable they actually are thanks to Musk’s proven track record of spouting complete BS.

author: wraper
author_rank: Unknown
timestamp: December 24, 2023, 03:56:41 am
content: Quote from: CatalinaWOW on December 23, 2023, 06:27:11 pmSurprisingly B1073 and B1075 F9 boosters launched Starlink as their first payload rather than some government or commercial stuff. Brand new B1082 should soon launch Starlink too.

author: bw2341
author_rank: Regular Contributor
timestamp: December 24, 2023, 05:54:34 am
content: Quote from: Dan123456 on December 24, 2023, 03:41:46 amThere's no need to speculate on how SpaceX does it. Here's a detailed article from Aviation Week:https://aviationweek.com/defense-space/space/spacex-building-airline-type-flight-ops-launch

author: nonlinearschool
author_rank: Contributor
timestamp: December 24, 2023, 07:17:53 am
content: Thanks BW2341 !!!never thought this much. re-usability may be one of the few things Mush did that was good. and the battery tech contribution...

author: RJSV
author_rank: Super Contributor
timestamp: December 31, 2023, 03:13:12 am
content: I've read through all so far, and thought about the technical points.Nobody mentioned, the power of having good morale, on a big project; I was actually stunned to view the first 'launch booster return', thinking that "...things are really moving and exciting lately!...".It's kind of a paradyme shift, freedom from the whole set of hassles when trying to refurbish safely. Plus, we still have the pre-existing way of doing things, using parachute sea landings and all the methods and designs.Technology amatuers watching a landing get to be 'inspired', that electronic control systems can really perform, in big real-time projects.So you get a confidence-inspiring visual, and...maybe some planners are checking what it would take, to include human passengers in some novel type of re-entry to runway function.Like a cheap emergency evacuation system.More options, and inspiring landings ...to the extent that they look like fake landings, (by playing video backwards).

author: Kim Christensen
author_rank: Super Contributor
timestamp: December 31, 2023, 04:42:04 pm
content: Quote from: RJSV on December 31, 2023, 03:13:12 amThe landing legs are not deployed on launch... Also, the payload and upper stage which are present on launch, are not attached to the booster upon landing. So zero chance that the video is simply reversed.Plus, the booster lands at a different location from the launch site.

author: coppice
author_rank: Super Contributor
timestamp: December 31, 2023, 04:47:39 pm
content: Quote from: Dan123456 on December 23, 2023, 05:09:29 amI like the way SpaceX save money and emphasise the look of reuse by the simple step of never cleaning the boosters between missions, so they gradually fade to black (well, dark grey by the 19th mission, where the recent booster was lost to sea-sickbness).

author: coppice
author_rank: Super Contributor
timestamp: December 31, 2023, 04:50:53 pm
content: Quote from: Kim Christensen on December 31, 2023, 04:42:04 pmI know its real, but the fakest seeming thing about those landings is how close to the ground they are when you hear the sonic boom. I know the sound takes a while to arrive, but damn those things are still dropping fast quite close to the ground.

author: Kim Christensen
author_rank: Super Contributor
timestamp: January 01, 2024, 12:55:19 am
content: Quote from: coppice on December 31, 2023, 04:50:53 pmFiring the the engines at the last possible moment is the most efficient method, not to mention being more impressive as well.

author: HalFET
author_rank: Frequent Contributor
timestamp: January 01, 2024, 01:30:42 am
content: Quote from: u666sa on December 21, 2023, 08:33:00 pmMost space hardware is extremely conservative and still designed/manufactured using components that were common in the late 80s/early 90s. So the hardware in question is already obsolete from a commercial point of view before you even begin breadboarding. You'll often even find discrete solutions that you wouldn't even consider using on earth due to harsh environment requirements that might seem non-obvious. So if we leave SpaceX out of consideration for a while, the obsolescence cycle looks somewhat different when comparing it to consumer hardware.On the other hand, most designs are also quite modular, so as long as the cabling harness and no structural components are damaged, I'd consider a satellite very salvageable. Especially if you could upgrade it with newer hardware that's slightly more power efficient, that might very well compensate for the reduced efficiency of the solar panels and batteries. A lot of missions are also "simply" a bunch of modules tied to a standard platform of sorts, so if you'd make those connections easier to swap out you could quite literally do something like take an old earth observation instrument off the satellite and install a new one and get your launch weight down to a fraction of the cost of launching a new satellite. So there's a potential market for it, and it makes sense, the question is if the economics and technical feasibility make sense.