[HN Gopher] Are we ready to see satellites built on an assembly ...
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Are we ready to see satellites built on an assembly line approach?
Author : cosmosguru
Score : 39 points
Date : 2021-04-27 18:38 UTC (4 hours ago)
(HTM) web link (blog.satsearch.co)
(TXT) w3m dump (blog.satsearch.co)
| walrus01 wrote:
| This URL appears to be specific to 1U through 6U cubesats, which
| are considerably smaller and less capable than a single starlink
| satellite. Or Oneweb, the most recent other medium large volume
| satellite manufacturing project.
|
| Of course neither company is publishing any photos/schematics or
| details whatsoever about their assembly line, because that's a
| competitive advantage.
| cosmosguru wrote:
| These smaller satellites can support cameras, low data rate
| communications like IOT via space, etc.
|
| I guess if you consider space as the 'highway', the size of the
| satellites can be motorcycles, small cars to big trucks!
| portillo wrote:
| There are multiple pictures of OneWeb's assembly line in their
| website, https://onewebsatellites.com/factory/ , including
| pseudo-blueprints: https://bit.ly/32QSDBS
|
| Still far from what you would expect from a truly automated
| production line, but it has dedicated stations that allows
| workers to assemble multiple satellites in parallel.
| kjrose wrote:
| I think it is an interesting idea, but I fear that unless we find
| a way to bring down the broken, disabled, etc. satellites we
| have, this will lead to accelerating the possibility of a Kessler
| Syndrome phenomena.
| modeless wrote:
| There is a simple and comprehensive solution to this problem
| which SpaceX has already implemented for Starlink. Simply put
| all of the satellites under 600 km altitude. Anything at that
| altitude will fall out of orbit in a few years due to
| atmospheric drag, unless it continuously boosts itself up. And
| before you ask: no, collision debris is _not_ ejected into
| orbits that decay significantly slower than the original
| orbits, just due to how orbital mechanics work.
| trothamel wrote:
| With 1,300 Starlink satellites in orbit, and many thousands
| scheduled to go up, I think we're already seeing the assembly
| line approach to building satellites.
| cosmosguru wrote:
| There are favorites coming up in Europe, China, India and Japan
| apart from the US.
|
| It almost seems like taking a leaf out of the auto industry.
| The question is, how many of these can survive eventually!
| TrainedMonkey wrote:
| Very few, capital cost to build and launch is quite
| significant, cost to operate is significantly less, but still
| substantial. You need a lot of subscribers to make this
| worthwhile and this is likely will be winner take most tech
| market. Left alone global LEO market would probably support
| 1-2 constellations. Given geopolitical nature it is likely
| that some constellations will be outlawed in certain areas.
| SpaceX will likely capture a 75%+ portion of the market
| everywhere it is not prohibited.
|
| It is feasible to see project Kupier and One Web eventually
| getting competitive with Starlink 1.0, but they are not
| launching or innovating fast enough. By the time they are
| ready to start offering V1 constellation SpaceX will be
| launching V2 and testing V3. Long term the only real
| competitor is China because they have a large protected
| market and capable of subsidizing launch and scaling up
| incredibly rapidly.
| jupp0r wrote:
| Sorry I can't resist but put my hacker hat on:
|
| How would effective prohibition work? Beams are directed
| enough to make them hard to find from a frequency
| perspective. Payments will probably be possible in BitCoins
| at some point given Teslas move in that direction.
| Controlling the import of hardware seems like a way to do
| it, but I bet it would still show up everywhere.
| aurelianito wrote:
| That's easy. If spacex does not respect the ban, China
| will fire anti-satellite missiles to the spacex
| constellation.
| modeless wrote:
| That's not easy. There will be tens of thousands of
| satellites. It would be prohibitively expensive to hit
| them all with missiles. Not to mention the debris cloud
| which, while temporary, would cause real problems for
| everyone in space for a few years.
|
| More feasible attacks would be hacking the satellites or
| ground systems, RF jamming, or just locating users on the
| ground by their RF emissions and throwing them in the
| gulag. Or how about holding the Shanghai Tesla factory
| hostage? Less fancifully, China can put pressure on
| SpaceX via the ITU. There are plenty of options for China
| and there is zero chance SpaceX will try to break Chinese
| law.
| justaguy88 wrote:
| Hitting one satellite is a hell of a warning shot though.
| Literally no one wants the debris clouds.
|
| Every country, US included, would pressure SpaceX to stop
| operating in countries that don't want it if it were to
| result in any debris.
| fennecfoxen wrote:
| no
|
| no no
|
| no no no
|
| please. if you want to make Starlink illegal what you do
| is state Starlink is illegal and maybe make it illegal to
| pay Starlink. that's a lot cheaper and doesn't piss off
| the international community.
| bernardlunn wrote:
| Anybody know how dead ones are recycled or is it junkyard in
| space?
| volkk wrote:
| random question for anybody that can answer:
|
| for satellites that are scheduled to be "deprecated," can we
| use a different rocket to gently nudge them out of orbit and
| have them float off into space? even if you nudge them at
| something super low velocity like 100MPH into a direction,
| presumably it would continue floating endlessly at 100MPH until
| it would hit something?
|
| i'm guessing the building a separate "rocket that nudges dead
| satellites out of earths orbit" is extremely expensive?
| simonh wrote:
| I seriously recommend investing in a copy of Kerbal Space
| Program. There is no better way to gain an intuitive grasp of
| orbital mechanics.
| knowaveragejoe wrote:
| You would deorbit the sat and let it burn up into the
| atmosphere. In orbit, you can't really "drift off into" space
| like you're saying here.
| dmurray wrote:
| It doesn't work like this. If you nudge something in a
| circular orbit by 100MPH, in general it moves into a very
| slightly higher, lower, or more elliptical orbit. For a
| typical satellite in LEO, the size of the "nudge" you need to
| get it to "drift away" is comparable to all the rocket fuel
| that went into getting it there in the first place.
| trothamel wrote:
| That isn't right, since all you have to do is lower the
| orbit until it hits the atmosphere, and let that do all the
| work. A Space Shuttle deorbit burn was ~90 m/s, versus the
| 7,600 m/s that the ISS moves at. (With even more lost to
| drag, gravity, etc, getting there.)
| maccam94 wrote:
| The ISS is in a relatively low orbit at ~400km altitude,
| geostationary satellites are up at 35,000km and have
| basically zero drag.
| GlenTheMachine wrote:
| "I'm guessing the building a separate "rocket that nudges
| dead satellites out of earths orbit" is extremely expensive?"
|
| Yes, at least as expensive as launching the original
| satellite, if not more (because it has to have the ability to
| intercept).
|
| Also, just adding a little nudge doesn't really help. It
| changes the orbit slightly, but it isn't like an additional
| 44 meters per second (which is what 100 mph is) of velocity
| is going to make the derelict spacecraft achieve escape
| velocity. You'll just change the shape of the orbit some. You
| need to add an additional ~ 3300 m/sec (7400 mph!) in
| velocity to get to escape velocity.
|
| _Decreasing_ the velocity, such that the derelict eventually
| de-orbits and burns up in the atmosphere is typically much
| less expensive. A few hundred m /sec would probably do it,
| but it depends a lot on what orbit the derelict starts in.
| cookingrobot wrote:
| If you give a satellite a shove, it will end up on a slightly
| higher or lower (or eccentric) orbit depending which way you
| shove. It won't keep floating off endlessly into space unless
| you shove it with enough energy to get to escape velocity.
| distribot wrote:
| Like any other externality that isn't constrained by
| regulation, the problem is raging out of control.
|
| https://www.bloomberg.com/opinion/articles/2021-04-17/space-...
| cosmosguru wrote:
| There is a junkyard for GEO i.e 360000km orbit. But there are
| now concepts and companies coming up to solve the junk problems
| for the 500-2000km orbits - https://www.bbc.com/news/science-
| environment-56420047
| GlenTheMachine wrote:
| "Recycled"? None.
|
| Deorbited: quite a few. Depends on orbital altitude. Low-earth
| orbit satellites generally deorbit by themselves eventually,
| but at the upper range of low-earth orbit that can take a few
| thousand years unless they are intentionally deorbited.
|
| In geosynchronous orbit, nothing is ever deorbited, it's too
| costly in terms of fuel. They are instead raised in altitude a
| few hundred klicks to get them out of the way.
| legulere wrote:
| Are we ready to just see satellites and no stars anymore?
| milesvp wrote:
| I see a double edged sword here. We already have enough light
| pollution that stars are hard to see in most cities. That
| amount of pollution grows yearly as cost per lumen drops. The
| problem ground based astronomers are having is the pollution
| these low earth sats are having. This is the down side. What
| makes me hopeful is how much better orbital optics can be.
| Couple this with signal processing and scores of telescopes in
| orbit, and you could create a virtual lens many times larger
| and clearer than anything planet side.
|
| As the price for getting satellites into orbit drops I imagine
| astronomy having some pretty major breakthroughs.
|
| That's at least my hope. Most of what I've been watching is low
| orbit satellites but I don't know how high an orbit you'd want
| for the kinds of things I'm imagining.
| cosmosguru wrote:
| Something that many in the astronomy community are asking
| https://www.cnbc.com/2020/04/29/elon-musks-spacex-reducing-s...
| bpodgursky wrote:
| The opacity desires of astronomy are different than human
| eyes. Painting satellites black (ongoing w/ Starlink) is
| enough to make them dark to the human eye.
| turbinerneiter wrote:
| I wonder if it will make sense to go back to multi sensor
| platforms. We could have a fleet of platforms in different
| altitudes, combining different sensors and comm tech. Might be
| better than to have a fleet for every specific wavelength (for
| observation) and radio band.
| cosmosguru wrote:
| The problem is how do you do that when 20 companies are flying
| the same type of satellites and are fighting for customers with
| almost similar capabilities. If it was a question of science or
| governmental cooperation, such agreements may be easier.
| ratsmack wrote:
| With the number of satellites slated to go up, there will be
| enough shade to cool the earth and save us from climate change.
| dmd wrote:
| I know you're not being serious, but I like estimating stuff
| like this.
|
| The biggest solar panel array in space right now, AFAIK, is the
| ISS at 2500 m^2.
|
| There are currently ~6000 satellites in (any) orbit. Starlink
| has 12000 more planned. Let's go nuts and say there's gonna be
| 50000 total satellites.
|
| Let's say ALL of them are as big as the ISS's, ridiculous as
| that is. And let's say they cast a 1:1 shadow, even though
| that's also patently ridiculous. I'm just making all of these
| number as big as possible so nobody can possibly say "no, it's
| bigger".
|
| 2500 m^2 * 50000 = 125 square kilometers.
|
| So with _many_ times the number of satellites planned, with
| each one being anywhere between 50 and 100 times as big as it
| really is, with each one casting a shadow as big as it is... we
| shade - out of the entire planet - an area about 1.5 the size
| of Manhattan.
| Kye wrote:
| You don't need to cover the whole planet, just the parts
| under the sun. I'm not an orbital machinist, but maybe we
| could park just enough blockers in an orbit that's always
| between the sun and Earth to halt the warming. How much of
| the sun would need to be blocked to bend the curve down?
| Everything necessary on the ground to stop putting CO2 in the
| air is already underway. All we need is more time.
| edrxty wrote:
| This is something that's been considered, particularly for
| doing things like terraforming Venus. There are these areas
| called Lagrange points[1] that provide a location where one
| can park a satellite where it'll remain stationary relative
| to the two-body system of interest. The point directly
| between the sun and earth is the L1 point and allows you to
| place a sunshade such that it'll always be directly between
| the sun and earth. It should be noted, however, that these
| points are generally not stable and so require some degree
| of station-keeping to remain viable long term.
|
| [1] https://en.wikipedia.org/wiki/Lagrange_point
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