# Continuing discussion of SpaceX launches \[edited title\] **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 22, 2015, 12:37am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048 "2015-12-22T00:37:01Z")\ **Posts on this page:** 20\ **Page:** 45
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [May 18, 2019, 11:06am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/881 "2019-05-18T11:06:20Z")
> [@Dr.Strangelove](#): > > [Musk: Each Starlink satellite has "about a terabit of useful connectivity](https://twitter.com/thesheetztweetz/status/1128786510478761991) Googling tells me this is 40 000 4K movies being watched simultaneously. Is that about right? How do other commsats compare? > [@Dr.Strangelove](#): > > The ISS has in the ballpark of 100 kW of solar capacity. So, each satellite here is probably ~1.5 kW. As each minisat gets thinner and lower power, all we’ll see on the flat faces may be solar panels. Aren’t LEDs capable of receiving light and solar panels capable of emitting light, depending on which way the electrons are shifting? They could use the solar panels to (power-inefficiently) send optical data. Is the tech that would enable constructive interference between optical emitters mature-ish? > [@Dr.Strangelove](#): > > Considering that SpaceX’s launch costs are probably \<$30M, and they’re launching 60, that means each satellite probably costs \<$0.5M. Less than $30M for 20 tons of payload to LEO? If it keeps going like that, it’ll be possible to take space rides for 5 figures. You must have thought about it. Half a million dollars for a satellite is probably the most important datum. There was a time when a computer would have cost about that much, accounting for inflation. Yet, today, pretty much everyone in developed countries and a growing number in developing countries have access to a computer. I’m not sure what the world will be like when nearly everyone can use a satellite for more than telecoms. Telecoms is important but phones used to be limited to telecoms and expanding their capabilities has been worth it. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [May 19, 2019, 9:48pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/882 "2019-05-19T21:48:19Z")
> [@MichaelEmouse](#): > > Googling tells me this is 40 000 4K movies being watched simultaneously. Is that about right? How do other commsats compare? HughesNet would be the closest competition, with their EchoStar XIX being the latest generation. They [claim to have](https://www.hughes.com/technologies/hughes-high-throughput-satellite-constellation/echostar-xix) 200 Gbps capacity. But they only have one of those, and a few other smaller-capacity ones. Certainly less than 500 Gbps total. Just an amusing factoid–note this line from the link above: _Employing a multi-spot beam, **bent-pipe** Ka-band architecture, EchoStar XIX delivers more than 200 Gbps of capacity_ “Bent-pipe” is satellite engineer speak for a satellite with no real on-board processing. It just takes the data coming from one source and bounces it to its destination without inspecting it at all. Like a golf ball whizzing through a pipe at a mini golf course. > [@MichaelEmouse](#): > > Aren’t LEDs capable of receiving light and solar panels capable of emitting light, depending on which way the electrons are shifting? They could use the solar panels to (power-inefficiently) send optical data. Is the tech that would enable constructive interference between optical emitters mature-ish? I guess that’s where you were going with your LIDAR question. Phased-array optical frequency devices exist, but I don’t think it’s really production ready yet. The StarLink inter-satellite links will be a mechanical laser turret of some kind. Maybe one day it can be entirely solid state. I doubt they’ll ever be able to combine with power generation, since the sun’s output is necessarily broadband, while the comms links would want to be at a narrow frequency band to reduce interference. Though maybe power beamed from the ground could use a monochromatic system. We could have _really_ tiny satellites if they didn’t need onboard power. > [@MichaelEmouse](#): > > Less than $30M for 20 tons of payload to LEO? If it keeps going like that, it’ll be possible to take space rides for 5 figures. You must have thought about it. That was just ballparking from me, though I expect it to be close to SpaceX’s marginal cost. If it were safe enough, I’d spend low 6 figures today. And low 7 figures a couple decades from now. So yes, I’ve thought of it :). ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 19, 2019, 11:02pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/883 "2019-05-19T23:02:13Z")
I had Wildblue satellite internet at my trailer in the woods. Everyone in the “spot” covered shared the bandwidth. Bandwith would be limited if you exceeded a certain amount. I hit it downloading graphics. Watching movies would screw my bandwidth quickly. They were bought by Viasat, offering[packages with “unlimited data”.](https://www.exede.com/plan-results/plat100/) ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [May 20, 2019, 4:10pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/884 "2019-05-20T16:10:57Z")
> [@Dr.Strangelove](#): > > I guess that’s where you were going with your LIDAR question. Phased-array optical frequency devices exist, but I don’t think it’s really production ready yet. The StarLink inter-satellite links will be a mechanical laser turret of some kind. Maybe one day it can be entirely solid state. I didn’t know that’s where I was going but hearing about solar panels made me realize it. Making things solid state has been a boon in electronics. Once you make it solid state, possibilities open up as we saw with vacuum tubes vs transistors, CRTs vs LEDs, HDDs vs SDDs. > [@Dr.Strangelove](#): > > I doubt they’ll ever be able to combine with power generation, since the sun’s output is necessarily broadband, while the comms links would want to be at a narrow frequency band to reduce interference. Though maybe power beamed from the ground could use a monochromatic system. We could have _really_ tiny satellites if they didn’t need onboard power. To avoid weather and coverage problems, you could have the equivalent of in-flight fuel tankers: satellites optimized to capture and store the sun’s broadband output then convert it to narrow freq band before sending it to tiny satellites with no onboard power on a need basis. Or you could use a small number of ground beams to power a few large power hubs in space which would then power tiny satellites. I have no idea if the beams would stay focused enough for it to make sense at these distances. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [May 24, 2019, 7:22am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/885 "2019-05-24T07:22:23Z")
I forgot to put out a notice of today’s launch–well, probably some of you saw it. You can watch a [replay here](https://www.youtube.com/watch?v=riBaVeDTEWI) if you want. Complete mission success: made orbit, [deployed all 60 satellites](https://twitter.com/SpaceX/status/1131765246664646657), [landed the first stage](https://pbs.twimg.com/media/D7TKO4YUEAAVGG3.jpg:large), and [recovered the fairings](https://twitter.com/elonmusk/status/1131783775396909056). I didn’t expect the satellites to deploy the way they did. They kinda just released all at once. I was thinking the stage would spin more quickly, and release the satellites one by one so they kinda shoot out to the side. Instead, they just slowly drift apart, bumping a bit as they do. They released [this CG video](https://twitter.com/SpaceX/status/1131748543373271042). Pretty neat–the solar array is quite big, and there’s just one of them that extends “up”. The main piece is horizontal against the plane of Earth. Here’s a [nice closeup](https://pbs.twimg.com/media/D7THAABVUAATipL.jpg:large) of the satellites. They look great! You can see the many layers of solar panels stacked up, and the white rounded squares with blue wires coming out the back are, I believe, patch antennas. Probably for low-speed maintenance comms–you want simple and reliable for that. The high speed phase array antenna probably takes up the entire bottom surface. I don’t know what the red-outline things are. Possibly something to do with the laser comms, but supposedly these units don’t have that feature yet. So I dunno. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [May 24, 2019, 7:38am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/886 "2019-05-24T07:38:45Z")
Lots of great pictures at the [Starlink web site](https://www.starlink.com/). The red outline things turn out to be star trackers for orientation. They have some kind of dust cover that is either a remove-before-flight thing or just pops off in space. They have at least four reaction wheels–one picture shows four but there may be room for more, and they appear to be at angles suboptimal for just four. Hard to say for sure, though. In any case, three would generally be considered a minimum (though you can sometimes get away with two), so they must have decided that backups were warranted. I wonder if they manufactured them themselves–SpaceX usually isn’t one to use expensive off-the-shelf items, and they’re going to need a _lot_ of these. ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [May 24, 2019, 7:43am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/887 "2019-05-24T07:43:05Z")
The ability to provide uncensored internet to nations like China would be a very strong political tool. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [May 24, 2019, 12:01pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/888 "2019-05-24T12:01:14Z")
> [@Dr.Strangelove](#): > > Lots of great pictures at the [Starlink web site](https://www.starlink.com/). Thanks for the links. I’m a little too easily amused by rotating the globe and seeing the satellites orbit around it. > [@Paul\_in\_Qatar](#): > > The ability to provide uncensored internet to nations like China would be a very strong political tool. That could be huge. Helping to turn China from an authoritarian state to a liberal democratic one could be a bigger boon to humanity than anything that happens on Mars. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 24, 2019, 12:25pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/889 "2019-05-24T12:25:49Z")
> [@Paul\_in\_Qatar](#): > > The ability to provide uncensored internet to nations like China would be a very strong political tool. My first thought is that China can destroy satellites. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [May 24, 2019, 1:51pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/890 "2019-05-24T13:51:44Z")
> [@Paul\_in\_Qatar](#): > > The ability to provide uncensored internet to nations like China would be a very strong political tool. Governments can still control the sale of antennas and receivers for accessing Starlink. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 24, 2019, 5:30pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/891 "2019-05-24T17:30:46Z")
> [@scr4](#): > > Governments can still control the sale of antennas and receivers for accessing Starlink. That certainly has less political fallout than shooting down the satellite. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [May 25, 2019, 3:29am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/892 "2019-05-25T03:29:03Z")
[This is pretty cool](https://vimeo.com/338361997). I count about 47 individual dots, although it’s pretty clear from the brightness that several of them are doubles or triples that can’t be resolved. > [@Paul\_in\_Qatar](#): > > The ability to provide uncensored internet to nations like China would be a very strong political tool. I’d love to be more optimistic here, but in all likelihood Starlink will simply follow local law. I doubt they want to rock too many political boats, let alone invite a physical or cyber attack on their network. Musk did [comment on exactly this thing a while back](https://www.businessinsider.com/spacex-internet-satellite-constellation-china-threat-2016-11): > [@](#): > > “Obviously, any given country can say it’s illegal to have a ground link. […] And from our standpoint we could conceivably continue to broadcast,” Musk said during the event. “I mean, I’m hopeful that we can structure agreements with various countries to allow communication with their citizens, but it is on a country-by-country basis.” > > So what if SpaceX continued to broadcast uncensored internet over China, despite not being given permission? > > “If they get upset with us, they can blow our satellites up, which wouldn’t be good,” Musk said. “China can do that. So probably we shouldn’t broadcast there.” Of course, if the US government wants to use the Starlink network as a kind of social weapon against our adversaries, they could conceivably give SpaceX some kind of dispensation and pay them for the additional risk. ---
**Author:** ![gaffa](https://avatars.discourse-cdn.com/v4/letter/g/e68b1a/32.png) [@gaffa](https://boards.straightdope.com/u/gaffa)\ **Post date:** [May 25, 2019, 6:06pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/893 "2019-05-25T18:06:28Z")
If each of these was equipped with a top-notch cell phone camera, is there a secondary income source providing real-time imagery of the entire Earth? ---
**Author:** ![gaffa](https://avatars.discourse-cdn.com/v4/letter/g/e68b1a/32.png) [@gaffa](https://boards.straightdope.com/u/gaffa)\ **Post date:** [May 25, 2019, 7:47pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/894 "2019-05-25T19:47:24Z")
I wonder what their plans are to retrieve the second stage are? A ballutte like in _2010_? ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [May 25, 2019, 9:55pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/895 "2019-05-25T21:55:11Z")
> [@gaffa](#): > > If each of these was equipped with a top-notch cell phone camera, is there a secondary income source providing real-time imagery of the entire Earth? An ordinary cell phone camera wouldn’t be enough for map-grade imagery, though it might be interesting for real-time weather tracking. That said, fairly modest optics would enable that kind of thing–Planet Labs has some pretty impressive results from optics that fit in a 10x10x30 cm box. That’s still pretty small compared to a Starlink satellite, and high speed comms come for free, so it does seem like they could do something there if they wanted. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [May 25, 2019, 9:58pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/896 "2019-05-25T21:58:34Z")
> [@gaffa](#): > > I wonder what their plans are to retrieve the second stage are? A ballutte like in _2010_? Haven’t heard anything about that lately. I’d suspect that they’re putting all their efforts into BFR at this point. It doesn’t seem like any second-stage recovery testing would really translate over with the current design, so it’s really not worth much even as an experiment. ---
**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\ **Post date:** [May 27, 2019, 9:07pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/897 "2019-05-27T21:07:42Z")
> [@gaffa](#): > > If each of these was equipped with a top-notch cell phone camera, is there a secondary income source providing real-time imagery of the entire Earth? Actually, at high resolution, the earth’s atmosphere is a significant problem. It takes considerable computing power to clean up the satellite images we all see. Not only the geometric distortion (remember the photo is of a sphere projected on a plane), but the atmosphere fogs up the image. There are very effective algorithms, but they are needed. Now for the current real-time satellites (Korean COMS is probably the best right now), they are all very high and have low enough resolution that the atmospheric distortion isn’t noticeable. Until you try to do science with the images-but the clean-up algorithms exist. Humidity ruins more than picnics and hair styles! ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [June 11, 2019, 8:20pm UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/898 "2019-06-11T20:20:01Z")
[There goes the (space) neighborhood](https://gizmodo.com/satellite-constellations-like-spacexs-starlink-could-ca-1835383293)! ---
**Author:** ![N9IWP](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/n9iwp/32/3154_2.png) [@N9IWP](https://boards.straightdope.com/u/N9IWP)\ **Post date:** [June 24, 2019, 12:04am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/899 "2019-06-24T00:04:31Z")
Just a reminder that a Falcon Heavy is planned to launch Monday, June 24 23:30 EDT (03:30 UTC) One the coolest things carried aboard is The Planetary Society’s Lightsail 2 solar sailing experiment: > **[One legacy of Carl Sagan may take flight next week—a working solar sail](https://arstechnica.com/science/2019/06/one-legacy-of-carl-sagan-may-take-flight-next-week-a-working-solar-sail/)** > > "We are carrying on a legacy that has been with us since the founders." > **[What to Expect when LightSail 2 Launches into Space](https://www.planetary.org/articles/what-to-expect-lightsail-2)** > > Our preview guide outlines the LightSail 2 mission from start to finish. Brian ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [June 24, 2019, 1:17am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/900 "2019-06-24T01:17:11Z")
I love how they’re now [mixing and matching cores](https://pbs.twimg.com/media/D9r-g_qVUAAYWB2.jpg:large). The side boosters are reused from the Arabsat mission; the center core is new. Once SpaceX has a few more FH missions under their belt, I have no doubt we’ll start seeing missions where all three cores have a different flight heritage. [Previous page](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048.md?page=44) [Next page](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048.md?page=46)