Since the linked article is somewhat ambiguous about this, and other commenters appear to be getting confused about the purpose and value of the laser links as well: these laser links are purely intended for satellite-to-satellite communications for Starlink. They are not (at least at this time, and for the foreseeable future) intended for ground-to-satellite communications.<p>The value that sat-to-sat laser links provide is that they create a low latency, high bandwidth path that stays within the Starlink satellite network. Before these 10 satellites, each Starlink satellite has only been capable of communicating directly to ground terminals (either consumer, transit, or SpaceX control). For traffic that is intended to move large geographic distances (think transcontinental), this can require several hops back and forth between ground and space, or the traffic from the user terminal is exited at a node that is geared for transiting traffic and most of the data transits along existing ground Internet links.<p>By performing this type of transit directly in space, and exiting at a transit node nearest the destination for the data, you greatly reduce latency. Bandwidth still might not be great, but what this does is unlocks a very financially lucrative consumer use case: low latency finance traffic and critical communications. There are many use cases around the world where shaving even 10-20 milliseconds of latency on a data path can unlock finance and emergency capabilities, and this is a long fought battle throughout the history of these industries. As an example, if you got a piece of news about a company in Australia, and wanted to trade on it as quickly as possible in USA, if you can beat your competitors by 10-20 milliseconds, that can mean a lot of money.<p>Laser comms for Starlink sats have long been planned, but have historically proven to be quite hard to get working. They also depend on a sufficient critical mass of satellites so that a given sat actually does have another sat within lock to send the traffic towards.
There are two different explanations that I've read over the last few months for why we didn't see laser links on previous rounds of Starlink satelites.<p>First, that the unit pricing was too high. SpaceX is targeting an extremely (absurdly) low price of $250,000 BOM per satelite, and it was theorized that the laser links were blowing the budget. Estimated that it would cost ~$100k for the lasers, targeting, and electrical systems to add the links.<p>Second, I've read that they had issues guaranteeing that all the components of the laser system would fully burn up in the atmosphere. One of the conditions of launching low-orbit satellites is that they will fully burn up on re-entry (therefore not posing any risk when they fall back down to earth). Apparently some of the optics components had a chance of survival and ultimately possible land-impact.<p>I'm not sure if we can say that this launch indicates that the cost issue has been solved. It could be worth blowing out the BOM to get some operational experience having a few birds with the lasers, so perhaps they haven't fully solved the pricing issue unless we start seeing lasers on every subsequent launch.<p>TFA has a great animation of a polar orbit. It's basically a longitudinal orbit, so it will absolutely pass over land for a lot of the time, so clearly they must have at least solved the burn-up issue, if in fact that actually was ever an issue in the first place.<p>Also, FYI, there was a scheduled attempt to launch SN9 today, but it just got scrubbed a minute ago due to winds. They will be trying again tomorrow! reddit.com/r/spacex is a good place to watch for updates: <a href="https://www.reddit.com/r/spacex/comments/krllbt/starship_sn9_test_no_1_high_altitude_launch/" rel="nofollow">https://www.reddit.com/r/spacex/comments/krllbt/starship_sn9...</a>
For others like me who are wondering how much bandwidth could be realistically achieved between sattelites, here is one real-world product from the company “Tesat”:<p>> The laser terminals supplied by Tesat needed less than 25 seconds on average to lock onto each other and begin transmission in both directions at 5.6 Gbit/s.<p><a href="https://www.laserfocusworld.com/lasers-sources/article/14104017/laser-links-will-link-small-satellites-to-earth-and-each-other" rel="nofollow">https://www.laserfocusworld.com/lasers-sources/article/14104...</a><p>Napkin math: that’s 56 clients using constant 100 MBit/sec. With overbooking coefficient of 0.01, that’s 5,600 clients on 100 MBit/sec plan per sattelite with 1 MBit/sec guranteed.
I recently read the book Eccentric Orbits about the Iridium comms system that was a lot like this (recommended by the way). One of the technical issues that was mentioned in it was that the satellites had to correct for the Doppler shift in the frequencies they used to talk to each other because of the high relative speed they were traveling at. I wonder if these satellites have a similar problem or if lasers are so directional they can afford to not be too discriminate in what frequencies they accept.
Does anyone have a good physical intuitive explanation for why laser and radar data bandwidth to space are such huge pipes?<p>I have always been amazed at how satellites quote bandwidths on the order of Tb/s, when I don't fundamentally see how they're so different from gigabit fiber, copper, etc. You've still got some oscillation going on and a receiver that has to "decode" it just the same.<p>Is there a physically intuitive way to understand why the bandwidth of these methods is so great?
SpaceX is disgustingly undervalued at $92 billion.<p>I would pay a 4x multiple to be able to dump my own money in here... sadly, I am not a billionaire, and have no access to this market.
I wonder if they will eventually offer network access from orbit. Ship a turnkey module with a 10G ethernet port out the back...that'd have to be worth a couple million dollars a year.
Does anyone have any information in what exactly goes into "refurbishing" the satellites which land? What exactly do they do to the rockets to get them mission-ready again?
I'm confused by the word "the" in "the polar orbit". Shouldn't it just "polar orbit" without the "the"?
> Musk has confirmed on Twitter that the black pipe-type objects at the end of each Starlink satellite are actually laser links.<p>Translation for all beltalowda: “Bossmang say each satellite have a tightbeam”
The title seems a bit sensational for HN: Space, lasers, stars, orbit. I know the drama is partly embedded in company and product names, but how about:<p><i>SpaceX places Starlink satellites in polar orbit.</i>