The Iridium situation was much more interesting than described in the video. It wasn't Iridium that threatened to deorbit the satellites after they went bankrupt, it was Motorola. Really, the whole thing was Motorola running a big financial scam that just so happened to involve some very neat technology. They had already extracted enough money from Iridium and partners to cover the costs of developing and launching the system, so were perfectly happy forcing Iridium into bankruptcy rather than continuing to support the constellation. The book Eccentric Orbits: The Iridium Story covers all this and is a surprisingly entertaining read.

Scott, you missed one fun fact. Iridium was originally designed to have 7 orbital planes with 11 satellites in each plane and hence 77 satellites which is the element Iridium. But they then changed the orbit height and so only needed 6 planes for the same coverage (set by minimum elevation angle..) and so only 6x11 = 66 satellites were needed.. So the constellation should be called Dysprosium.

in some ways Iridium is why Starlink exists, IridiumNEXT was certainly one of the most important non government contracts for a young SpaceX.

Glad you covered this one, Scott. My first job after the Navy was working for Qualcomm as a Field Service Engineer, installing Globalstar ground sites. I installed the South Africa and Nicaragua sites, and did upgrades at the Clifton, TX site, three sites in Australia (Meekathera, Dubbo, and Mount Isa), and the Italy site. I also installed the system that controlled the entire GS network at both the primary command center in San Jose and the backup site in Sacramento.

Hah! I was working at Globalstar during the initial launch period, and was there for the Zenit failure. The system had lots of promise, but international roaming happened much earlier than expected, and pulled the rug out from under us. Glad to see the system still being used for SOS services!

I worked for a large company in the 80's, who rented a transponder 24/7 (at times more than one). They would broadcast video to branches all over the US, which used 4.5 Mb/s. Transponders were good for 6Mb/s, so you had a T-1 sized data path that was mostly used for maintenance and ignored otherwise. But when not needed by the satellite providers (usually about 23 hrs/day) you had this available. The ground sets would strip off the video signal, and many sites had a (company built) card to grab the data path. The uplink was at one of the research locations, and a few sites sent most of their outbound traffic over the satellite, especially that going cross-country. This was before the widespread internet, and most of the corporate traffic was over leased T-1 lines (which multiplexed 24 channels of 56Kb/s, each channel either a data path or a single phone call). Getting bursts of 1.5Mb/s data sped up the entire corporate network significantly.

Sat phone calls used to be absolutely absurdly priced, like *$20 a minute* sometimes.

Another major contributing factor to their downfall was the unexpected rapid globalization of IS-136 TDMA, IS-95 CDMA, and GSM cellar technologies, as well as International Roaming. In fact, more cellular was installed in "2nd and 3rd world countries" in the 90s than first world countries. And that's because cellular was cheaper than installing landline infrastructure, which these 2nd/3rd world countries either didnt have at all, or was extremely limited. People were on waiting lists for YEARS to get a landline installed to their home. Cellular simply killed the business model for widespread use of Sat Phones. They still had their niche market, but it forced the cost per minute to be ridiculously and forever out of reach for the common person.

I remember supplementing my regular internet with DVB-S reception of usenet group content. That was in Europe on an open channel and your client software would just keep the data for the groups you were interested in.

Iridium flares are what got me into astronomy. Was very sad to see my last ones knowing they weren’t coming back

I'm hoping the Island of Stability exists so that Starlink gets an atomic-number name

Looking for Iridium flares used to be a favorite hobby for me. Sadly, the satellite tracking sight I use no longer predicts the flares. I suppose they are still orbiting up there, so if you see a super bright light in the night sky (magnitude minus six to eight) that is moving at the speed of a satellite, it is probably an Iridium.

The simplicity of the GlobalStar system was actually thought of as an advantage over Iridium at the time. Keeping the sophisticated electronics on the ground meant it was much easier to repair or upgrade them, simpler satellites were (in theory, at least) more reliable, and the downsides of the "bent pipe" approach didn't really matter much in the real world because the vast majority of the customers were located at lower latitudes. Yeah, you couldn't do cool stuff like routing calls around the world over just the satellites, but did anyone really care? Ultimately both of the services failed because ground-based cell networks rolled out faster than expected. Dead spots largely disappeared (at least in places where most people went) and so very few people wanted buy the very expensive phones with the very expensive service, just to get a satellite capability that they would basically never use. Also, the phones were large and bulky, even for the day.

I was out with my telescope one night in the back yard when i observed a bright flare. At first i thought it was a meteor but it was slower moving than a typical meteor. After doing some searches on the internet i learned about Iridium satellite flares. I found a satellite tracking site called Heavens Above, and sure enough one would have been visible in my location at that very time!

Was in the military when we got orders to head out overseas. We had a case of Iridium phones. My job was to op check. All the SIMs , and they had expired. Folks there who kept them up were gone. They had new SIMS in 6 hours. I hate to think what that cost. We used those things for data, secure fax and voice. I still have one. It a racket how they sell time limited (like 6 months) SIMS.

I've seen some Iridium passages. Amazing stuff indeed! Thanks, Scott! 😊 Stay safe there with your family! 🖖😊 And happy holidays!

Hey Scott! Love your channel! Happy Holidays from Boise, Idaho!!

appreciate this series of videos, great stuff

*Digitizing the signals with/ plus “Data Compression & Error Correction” were the capacity game changers.*

Absolutely loving this series.

Thanks for this snapshot of satellite comms - it’s on my “training” to-do list for my day job in mobile telecoms 😊👍

Merry Christmas Scott

Skort Munley! Whaddy'at?! Can't wait to see ya at the Astra awards!

This just goes to show how much launch capacity is the game changer for a viable service.

Good background video, thank you!

Was definitely expecting some sweet iridium flare pics/vids. They were the only naked-eye manmade objects that were better viewing than an ISS overhead pass

Great video, Scott...👍

Been looking forward to this video. Love this series! Wish this and the atomic bomb series would never end

Omg a new episode awesome series.

I had a brief spell carrying around a company-paid-for iridium handset circa 2002, I recall as soon as I was back from whatever I was doing in the middle of nowhere in the Australian outback it'd be snatched back off me and I'd have to give some justification to the bill I'd racked up on any *actual phone calls* I used it for out there lol. I forget exactly what the wording was like, but I still remember you'd get an american accent voice message to the effect of "Please wait while your call is connected over the iridium satellite network" or the like every time you made or received a call

Scott -Remember, it wasn’t until the late 80s that the Signals were Digitized. Prior to that, signals/ handsets was analog! This held up capacity and the value of putting these satellites up any earlier. I know I worked for Alltel and BellSouth mobility from the beginning of the cellular in industry.

Very cool. I had no idea. Thank you.

Great video, thank you!

We used a home satellite internet service for a while in the late 90s, something our local ISP started offering. No idea how it worked technically, but it used a big dish on the roof for downlink, while still using the dial-up modem for uplink, so probably similar to the DirectPC setup. Not bad for the time - I remember using it to download Linux ISOs insanely quickly - but it was never very reliable, and obviously the latency was pretty dire.

Interesting video, thanks!

Do you think the communication satellite series might include a Sirius/XM installment someday? Cellular broadband has taken the place of satellite radio for me now, but I was an early adopter of XM back in the day. I'd be interested to hear about the history of the industry.

I am grateful to Iridium for the safety net they provide while hiking. The Garnin inReach iridium terminal is tiny!

Did a 2 year tour on an arctic base in the early 2000's. Our only link with civilization were voice calls over Iridium and HF radio. I suppose they have broadband Starlink these days, what a world.

I remember hacking this Directpc thing, from Vladivostok, in 99 or something. We only got 5-15 minutes a day of connection.

Marine realm guy here .. Mini Vsat is still a thing alongside Iridium (see the Go!) and others like starlink .. fun times

Are yoy going to play ksp 2 ? Love your ksp 1. Your mind is crasy good for the fun and still make it fun to hear 🙌🙏

Apple has Globalstar (GSAT) under it's umbrella now. Launching new gen satellites with SpaceX newt year. LOADED Globalstar stocks!!! Hope you don't miss out.

My uncle worked for Motorola in the late 80s and 90s and helped to write the OS for the Iridium satellites.

While looking at real estate a few days ago, I saw one of those old one-way DirectWay dishes in the front yard of a house.

Wiuld be interesting to see some numbers for Iridium - total cost of development and launches, how much did it cost for the customer and how many customers they actually got

Iridium flares got me interested in space and rocketry many years ago

Scott, You completely missed Loral Cyberstar. We were building a leo constellation for Datacom. I was there 1997-2000. The only reason why it failed was because in 1999 Bernie Schwartz announced Cyberstar wouldn’t go public. All the engineers bailed looking elsewhere for stock options. I ended up at Cisco.

I remember staring at the DirectPC display at CompUSA the day I went in and bought my USR 56K modem.

I was running a venture fund and had the deal, said iridium would fail-it didn't work inside a building! But Then in bankruptcy I wanted to buy it for things we were doing like fleet logistics and handheld sync data. $25 million for the whole thing!!! But we failed to raise a new VC fund.

Mentions of those "brick-sized" cellphones always remind me of "The KLF - 3AM Eternal" music video.

I remember the iridium flare app that would tell you the transit time and intensity and if you found the right one with the right weather at the right location you were in for a truly incredible viewing experience after a few seconds your perspective shifts and all the stars start flying past the satellite and you as you lock onto the satellite you really feel the speed of you and the satellite now with space X I just saw 20 launch and I thought it was world War 3

Merry Xmas.

Nice blog and like revisiting history, Were there any engineering challenges too related to real-time data transfer latencies from earth to satellites and satellites-satellites hops ?

I remember having a sat connection in 2002 at work in the uk.

I once used a Spot Tracker powered by GlobalStar to track the flight of a balloon to stratosphere. Undortuntely I did not know, that tracking is started when the tracker is sensing some amount of acceleration. So no data was received until the balloon finally burst.

Watching this on Starlink... I've had to carry an Iridium phone before, it was trash 😂 I also had DirecPC in the 90s, it wasn't bad for downloads but the latency was atrocious, like 1000ms+.

I wish satellite internet had gotten off the ground earlier, it probably would have helped Net Neutrality and forced investment by cable, fiber, and DSL. There are still many areas (including NY and CA) that have monopoly providers with dubious service and no alternatives.

I was working for Motorola when Iridium was introduced. I remember sitting in an auditorium in Austin when management presented Iridium to the employees that would be involved in building it. I remember a video with a guy walking at what looked like one of poles, by himself, when his phone rings and he answers it. I never really understood why they thought they could make money with it. How many customers were in that video?

Used to love watching for Iridium flares!

9:25 It looked pretty busy at the poles!

Company I worked for had DirecPC, yeah it was a weird arrangement. But prior to cable modems, that download speed was amazing 😅

A side note to Iridium is that the first collision between two satellites was between an Iridium vehicle and an old Russian satellite in 2009.

See also: Air & Space Smithsonian Sept 2004, Page 60 " The rise and fall if Iridium " ( And yes, it was the last magazine on the pile I was looking through . ) This also has a Beech Starship on the cover.

It really blagged my head a few years ago to find out that our overseas internet was carried by cables on the sea floor. As I had assumed that continents and island nations were connected via satellite. It makes more sense when payloads to orbit was explained and how much it costs to get enough satellites into orbit to cover the connections. Which would then be costly for the consumer who will want a large band width at a competitive price.

Interesting subject, and very useful, but I truly worry about so much hardware up there. It really is getting out of hand, and now Blue Origin wants to get a constellation going too 😢

West Ford - that made me chortle...

20 years ago, a system like you describe for "fast internet" indeed was operational here in Europe as well. It used Eutelsat satellite transponders. The users would connect via a phone modem and receive their downlinks via the satellite. The transmission actually used a PID on a standard DVB-S multiplex, so there could be radio and TV stations on the same transponder. On the specific PID used by the service, IP datagrams were sent just like MPEG streams would be sent for TV. Actually it wasn't encrypted at all! Probably encryption for such "fast links" was not really feasible at that time or would conflict with export regulations. And because almost all traffic was in plain http those days, one could actually eavesdrop on the traffic for the users of that system. There was a program (appropriately named "skynet") that collected all complete TCP sessions and wrote them to files, identifying the content and assigning an appropriate (random) name to each file. Letting that run for a while would yield a large number of files, e.g. BMP, JPG, MP3, MPG etc. As you rightly remark, all the users shared the single bandwidth, which would only be a couple of Mbit/s. So for each individual file, the actual transfer rate was not high at all, not even as fast as a phone modem.

I miss the iridium flares, so cool to ask the wifey to look up there will be a bright spot.

HOLY DIAL UP TONE BATMAN! say it with us Scott. MO-DEM MO-DEM You madlad you.

A little bit of crazy history: Teledesic - bankruptcy Iridium - went through bankruptcy and was rescued by the Pentagon Globalstar - went through bankruptcy Orbcomm - went through bankruptcy O3b - sold to a geostationary satellite operator LeoSat - project closed Telesat Leo - launches delayed for years OneWeb - went through bankruptcy Starlink - 1st to survive without bankruptcy🎖 Kuiper - launches delayed for years

So are all those satellites still orbiting , or how many are redundant and still circulating ? Scot Manley can you please do a video on this

I wonder if any of these countries packed on any extra eavesdropping hardware on those satellites they launched for Iridium?

*Anyone else miss: “Iridium Flares”?*

Encrypted downlink? I distinctly remember leeching these (or in any case a) downlinks with my scsi equipped nokia sat receiver.. was fun seeing the images scroll by..

56 kpbs wasn't "terrible" It was pretty fast when it came out, and all you had were BBS and then the early Internet...it's just that data grows to match capacity.

I really miss watching "iridium flares" from those satellites! : (

Just wondering: at what date did Starlink exceed the original planned size of Teledesic?

In 2004 I tried to help a friend on his yacht in Brazil download an update on his laptop using his Iridium link. I failed because every time I tried, it lost connection of a packet part way through the download. Iridium was OK for voice and short emails though.

LOL at the Westford comment.

I manage a number of satellite phones. We used Gloalstar back in their Dark Ages and it was truly dreadful. Between the complexity of their normal operating procedures and timing use of the degraded constellation it was close to unusable. We then had an opportunity to change over to Iridium at very low cost and I jumped at the chance. One still has to drum into people that satellite stuff happens s-l-o-w-l-y but the simplicity and reliability was hugely improved. Globalstar have since upgraded their constellation and found ways of using their constellation for data tasks, like SPOT, that are not as demanding as voice. One of our problems with Globalstar was the 52 degree orbit tilt which, since we operate at around 57 degrees North and in mountainous terrain, meant we often could not register with a satellite. Iridium, on the other hand, being a polar orbiter, or 84 degrees, is more latitude independent, or possibly better at higher latitudes. The same latitude problem arises, but to a lesser extent because they are MEO, with GNSS and SAR satellites since most are on 55 or 56 degree tilt. This explains why GPS says I was walking across Knoydart at 1000mph. 🙄

I find it interesting how communication using electrical technology had gone from wired, to wireless, back to wired, and now back to wireless. I.E. Telegraph to broadcast radio/tv to cable/internet to sattelite. What i would to see is starlink having outward looking antenna, so that deep space craft and communicate to earth ground stations using hundreds of satellites nearly simultaneously receiving the data. Would make for a very robust solution that doesn't need super precise aiming, and you'd get a lot of redundancy, which should help data reliability.

Decoding satellite traffic was very easy btw.

I like the fact a few companies are trying to compete with Starlink. We all benefit from that.

We had 7mbit in 96ish!

Iridium user here: I still use my 9505A Iridium phone on a daily basis... There are many areas I go, daily, that do not have 5G/LTE/3G/2G cellular service, and where Starlink would take way too long to set up, yet my old Iridium phone just instantly works.

Fun Fact: I worked with a guy at Motorola in the late 1980's who left my group to go work on Iridium.

The ping of satellite interest was painfully slow! 😂

We called the last resort, back up satalite comms the "iridium phone".

Wow. Looking down through the comments reveals that most of Scot Manley's audience are satellite internet technology experts. 😁

I remember my first pc was a Hewlett Packard, 830 mb hard drive, 2400 bps. About a year later upgraded the modem to 9600 bps. 33k bps with a new IBM clone, and last modem was 56k. I was blazing……until I found DSL. Those days were something

Get well soon Scott.

Internet via satellite was (and still is) also offered in Europe. But I can't find what the first service was. Astra 1K (2002) seemed to support internet, don't know about the 90s though. Also Eutelsat and other companies are in the business. I remember tariffs using the same trick mentioned in the video: upload via modem, download via satellite. But Europe is more densely populated than the US and since mobile networks support fast internet speeds (LTE) today I don't see much potential for customers there.

I remember thinking we were all going to have satellite phones. Only a couple people I knew did.

I miss the Iridium Flares.

You should do a video on the Soviet's idea for a response to the star wars program, the 'sunsat' program. There's an article about it in the New York Times from 1987 you can find on Google. They planned to use their new ultra heavy lift boosters to put city-sized solar collectors into geostationary orbit and beam the energy back down as microwaves to pave the way for the industrialization of space and solve the energy crisis. David Graeber talks about this in his lecture "On Bureaucratic Technology and the Future as Dream-Time" as well as how they planned to seed the world's oceans with edible Spirulina to solve the hunger crisis. Stuff like this and other stuff like an automated cybernetic economy really makes you realize how much of futurism like star trek came from the Soviet vision for the future.

So which Apple devices can send and receive faxes by satellite to any regular fax, a bit like the one used by Steven Seagal in that train heist movie (where he hooked his Apple device into a mobile payphone to indirectly fax the Pentagon about a hijacked NRO asset)?

nice

If Elon Musk and Starlink really develop direct to cell phone service for existing phones, he will become the richest man in the world has ever seen by ten fold

"Space Porn" Sounds like a great 70's movie.

Wouldve been intresting to hear the 2.4kbps audio, as the stories make it sound almost unintelligbe 😅