zlacker

Based on the photo from the NASA website ([1]), they use a Thales Satellite modem ([2]). My best guess it's VesseLINK 700 ([3]) that uses Iridium Certus constellation ([4]) and costs around $8K ([5]).

Key Features:

* Robust, Light-Weight Communications for at Sea Operations

* Certus 700 Services (352 kbps Up/704 kbps Down & 256 kbps Streaming Capable)

*100% Global Satellite Coverage and Low Latency for Critical Data and Voice Communications

1. https://blogs.nasa.gov/earthexpeditions/wp-content/uploads/s...

2. https://www.thalesgroup.com/en/markets/market-specific-solut...

3. https://www.thalesgroup.com/sites/default/files/database/doc...

4. https://en.wikipedia.org/wiki/Iridium_satellite_constellatio...

5. https://seatech.systems/product/thales-vesselink-700-for-iri...

>>krasin+(OP)
Jeez. When I work with Iridium I'm constrained to 300 byte messages (for budgetary reasons).

>>krasin+(OP)
I would bet that modem is using a phased antenna array [1] (I'm guessing this is what "solid state, no moving parts" means on the product page). With the right sensors (gyros, etc), a solid-state system like that should be able to keep a pretty tight lock on the satellite even in the roughest conditions.

1. https://en.wikipedia.org/wiki/Phased_array

>>krasin+(OP)
If someone comes along with a plan and budget for 10K drones does the system have spare capacity ?!

>>krasin+(OP)
Damnit, this is why love HN.

>>krasin+(OP)
Just stick a Starlink antenna on it, dummies. /s

>>algo_t+eH
at 8000 each for hardware, that's 80 Million, plus the data plan charges for each line.

With that amount of money I'm sure the system would be able to grow to accommodate (including sending up more satellites) if only to make sure the money doesn't go to another competitor.

>>willis+5h
Yes, me too. But Iridium recently (2017-2018) launched the new constellation that they call Iridium NEXT which supports L-Band and offers significantly more bandwidth. So, it's now possible to get a 1GB plan for ~$1300/month ([2]). This obvisouly means that one needs to use a different modem. RockBLOCK modems are great but limited to the Iridium "Classic" with these tight limits and insane prices (~$1/KB).

1. https://en.wikipedia.org/wiki/Iridium_satellite_constellatio...

2. https://www.satphonestore.com/tech-browsing/satellite-intern...

>>moffka+DN
Noting the satire marker, I’ll just say for completeness: Starlink consumes 100W continuously to operate its phased array beam and the computation requires to drive it. That’s too much power for a sail drone.

>>ttul+oY
It's really not. Assuming your power source has the required amperage, short, infrequent bursts are much more effective than continuous operation. In embedded systems, it's all about duty cycle, and by that metric, Starlink blows the Thales modem out of the water.

The Thales VesseLink modem they used consumes 65W nominal/120W maximum. It offers a connection speed of a couple hundred kbps, so sending up a video file of a fixed size will require it to be on for quite a while - Assuming 200 kbps average, and a 360 MB video, that's 4 hours of uploading or 260 Watt-hours. Also, it's 12x9x2", and weighs 7.5 lbs; this is a boat not a hobby quadcopter. 260 Watt-hours is a lot; that's like 3 laptop batteries, but that's still smaller than the modem itself.

Starlink does consume 100W, but offers a connection speed of about 200 Mbps. The 360 MB video upload could complete in 14.4 seconds, which consumes 100 W * 14.4 seconds / 3600 seconds/hour = 0.4 Watt-hours. It is significantly larger, and it would probably have a harder time handling rough seas (not to mention saltwater intrusion), but that's a lot less power.

Whichever modem you're using, you'd want to turn it on infrequently.

Edit: The Saildrone product brief is here:

https://assets.website-files.com/5beaf972d32c0c1ce1fa1863/61...

It describes a 23' or 7m boat. The 33'/10m larger version has 300W continuous sensor power/2kW peak available from the solar panels, which appear to be of a comparable size to those on the Saildrone.

>>ttul+oY
Just harvest the hurrican’s windpower /s

>>willis+5h
This is using the next-generation Iridium network which is capable and marketed for offshore maritime, for aviation purposes, land mobile data, land based portable terminals (where people would previously need an INMARSAT BGAN), etc.

It is still very costly on a dollars per MB of data transferred basis.

>>krasin+(OP)
It's great tech. Same next generation Iridium network is used for offshore maritime, aviation, land mobile data, etc. Lots of places where a traditional two way VSAT is much too large. Its main market competition is the INMARSAT I-4 and I-5 series satellites and BGAN network.

The main problem with it is the very high dollars per megabyte cost. If you're a billionaire or a nation state with a $30 million Gulfstream jet and an Iridium terminal on it you probably don't care. But it can be cost prohibitive for any appreciable amount of data transfer from remote scientific systems.

>>LeifCa+W61
This particular saildrone seems to be a larger model: 72' long.

>>LeifCa+W61
Oh, on second thought this boat is a beast. It has a 75 HP diesel engine in it, along with the solar panels. It can surely crank out 100W continuously forever. Sadly, Starlink is not for mobile use.

>>willis+5h
Per this little video, the Thales Vessel link does some 350kbs uplink and downlink.

https://www.youtube.com/watch?v=OoVbH7gFrVY

>>ttul+oY
I always thought /s was 'sarcastic'. And, oh so very often, very not needed.

>>claudi+1C
Look at the Terminal Equipment tab of this page linked below. It shows the Cobham ( different manufacturer from Thales) antenna for the same satellite service. It looks like it is a set of six or so patch antennas. It's not clear if it is switching between patches or combining the signals to/from the patches. If the latter, it is indeed a phased array. That seems likely because the other manufacturer, Intellian, describes their antenna as a 12-element phased array. I'm guessing the Thales also uses a phased array.

https://www.otesat-maritel.com/article/2128/iridium-certus

>>ttul+DS1
Starlink will be available for marine uses: https://www.pcmag.com/news/spacex-preps-ruggedized-starlink-...

It will be a life-changing event for maritime robotics, assuming they don't get too greedy.