Also, Spire Global, with a network of cubesats, have ADS-B receivers in their sats already. [1][2]
I proposed something similar a few years ago, using cubesats to track airliners, but it didn't go anywhere because Spire Global was already working on that.
It’s noteworthy because something that could previously only be done with billions of dollars of capex can now be a competitive marketplace (global RF surveillance) using micro/nanosatellites.
Any RF you can receive from low earth orbit is up for grabs. What would you do with a global satellite constellation of software defined radios?
(Though first, help me validate it actually makes sense. I know very little of interferometry - enough to imagine this could work, but not enough to be sure an equivalent result won't be achievable through a bunch of ground stations on opposite ends of the globe.)
Going for cubesats, since info is easier to assemble.
Cost of the satellite itself depends on the payload and on the attitude-control requirements - you can get a feel for rough costs by looking at the parts costs from suppliers like [1], adding in highly-skilled labor costs, etc. Numbers I've heard for simpler, smaller RF-only sats can be about $50K, while fancier things like Planet's Dove earth-observation sats (custom-built telescopes, precise pointing, high-bandwidth ground links) can run in the hundreds of thousands of dollars. (This is from what they've said to the press; Planet is very cagey about revealing precise cost numbers.)
Once you've built them, it's about $100K-$500K to launch them to LEO, depending on size (e.g. Nanoracks [2] will launch a 1U via the ISS for $85K, while Spaceflight Inc. [3] launches a 3U for $300K, or a 6U for $550K, or a 12U (who even builds those??) for about $1M).
So let's say a moderate-cost example would be a 3U with off-the-shelf payload hardware. Construction cost ~$100K, launch cost $300K, so $400K per satellite. You want a constellation of 50, that puts you at $20M.
For a more general Fermi-esque estimate, I'd say $2M-$200M depending on size and complexity of your constellation. Compare this to the cost of a single Falcon 9 launch at ~$60M, or to the $3.5B total cost of the Iridium NEXT constellation that SpaceX just finished launching.
Launches seem to be about $100k USD for a 1U cube sat, I’m unclear how large these would be, and you’d have to include the cost of the hardware and I’m sure a bunch of other things.
I’m also curious if anyone can explain everything which goes into something like this and the costs.
Really depends on the number of satellites, the target orbit(s), the payload/application, link strategy, the risk profile that you're willing to accept, etc.
There are quite a few constellations that you can benchmark by:
- Astrocast (IoT) [1]
- Fleet (IoT) [2]
- Iceye (Earth Obs) [3]
- Planet (Earth Obs) [4]
- Spire (Earth Obs, Navigation) [5]
- Capella Space (Earth Obs) [6]
Does anyone know what the business model for these plane tracking websites is?
I assume there's some money in it, because there's a bunch of them: flightradar24, flightaware, planefinder and radarbox24.
I've heard of one or two applications that would need them a lot - taxi drivers scheduled to pick up passengers from particular flights, and hedge funds tracking corporate private jets - but I'm surprised either of those is big enough to support a single company, let alone four of them with their own satellites.
What are the paying customers of these tracking services doing with the data?
A hint is in how they go out of their way to reassure the reader that no new hardware needs to be installed on the aircraft to support this. The actual answer, though, is down in the "Impact" section:
> Customers who operate an aircraft or an aircraft fleet and are looking to be compliant with the mandatory FAA/ICAO/EASA flight tracking requirements, can do so now with our space based ADS-B constellation network and tracking their fleets under RadarBox.com Business accounts.
i.e. airlines (by law) need to constantly know where their planes are, especially when something goes wrong, and they pay companies like this to do the tracking.
What else can be tracked this way?