
Space Based ADS-B - zeristor
https://www.radarbox24.com/blog/space-based-ads-b
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dzhiurgis
How is this different from Iridium who also does AIS?

What else can be tracked this way?

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toomuchtodo
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?

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420codebro
What would be the rough estimate for a fleet of cube/micro/nano-sats?
Legitimately curious what the rough cost is.

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azernik
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.

[1] [https://www.isispace.nl/products/](https://www.isispace.nl/products/)

[2] pricing buried in
[http://nanoracks.com/resources/faq/](http://nanoracks.com/resources/faq/),
description of the service is at [http://nanoracks.com/products/iss-cubesat-
deployment/](http://nanoracks.com/products/iss-cubesat-deployment/)

[3] [http://spaceflight.com/schedule-
pricing/#pricing](http://spaceflight.com/schedule-pricing/#pricing)

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michaelt
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?

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black-tea
Why would hedge funds need to track corporate jets?

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objclxt
Because you can use that information to speculate on mergers and acquisitions:
[https://www.bloombergquint.com/business/hedge-funds-
track-j-...](https://www.bloombergquint.com/business/hedge-funds-track-j-j-
private-jet-for-an-edge-on-actelion-score)

