Bitcoins in space!

[marcus_of_augustus]

Not sure if anyone brought this up, a satellite orbits earth about every 90 minutes, meaning we'd get connection for about 30 minutes when it's around and then silence 60 minutes. But likely there's some option to rent something "cheap", low bandwidth on a global level.

A satellite orbits earth however often you want it to.

This is not entirely correct since at the shorter orbital periods you will encounter an increasingly thicker atmosphere as altitude decreases. Typical Low Earth Orbit (LEO) period is ~90 mins.

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[geri]

Doesn't really matter what time it is, the point remains that with a single piece of HW you won't reasonably cover all you need to cover in a reliable way.

Also, how about the receiving parts on land? How much would one cost to buy?

And lastly, is it really useful to have one-way communication? The amount of transaction data is quite low, it might be beneficial to do a two-way possibility to get Bitcoin anywhere, even without internet or electricity (solar).

[matthewh3]

Not sure if anyone brought this up, a satellite orbits earth about every 90 minutes, meaning we'd get connection for about 30 minutes when it's around and then silence 60 minutes. But likely there's some option to rent something "cheap", low bandwidth on a global level.

A satellite orbits earth however often you want it to.

This is not entirely correct since at the shorter orbital periods you will encounter an increasingly thicker atmosphere as altitude decreases. Typical Low Earth Orbit (LEO) period is ~90 mins.

Did you watch Gravity too 

[marcus_of_augustus]

Not sure if anyone brought this up, a satellite orbits earth about every 90 minutes, meaning we'd get connection for about 30 minutes when it's around and then silence 60 minutes. But likely there's some option to rent something "cheap", low bandwidth on a global level.

A satellite orbits earth however often you want it to.

This is not entirely correct since at the shorter orbital periods you will encounter an increasingly thicker atmosphere as altitude decreases. Typical Low Earth Orbit (LEO) period is ~90 mins.

Did you watch Gravity too 

...haven't seen it, actually in another life I'm actually a rocket scientist

[Altoidnerd]

Not sure if anyone brought this up, a satellite orbits earth about every 90 minutes, meaning we'd get connection for about 30 minutes when it's around and then silence 60 minutes. But likely there's some option to rent something "cheap", low bandwidth on a global level.

A satellite orbits earth however often you want it to.

This is not entirely correct since at the shorter orbital periods you will encounter an increasingly thicker atmosphere as altitude decreases. Typical Low Earth Orbit (LEO) period is ~90 mins.

Did you watch Gravity too 

...haven't seen it, actually in another life I'm actually a rocket scientist

Beginning with "not sure if anyone brought this up..." this entire thread needs to die.  That original comment makes too many errors to address so just end it.  This doesn't present a technical problem for signal transmission.

[Athanasios Motok]

Wow this sounds like a great idea!
-AM

[syedkarim]

Hi everyone. I was in touch with Jeff earlier about this idea, which is similar to something that I'm working on. Everyone who is interested in broadcast data from space should join forces.

http://outernet.is

WiFi for the world from outer space. Unrestricted, globally accessible, broadcast data.

[jgarzik]

Something's brewing: http://www.dunveganspace.com/goals/bitsat

Should have something available late tonight or early tomorrow.

[syedkarim]

Hey Jeff: Glad to see BitSat maintaining the momentum. Let know if you'd like contact information regarding transponder pricing on an existing geostationary satellite. The cost of a 64kbit circuit on C-band over three transponders is not only incredibly affordable (when compared with building and launching a small satellite constellation) it also provides a global broadcast almost immediately. SES and Intelsat are comparably priced.

Ku-band pricing is more or less the same per MHz, but it requires 12-transponders, rather than the three on C-band.

[benjamindees]

Based on your stated plans, I'm wondering what is the goal of this project exactly?  One satellite doesn't cover the whole world very well.  Is it just local coverage?  US only?  Not related to BitPay, though?

Let's take a guess...

Rough cost estimates of a single cubesat:

• Launch: $1m

This sounds high...

Through companies like Eurokot and Kosmotras, the launch costs are currently about US$40,000 per single cube.

http://www.satmagazine.com/story.php?number=602922274

This is an older article, but even considering a 2.5x increase in the price of oil and quite a bit of inflation, launch costs for a 3 cube satellite really shouldn't be more than $0.5 mil today.

And if we look here, for instance, we see that a 3u cubesat launched to LEO costs $325k.  But, a geosynchronous orbit costs $1 million.

So... what's the plan?  Where is this thing going to broadcast?

[Dumbo]

If it has anything to do with Cubesats, I would like to be a part of it. I have some experience with AGI's STK and my masters thesis has to do with Cubesat science instrumentation.  

One thing that you may look at (for launch) is Nasa's ELANA deal ( part of cubesat initiative). If you can go through a university, things would be a lot cheaper.

[syedkarim]

Yes, you can definitely make this a university or ELANA, but then you will have no control over the timeframe. One of the PhoneSats that Ames launched was sitting on a shelf for 18 months, literally.

I don't know much about Jeff's plans, but he and I are working on similar projects. Geostationary orbit is going to be way too far away--free space loss will be huge. Even at the higher transmit powers allowed under Part 97/amateur radio satellite rules, a signal will be tough to pickup by a consumer-grade ground station/dish.

The way to get immediate (as in next month) global coverage of transaction broadcasts is by using currently operational GSO satellites.

It would cost about $60,000 a year to have an unencrypted global broadcast at 64kbps.

[Dumbo]

Aye! that is true

Another thing about Cubesats in geostationary  orbit is power requirements on the satellite itself . At LEO say at 350-400 km on a 1U cubesat, you will get about 2W max power from body mounted solar panels. Now I am not sure how that will scale up when you go in higher orbit,  but for transmission from that altitude  power requirements would be significantly higher.  Someone needs to look into it. How big of a satellite you are planning on launching anyway? it might be hard to fit everything in 1U. Deployable solar panels may be the answer here. But that brings you to sizes larger than 1 U.

Moreover isn't there strict guidelines you have to follow at geostationary spots? cubesats have strict regulation to keep debris hazards in check even when you launch in LEO. Explosive bolts, for example is forbidden. I would imagine there would be stricter restrictions for geostationary orbit.

Edit: @ Syed, It seems you are an UIUC alum (from the outernet.is website). You know about the LAICE project?

[syedkarim]

Oh, I'm not talking about cubesats in geostationary orbit--I'm referring to transponder leases on Intelsat and SES satellites. But you're right, orbital slots are tightly controlled. I believe all nations have a slot, which is why you see some satellites flying under the flag of Isle of Man or Bermuda.

You can put deployable solar panels on a 1U. Check out the Ecuadoran Pegasus: http://en.wikipedia.org/wiki/NEE-01_Pegaso

There are many things to keep in mind regarding risk and orbital debris mitigation, but it's a pretty standard punch list. As long as the satellites naturally de-orbits in less than 25 years, all is good. A cubesat at less than 600km only has a 5-7 year mission duration before orbital degradation causes it to burn up on re-entry.

I was not aware with LAICE--thanks for the tip. But it's a 6U, which is considerably more expensive to launch. Still a very interesting project.

[btc_enigma]

Awesome Project Jeff !
Chubacca approves this ! Gr Gr.  . !

[jgarzik]

Big project update:

Project update #1 (PDF): http://www.dunveganspace.com/goals/bitsat/BitSatUpdate1.pdf

The beginnings of the technical specifications needed for satellite uplink and downlink,
BitSat architecture, v0.1 (PDF): http://www.dunveganspace.com/goals/bitsat/BitSatArchitecture-0.1.pdf

Files posted on http://www.dunveganspace.com/goals/bitsat

[papamoi]

Based on your stated plans, I'm wondering what is the goal of this project exactly?  One satellite doesn't cover the whole world very well.  Is it just local coverage?  US only?  Not related to BitPay, though?

Let's take a guess...

Rough cost estimates of a single cubesat:

• Launch: $1m

This sounds high...

Through companies like Eurokot and Kosmotras, the launch costs are currently about US$40,000 per single cube.

http://www.satmagazine.com/story.php?number=602922274

This is an older article, but even considering a 2.5x increase in the price of oil and quite a bit of inflation, launch costs for a 3 cube satellite really shouldn't be more than $0.5 mil today.

And if we look here, for instance, we see that a 3u cubesat launched to LEO costs $325k.  But, a geosynchronous orbit costs $1 million.

So... what's the plan?  Where is this thing going to broadcast?

hi
the geo one costs is only the sat or launch included?

ok it s only the launch cost

how about the sat itself?

i had a project for providing cheap internet access to poor countries using this type of sat ....but costs for geostationnary sat is too high to make is possible

[jgarzik]

i had a project for providing cheap internet access to poor countries using this type of sat ....but costs for geostationnary sat is too high to make is possible

Correct, geostationary tends to be considerably more expensive.

[matthewh3]

Is this project working with - https://www.outernet.is/ - who aim to broadcast the blockchain from space.

[foosub]

What you are intending is not in goodwill of the amateur radio service.

There is a flood of cubesat´s the last years, most of them using frequencys of the amateur radio service, while not providing good services to radio amateurs. This is due that the hardware available is usable on the amateur radio service frequencys.

But none of those is providing something what is of use for the amateur radio service, like transponders, pictures from orbit etc. And also even most of them do not provide all data to decode by amateur radio operators. The amateur radio community should be included in every satellite project, which is not the case with most of the cubesats, while using our frequencys.

Also see:
http://www.klofas.com/papers/klofas_upcoming_cubesat_launches.pdf
http://www.spacenews.com/article/opinion/37890editorial-cubesats-need-coordination-too

I do not think of that a satellite like "BitSat" is of use.
But if done on other frequencys ok.