Yes, we’re talking about taking Blockchain where no distributed ledger has gone before. 

The fact is that everyone is putting a special spin upon blockchain this minute. Given that, it’s no surprise a number of companies are discussing distribution of blockchain information via satellite and only a mild surprise there's a proposal by at least one firm to incorporate blockchain as a way to enable a commercial economy in space.  But are these ideas viable?

Two companies advocating distribution of blockchain from space for cryptocurrency are Blockstream and Nexus Earth.  Blockstream, privately funded to the tune of at least $75 million, is currently broadcasting real-time Bitcoin blockchain data from four communications satellites, with a fifth "TBD," according to the company's website.   The satellite architecture uses one-way, off-the-shelf Ku-band capacity at 64 Kbps, with different transponders over North America, South America, Africa, and Europe. "Phase 2"/"TBD" listed on the website is presumably one or more transponders for Asia distribution; this makes sense due to the relative expense of capacity in the region.

Satellite broadcast provides another option for protection against network interruptions, according to the Blockstream Satellite FAQ, along with a redundancy connection to the blockchain that doesn't require a traditional Internet connection.   However, transactions – spending BitCoin – require a traditional a two-way communications channel.

Blockstream is providing the blockchain data for free, but plans to charge for future add-ons.  Connections require a small Ku-band satellite dish – size will depend on location – an LNB receiver, a USB software-defined radio interface, and free GNU Radio software for the receiver, with an estimated $100 or so for equipment.  Free documentation is available at Github.

Nexus Earth plans to use satellites to support the distribution and use of its NXS cryptocurrency as part of decentralized ground and space-based networks.  The company has partnered with Vector Space Systems for hosting its application on Vector's GalacticSky software-defined satellite platform.   Multiple satellites will host Nexus blockchain distribution, with the first launch of GalacticSky and deployment of NXS expected to take place next year.  Vector will also allow future customers to pay for nanosatellite launches with its rockets using NXS cryptocurrency. (Yes, Vector is selling both launch services to put very small satellites into orbit AND a fleet of software-defined satellites to host applications, but that's a story for another day.)

At the end of the day, Nexus says it plans "approximately" 2000 nanosatellites in orbit, ranging in size from some smaller than a 1U (10x10x10cm) cube, all the way to a larger 3U (30x10x10cm) form factor.  A large distributed cloud of nanosatellites can be launched and turned up on an incremental basis based on available cash flow, slowly expanding space-based service coverage to a 24-hour basis as more satellites are launched.

SpaceChain is the most radical departure from conventional thinking on space technology and blockchain.  The company says it is building the world's first "open source satellite network" to enable a next-generation infrastructure for blockchain.  Under SpaceChain's plan, satellites will incorporate blockchain as an operating system and interface for decentralized applications. The SpaceChain OS is an open source platform to permit organizations to work on collaborative projects, with smart contracts, as well as a way to aggregate and utilize current space resources in an open source, audited and secure system.

The company's white paper says SpaceChain OS will, among other things, enable blockchain-based satellite-to-satellite communication. Since SpaceChain OS will be a "sandboxed" application, it will be able to enable blockchain-based distributed applications on satellites, such as data collection, computing, storage, and other functions.  Similar to GalacticSky, satellites following the SpaceChain model will have flexible software capabilities, as well as being able to host multiple tenants and/or uses.

Data from sensors on a SpaceChain OS-using satellite, such as satellite position, location, temperature, and orientation will be accessible from any app running in the blockchain sandbox, but control and power systems will not.

A SpaceChain demonstration satellite was launched into orbit in February onboard a Chinese C-2D vehicle.  The 3U cubesat runs Qtum's blockchain software on a Raspberry Pi device.  Larger, heavy satellites with more powerful and open source-based processors are planned in the future and will include camera and sensor APIs for developer access.   Like other open source projects, SpaceChain plans to provide a SDK, with a development environment similar to JavaScript, plus code examples and tutorials. A hardware developer's board is also expected.