Blockchain technology company Blockstream, which is one of several institutions funding the development of Bitcoin Core, announced in August 2017 the launch of a satellite network beaming bitcoin from space to people across earth without internet. Blockstream, to be certain, did not launch the satellites themselves. It is leasing bandwidth on four commercial satellites: GALAXY 18, EUTELSAT 113, TELSTAR 11N and TELSTAR 18V.
In order for Blockstream’s satellite network to beam the blockchain to your computer, you’ll need a computer, a TV satellite dish, a receiver, and a Software-Defined Radio (SDR) USB stick to receive radio frequencies.
The company recently completed coverage for the Asia Pacific region and announced the Satellite API, an API that developers can use to pay via the Lightning Network, a second-layer protocol, utilizing a large network of open two-party channels, to enable multiple payments, without the need to record each one individually to the underlying Bitcoin blockchain, for the transmission of private messages from space.
According to British cryptographer Adam Back in an AMA recently posted to r/bitcoin, it was Chris Cook and Greg Maxwell who came up with the idea to beam Bitcoin from space. “Work began heavily in late 2016 with surprise product launch in Aug 2017,” said Mr. Back. He also noted that Blockstream operates two teleports (uplink sites), including a 9m dish to reach Telstar 18V, which beams to Asia Pacific.
“The teleports have multiple dishes and can reach each others satellite for data connectivity,” Mr. Back continued. “In terms of payment we expect to use incremental per transaction or message fees to sustain and grow these kind of use cases…” The service is free using testnet coins for a short time while in testing.
“The cost per message or transaction is often reasonable because while it costs a lot relative to average salary in some emerging markets, to have an internet connection fast enough to maintain a full node, the cost per transaction to send or receive a transaction becomes small because they are small typically 250bytes range,” wrote Mr. Back. “[S]o that even at $10/MByte a single transaction could cost less than 1c.”
Blockstream maintains the system at present. But, “In the event that something happened I expect there would be community interest to take over it’s operation,” wrote Mr. Back. “It’s certainly something I would support.”
Currently, Blockstream is leasing bandwidth on 4 Geo-stationary satellites for close to global coverage.
- GALAXY 18 (North America),
- EUTELSAT 113 (South & North America),
- TELSTAR 11N (Africa & Europe),
- TELSTAR 18V (Asia Pacific combined area).
“They are general use satellites providing satellite TV and other industrial data applications,” explains Mr. Back. “They are geo-stationary. It does add privacy. The data is all public information and the same data is broadcast globally.” Some might feature different FEC encoding so as to increase data rates where there are two satellites covering one area, like over North America, Mr. Back notes.
“You can send messages at a minimum data price of 50millisatoshis/byte, minimum 1kB message so 50satoshis minimum, about 0.2c today,” writes Mr. Back.
Can You Trust The Operator?
Well-known bitcoin educator Andreas Antonopoulos has openly questioned whether Blockstream can be trusted operating the satellites. Mr. Back addressed this in the AMA. “[D]on’t trust the operator, verify you are on the right chain by fetching headers from other low bandwidth sources,” said Mr. Back. “About scaling, Lightning is very promising and scalable way to grow Bitcoin adoption to more users than can be achieved with a broadcast-only single-layer approach. I think internal competition between layers makes them efficient for the things they provide best.” (You can read more of Mr. Back’s thoughts on this here)
Blockstream is at first offering this service for free. But it eventually will charge. Blockstream, according to Mr. Back, foresees mining companies paying a premium to have a backup link to the bitcoin network that doesn’t need the internet. The company also sees developers using the network to code bitcoin apps that beam data down to cell phones.