NASA to Set Up Solar System Wide Internet Connection
US space agency NASA has taken the first step towards setting up a Solar System-wide Internet connection with the completion of its Delay/Disruption Tolerant Networking (DTN) service on the International Space Station (ISS). While the technology and the DTN on the ISS will have benefits for Earth, especially during emergencies, there are other reasons why NASA is planning a Solar System-wide Internet connection system.
How the DTN technology works
The DTN system is designed to be just the groundwork – or the first step – in the eventual Solar System-wide Internet connection network. The DTN system is intended to be as reliable as any home Wi-Fi signal, in contrast with the signal interruptions common in space exploration.
Wi-Fi systems in public areas can be patchy, particularly when there are objects or people blocking the wireless modem and the wireless device. This results in a slower, static signal or an entirely interrupted service. Similarly, when the ISS send transmissions to Earth or to spacecraft, the connection can be disrupted when other spacecraft, radiation waves, or even planets get in the way. For the ISS, this can lead to not just disrupted or slow transmissions, but lost data for the receiving party.
DTN helps overcome these challenges by not streaming data bit by bit, but by storing data if a connection is interrupted, and then using nodes or relay stations to forward the data to the recipient. That is, bundles of data are stored at these nodes along the communication path until they can be forwarded on and later assembled or re-bundled as a whole message or data set at the recipient destination. This automatic ‘store and forward’ technology, which relies on the storage of fragments of data, allows smooth data transmission even when a recipient server is offline. As NASA states, ‘only the next hop needs to be available’ for DTN-based communications.
NASA refers to DTN as a ‘computer networking model’ and a ‘system of rules for transmitting information’ or a protocol suite. This system or model allows Internet capabilities to be extended into difficult transmission environments in space and where disruptions are frequent. Communications without the DTN technology in these environments can be characterised by long delays and significant error rates, all of which can be highly disruptive for time-critical tasks.
The DTN technology can be contrasted with the traditional Internet protocols that are used in everyday Internet connections and which require all nodes along the transmission route to be available at the same time for the data to be sent and received. Prior to the new DTN technology, astronauts aboard the ISS used relay systems similar to these Internet protocols, which meant that every node of the network – usually satellites – had to be available at the same time for a transmission. As such the communication might be frequently disrupted due to satellites not being available or not in position.
According to NASA, DTN technology also enables automation of data availability in space and contributes to more efficient bandwidth utilisation and data return. Data transfer processes between the ISS and Earth will be sped up, along with all communications between any space modules sent out into space.
Applications of DTN technology
NASA has added DTN to its Telescience Resource Kit, which is a software package that can be used to send and receive data from its ground-based centres to nodes on the ISS. In a way, this means the ISS, located 400 kilometres above Earth, can function as a node or a router for the future Solar System-wide Internet connection service.
NASA will use DTN technology for its operations centres and payloads aboard the station, and it is expected to play an important role also with mission support applications such as operational file transfers. Future Moon, Mars, and other space missions could make use of this technology to support accurate and complete data transmission and communications during erratic connections or connection availability, by linking with the ISS and its relay stations.
How NASA developed the technology
The DTN technology has been under development for some time, with NASA experimenting with DTN technology for more than a decade to address the peculiar challenges of communicating in the challenging space environments. It was developed by one of the ‘fathers of the Internet’, Dr Vinton G. Cerf, the vice president and chief Internet evangelist for Google and a distinguished scientist at NASA’s Jet Propulsion Laboratory in California, who worked together to bring the technology to fruition.
Possible applications on Earth
While NASA specifically developed this new technology for space missions, DTN technology is likely to be just as useful on Earth. It could fulfil a vital need during emergencies such as natural disasters, when mobile, Internet, and other telecommunications connections can be unstable or discontinuous. The store and forward method of communication lends itself well to emergency contexts where many networks might be down and you can only ‘hop’ to the nearest module.
DTN could also be useful if battery power on communication devices is exhausted and people need to wait to recharge before they can transmit data. All of these Earth applications could support or impact the rising Internet of Things technology in some way, Dr Cerf noted.
For the DTN to work over the long term and on the Earth, the technology needs to be compatible globally with other Earth Internet networks. NASA has been partnering with various groups, such as the Internet Research Task Force and the Internet Engineering Task Force, to ensure the DTN’s compatibility and future application in everything from disaster relief to Solar System-wide communication networks.