Crowd sourcing deep space communication
Deep space communication poses a range of significant challenges. To overcome them, NASA is taking more flexible approaches to problem solving than ever before. We look at how their collaboration with TopCoder is evolving the uses of crowd-sourced code, and consider what lies ahead
Email is so ubiquitous and fast that we may be inclined to take it for granted, but what if you were trying to email home from another planet? In this context – or the ‘Matt Damon scenario’ as I now call it – a number of issues may cause you problems, including distance, planet rotation and transmission power limits. These obstacles are not just hypothetical; astronauts on the International Space Station often suffer email issues, particularly when attempting to send large attachments. To achieve effective deep space communication, space agencies therefore need to build what are known as disruption-tolerant networks.
TopCoder has hosted technical competitions since 2001 and they’re understandably considered to be at the premium online technical community. Members select contests and view individual contest requirements. Specialists within the community then compete in a series of competitions that comprise the whole project.
In April 2014, NASA launched a project with TopCoder to improve computer network architecture for deep space, and it completed in June 2015. In total, there were 12 challenges they were worked on by 146 contributors from 42 countries.
Bundle of fun
So what exactly were the coders working on? The goal was ultimately to provide a shared framework for algorithm and application development in disruption-tolerant networks.
NASA had previously published a couple of ‘requests for comment’ on an experimental protocol (commonly known as the Bundle Protocol) they were running on disrupted networks, which defines a series of contiguous data blocks as a bundle. Each of these bundles provides sufficient semantic information for the application to make progress where an individual block might not.
Overcoming disruption issues would also help improve security as authentication and privacy are often critical to data sent via disruption-tolerant networks. These security guarantees are difficult to establish in a network without persistent connectivity: the disruptions to the network can hinder complicated cryptographic protocols and key exchange, and each device must identify other intermittently visible devices.
Successful solutions
The solution the coders developed includes both client- and server-sides of the communication. Importantly, the support code doesn’t interfere with ground users using the same exchange server. The code supports unpredictable suspension of communication for up to four hours, unpredictable loss of data, and round-trip times on the order of .6 s – 1 s. In short, the project outputs ably met NASA’s requirements.
This isn’t the first collaboration between NASA and TopCoder. In fact, the NASA National Tournament Lab was actually established in 2011 as a result of a 2009 TopCoder challenge. Clearly then, NASA sees this crowd sourcing approach as broadly beneficial. However, while this challenge won’t be the last, in the realm of deep space communications, NASA seems intent on prioritising lasers.
According to Kevin Carmack, NASA’s Laser Communications Relay Demonstration Project Manager, lasers represent the “optical communication of the future”. This new technology is already proving to work as effectively as many in the sector believed it would. As such, the gains in bandwidth and the consequent speed of large data transference, means disruption-tolerant networks may soon be rendered a thing of the past. Not only do lasers require less transmission power, the low divergence of laser beams makes them a secure option for long range communications.
New miniature OCSD satellite launches
To help test the potential of laser communication on small scale satellites, NASA and The Aerospace Corporation of El Segundo, California have just launched the Optical Communications and Sensor Demonstration (OCSD) CubeSat. The innovation here is that the laser is hard-mounted to the spacecraft body, and the orientation of the CubeSat controls the direction of the beam, allowing design of the most compact system ever.
Along with other government agencies, academia and commercial companies, NASA can use the results of the test to incorporate laser communication technology into future space missions, as Steve Jurczyk, associate administrator for NASA’s Space Technology Mission Directorate states: “Technology demonstration missions like OCSD are driving exploration. By improving the communication capability of small spacecraft to support data-intensive science missions, OCSD will advance the potential to become a more viable option for mission planners.”
With the rapid speed of technology convergence, it therefore seems that NASA has started to understand how to allow open innovation to flourish more readily within Administration projects.
