Our work in space in 2008

A new year has started. What happened around the Cisco router in Low Earth Orbit (CLEO) in 2008? I looked back, and found quite a lot; I thought it might be interesting to summarise it.

We look back on five years of our testing around CLEO in a short retrospective paper: Investigating operation of the Internet in orbit: Five years of collaboration around CLEO.

The CLEO router and the UK-DMC satellite that CLEO lives on were launched into orbit on 27 September 2003, and passed five years on orbit on 27 September 2008. Five years is the design lifetime of these DMC satellites, so the router and satellite are exceeding expected life. (We powered up CLEO and tested it on 24 September and 22 October 2008.) UK-DMC's similar sister satellite AlSAT-1 has already passed six years working in orbit (launched November 2002), so we can hope to be using CLEO and the UK-DMC satellite occasionally as test platforms for some time to come.

The team of NASA Glenn Research Center, Cisco Systems and Surrey Satellite Technology Ltd (SSTL) has gone on from focusing on testing the CLEO router to developing and testing Internet-Protocol (IP)-based communications from space, using the CLEO testbed at NASA Glenn to develop code later uploaded to a computer on the UK-DMC satellite. NASA Glenn has been working on modifications to SSTL's Saratoga protocol for delay-tolerant networking.

The team has provided a specification of Saratoga, used daily to transfer remote-sensing images from space over IP, to the Internet Engineering Task Force in Saratoga: A Scalable File Transfer Protocol, work in progress as an internet-draft.

We also looked at modifying Saratoga to carry the 'Bundle Protocol' developed by the Delay-Tolerant Networking Research Group, in Using Saratoga with a Bundle Agent as a Convergence Layer for Delay-Tolerant Networking, work in progress as an internet-draft.

We tested the Bundle Protocol from space over Saratoga from the UK-DMC satellite, first, revealing some problems in design and implementation, in January 2008, and then successfully in August 2008 - and then announced that success in September. These tests are summarised in a paper we've now sent to the International Journal of Satellite Communication and Networking: Experience with delay-tolerant networking from orbit.

Our thoughts on the design of the Bundle Protocol itself, based on our practical experience, are written up in a paper to be presented in March at the IEEE Aerospace conference: A Bundle of Problems.

We are the first to test this Bundle Protocol from space - significant because the Bundle Protocol is 'blessed' as the way NASA's future 'Interplanetary Internet' is intended to communicate. This led to our tests being mentioned by Time Magazine in November 2008 when they made the "Orbital Internet" one of their top ten inventions of 2009.

NASA's Jet Propulsion Lab has now also tested the Bundle Protocol in space on their Deep Impact/EPOXI probe, and announced this 'first deep space Internet' later in November. Those tests used their CCSDS protocols in communications to and from space, rather than the Internet Protocol that CLEO and the DMC satellites rely on.

Cisco is also readying its IRIS Internet Router in Space for launch to geostationary orbit on the Intelsat-14 satellite this year. The success of CLEO helped make planning IRIS possible.

It's been a busy 2008. 2009 should be interesting.