Pinging Mars and Beyond
Andrew McLaughlin's C-Note 2012-03-29
Let’s tell it like it is: The Mars Rovers rule. Ask your inner nerd: Is there anything cooler than being able to see virtually-real-time images snapped on the surface of another planet? NASA’s JPL posts daily-updated raw footage archives for both Spirit and Opportunity.
After the depressing loss of the Columbia and its crew, it’s a thrill to see NASA scientists kicking so much butt and pulling off such incredible feats. Their rapid diagnosis and resuscitation of the crippled Spirit reminded me of the storied Apollo 12 launch, during which the command module lost power (due to a lightning strike during lift-off), cutting off communications to flight control and threatening to scuttle the mission, until a brilliant 24-year-old flight controller named John Aaron called out “Flight, try SCE to ‘Aux’“, a suggestion to flip an onboard switch so obscure that neither his colleagues nor the crew knew what it meant. But it worked: the power came on, the telemetry flowed, and the crew was on its way to the moon.
A happy side-effect of the success of the Mars Rovers is the attention that they are bringing to NASA’s accellerating plans for an interplanetary Internet. While working with Vint Cerf over the past few years, I became semi-obsessed with the progress of his efforts (together with an incredible team of engineers at JPL and elsewhere) to create an efficient and flexible suite of communications protocols that could operate across the vast reaches of the solar system. Drawing on the core lessons of TCP/IP, the internetplanetary Internet would deal with the vast distances of space by using a highly delay-tolerant version of store-and-forward packet switching.
Among the recent flurry of stories about interplanetary Internet, the most accessible is “E-Mail from Mars: Plans for an interplanetary Internet are taking shape,” an interview with Scott Burleigh, one of the leading architects of the initiative. He discusses the fact that the new protocols will be first be deployed later this year, on NASA’s Deep Impact comet mission. In addition, NASA is planning to deploy a Martian network of multiple orbiting relay satellites, to be launched starting in 2005.
Background: For the interested and detail-tolerant, I recommend two papers: “Interplanetary Internet (IPN): Architectural Definition” and the clunkily-named but well-written “Delay-Tolerant Network Architecture: The Evolving Interplanetary Internet“, both by Cerf, Burleigh, Hooke, and others. If you can handle a PowerPoint .pdf, Adrian Hooke has posted a great overview presentation on the overall IPN strategy. Vint keeps a helpful page of links on Interplanetary Internet. The Internet Society’s IPN Special Interest Group is a great resource, with a discussion list. Finally, if you want to know the nitty-gritty on why the standard Internet protocols aren’t up to the job of interplanetary communications, read this.