/ 21 August 1998

E-mail an astronaut

Karlin Lillington

For most earthlings, just finding a hotel with Internet access is a challenge. Nasa, however, thinks big. The space agency intends to have Mars “Internet-enabled” in the next three to four years.

Last week at Nasa’s Jet Propulsion Laboratory (JPL) in Pasadena, Dr Vinton Cerf, a senior vice-president at telecom company MCI, joined with Nasa to announce the launch of a project tentatively called InterPlaNet – the interplanetary Internet. Cerf has noted: “It’s a big opportunity to bring together the astronauts and the Internauts” – Cerf’s term for explorers of cyberspace.

The project might seem a bit ambitious for a phone company man, but Cerf couldn’t be fitter for the task. He’s widely known as the father of the Internet for co-creating Internet Protocol, the language that lets computers speak with each other over the Net.

While the idea of an interplanetary Internet may seem odd, the intentions are down to earth. For some time Nasa had been looking at ways of streamlining complex space data communications into a single, internationally used standard. Then last year, Cerf began touting the notion of developing a set of interplanetary Internet protocols, as he believed the Internet was an ideal way for spacecraft or space-bound humans to keep in touch with Earth. Before long, a partnership was forged between Cerf and Nasa.

As Cerf explains it, the goal is to take “dirtside” – or land-based – Internet protocols, and migrate them “spaceside”. It’s the obvious step for the Internet, he says, noting that it took more than 20 years for today’s Net to evolve from its research origins into an everyday tool.

Nasa, looking 40 years ahead, is calling the project their “2040 Vision”, says Adrian Hooke, manager of JPL’s space data systems program. Hooke worked for Nasa on the Apollo moon landings and has been involved with the Mariner trips to Mars, Venus and Mercury and the Space Shuttle missions.

“What we hope to do is develop an architecture whereby we can replicate the Earth’s Internet in other places throughout the solar system – the moon, Mars, the satellites of the outer planets, on and around comets and asteroids – and to allow each of these local dirtside Internets to intercommunicate via long-haul spaceside protocols,” he says.

Dirtside Internets will communicate across space through proposed “interplanetary gateways”, computer programs that will allow Earth protocols to be converted into the as yet uncreated spaceside protocols.

The greatest challenge the agency faces is finding a way around the very long delays in sending data across the vast reaches of space. It takes several seconds for a radio signal travelling at the speed of light to reach the moon and return to Earth, while Mars is a 20-minute to 50- minute round trip.

“Also, all the data channels we use to communicate into space are very weak and noisy,” says Hooke. “We therefore have to deal with errors and outages on a scale that is seldom encountered in today’s Internet. Finally, the systems we put in space are very constrained in terms of weight, volume and power consumption.”

Hooke and Cerf say the InterPlaNet would allow anyone with a Net connection to explore space “directly” – linking straight to a Mars Rover- type vehicle and receiving the same images and data as Nasa, rather than passively by linking to a website created by Nasa staff.

Mission costs can be reduced by using an interplanetary Internet as well, believes Hooke, as hardware and software won’t need to be bought as often – applications and machines can be shared by several users – and researchers can study and share data without having to leave their institutions.

Funding will come from Nasa and private research institutions and companies, he says, and by space program standards, development costs should not be high – “a few million dollars a year may be enough”.

The first generation of the interplanetary Internet will involve large fleets of robotic spacecraft, probably followed by astronaut explorers and, eventually, permanent space colonies. Hooke says some initial Net capabilities should be working on missions between 2001 and 2003.

“The InterPlaNet will grow as missions permit,” says Cerf. Perhaps contact him in the future at cerf@ mci.mars.