NASA is preparing, it says, the "most advanced spacecraft advanced-intelligence software yet developed", for launch aboard its Deep Space 1 (DS1) spacecraft. The computer is the nearest thing yet to HAL 9000, the computer featured in the landmark science-fiction story, 2001: A Space Odyssey, written in 1968 by Arthur C Clarke, and which later became a film.

Unlike HAL's spaceship, the robotic DS1 spacecraft carries no crew and, at 945kg, is much smaller than its literary equivalent. Its computer artificial-intelligence program, known as the Remote Agent, shares the same basic goal of operating and controlling a spacecraft with the minimum of human assistance.

The DS1 is the first scheduled mission in NASA's New Millennium programme, which is designed to test cutting-edge technology for systems and instruments on board future NASA science spacecraft. The programme has "-already accelerated spacecraft automation technology by at least ten years", says Dr Guy Man, the co-leader of the programme's autonomy-integrated product-development team.

"We don't want to give the impression that the Remote Agent is an artificial life-form," like HAL, says Kanna Rajan, a DS1 computer scientist at NASA's Ames Research Center, California. "However, the software will reason logically about the state of the spacecraft and the Remote Agent will consider all the consequences of its actions". The Remote Agent is being developed in a collaborative effort between Ames and the Jet Propulsion Laboratory (JPL) of California.


Fly-by schedule

Following its launch aboard a McDonnell Douglas Med-Lite Delta booster from Cape Canaveral, in July 1998, the DS1 will fly-by the asteroid McAuliffe in 1999, and the comet West-Kohoutek-Ikemura and the planet Mars in 2000. The spacecraft, built by Spectrum Astro, of Arizona, in association with the JPL, is equipped with a suite of 13 advanced technologies, including a camera.

"The goals of the Remote Agent development are to reduce the cost of exploration and to extend exploration to realms of space where no ground-controlled craft could venture," says Dr Bob Rasmussen, a JPL computer-autonomy expert. The Remote Agent should enable future spacecraft software to be designed more easily.

The first version of Remote Agent software "-will be the hardest to write", says Dr Barney Pell, an Ames computer scientist. "After that, we can copy it for the next mission and make improvements in it," he adds.

Given NASA's continuing efforts to develop "smaller, faster, better, cheaper" spacecraft, each mission needs to be performed with fewer than a dozen ground controllers, instead of the hundreds of people now needed to run a major planetary science mission, such as the Galileo's orbits around the planet Jupiter.

"The large distances inherent in planetary exploration result in communications that can be too slow during emergencies," says Pell. "Sometimes your communications pathway is blocked when a planet is between the spacecraft and the Earth," he adds.

Three parts of the Remote Agent - planning and scheduling, model-based fault protection, and command activity - will work together to demonstrate that a spacecraft can be operated autonomously.

"Some estimates show a projected 60% reduction in mission costs using the Remote Agent," says Dr Nicola Muscettola, software-planning team leader, who adds: "The software would replace a large section of the human spacecraft-control team back on Earth."

The high-level planning and scheduling, or "The Planner" part of the Remote Agent will constantly look ahead to the schedule for several weeks of mission activities. "The Planner is mostly concerned about scheduling spacecraft activities and distributing resources such as electrical power," says Muscettola. "The Planner allows a small spacecraft-control team on Earth to command the spacecraft more effectively by sending goals instead of detailed instructions to the DS 1."

The fault-protection portion of the Remote Agent, called the Livingstone, functions as the mission's virtual chief engineer. If something goes wrong with the craft, the Livingstone - named after Dr David Livingstone, who was concerned with exploration and the health of explorers - would use the computer model of how the spacecraft should be behaving to diagnose failure and suggest recoveries.

The third part of the Remote Agent software, the Smart Executive, will act like an "-executive officer of the mission, issuing general commands to fly the DS 1", says Pell. The Smart Executive has to be able to execute the plans which are produced by the Planner and the Livingstone. "If the Planner had to worry about every single detail, it would be hard pressed to produce a plan. So, the Executive takes care of the details," he says.


Direct ground contact

The Executive can also receive a plan directly from ground controllers. "If the ground's plan won't work," says Pell, the Executive can say: 'Sorry, Ground, I can't do that.' This can actually be a big help to ground controllers," Rasmussen says.

"In the event that the Remote Agent won't co-operate under some unusual circumstance, we will be developing a surgery mode where ground control can really get into the Remote Agent and do a lobotomy," Pell says. The Remote Agent "-may some day lead to software that would be incorporated into a space robot that would be an intelligent as HAL", he says.

Source: Flight International