The Mars Polar Lander (MPL) mission was the first planetary mission to use Internet-based distributed ground operations where scientists and engineers collaborate in daily mission operations from multiple geographically distributed locations via the Internet. This paper describes the operations system, the Web interface for telescience (WITS), which was used by the MPL mission for Internet-based operations. WITS was used for generating command sequences for the lander's robotic arm and robotic arm camera, and as a secondary tool for sequence generation for the stereo camera on the lander. WITS was also used as a public outreach tool. Results are shown from the January 2000 field test in Death Valley, California.

The Web Interface for Telescience (WITS) is an Internet-based tool that the Mars Pathfinder mission used for both mission operations at JPL and public outreach. WITS enables the viewing of downlinked images and results in various ways, terrain feature measurement and annotation, and planning of daily mission activities. WITS is written in the Java language and is accessible by mission scientists and the general public via a web browser. The public can use WITS to plan and simulate their own rover missions. WITS will also be used in the 1998 lander and 2001, 2003, and 2005 rover missions to Mars.

The Web Interface for Telescience (WITS) has been developed to enable scientists to participate in planetary rover missions from their home institutions, rather than having to travel to JPL as has been required in the past. A scientist accesses WITS via a commercial web browser. WITS provides various views of the scene: including a descent image view which allows the user to see where the rover has been and currently is in a global perspective, a panoramic view which is an overhead view of the area immediately around the rover, and a wedge view which is an image from a rover-mounted camera. Scientists can select science targets in a wedge image and science subtasks to perform at those targets. A mission planner can select rover waypoints to traverse between science targets, and waypoint subtasks to perform at those locations. A public version allows the general public to view the same information and plan their own simulated missions.

This paper describes the design and implementation at the Jet Propulsion Laboratory of a small rover for future Mars missions requiring long traverses and rover-based science experiments. The small rover prototype, called Rocky 7, is capable of long traverses, autonomous navigation, and science instrument control. This rover carries three science instruments, and can be commanded from any computer platform from any location using the World Wide Web. In this paper we describe the mobility system, the sampling system, the sensor suite, navigation and control, onboard science instruments, and the ground command and control system. We also present key accomplishments of a recent field test of Rocky 7 in the Mojave Desert in California.

The development of a ground control station for Earth based control of the dexterous orbital servicing system (DOSS) is described. The DOSS flight test program provides a manipulator which is mounted on a multi-purpose experiment support structure (MPESS) in a Space Shuttle payload bay and may execute tasks from the MPESS or while held by the SSRMS manipulator. The DOSS demonstrates the ability to perform dexterous robotic operations both from an on-board control station and from an Earth-based control station. The initial prototype ground control station for DOSS is described.

It is noted that a head-mounted display (HMD) system would be a useful teleoperator system display if it increased operator performance of the desired task but could degrade performance because of display update rate limitations and communication delays. 3-D tracking and pick-and-place tasks are simulated to characterize performance levels for a range of update rates and delays. How performance changes as the display is altered to maintain the update rate is also examined. The results of the update experiments indicate that performance levels degrade only slightly until the update rate is below 1 or 2 Hz. Attempts to maintain update rate by eliminating display features such as stereo and occlusion cues show that the presence of either cue alone is sufficient to maintain performance levels in the simple, short-term tasks considered. Delays also degrade performance in both manipulation tasks considered. These HMD performance problems are not lessened by the presentation of a predictive feedback display. Instead, the delay in the head movement tracking loop must be eliminated.>

A hierarchical telerobotic control system for experiments with model-based vision feedback is described. The human operator issues commands to a high-level controller which plans actions to be carried out by the low-level controller. A feedforward model of the robot's motion is used by the vision system to look for visual enhancements on the robot in their anticipated positions. A middle-level module is planned which will alter low-level control gains to maintain performance within error bounds. Results of experiments with the vision system and studies of control strategies for vision feedback are discussed.>