A significant scientific opportunity is to use microgravity to grow crystals of biologically significant proteins. NASA has a large program in microgravity protein crystal growth. Protein crystals are necessary for X-ray crystallography, the major technique for determining the chemical structure of proteins. It is hoped that the use of microgravity will allow determination of the structure of new and medically significant proteins [1,2,3].

There are significant concerns about the availability of crew time for experiments planed for the space station. Telerobotics may provide a solution to this problem by allowing some scientific operations to be conducted from earth by remote control. This experiment was a beginning demonstration of telerobotic capabilities for the handling of materials and samples in micro-gravity protein crystal growth experiments.

In this demonstration, the Biorobotics Laboratory teamed up with Boeing Defense and Space (Huntsville, Al) , to demonstrate the ability of the UW Mini Direct Drive robot to manipulate fluid samples and crystals. The robot was installed on a 12 inch linear motion rail in a mockup of the Space Station science glove box. Commands were sent from a control station in Huntsville to the robot in Seattle via a T1 communication link running internet protocols. Video from three camera views was sent back to Huntsville using Cu-SeeMe software from Cornell University and/or White Pine Software

The demonstration started with a few salt (NaCl) crystals visible in the "Cryschem" well which was imaged by a dissecting microscope. The robot was fitted with a capillary tube connected to a syringe operated by a human (who will be replaced by a syringe pump next year). Using pre-defined trajectory macros, the operator in Huntsville directed the robot to a dish of super-saturated salt solution. Solution was drawn into the pipette, and the operator directed the robot to the well. At this point the solution was released, filling the well. Now the operator used incremental motion commands to direct the capillary tip to be adjacent to a salt crystal. The syringe then drew up fluid and captured one or more crystals behind the fluid meniscus. Finally, the operator directed the robot to the "show-me" position where the capillary was positioned in front of a small CCD camera and imaged, showing the captured crystal to the operator back in Huntsville. This process took about 3 to 5 minutes. While the performance of this system has not yet been systematically studied, the system successfully captured crystals on 3 out of 4 attempts.

Photos of Equipment

	Glove Box mockup - White circles are astronaut hand access glove ports (gloves removed). Visible between the glove ports is a dissecting microscope with TV camera. Above the glove box is a monitor showing the microscope view of the capillary tube and salt crystals. [ Full size image is ~75kB]
	Another view of the Glove Box - Another view of the glove box showing Chief Engineer Steven Venema. Electronics are contained in the small shelving stack visible in the left foreground. [ Full size image is ~80kB]
	Glove Box front view - Fiber optic "goose-neck" illuminators are visible at the left. Mini Robot is faintly visible behind microscope. [ Full size image is ~73kB]
	Mini Robot view - Mini robot shown positioning the capillary tip in the "Cryschem" well. Plastic capillary tube is visible leading away from tip. [ Full size image is ~60kB]
	Mini Robot view - Another image with better color imaged through the glove box front window. Fluid dishes are visible in lower center of image containing pure water rinse (black) and super saturated salt (blue). [ Full size image is ~67kB]

References

1. D. Normile, "Search for Better Crystals Explores Inner, Outer Space," Science, vol. 22, pp. 1921-1922, 22 Dec 1995.
2. B.L. Stoddard, R.K. Strong, A. Arrott, G.K. Farber, "Mir for the Crystallographers' Money," Nature, vol. 360, pp. 293-4, 26 Nov. 1992.
3. B.L. Stoddard, G.K. Farber, R.K. Strong, "The Facts and Fancy of Microgravity Protein Crystalization," Biotechnology and Genetic Engineering Reviews, vol. 11, pp. 57-77, Dec 1993.