LIST OF FIGURES - mit.edu

1 17 LIST OF FIGURESF igure research process .. 32 Figure in complexity, risk, and cost at each TRL .. 39 Figure roadmap .. 44 Figure of the scientific method by Gauch .. 74 Figure five flight-qualified SPHERES nano-satellites .. 100 Figure operational concept .. 101 Figure satellite .. 103 Figure avionics overview .. 105 Figure software layers .. 109 Figure operations overview .. 111 Figure nano-satellite structural design .. 114 Figure research process for SPHERES .. 118 Figure iterative research loop .. 121 Figure MIT SSL on-site iterative research loop .. 123 Figure MIT SSL off-site iterative research loop.

2 124 Figure ISS iterative research process .. 127 Figure SPHERES programs composition .. 130 Figure SPHERES satellites initialization .. 134 Figure Accelerometer and gyroscope measurements in micro gravity .. 140 Figure Global metrology system time-of-flight distance measurements .. 142 Figure Measuring the state vector with the layered metrology system .. 143 Figure Differential measurements between two satellites.. 144 Figure Sample real-time and post-test data telemetry algorithms .. 146 Figure High priority scheduling of system timing and controller interrupts .. 152 Figure Test synchronization via communications.

3 153 Figure Test synchronization to within 1ms .. 154 Figure SPHERES GUI for ground-based operations .. 156 Figure ISS astronaut interface .. 15818 LIST OF FIGURESF igure SCS interfaces to user code, DSP/BIOS, and hardware .. 170 Figure GSP simulation window .. 174 Figure SPHERES satellite expansion port face (without cover) .. 178 Figure SPHERES expansion port design overview .. 179 Figure SPHERES -X "docking face" .. 185 Figure FLASH memory map .. 193 Figure iterative research process .. 204 Figure TRL transitions .. 216 Figure principles application strategy .. 225 Figure trend of cost J using cost function.

4 231 Figure effective iterations though flexible scheduling.. 235 Figure curves for ISS unique resources .. 240 Figure paths to flight operations .. 243 Figure inertia estimate from ground-based tests .. 261 Figure results of docking algorithms at the MIT SSL .. 262 Figure satellite TPF maneuvers at the MSFC Flat Floor .. 263 Figure s conception of MOSR aboard the ISS .. 265 Figure and three satellite tethered setups at the MSFC Flat Floor .. 265 Figure cost of enabling multiple areas of study .. 271 Figure iterative research loop .. 275 Figure Flat Floor iterative research loops .. 278 Figure of iterations with SPHERES.

5 280 Figure SPHERES Functional Requirements .. 297 Figure operations aboard the KC-135 RGA .. 320 Figure drop tower .. 358 Figure Neutral Buoyancy Laboratory .. 359 Figure KC-135 airplane and flight path .. 362 Figure Shuttle payload bay and middeck .. 364 Figure ISS on October 2002 .. 369 Figure Skylab .. 372 Figure MIR Space Station .. 375 LIST OF FIGURES19 Figure research stations .. 380 Figure research vessels Knorr (left) and Alvin .. 388 Figure ISS at US Core Complete .. 394 Figure Destiny laboratory .. 398 Figure Centrifuge Accommodation Module .. 398 Figure Truss Attachment Points (4).

6 399 Figure Experiment Module .. 400 Figure Module .. 400 Figure Structural Test Article with Alpha joint .. 411 Figure Experiment Support Module w/ Fluid Test Article .. 411 Figure handhold and foot restraint .. 412 Figure operations on shuttle mid-deck .. 415 Figure Experiment Support Module .. 415 Figure operations aboard the ISS .. 419 Figure avionics overview .. 423 Figure sub-system functional block diagram .. 425 Figure spike and hold timing diagram .. 438 Figure spike and hold circuit .. 439 Figure avionics functional block diagram .. 439 Figure functional block diagram .. 447 Figure sub-system functional block diagram.

7 449 Figure firmware design .. 454 Figure boards functional block diagram .. 455 Figure Ultrasound amplification schematic .. 455 Figure Communications sub-system functional block diagram .. 472 Figure Expansion port functional block diagram .. 482 Figure Laptop communications functional block diagram .. 488 Figure Metrology beacon functional block diagram .. 490 Figure Beacon tester functional block diagram .. 494 Figure Expansion port beacon functional block diagram .. 500 Figure Expansion port tether functional block diagram .. 50420 LIST OF FIGURESF igure software components .. 507 Figure program development sequence.

8 508 Figure loader transfer protocol .. 510 Figure loader transfer protocol error handling .. 512 Figure loader command/reply packets .. 512 Figure loader first data packet structure .. 513 Figure loader general data packets structure .. 514 Figure program state diagram .. 515 Figure boot loader state diagram .. 516 Figure Satellite boot loader general algorithm .. 518 Figure SPHERES Core Software overview .. 522 Figure SCS threads .. 524 Figure SCS real-time clocks .. 525 Figure SCS controller module threads and general algorithm .. 531 Figure SCS controller state diagram .. 532 Figure SCS propulsion module threads.

9 534 Figure Propulsion modulation options .. 535 Figure Propulsion module timing diagram .. 535 Figure SCS communications module threads .. 537 Figure Communications data reception process .. 539 Figure Communications data transmission process .. 541 Figure SCS metrology module threads .. 546 Figure SCS metrology module general algorithms .. 548 Figure SCS metrology treads scheduling .. 549 Figure SCS housekeeping module threads .. 551 Figure SCS GSP module threads .. 554 Figure packet structure .. 562 Figure packet structure (n=32) .. 566 Figure transmission sequence .. 568 Figure Division Multiple Access scheme.

10 570 Figure acknowledgement sequence example (1 lost packet) .. 573 LIST OF FIGURES21 Figure purpose command structure .. 574 Figure packet structure .. 578 Figure packet structure .. 58622 LIST OF FIGURES