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ISS Flight Preparation & Hardware Status. 08 July 2002 Steve Sell (sell@payload.com) Stephanie Chen (chen@payload.com). Agenda. Payload Systems activities Mission description and logistics Integration activities Hardware build status. Payload Systems Activities.
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ISS Flight Preparation & Hardware Status 08 July 2002 Steve Sell (sell@payload.com) Stephanie Chen (chen@payload.com)
Agenda • Payload Systems activities • Mission description and logistics • Integration activities • Hardware build status
Payload Systems Activities • Design and construct SPHERES flight hardware • Spheres • Beacons • Laptop hardware • Conduct NASA International Space Station integration activities • Safety review process • Develop experiment procedures • Conduct crew training • Create Graphical User Interface (GUI) • Conduct training of ISS crews • Conduct hardware analyses and testing • Safety verification analysis • Flight certification testing • Vibration • EMI acoustic
Major Components Laptop Assembly SPHERES Satellites Ultrasound Beacon (5 Total)
Hardware Components • SPHERES consists of three “satellites”, eight inches in diameter • Each satellite is self-contained with power (AA batteries), propulsion (CO2 gas), computers, and navigation equipment • The satellites communicate with each other and an ISS laptop through a low-power wireless (RF) link • Five ultrasound beacons located in the SPHERES work envelope act as a navigation system • Each beacon is self-contained and uses two AA batteries • A single beacon is approximately the size of a pager • Operational volume is 6’ x 6’ x 6’ (up to 10’ x 10’ x 10’ is possible) Satellite PADS beacon
SPHERES Satellite - X Thruster Ultrasonic receivers CO2 tank Adjustable regulator Pressure gauge + Z Satellite body axes - Y
Operational Configurations • Mode 1: Single satellite operations • Long term station-keeping • Minimum propellant maneuvers through pre-determined profiles • Isolated multidimensional rotation, multidimensional translation • Combined rotation & translation • Modes 2 and 3: Multiple satellite operations (two or three satellites) • Docking • Topological orientations • Independent control • Collision avoidance • Hierarchical control (leader-follower) • Distributed control (consensus) Example configurations on the KC-135
Typical Test Session Each satellite calculates position from PADS beacons Transfer protocol/commandsvia wireless link to satellites ISS Laptop Satellites perform formation flying maneuver Control loop Uplink protocols to OPS LAN prior to SPHERES ops Appropriate thrusters fire Data continuously downloaded to laptop ISS Laptop Downlink experiment data to ground after SPHERES ops
Typical Crew Operations Take down and stow equipment Setup test area (position US beacons) Unstow equipment Load tanks & battery packs into satellites Upload protocols from laptop to satellites Run protocols from laptop YES NO Test session over? Satellites out of gas / power? YES NO
Mission Logistics • SPHERES manifested on ISS for two increments • Ascent flight ISS-12A.1 (STS-116, June 2003), • Resupply flight ISS-13A (STS-117, September 2003) for replacement of consumables • Descent flight ISS-15A (STS-119, January 2004) • Operation Time • Allocated 20 hours operation time (nominally spread over twelve sessions) • Initial stowage requirements • Three SPHERES satellites • Five US beacons • Laptop transmitter • Consumables (CO2 tanks and battery packs) • Spares TBD
Stowage Allocation • SPHERES is allotted 1.83 Middeck Locker Equivalents (MLEs) over ascent and resupply flights • 1.5 MLE total on ascent flight • 0.33 MLE total on one resupply flight • Stowage allocated in Cargo Transfer Bags in the SpaceHab Module • Possible to be stowed in any locker location
Consumables • Two approaches were taken to determine consumable estimates: top-down (fixed stowage constraint) and bottom-up (fixed operation hours) • CO2 tanks • Part of the SPHERES mission investigates ways to minimize propellant usage • This means that no exact number of tanks can be determined for total operations • Initial estimate is 94 tanks • Batteries • Current estimate is 88 battery packs Replacement CO2 tanks and battery packs
ISS Equipment • Workstation • SPHERES will use Payload Equipment Restraint System (PERS) as a temporary workstation • H-Strap interfaces with seat track provide two sides of velcro • Attach laptop restraint for configurable laptop station • Belly bag can be used to contain extra hardware (satellites) during test session Belly Bag H-Strap Laptop Restraint
ISS Equipment • Laptop • SPHERES GUI runs protocols from laptop • Protocols uplinked to OPS LAN but no connection is required during testing • Data stored on laptop until downlinked to ground following test session • US beacons will attach to seat-track interfaces and/or handrail clamps • Locations will be entered into laptop prior to operations ISS Laptop Handrail clamp
Operational Scenarios • SPHERES will operate in United States Operational Segments (USOS) only • Ideal test area is 6’ x 6’ x 6’ • Most likely will operate in 5’ x 5’ x 10’, given ISS Node configuration Envisioned operations in US Lab Envisioned operations in ISS Node 1
Integration Status & Milestones • Status • Completed Phase II Safety Review Feb 2002 • Payload Integration Agreement baselined June 2002 • Preliminary draft of crew procedures submitted June 2002 • First test of positioning system in ISS node mockup conducted June 2002 • Upcoming milestones • KC test of engineering Sphere scheduled July 2002 • October 2002 – EMI and Vibe testing • November 2002 – Payload Training Dry Run • November 14, 2002 – Phase III Safety Review • December 2002 – Training Session 1 • January 31, 2003 – Flight hardware delivery to JSC • June 5, 2003 – Launch on STS-116, 12A.1 to ISS
Flight Hardware Status • First unit build is 95% complete: all components are in-house • All structural components completed and assembled • All avionics components completed and assembled • All pressurized components installed • Not all tubing and wiring has been routed • Shell is prototype • Anticipated 100% complete build in 1-2 weeks
Structural Frame • Aluminum structure • Six laser cut rings • Six sheet metal brackets • Twelve cross members • Provides stiffness and mounting points for satellite components Metal bracket Laser cut rings Cross members
Electronics Board Locations • Electronics are divided into two assemblies • PADS and computing • Signal processing • Computing • Propulsion and power • Thruster valve control • Power distribution Propulsion and power boards PADS and computation boards
Structural Assembly Stage One • Electronics assemblies • Electronics are assembled inside a partial structure and wired • Avionics can be tested on the bench top
Structural Assembly Stage Two • Remaining sheet metal brackets are attached • Battery packs and regulator/tank assembly can then be installed Mounting brackets
Structural Assembly Stage Three • Propulsion system tubing is routed • Tubing is assembled prior to final structural element placing • Manifolds distribute gas from CO2 tank to twelve thruster nozzles Tubing manifolds Thrusters
Full Assembly • Satellite is fully functional without shell Ultrasonic receiver Thruster Aluminum frame Pressure gauge CO2 tank Battery pack
External Shell Structure • Two part shell assembly • Constructed of polycarbonate • Secured with four fasteners per side • Hinged door for battery access • Cut-outs for thrusters and sensors Polycarbonate half shell Attachment screw
Schedule Milestones • July 29 - August 3, 2002 – KC-135 Flights • October 2002 – EMI and Vibe testing • November 2002 – Payload Training Dry Run • November 14, 2002 – Phase III Safety Review • December 2002 – Training Session 1 • January 31, 2003 – Flight hardware delivery to JSC • June 5, 2003 – Launch on STS-116, 12A.1 to ISS