The development phases for the BOLAS mission and their corresponding schedule is shown in the figure below. The figure following describes the work breakdown. More details regarding the current phase of development can be found after these figures.

BOLAS mission schedule.

Considerable trade-off studies and analyses have been conducted to minimize complexity and cost while maintaining the capability to conduct a world class space science experiment. Phase A is focused primarily on refining several key issues to complete the preliminary design for the mission, a detailed development plan, and a detailed cost estimate. Phase A will also establish the mass and power budgets for the hardware items. Phase B is then the development of the scientific instruments and new technology elements (i.e., the tether deployer and retriever, and the dynamics of the tethered spacecraft in all mission phases). The detailed design, build, integration and test of the two subsatellites are undertaken in Phase C. This phase would be undertaken in a cost effective manner; little design iteration should be required since the flight instruments are already completed and the new technology elements have been developed. Phase C is a fairly rapid schedule that is practical and yet designed to ensure maximum effectiveness of the development team. The launch of the mission takes place in the final quarter of 2001. Phase D addresses the on-orbit operations during the 6-month lifetime of the mission. This phasing accommodates the expected launch date of the Radarsat 2 spacecraft in late 2001.

Work breakdown structure for the BOLAS mission.

BOLAS Work Breakdown Structure

Phase A Work Plan - Finalize Mission Definition and Preliminary Design

  1. Refine Designs of Instruments
    1. HF Receiver: conduct systems studies and trade-offs - update receiver design and configuration
    2. Suprathermal Ion Instrument (SII): finalize system parameters to optimize readout rate and power consumption - use trajectory simulation to determine appropriate sensor biases - investigate thermal control issues in the sensor head
    3. TECHS: develop preliminary design of instrument based on previously flown units

  2. Refine Designs of Subsatellite Subsystems
    1. Mini-SEDS Deployer and Tether Material Specification
    2. Tether Retriever: develop concept of spool and general configuration - determine specefications for the motor - design simple level wind system - identify encoder for computing rotation - estimate size, mass and power requirements for the retriever system - conduct low tension tests with a retriever model at CSA
    3. Deployable Booms: refine spec - work with Astro to do a concept of custom "lab units" (like OED-C) - estimate size, mass and power of the boom units
    4. Attitude Determination and Control: update hardware spec for mag and accelerometers - review att detetermination algorithm (based on SEDS algorithm) - update design torquer coil for open loop spin control about tether
    5. Communications System: refine spec for Tx and Rx, identify candidate hardware suppliers - identify any h/w modifications needed and determine costs - work with Carleton to establish S-band & UHF ant. concepts (for dev't in Phs B) - assess manufacturing options for the flight antenna & estimate build/test costs
    6. GPS: refine spec for GPS receiver from AOA (e.g., finalize what mods are needed) - work with Carleton to establish antenna concept (work to define plan for Phs B) - review possibility of support from CRC in the antenna design - S/C UNB to investigate processing for synch of the HF Rx's and to support refining the GPS specs
    7. On-Board Computer and Memory Unit: Marshall will lead the prelim design effort & develop architecture - develop detailed requirements - review design (chip and board level) with Marshall and iterate - review mass & power estimates from Marshall - investigate board manufacturing and system testing issues and get costs
    8. Power System: repeat sizing analysis for solar arrays & batteries with updated S/C power req'ts - write prelim spec for solar arrays and get quote from suitable supplier - develop prelim design of Power Distribution Unit (PDU) - confirm that BCR is not required (investigate battery operation issues) - investigate manufacturing options for PDU board and estimate dev't costs - develop prelim. design of battery using commercial NiCd cells & estimate costs
    9. Structure and Thermal: refine mass of primary and secondary structure elements - design pin-puller for delayed release of BOLAS-2, select h/w - conduct simplified thermal analyses, select mat'l for thermal design, size heaters

  3. Refine Subsatellite Configuration and Overall Mission Design
  4. update layout and overall subsatellite mass properties (Cg and inertia) - update mass and power summaries - conduct orbital studies to get pass times and refine operational scenarios

  5. Conduct Tether Dynamics and Subsatellite Stabilization Analyses
  6. refine model of tethered system with booms in orbit during deployment and spin-up - refine tether retraction profile for spin-up - investigate de-spin of system during mission - investigate out-of-plane dynamics with precessing orbit - conduct animations of BOLAS config in Orbit - address subsatellite stabilization, determine damping and tether tension needed - investigate damping properties of BI-STEMs - Marshall will run their models to verify analysis - Marshall will refine tether deployment scenario

  7. Delta II Secondary Payload Accommodation Issues
  8. refine the Delta timeline issues and finalize BOLAS orbit acquisition scenario - do first iteration of the Delta interface ICD for BOLAS - resolve how to route the tether between the subsatellites - confirm concept of the delayed release of BOLAS-2 with McD

  9. Finalize Mission Operations Issues
  10. confirm with CSA the ground stations to be used - establish operations concept - CSA space tech will lead discussions with CSA Operations branch

  11. Support Establishing International Agreement between CSA & NASA
  12. support discussions between CSA & NASA Mgmt - help to establish clear roles and responsibilities - review terms and conditions of MOU - CSA Space Technology would also support discussions

  13. Establish Detailed Development Plan for BOLAS
  14. refine work plan for Phase B, C and D - develop draft spacecarft I&T plans - update cost estimate for spacecraft development - establish details of participation of DREO in the GPS aspects of the mission - develop proposal for NSERC partnership grant for UNB

  15. Update BOLAS Mission Proposal
  16. update Part 1 and science related sections in Part 2 - update part 2 of the proposal (mission Implementation)

  17. Management
  18. project management (establish subcontracts, monitor budgets & schedule, progress reports) - status meetings & bi-weekly telecons - kickoff meeting