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Satellite Control Networks (cont’d)

Satellite Control Networks (cont’d). U.S. Space Command tracks all DoD spacecraft using the Space Surveillance Network (SSN). SSN is a world-wide network of high-power radars that track about 8100 objects in Earth orbit.

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Satellite Control Networks (cont’d)

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  1. Satellite Control Networks (cont’d) • U.S. Space Command tracks all DoD spacecraft using the Space Surveillance Network (SSN). • SSN is a world-wide network of high-power radars that track about 8100 objects in Earth orbit. • These objects range from the Space Shuttle orbiter to Astronaut Ed White’s glove, lost during a Gemini mission. Unit 4, Chapter 13, Lesson 13: Space Operations

  2. Satellite Control Networks (cont’d) • Radar data goes to the Space Surveillance Center in Cheyenne Mountain AFB, Colorado where orbit analysts maintain the space catalog. Space Surveillance Network (SSN) Radar Unit 4, Chapter 13, Lesson 13: Space Operations

  3. Satellite Control Networks (cont’d) • U.S. Space Command controls some DoD spacecraft using the Air Force Satellite Control Network (AFSCN). • Communication sites are in Guam, Diego Garcia, Hawaii, and other locations. • These stations connect with control centers at Schriever AFB, Colorado, and Onizuka AFB, California. Unit 4, Chapter 13, Lesson 13: Space Operations

  4. Satellite Control Networks (cont’d) • The U.S. Space Command uses the SSN to track and catalog the whereabouts of thousands of satellites and pieces of space junk in orbit. But we still need a dedicated ground station for our spacecraft operations. • A simple ground station to control small satellites can be assembled from personal computers and off-the-shelf communications gear. Figure 13-19 shows the ground station used to control the FalconSAT spacecraft at the U.S. Air Force Academy. A Simple Ground Station Unit 4, Chapter 13, Lesson 13: Space Operations

  5. Mission Management and Operations • Managing Missions • Mission Teams • Mission Management • Spacecraft Autonomy Unit 4, Chapter 13, Lesson 13: Space Operations

  6. Managing Missions • Managers must control the systems- engineering process. • Define mission objectives. • Define mission requirements and constraints. • Define and derive system requirements and constraints. Unit 4, Chapter 13, Lesson 13: Space Operations SECTION 13.2

  7. Managing Mission (cont’d) • Actively manage the “requirements loop” to trade mission and system requirements and constraints. • Create analysis and design tools needed to effectively trade among options. • Establish necessary operations systems to support the mission. Unit 4, Chapter 13, Lesson 13: Space Operations

  8. Managing Missions (cont’d) • Actively manage the “design loop” to trade requirements and constraints to develop a final design. • Oversee the “validation loop” to make sure we pay for what we want and get what we pay for. Unit 4, Chapter 13, Lesson 13: Space Operations

  9. Mission Teams • Mission Design and Manufacturing Teams • Launch Teams • Operations Teams Unit 4, Chapter 13, Lesson 13: Space Operations

  10. Mission Management Mission Planning and Analysis Systems Engineering Tracking and controlling a project’s cost, schedule, and performance Juggling money, time, facilities, people, and other resources Managing teams and project spirit Planning mission timelines and sequencing events Analyzing trade-offs between competing technical options Defining flight rules to govern actions during normal and abnormal flight conditions Defining and validating system- and subsystem-level requirements Applying analysis and design tools to define system architectures Designing subsystems and other components Table 13-1 Major Mission Tasks and Examples Unit 4, Chapter 13, Lesson 13: Space Operations

  11. System Assembly, Integration and Testing (AIT) Simulations and Training Flight Control Screening components for form, fit and function Assembling components to build subsystems and putting subsystems together to build systems Testing subsystems and systems to make sure they work under flight conditions Developing computer software to simulate major mission events Practicing operational procedure using simulations Monitoring and interpreting telemetry to determine a spacecraft’s health and status Table 13-1 Major Mission Tasks and Examples (cont’d) Unit 4, Chapter 13, Lesson 13: Space Operations

  12. Flight Control (cont’d) System Maintenance and Support Data Processing and Handling Tracking a spacecraft’s or launch vehicle’s position and velocity Sending commands to spacecraft to change operating conditions or fix problems Routinely maintaining clean rooms, thermal/vacuum chambers, and other operations systems Updating ground software to enhance performance or correct problems Distributing mission data to users Analyzing and archiving engineering data from spacecraft Table 13-1 Major Mission Tasks and Examples (cont’d) Unit 4, Chapter 13, Lesson 13: Space Operations

  13. Mission Teams (cont’d) • From the initial concept through flight readiness, the manufacturing team’s focus is on: • Systems engineering—Defining system and subsystem requirements and constraints and taking them through the complete design of the spacecraft and other operations systems. • Mission planning and analysis—Planning mission timelines and analyzing engineering performance data to determine operational scenarios and training requirements. • System assembly, integration, and test (AIT)—Assembling subsystems from components, integrating the entire spacecraft, and doing environmental and functional testing. Unit 4, Chapter 13, Lesson 13: Space Operations

  14. Simulation • Years before their first flight, astronauts work through every phase of a mission, using simulators such as this motion-based simulator housed at the NASA Johnson Space Center in Houston, Texas. Shuttle Simulation Unit 4, Chapter 13, Lesson 13: Space Operations

  15. Assembly, Integration and Testing • Assembly, integration, and testing (AIT) is a coordinated team effort by assembly technicians, system integrators, testers, and appropriate engineers and scientists. They are backed by administrative support people. Unit 4, Chapter 13, Lesson 13: Space Operations

  16. Assembly, Integration, and TestingAssembly • During assembly, skilled technicians (shown in Figure 13-22) perform delicate touch labor to manufacture circuit boards and other critical components. Spacecraft Assembly Unit 4, Chapter 13, Lesson 13: Space Operations

  17. Assembly, Integration, and TestingIntegration • Part of spacecraft assembly is pulling together components into completed systems. In Figure 13-23 an engineer does final integration of the FalconSAT spacecraft. Spacecraft Integration Unit 4, Chapter 13, Lesson 13: Space Operations

  18. Assembly, Integration, and TestingTesting • Testing is vital to make sure everything will work in the harsh space environment. • In Figure 13-24, engineers are preparing the Advanced X-ray Astrophysics Facility spacecraft for thermal/vacuum testing. Spacecraft Testing Unit 4, Chapter 13, Lesson 13: Space Operations

  19. Launch Teams • The launch teams’ jobs start long before the spacecraft arrives at the pad. Their main focus is on two major tasks: • System AIT—integrating the spacecraft to the launch vehicle and doing a final checkout • Flight control—monitoring the launch vehicle’s telemetry and trajectory and sending commands that make corrections as needed to deliver the payload to the promised orbit Unit 4, Chapter 13, Lesson 13: Space Operations

  20. Launch-Readiness Review • The launch-readiness review is a formal process used to make sure everything is prepared for launch. • It includes spacecraft manufacturers, users, and mission managers. Titan IV Liftoff Unit 4, Chapter 13, Lesson 13: Space Operations

  21. Operations Teams • Members of this team also are called flight controllers, the flight-control team, or simply operators. • The flight-control team’s leader is the operations director (or flight director for Space Shuttle missions). • The operations director coordinates input from other team members. • He or she must make the final decisions on what to do throughout the mission. Unit 4, Chapter 13, Lesson 13: Space Operations

  22. Operations Teams (cont’d) • Under the operations director, team members hold positions that follow the spacecraft’s functional lines. • Subsystem specialists are experts on individual parts of the spacecraft. • Payload specialists are responsible for the payload—its health, status, and operation. Mission Operators Unit 4, Chapter 13, Lesson 13: Space Operations

  23. Simulation and Training • Simulation and training—preparing for launch and on-orbit operations, as well as contingency procedures Astronaut Practice Unit 4, Chapter 13, Lesson 13: Space Operations

  24. Flight Control • Flight control—monitoring the spacecraft’s telemetry and trajectory and sending commands to make corrections or other adjustments to deliver the payload data to mission users Telemetry Monitoring Unit 4, Chapter 13, Lesson 13: Space Operations

  25. Flight Control (cont’d) • With the spacecraft safely in its mission orbit, operators must verify that all subsystems are working normally during a period of on-orbit checkout often called commissioning. • Years before, operators and mission engineers worked out detailed procedures, called flight rules. • These flight rules told them how each subsystem should work and what to do during any possible event to save the mission. Unit 4, Chapter 13, Lesson 13: Space Operations

  26. Data Processing and Handling • Data processing and handling—receiving, analyzing, storing, and distributing mission data to engineers and users. Unit 4, Chapter 13, Lesson 13: Space Operations

  27. Data Processing and Handling (cont’d) • Figure 13-29 shows SPOT, the small constellation that takes Earth observations and sends them through many downlink sites to the operations center at Toulouse, France. Satellite Pour L’Observation de la Terre (SPOT) Unit 4, Chapter 13, Lesson 13: Space Operations

  28. System Maintenance and Support • System maintenance and support—maintaining and supporting all the hardware and software operations systems to keep the mission flying • The ground-systems specialist links the operations team and the spacecraft. Unit 4, Chapter 13, Lesson 13: Space Operations

  29. Mission ManagementTeam Management • Management ensures the team understands mission objectives and their individual roles in the mission’s success. • Team leaders must establish an effective way to communicate and make decisions. • Team leaders solve or avoid problems by working on areas such as: • the norms set for the team • how well the team works together • the method for resolving conflicts Unit 4, Chapter 13, Lesson 13: Space Operations

  30. Mission ManagementTeam Management (cont’d) • Team norms are standards of conduct that guide a team member’s behavior. They typically aren’t written down but are understood throughout the team. Unit 4, Chapter 13, Lesson 13: Space Operations

  31. Mission ManagementTeam Management (cont’d) • Team leaders can enhance how well the team works together by setting common goals and increasing team interaction. Unit 4, Chapter 13, Lesson 13: Space Operations

  32. Mission ManagementTeam Management (cont’d) • One style of conflict management may not work for all situations. • Compromise works sometimes. • Competition or working with people is preferred at other times. Unit 4, Chapter 13, Lesson 13: Space Operations

  33. Mission ManagementManagement Tools • Multi-billion-dollar international space programs, such as the International Space Station (ISS), must track a staggering number of details. Fortunately, astute project managers have useful tools in their kit to help them keep things on schedule and within budget. Big-Project Management Unit 4, Chapter 13, Lesson 13: Space Operations

  34. Mission ManagementManagement Tools (con’td) • Work breakdown structure (WBS) separates a project into manageable pieces. • A WBS helps us determine the resources required as well as the time needed for each piece. Unit 4, Chapter 13, Lesson 13: Space Operations

  35. Mission ManagementManagement Tools (cont’d) • Typically the WBS tasks break into sub-areas: • Project management • Systems engineering • Subsystem design and fabrication • Subsystem and system-level testing Unit 4, Chapter 13, Lesson 13: Space Operations

  36. Mission ManagementManagement Tools—WBS Unit 4, Chapter 13, Lesson 13: Space Operations

  37. Mission Management Management Tools (cont’d) • Network modeling includes: • Program Evaluation and Review Technique (PERT) • Critical-path Method (CPM) Unit 4, Chapter 13, Lesson 13: Space Operations

  38. Mission Management Management Tools (cont’d) • These network modeling tools have several advantages: • They allow us to see relationships among activities. • They show which activities can be done at the same time. • They help us focus on the tasks that are most critical to completing the project on time. Unit 4, Chapter 13, Lesson 13: Space Operations

  39. Mission Management Management Tools (cont’d) • To begin scheduling with the CPM, we need to determine: • Which activities should we finish immediately before we start this activity. • Which activities can we do at the same time as this activity. • Which activities can’t begin until after we finish this activity. Unit 4, Chapter 13, Lesson 13: Space Operations

  40. Procure components Kit parts Assemble sun-sensor components Assemble GPS components Verification None 6 A 4 B 6 B 9 C, D 3 Total 28 Table 13-2 FireSat Project Data As part of the Critical-path Method of project management, we need to list each activity in the WBS, determine which activities come before it, and estimate how long it will last. Activity What comes before How long (Months) How long (Months) Unit 4, Chapter 13, Lesson 13: Space Operations

  41. Network Diagram for FireSat • Figure 13-33 shows the sequencing of activities for FireSat’s attitude and orbit-control subsystem. Unit 4, Chapter 13, Lesson 13: Space Operations

  42. Network Diagram for FireSat (cont’d) • Figure 13-34 shows earliest-start and earliest-finish times (in parentheses) and latest-start and latest-finish times (in brackets). Unit 4, Chapter 13, Lesson 13: Space Operations

  43. Network Diagrams • The activities that we can’t delay without delaying the entire project are on the critical path. • Any activity on the critical path will have zero slack. Slack is the amount of time we can delay an activity without delaying the overall project. Unit 4, Chapter 13, Lesson 13: Space Operations

  44. Mission ManagementManagement Tools • Project Control • Answers the question: “How is it going?” • Uses earned value as one way to answer this question. • Shows value of work completed at any time. • Shows whether work done is keeping up with money spent. Unit 4, Chapter 13, Lesson 13: Space Operations

  45. Aligned with goals Simple and easy to understand Actionable Performance indicators need to tie to project objectives so our measures are measuring only mission-critical areas. We can’t act on information if we don’t understand what a measure is telling us about the project. We must do something about the measure if there is a deviation; otherwise, the information is of little use. Table 13-3 Characteristics for Effective Indicators of a Program’s Performance Unit 4, Chapter 13, Lesson 13: Space Operations

  46. Timely Flexible The indicator must provide information in enough time for us to make changes, if a problem exists. Measures should be changeable, if necessary, depending on external circumstances. Table 13-3 Characteristics for Effective Indicators of a Program’s Performance (cont’d) Unit 4, Chapter 13, Lesson 13: Space Operations

  47. Spacecraft Autonomy • Mission autonomy refers to a spacecraft’s ability to handle some or all of its functions without human intervention. Autonomy means being able to function independently. • Spacecraft autonomy is one way engineers and operators have sought to streamline operations and cut costs. • By placing more functions onboard the spacecraft, the need for costly operations-the number of team members decreases. • Commercial missions, ever focused on the bottom-line budget, turn to autonomy as a way to cut costs by decreasing the number of control centers and operators. Unit 4, Chapter 13, Lesson 13: Space Operations

  48. Spacecraft Autonomy (cont’d) • For certain missions, some autonomy is essential. • Interplanetary missions, for example, must operate with long time delays because of the extremely long distances. • Their onboard software needs to deal with any contingency (something that goes wrong) without waiting for advice from Earth-bound operators. • Finally, there is another strong argument for increased spacecraft autonomy: reducing human errors. Unit 4, Chapter 13, Lesson 13: Space Operations

  49. Summary • Mission Operations Systems • Elements of Mission Operations Systems • Spacecraft Manufacturing • Launch • Operations • Communication • Satellite Control Networks • Mission Management and Operations • Managing Missions • Mission Teams • Mission Management • Spacecraft Autonomy Unit 4, Chapter 13, Lesson 13: Space Operations

  50. Next • This section has shown how to put together all we’ve learned about space to create fantastic space missions. • For the next part of our exploration of space, we’ll look at the economic and political aspects of space. Unit 4, Chapter 13, Lesson 13: Space Operations

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