- Nasa space shuttle development full#
- Nasa space shuttle development software#
- Nasa space shuttle development series#
While vernier jets were only commanded when at least one rotation control axis had an error in a phase plane zone mandating jet activity, whenever jets were commanded, the errors in all rotation axes were included in the dot product computation to promote overall pointing error reduction. Taking advantage of its configuration of 6 thrusters that pointed into six different directions, it used a new, and deceptively simple "dot product" selection logic that picked 1 to 3 thrusters that produced a combined rotational acceleration closely aligned to the desired direction of control. The vernier RCS control loop, in its initial flight implementation, provided a dedicated fine-rotation control loop that was unique to the Shuttle.
Some of the primary RCS fault tolerance demands resulted in application of novel, fault-driven, Boolean rule-based logic that directed the jet selection to acceptable look-up tables for specific classes of fault combinations.
Nasa space shuttle development full#
Some specific primary RCS control loop design challenges included: Assuring stability of the OMS TVC wraparound given fundamentally different OMS TVC and RCS control criteria meeting control precision goals despite large minimum impulse values (driven by an 80 ms minimum thruster on time necessitated by unacceptable water hammer effects found to be possible in the propellant lines if shorter on/off cycle times were allowed) assuring sufficient control authority for the full spectrum of two-fault conditions. Also, the primary RCS control included a wrap-around of the OMS TVC loop to assure that the Shuttle fault tolerance requirements were fully met. Major modifications to the Apollo phase plane control loop (combined axis-by-axis attitude error and attitude rate error tracking logic) were needed to address Shuttle hardware and operational environment effects. While the OMS TVC was adapted from Apollo, the Shuttle-unique RCS configuration with thrusters pointing into 14 different directions required an entirely new table look-up-based jet selection algorithm. Docking was not a feature of the early Shuttle design. Significant training and flight procedures were developed to provide the crew appropriate techniques for flying to within close proximity of payloads to allow their capture by the robotic arm.
Orbit Phase Plane For all proximity operations the absence of close-in range sensors required that the crew continue to fly operations manually. Finally, some of the interesting flight operations experience is provided to inform future developers of flight experiences. Emphasis is placed on key architecture decisions, design trades and the lessons learned for future complex space transportation system developments. This paperprovides a history of the development and evolution of the Space Shuttle GN&C system. Upgrades to the GN&C ranged from the addition of nose wheel steering to modifications that extend capabilities to control of the large flexible configurations while being docked to the Space Station.
Nasa space shuttle development series#
Over the past thirty years, the Shuttle GN&C continued to go through a series of upgrades to improve safety, performance and to enable the complex flight operations required for assembly of the international space station.
Nasa space shuttle development software#
For example, the Space Shuttle GN&C system incorporated redundant systems, complex algorithms and flight software rigorously verified through integrated vehicle simulations and avionics integration testing techniques. Numerous technical design trades and lessons learned continue to drive current vehicle development. Development of the Space Shuttle GN&C represented first time inclusions of modern techniques for electronics, software, algorithms, systems and management in a complex system. One of these is the development and operation of the first extensive fly-by-wire human space transportation Guidance, Navigation and Control (GN&C) System. Developed in the 1970’s, first launched in 1981, the Space Shuttle embodies many significant engineering achievements. Completion of the final Space Shuttle flight marks the end of a significant era in Human Spaceflight.
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