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March 05, 2009 PowerPoint Presentation
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March 05, 2009

March 05, 2009

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March 05, 2009

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  1. 100g Toy Ball Mission ProfileToy Ball Integration & Structural Analysis‘Fallback’ Lunar Circularization Concept March 05, 2009 [Cory Alban] [Mission Ops] [Locomotion] [1]

  2. Toy Ball (100g payload) [Cory Alban] [Mission Ops] [Locomotion] • Design at 90% completion! • Mass: 2.52kg • Power: 0.9984Wh upon arrival (Self-Sufficient) • Volume: 0.25m diameter sphere (8.18*10-3m3) • Remaining tasks include: • Determining power requirements for transceiver and camera • Finding a camera better suited to our mission • Exploring possible commercial ventures ($$$) • Short mission time versus life of components [Cory Alban] [Mission Ops] [Locomotion] [2]

  3. 100g Mission Profile (locomotion) • Total mission time outside of Lander < 20 minutes [Cory Alban] [Mission Ops] [Locomotion] [Cory Alban] [Mission Ops] [Locomotion] [3]

  4. Toy Ball Shell Material: Lexan [Cory Alban] [Mission Ops] [Locomotion] • Pressure vessel calculations(1atm of N2 gas) • Minimum thickness: 1.58*10-5m • Impact strength calculations(1m/s slam into rock) • Minimum thickness:1.27*10-3m • Driving factor in shell thickness is impact strength. With a factor of safety of 3, total thickness =3.82*10-3m [Cory Alban] [Mission Ops] [Locomotion] [4]

  5. Toy Ball Heavy Mass Components [Cory Alban] [Mission Ops] [Locomotion] • Radiation Hardened Camera 0.725 kg • Exterior Shell 0.872 kg • (driven by system mass!) • Transceiver 0.210 kg • For every half kilo of onboard mass we remove, we lower shell mass by 0.22kg! • Cascade effect onto power and volume reqs! [Cory Alban] [Mission Ops] [Locomotion] [5]

  6. Fallback Lunar Circularization [Cory Alban] [Mission Ops] [Locomotion] Last week (Week 7) Kara Akgulian presented on a lunar circularization method of providing an instantaneous burn at lunar periapsis. This method expands on her method by using the EP system to give a controlled burn for a finite time before and after periapsis. (See graphic on next slide) [Cory Alban] [Mission Ops] [Locomotion] [6]

  7. Fallback Lunar Circularization [Cory Alban] [Mission Ops] [Locomotion] Last week (Week 7) Kara Akgulian presented on a lunar circularization method of providing an instantaneous burn at lunar periapsis. This method expands on her method by using the EP system to give a controlled burn for a finite time before and after periapsis. (See graphic on next slide) [Cory Alban] [Mission Ops] [Locomotion] [7]

  8. Fallback Lunar Circularization [Cory Alban] [Mission Ops] [Locomotion] By calculating orbit at periapsis, we can find out how long it will take for the craft to reach a theta_star of 45 degrees. We burn the EP engine until this point. The craft will then coast until it reaches a negative 45 degree theta_star. The engine will burn until we reach periapsis again, where we calculate the new orbit conditions. The process continues until we reach a circular, or nearly circular orbit. Results of matlab code are on the next slide. [Cory Alban] [Mission Ops] [Locomotion] [8]

  9. Fallback Lunar Circularization [Cory Alban] [Mission Ops] [Locomotion] This process was run for fifty iterations. Process will take a long time (>1 year based on thrust and initial conditions) NOTE: This process does converge! Though not recommended, this process will eventually lead to a circular orbit and could be considered as a backup option. [Cory Alban] [Mission Ops] [Locomotion] [9]

  10. Fallback Lunar Circularization [Cory Alban] [Mission Ops] [Locomotion] Here is a view of the circularization with the moon’s orbit included. Note that to fully circularize the moon will make its way around the earth many times over the course of the process. Red represents the circularization of the orbit around moon. [Cory Alban] [Mission Ops] [Locomotion] [10]