Gravity Gradient Boom Design

  • View
    1.544

  • Download
    1

Embed Size (px)

Text of Gravity Gradient Boom Design

Gravity Gradient Boom DesignMIM 702

The Capstone Design Course Report FormatProject #9 Second-Quarter Report

Design Advisor: Prof. Gregory Kowalski Design Team Jason Stricker, Arthur Inglot, Gene Rossov, Jack Rafalowski, Steve Souza

Department of Mechanical, Industrial and Manufacturing Engineering College of Engineering, Northeastern University Boston, MA 02115

Gravity Gradient Boom Design

Design Team Art Inglot, Jack Rafalowski, Gene Rossov, Steve Souza, Jason Stricker

Design Advisor Prof. Gregory Kowalski

Sponsor NASA, Ames Research Center John Hines

AbstractAttitude control systems are a very important aspect in satellite design. The Northeastern design teams goal is to develop a passive gravity gradient boom design that can be used on the ONYX satellite or be adaptable to other micro satellites. The ONYX, designed by Santa Clara University in collaboration with NASA, is a micro satellite in an Earth reconnaissance and research mission. During its intended 45 day mission, the ONYX will operationally test autonomous computer control techniques while conducting an Earth observing mission, providing educational services as well. Attitude control for an imaging satellite is vital. The objective of the design team is to develop a gravity gradient boom (GGB) for passive attitude control, while following specified design parameters set forth by NASA and Santa Clara Universitys ONYX satellite team. These design parameters are: the GGB system must not exceed a physical volume of 12cm x 12cm x 15cm, the system must stabilize the satellite to +/- 5 with respect to the Earth pointing Nadir vector, it must be under a 10kg weight, must not hinder physical properties of the overall satellite (ONYX), must be inexpensive, and strong enough to withstand launch vibrations. The key design features of this system consist of space qualified materials, a tip mass, a single bolt release mechanism, a non motorized mass launch, and a spool of specifically chosen wire.

2

TABLE OF CONTENTS Error! Bookmark not defined. 1.0.0 PROBLEM STATEMENT.................................................................................................................... 5 2.0.0 PROJECT RESEARCH ........................................................................................................................ 6 2.1.0 Micro Satellites.................................................................................................................................. 6 2.2.0 ONYX ............................................................................................................................................... 6 2.3.0 Orbital Study ..................................................................................................................................... 7 2.3.1 Orbital Paths................................................................................................................................... 8 2.3.2 Polar Orbit ...................................................................................................................................... 8 2.3.3 Sun synchronous............................................................................................................................. 8 2.3.4 Low Earth Orbit (LEO) .................................................................................................................. 9 2.4.0 Attitude Sensors and Control Devises ............................................................................................ 9 2.4.1 Sensors............................................................................................................................................. 10 Sun Sensors ........................................................................................................................................... 10 Horizon sensors..................................................................................................................................... 10 Magnetometers ...................................................................................................................................... 10 Star Sensors........................................................................................................................................... 11 2.4.2 Attitude Control Devises ................................................................................................................. 11 Active Attitude Control ............................................................................................................................ 12 Reaction Wheel...................................................................................................................................... 13 Momentum Wheel.................................................................................................................................. 13 Torquer Coils ........................................................................................................................................ 14 Controlled Momentum Gyro ................................................................................................................. 14 Gas Actuators........................................................................................................................................ 14 Passive Attitude Control........................................................................................................................... 15 Radiation Pressure................................................................................................................................ 15 Hysteresis Rods ..................................................................................................................................... 15 Gravity Gradient devices........................................................................ Error! Bookmark not defined. 2.5.0 Gravity Gradient Boom Physics ........................................................... Error! Bookmark not defined. 2.6.0 Deployment Devices ........................................................................................................................... 29 2.6.1 Importance to the ONYX ................................................................................................................ 29 2.6.2 Types of Deployment Devices......................................................................................................... 30 Tethers................................................................................................................................................... 30 Wire Drum Deployer............................................................................................................................. 34 Tubular Booms...................................................................................................................................... 35 Telescoping Booms................................................................................................................................ 36

3

Coilable Booms ..................................................................................................................................... 37 2.7.0 Launch Vehicles ............................................................................... Error! Bookmark not defined. 2.8.0 Thermal Concerns ................................................................................ Error! Bookmark not defined. 2.9.0 Electrical System .................................................................................. Error! Bookmark not defined. 2.10.0 Space Collisions ................................................................................. Error! Bookmark not defined. 3.0.0 Final Deployment Device..................................................................... Error! Bookmark not defined. 3.1.0 Telescoping Booms ............................................................................................................................. 39 3.2.0 Wire-Drum Deployers ..................................................................................................................... 40 Size........................................................................................................................................................ 40 Weight ................................................................................................................................................... 40 Mechanical Complexity ........................................................................................................................ 41 Retractability ......................................................................................................................................... 41 Thermal Characteristics......................................................................................................................... 41 Length of Boom .................................................................................................................................... 41 Adaptability to other missions/small satellites ...................................................................................... 42 Structural Predictability......................................................................................................................... 42 4.0.0 The design ........................................................................................................................................... 42 4.1.0 Final Design ........................................................................................................................................ 42 5.0 Final Conclusion...................................................................................... Error! Bookmark not defined. REFERENCES................