Attitude Determination and Control

1. Attitude Determination and Control Stephen Levin-Stankevich Jeff Parker Tim Shilling

2. Internal Hardware • Magnetometers • Sun Sensors • Horizon sensors • Magnetic Torquers • Rate Gyros

3. Electrical Safety • Hardware will not receive power until given by Power subsystem. • Wire sizing and circuit protection requirements will be met per NASA TM 102179.

4. Fracture Control • Parts will meet requirements for low-risk fracture classification • Failure will not result in catastrophic hazard to the space shuttle. • All materials including hardware components and fasteners will be low-risk acceptable per NASA-STD-5003 or acceptable under a materials usage agreement (MUA)

5. Parts and Materials • Instruments will meet safety specifications for limited outgassing of CVCM < .1% and TML < 1%. • Corrosion requirements will be met through the use of space-rated materials or surface treatments.

6. Gravity Gradient Boom • Tether Material • Three braided strands • Spectra 1000 material • 0.003 inches thick • Rip-stop protection, not load-bearing • Plastic sheath • Low-density polyethylene tape • 1 inch wide, 0.005 inches thick • 0.002173 kg/m3 • Total Mass less than 0.045 kg.

7. Outgassing • In-depth analysis of outgassing properties for tether material required. • Required properties are CVCM < .1% and TLM < 1%.

8. Other Concerns • Prior to deployment the tether does not bear the load of the tip mass. • Non-Fracture Critical per low-released mass part requirements. • Safety concerns dealing with deployment or stowage of the tether and mass will be addressed by the structures/deployables team.