AAE450 Senior Spacecraft Design

Breanne WootenWeek 2: January 25th, 2007

Human Factors/APMHuman Limitations/Taxi Capsule

AAE450 Senior Spacecraft Design

Human Limitations• Artificial Gravity

– Constraints:• Spin rate less than 4 rpm• Min habitat tangential velocity

(10 m/s)• Radiation Shielding

– Taxi Capsule: 12000 kg– Hab

• Safe room: 7176 kg• External: 19462 kg• Total: 26,638 kg

• Acceleration– Assuming properly restrained,

pre-conditioned crew– Less than 5 g’s for sustained

burns

Comfort Zone

1g

1/3g

4 RPM

Min Tangential Velocity

Human Tolerances for Artificial Gravity (Based on Hall, ref 1)

AAE450 Senior Spacecraft Design

Taxi Capsule

# Crew 4

# Days 4

Units

Mass 15500 kg

Power 3 kW

Habitable Volume

12 m3

• Includes:– Food– Water– Life Support– Radiation Shielding

• Does NOT include:– Structure– Heat Shield– Reaction Control

System

AAE450 Senior Spacecraft Design

References

[1] Hall, Theodore W. “Artificial Gravity and the Architecture of Orbital Habitats”. 20 March 1997.

[2] Larson W.J, and Linda Pranke. Human Spaceflight: Mission Analysis and Design. The McGraw-Hill Companies, Inc. Crawfordsville.

[3] Hanford, Anthony J. Ph.D., Advanced Life Support Baseline Values and Assumptions Document. NASA-Lyndon B. Johnson Space Center. Houston, Texas. 2004.

[4] Man-Systems Integration Standards. NASA-STD-3000. Revision B. NASA-Lyndon B. Johnson Space Center. July 1995. Last updated:

6/15/05. < http://msis.jsc.nasa.gov/>

AAE450 Senior Spacecraft Design

Backup – Artificial Gravity

a – acceleration

Ω – angular acceleration

r – rotational radius

t – angular velocity

Rpm = (π/30)*Ω

a = Ω2r r = a/ Ω2

t = Ωr

To minimize nausea, dizziness, etc: t > 10 m/s; RPM < 4;

AAE450 Senior Spacecraft Design

Backup – Radiation Shielding

• Suggested Taxi Shielding: 5 g/cm2

• Suggested Material: Aluminum (2.78 g/cm3) and

Polyethelyne (1.00 g/cm3) 5 ≈ tAl*ρAl+ tPE*ρPE

=(1)(2.78)+(3)*(1)

= 5.78 g/cm2

Mass of Shielding = 5.78*Surface Area = 5.78*207

=12000 kg = 12 mt