L7 - Space Environment & Space Systems Design

Question 1

What are the four main environments that a spacecraft experiences during its lifetime.

Answer 1

• Earth
• Launch
• Atmosphere
• Space

Question 2

What problems can arise in the Earth environment?

Answer 2

• Atmosphere
• Corrosion
• Atmospheric particles/dust
• Vibration/Shock during transport (road/air)
• Need for ground support equipment

Question 3

What problems can occur during launch?

Answer 3

• Axial loads
• Lateral loads
• Mechanical vibrations
• Acoustic energy
• Thermal loads
• Shock transients

Careful design can help mitigate those.

Question 4

What impact can the Earth’s atmosphere have on a spacecraft?

Answer 4

Lower atmosphere is mostly neutral gas-like.

Upper atmosphere varies with solar activity:

• Atmospheric drag shortens orbit lifetimes
• Atomic oxygen degrades spacecraft surfaces.

Atmospheric particles/dust can:

• Interfere with delicate mechanisms
• Reflect light and fool star sensors
• Contaminate other planets

Question 5

What are the different types of space environment concerns?

Answer 5

• Vacuum
• Gravity
• The Sun
• Electromagnetic Radiation
• Charged Particles
• Micrometeoroids
• Orbital Debris

Question 6

List the issues related to the Vacuum environment.

Answer 6

• Outgassing
• Cold Welding (mitigated with lubricant)
• Heat transfer problems, radiation must be guided efficiently

Question 7

List the issues related to Gravity.

Answer 7

• Microgravity is hard to simulate on ground
• Liquid handling

Question 8

List the issues related to the Sun environment.

Answer 8

• EM radiation
• Charged particles
• Coronal mass ejections

Question 9

List the issues related to electromagnetic radiation.

Answer 9

• Ultraviolet
• Visible
• Infrared

Question 10

List the issues related to the Charged Particles.

Answer 10

• Solar wind and flares
• Galactiv cosmic rays
• Van Allen Belts

They might damage a spacecraft:

• Charging
• Sputtering (through high velocity impact)
• Single-event phenomena (one impact which penetrates deep enough to disrupt electronics)
• Total dose effects

Question 11

List the issues related to micrometeoroids.

Answer 11

• Velocity ~ 20 km/s
• Size: ~ 0.01cm
• Fairly rare

Question 12

List the issues related to orbital debris.

Answer 12

• Velocity: 7-10 km/s
• Size: wide range, over 1 cm = Hazard
• 100,000-150,000 pieces, but growing

We must design to avoid debris production. GEO/GTO S/C to be boosted to higher orbits while LEO must re-enter after 25 years.