Two Topics Getting One Light Pass
This module is intentionally short. Space law and space life sciences each deserve real depth — the policy layer gets a full course in SSA-04 — but neither has appeared directly yet, and later modules assume you've seen the basics. Consider this the minimum you need to keep going.
One Treaty, Still Governing Everything
The Outer Space Treaty (1967) is the foundational document of space law. Almost every policy debate in this field — including Module 4's resource-rights question — traces back to one of these five principles.
Non-Appropriation
No nation can claim sovereignty over the Moon or any celestial body — space is not territory to be annexed.
Peaceful Use
Space is to be used for peaceful purposes — nuclear weapons and other weapons of mass destruction are explicitly barred from orbit and from celestial bodies.
State Responsibility
A nation is legally responsible for its government's activities in space — and for its private companies' activities too. This is the root of the national launch-licensing regimes touched on in Module 4.
Avoiding Harmful Contamination
States must avoid harmful contamination of celestial bodies and adverse changes to Earth's environment from material brought back — the earliest legal root of planetary protection policy.
A fifth principle is worth knowing by name: astronauts are treated as "envoys of mankind," owed all possible assistance and safe return in an emergency, regardless of which country they're from. SSA-04 covers what happens when these principles run into real disputes — starting with the one Module 4 already raised.
What Spaceflight Does to a Body
Module 1 named this as its own research field for a reason — the human body starts changing within hours of reaching orbit.
Musculoskeletal
Without gravity's normal loading, bone density and muscle mass decline measurably within weeks — astronauts follow strict daily exercise regimens specifically to slow it down, not eliminate it.
Cardiovascular
Fluids that gravity normally pulls toward the feet instead shift toward the head and chest — the "puffy face" astronauts get — while the heart, doing less work against gravity, gradually deconditions.
Vestibular & Sensory
The inner ear's balance system, built for gravity, gets confusing signals in free-fall — commonly causing disorientation and nausea in the first days, sometimes called space adaptation syndrome.
All three are active, ongoing research areas — NASA's Human Research Program (from Module 1's glossary) exists specifically to study and develop countermeasures for them, especially as mission durations stretch toward Mars-length timelines. International partners run their own share of this research too — JAXA's Kibo laboratory module on the ISS hosts its own life- sciences experiments alongside NASA's.
Key Terms
- Outer Space Treaty
- The 1967 treaty that forms the foundation of international space law — non-appropriation, peaceful use, state responsibility, and more, all trace back to it.
- Non-Appropriation Principle
- The Outer Space Treaty rule that no nation can claim sovereignty over a celestial body — the starting point for the resource-rights debate covered fully in SSA-04.
- Envoys of Mankind
- The Outer Space Treaty's description of astronauts — owed assistance and safe return in an emergency, regardless of nationality.
- Fluid Shift
- The redistribution of bodily fluids toward the head and chest in microgravity, since gravity is no longer pulling them toward the feet.
- Space Adaptation Syndrome
- Short-term disorientation and nausea some astronauts experience in the first days of spaceflight, caused by the inner ear's balance system adjusting to free-fall.
- Countermeasures
- Interventions — like daily exercise regimens — designed to slow or offset the physical effects of spaceflight on the body.
For This Module
The Outer Space Treaty text (UN Office for Outer Space Affairs), and NASA Human Research Program public materials on musculoskeletal, cardiovascular, and vestibular effects of spaceflight.
Continue the Sequence
Module 7 closes SSA-01: who operates in space today, and why.