Chapter 3: The Space Enviroment Flashcards
Exam 2
Where is space?
80 km astronaut wings
100 km is when a spacecraft can orbit the earth for about a day before having to renter the atmosphere
What are the two bi products of fusion?
- electromagnetic radiation
2. charged particles
What is eleromagnetic radiation?
EM is light and heat, a way for energy to get from one place to another
What are charged particles?
protons and nuetrons
Plasma is?
the fourth state of matter
atoms that have been broken down to their basic particles (needs intense heat)
Solar wind is a stream of?
charged particles flying off of the sun at 300 –> 700 km/s
What are solar flares or solar particle events?
gigantic, intense bursts of charged particles
large magnetic energy becomes available, highly explosive and concentrated release of energy/radiation in the solar atmosphere
How long is 1 AU?
150 million km or 93 million miles
What is a cosmic year?
the time it takes for the milky way to rotate once around its gallactic center ( about 255 million years)
What are some causes and concerns towards spacecraft in the space environment?
gravitational environment earths atmosphere vacuum in space natural man made objects (collisions) radiation and charged particles
Describe free fall.
when an object is falling under the influence of gravity
What are the two major affects from the atmosphere?
- drag
2. atomic oxygen
Atmospheric density is the measure of?
how much air is packed into a given unit of volume
Describe atomic oxygen?
because oxygen molecules are so spread out, when charged particles break up the O2 molecule, it remains an O molecule. Atomic oxygen is that O1 molecule in space
What is ozone?
O3 molecules which are formed when oxygen (O2) molecules combine with atomic oxygen
What issues do spacecrafts encounter in a vacuum?
- outgassing - release of gasses from the spacecrafts materials
- cold welding - fusing of metal components together
- heat transfer - limited to radiation
Explain outgassing.
because the pressure in the material is so high compared to the vacuum, the material gases want to equalize, and therefore a flow of gas from the materials into space forms. The gas can stay around the spacecraft and cause sensor damage
How is heat transferred on a spacecraft?
- conduction - heat flows directly from one point to another through a medium
- convection - some force moves a liquid or gas over a hot surface
What is radiation?
transfer of heat (energy) from one point to another
What are the affects of visible light?
- heating on exposed surface
- degradation or damage to surface and electronic components
- solar pressure
Photons are?
mass-less bundles of energy that move at the speed of light
What is solar radiation pressure?
pressure from light or photons hitting the surface of an object
Where do charged particles come from?
- solar wind
- galactic cosmic rays (GCRs)
- the Van Allen Radiation belts
What are GCRs?
similar to particles from solar wind/flares, but are from areas outside our solar system
The magnetosphere is?
a magnetic field from earths poles
What is the shock front?
the point of contact between solar wind and earths atmosphere
The magnetopause is?
point of contact between charged particles and magnetic field lines
What are the Van Allen radiation belts?
areas of trapped particles (concentrated between field lines)
Are the Van Allen belts radio active?
No, the belts are just charged particles
What harm do the Van Allen radiation belts pose to spacecraft?
- charging - charges build up around spacecraft
- sputtering - like sand blasting using particles
- single event phenomenon - a single particle gets into electronics and messes everything up ex. bit flip
- total dose effects - long term effects on electronics
List the potential hazards to free fall.
- fluids shift (hydrostatic gradient)
- motion sickness (altered vestibular functions)
- reduced load on weight bearing tissues
Describe fluid shift.
equal pressure in the body in space vs on earth, more pressure in the feet than the head due to gravity. This causes extra fluids in the upper body, more than usual, which can cause kidneys to work over-time, heart rate increases, head rush when returning to earth
What induces motion sickness?
inner and outer ear sensors compute, but what the eyes compute (or dont compute) does not match
How does the sun ‘work’
particles originate at the core where nuclear fusion takes place, hydrogen into helium occurs.
particles then leave the core as high energy photons and bounce around in random directions
On the sun, what is the convection zone?
some recombination of ions,
steep temperature gradient appears as granules
driven by upwelling of cooler less dense plasma
What is the photosphere?
highest level of solar plasma that radiates as a black body
Where do solar winds originate?
The corona
What is the EM theory equations?
λf=c and E=hf
where h = 6.626E-36
What encompasses solar weather?
solar wind, solar cycle (average 11 years, poles flip, large sun spots form)
What are sun spots?
local magnetic fields become high enough that flux tubes raise to the photosphere.
reduced temperature causes a ‘dark’ spot
sun spots are closely related to solar cycles
What are coronal mass ejections (CME)
large scale eruptions of solar atmosphere in which coronal material is ejected into space,
takes 3-4 days to reach earth
What is the South Atlantic Anomaly?
Van Allen belts titled due to unmatched magnetic field and rotation of axis
influences are strongest in region of south america (closer to the ground the the Atlantic ocean)
What are the general layers of Earth’s atmosphere?
Space
1. stratosphere
2. troposphere
Earth
What is the ionosphere?
a combo of UV rays and atmosphere of layered ionized particles that are electrically neutral and located near the low to mid latitudes
