Lecture 1: The Problems with Spaceflight Flashcards
Our body’s physiology and anatomy are STILL THE SAME/DIFFERENT as our plane-dwelling ancestors and yet we are exposing them to novel and extreme situations.
STILL THE SAME
we have to place human physiology under ____ to achieve space exploration
GREAT STRESSES
why do we even bother with space exploration??
- curiosity (exploration)
- resources (mind astroids etc)
- aliens
- our suns going to die, next life??
what are the key events during a flight into orbit and beyond?
- take off (lift off)
- massive acceleration –> HIGH G phase (3-4g)
- -2 minutes = 3000mph
- -into orbit = 17,500 mph
- once in orbit = microgravity
- deorbit = high g on deorbit and reentry ~1.5g
- landing = 235mph
lunar missions: flight path
- lift off (cape kennedy)
- orbit earth once (accelerate
- slung away from earth hyperbolic orbit
- moons gravity capture you,
- spacecraft orbits moon, part of spacecraft break off
- spacecraft then launch from moon, accelerate to leave moon gravity
- capture in earths gravity
g loads in lunar missions
similar g loads on ascent but greater on re-entry but greater on re-entry because velocity is much greater (25,000mph compared to shuttles 17500mph)
What exactly is orbit?
- golf ball on top of mountain (hit hard and harder)
- curve round the earth, because travelling at speed will never touch earth again
- 90 mins to go all way around
- Apogee and Perigee
apogee
= place of take off in orbit, furthers point from earth
perigee =
closes part to earth in orbit
orbit can happen at which distance from earth?
ANY, if going fats enough.
-just obstacles get in the way
ON /IN orbit
ON
human body and high g
lying semi-recumbent, v high ^-forces can be tolerated for short times (35g for 0.03 sec) but 10g for 30secs plus
– position favourable as doesnt starve brain of blood
G-LOC
gravity induced loss of consciousness
mars cycler
- special kind of spacecraft trajectory that encounters Earth and Mars on a regular basis
- take much longer than a direct flight
- invented by Buzz Aldrin
how does space effect the eyes:
eyes become primary motion sensors, more relied upon to determine orientation
getting a person into space is a balance between
balance between engineers and physiological issue
engineers vs physiological issues VELOCITY
engineers: adequate velocity required to get onto orbit and beyond
- physiological issue = too fast, leads to death
engineers vs physiological issues ENVIRONMENT
E = earth-like environment (‘shirt sleeves) (including adequate nutrition) –> PI = must be maintained for whole time
engineers vs physiological issues RADIATION
E = protection from radiation (Solar) PI = exposure to radiation can result in cancers and immediate death
what does the body have to deal with when travelling in a spacecraft
- high G-force on take off
- microgravity (loss of bone density –> renal calculi, loss of muscle mass, vestibular system, visual system[scott kelly])
- radiation (solar mass ejections- ‘solar flares’ very damaging in deep space)
What does the body have to deal with when outside the spacecraft?
- space suit = mini space craft
- atmospheric stability needed (breathable gas mixture and gas pressure)
- thermal stability (humans survive only in small range)
- micrometeroid impact (puncture suit)
space temp =
shade = -200 celsius to sun = + 200 C
