lecture 10 Flashcards
What is the purpose of the Parker Solar Probe?
spacecraft launched by NASA to investigate the sun
- must travel over 600,000km/hr to not burn up
- satellites observing the sun make it look featureless bc of the radiation it gives off
- flys into suns outer atmosphere (corona) to sample it
Name mentioned facts about the sun
- gives heat and light to earth
- controls motions (orbits) in solar system
- powered by nucelar fusion (H->He; photosphere)
- sphere of plasma with strong magnetic field
- will remain for another 5 billion years (9.5 total) before it becomes a red giant dwarf (dead)
- center is 15millionºC, surface is 6000ºC
Explain what combustion is and relate it to rockets
chemical process that releases energy in the form of heat (fuel + oxygen + heat -> exhaust + heat)
- fuel and oxidizer brought together and ignited
- exhaust has an exhaust speed
rockets
- combustion necessary to get rockets out of earths gravity
- higher = more thrust acheived
- solid = more thrust in less time
What is chemical propulsion?
- rockets always carry fuel and an oxidizer
- presence of oxidizer allows rockets to use fuel in space (no air)
- liquid fuel can be stopped and started again
- solid fuel burns fully once ignited; more stable + falls off once burned so less weight = more thrust
What are the types of rocket fuels?
Liquid
- liquid oxidizer
- kerozene and hydrogen
- liquid methane -> CO2 and H2O vapour released
Solid
- ammonium perchlorate and ammonium nitrate
What are the main points of ion propulsion?
- uses inert gases (xenon and argon) by putting them in a chamber and making them electrically charged
- this creates an electrical gradient; shoots ions out to produce trust
- requires solar panels; electrical field for it to work
- generates low thrust; slowly gathers speed
What are some missions that used ion propulsion?
- Deep space 1
- Dawn (most successfull; visited vesta)
- Lunar gateway (spacestation; using 4 ion thrusters to maintain orbit) utilizes solar radiation
What is solar sailing?
- using solar pressure for sun sailing;using the suns pressure to change speed and direction in space
- c clarke thought of it in a novel
- acceleration gatherd in small
- sail must be large in area but small in mass + strong to steer
- JAXA and NASA deployed as a demonstration
What is matter-anti-matter propulsion?
matter and anti-matter cause annihilation which releases a lot of energy
- 100% conversion of mass into energy (einstein)
- anti-particles are abundant (electrons anti-particels are positrons) which have same mass but opp charge
- producing anit matter is not an issue, storing them is (difficult and costly) as they annihilate after creation with matter
Explain the characteristics of a nuclear powered rocket
- never actually been used in space
- if it were used, it would not be used for launching a rocket, but similar to ion propulsion
- energy would be suppled by nuclear fusion plant uranium get hits with neutrons, breaks it apart and energy is released)
- low but long-term thrust
- may be dangerous if failed
What are radio-isotopes?
radio isotope thermoelectric generators; nuclear battery 1954 (uses decay heat from radioisotope)
- temperature difference bewtten 2 metals geneartes electricity
- low amount of energy, but efficent
- must have high power density
- any radiaiton must not impact crew
isotopes used
- plutonium (most efficient)
- strontium
- americium
When will we return to the moon?
with the artemis project (2030) using the spacelaunch system (SLS)
- going back to moon for science, money, and inspiration
Artemis 1
- launched 2022
- SLS and Orion
- 25 days, uncrewed
Artemis 2 (planned)
- test of artemis acrchitecture
- SLS and Orion
- 10 days, crewed with canadian
Artemis IV and beyond
- similar to 3
- for lunar gateway (long term stay on moon) which is staging area for crewed arriving from earth
- canada building canadarm
- SLS will likely be replaced by starship due to cost differences
Will humans every be able to live fully on the moon?
- not sufficient in this current generation
- Ice near lunar poles sufficent for air (O), farming (H2O) and fuel (H) breaking apart H2O)
- using laval tubes (made of lunar material) to build settlements with to humans from radiation
- requires battery storage for the 2 weeks of darkness the moon experiences
What are some current challenges that we face in the solar system?
current propulsion methods dont allow for far space exploration given human life spans
- bone calcium loss, muscle degradation, radiation exposure, food, water, air
- body reacts differently in space
- psychological challenges with isolation
Why is spacecraft sterillization so important?
to keep potential habitable environments free of terrestrial contamination; forward contamination
- sterilize spacecraft to prevent this
- opposite is possible too (alien life)
total sterilization is not possible however, 1 in 10,000 is a good estimate
- also depends on the mission; mission to sun requires none, while mission to mars requires the most
- many locations (mars, gallilean, titan) deemed in need of protections from contamination
