Exam 3

Question 1

What is the system used to navigate our way to the planets?

Answer 1

Hohmann Transfer Orbit

Question 2

elliptical orbit where perihelion point touches the Earth’s orbit and aphelion point touches target planet’s orbit – by Kepler’s 1st law the Sun defines where one of the focal points must be, thus setting the size and eccentricity of the elliptical trajectory: aHoh = (aEarth + aPlanet)/2

Answer 2

Hohmann Transfer Orbit

Question 3

HTO uses Kepler’s ___ Law to calculate period of ____ _____.

Answer 3

3rd, transfer orbit

Question 4

a spacecraft which follows a parabolic or hyperbolic path by orbiting planets can gain or lose energy to the planet: several robot spacecraft have used this technique to travel to the outer planets and beyond

Answer 4

sling shot trajectories

Question 5

What is another name for sling shot trajectories?

Answer 5

Gravitational assist

Question 6

What does F1 on 2 = -F2 on 1 mean?

Answer 6

Object 1 pushes on object 2, then object 2 pushes on object 1

Question 7

How do rocket engines work?

Answer 7

high pressure gas generated in “combustion” chamber escapes through nozzle (is “pushed” out the nozzle), gas “pushes” back on rocket body producing thrust = force on rocket

Question 8

FR = vex(ΔM/Δt) where: FR = thrust (force on rocket body), vex = exhaust vel., (ΔM/Δt) = fuel/oxidizer consumption rate = mass expulsion rate

Answer 8

the rocket equation

Question 9

units of seconds – no. of seconds engine could thrust with a force of 1 pound while using 1 pound of fuel/oxidizer, or, measure of total energy available for propulsion per unit mass of fuel (engine efficiency)

Answer 9

specific impulse

Question 10

major planets orbit (approx.) in a _____ plane (same as Sun’s equatorial plane) in approx. circular orbits and all in _____ direction

Answer 10

single, prograde

Question 11

Refractory materials include…

Answer 11

rock, metal

Question 12

Volatile materials include…

Answer 12

gas, ice

Question 13

Refractory materials are found ___ the sun, while volatile materials are found ___ the sun

Answer 13

near, away from

Question 14

Many of the “exo-planet” planetary systems discovered over the last 10 - 15 years have…

Answer 14

gas giant planets

Question 15

low relative velocities allow colliding particles to “stick together” into larger particles more often than fragmenting into smaller particles

Answer 15

accretion process

Question 16

average size of particles grow from dust size _____ to mountain size _______ through the process of _____

Answer 16

grains, planetesimals, accretion