____ is another term commonly used for a spacecraft primary structure
Three basic types of spacecraft structural elements used for support and load are columns. ____ & _____ and _____
The favored shape used for the structures of early Soviet spacecraft was the _____
Vacuum effects on solid materials including metals can produce _________, which could result in the formation of "whiskers."
Both solar wind and cosmic ray particles present potentially ______ effects on surface materials in space, including metals
Atomic oxygen that oxidizes metal surfaces in low-Earth orbit requires a ______ _______ for protection of spacecraft surfaces
Torques from external magnetic fields can be
minimized by avoiding __________ materials in the spacecraft.
Although the most abundant particles in space are extremely small, spacecraft _____ ______ and _____ can be significant over long periods of exposure
surface erosion and pitting
Charge buildup from ____ _____ and _______ makes careful grounding necessary for both metal and composite structures.
solar wind and radiation
One of the most effective spacecraft debris shields is not a thick, solid chamber walls, but a ________ _____ that disperses any impacting particle energy over a large area.
One of the serious disadvantages of using titanium for spacecraft structures is that it is difficult to ______.
Many of the early American spacecraft, and even some today, employ an _______ shaped bus structure
A spacecraft is subjected to high amplitude ______ and ______ loads during launch and its ascent phase
vibrations and acoustic
The greatest vibrational energy source on a spacecraft during its operation (launch through termination) is in the _____ phase
The vibrational frequency of an elongated structural element will be _______ if its length is increased
The vibrational frequency of an elongated structural element will be _______ if its mass is increased
The strength or amplitude of a resonant vibration in a structural element will ______ as the difference in the resonant frequency and the drive frequency becomes smaller (drive frequency approaches the resonant frequency).
Can the amplitude of the vibrational
(drive) frequencies on a launch vehicle change with altitude?
The highest range in temperature range in the solar system is at/near the planet _______.
The narrowest range of temperatures in the solar system is at/near the planet ______
The temperature of a surface material with high emissivity would have a _____ temperature compared to material of low emissivity
The temperature of a surface material with high absorptivity would have a ______ temperature compared to material of low absorptivity
Temperature is a measure of _____ energy
A temperature that has reached a relatively constant value is called _______ temperature
Kirchkoff's law suggests that a material with high emissivity (ɑ) also has ____ absorptivity (ϵ).
______ paint is an example of a coating/material has both high ɑ and high ϵ.
Of the heat transfer mechanisms used on spacecraft, only ______ systems and ______ systems are used for heat removal.
passive and active
Except for heat pipes, _______ heat transfer is not significant on spacecraft because of the lack of gravity.
____ radiates as a blackbody
According to the zeroth law of thermodynamics, heat always flows from ___ to ____
hot to cold
An active thermal control system uses ______ and/or ______ systems
mechanical and or electrical
The most extreme temperatures are moderated by a spacecraft's ______ thermal control system components.
The most extreme heat source in the inner solar system come from ____.
The approximate energy available from solar radiation in the visible and IR at 1 AU is approximately _____ W/m2
At Mars (1.52 AU), this would be approximately ___ W/m2
Heat energy radiated from a surface is proportional to the equivalent temperature of the surface to the ____ power.
One of the most common surface coatings for spacecraft radiators is Z___.
A heat pipe is an example of a _______
thermal control system
The approximate lowest temperature available on a spacecraft using radiative cooling is __K.
The Space Shuttle used ______ for the cooling fluid in its external active cooling loop.
The International Space Station uses ______
for the cooling fluid in its external active cooling loop.
Thermoelectric cooling employs the _____
effect by using electrical energy for cooling.
The Mercury spacecraft used _______ for
it high-temperature, high-strength structural material.
The Mercury capsule used a/an _______
type of material for its heat shield
The highest temperature region near the Mercury capsule was the shock from that reached nearly ______ F during reentry
A higher beta angle (related to orbit inclination angle) will _______ the maximum temperature (and heat loading) of an orbiting spacecraft compared to a lower beta angle.
Guidance is generally assumed to be the ______ phase of a booster's or spacecraft's flight
Gravity gradient is a ______ type of attitude stabilization
To prevent over-controlling and wasting energy or propellants, the accuracy of the attitude control component of a guidance, navigation & control system (GNC) should be ____ than the
accuracy of the attitude determination component
The three basic types of attitude and trajectory acceleration sensors are
The two types of motion sensors that relate to the two types of motion are ______ and _______.
rotational and translational
A ring ____ gyro can measure both types of motion on a spacecraft
____ trackers are used to determine the position of a spacecraft in three dimensions.
A horizon or limb sensor is used to find the relative position of a spacecraft with respect to a celestial body's _______ or _____.
position or cone
Optical terrain guidance was used in the ______-manned spacecraft.
The military's NAVSTAR Global Positioning System (GPS) can be used to determine position and velocity for spacecraft in ___ orbit
Spacecraft attitude and trajectory control can be either _____ or ______, or both
active or passive
Solar radiation (photon) pressure can be used for spacecraft and ______ attitude and trajectory control, as was the case for the Mariner 10
The two fundamental types of attitude spin stabilization are simple ____ and dual-____.
simple spin and dual-spun
Three-axis spacecraft attitude control if furnished by either _______ or by _______ control, or both
thrusters or gyroscopic
The most accurate of the three gyroscopic control systems is the _______ _______.
The greatest torque of the three gyroscopic control systems is provided by the _______ ________ gyros
Accumulated error in a spacecraft or aircraft navigation system is also called _____ error.
The Apollo spacecraft used a basic _____ guidance system with optical measurements to refine absolute position
Apollo's optical guidance instruments
included both a telescope and a _____ tracker.
The heart of the Apollo inertial navigation unit was the _________ _______ Unit (IMU) which was also incorporated in the Space Shuttle's inertial navigation system
The two hand controllers in the Apollo Command Module were the ______ controller and the _______ controller, both of which are found on the Space Shuttle flight deck
The Apollo Command and Service Module employed _______ jets to control the attitude of the spacecraft.
A flight director- ______ indicator was used for the 3-dimensional positional and velocity information display for the Apollo astronauts, similar to what is found on the Space Shuttle flight deck.
The two primary attitude and trajectory sensors for the U.S. segment of the International Space Station (ISS) are the _____
gyros and the _____.
The U.S. segment employs ____-_______ units for the attitude control element on the ISS
The ISS Russian segment uses both ____-_____ and ______ units for attitude control.
non-propulsive and propulsive
The ______ vector carries the attitude, position, and time data used for the ISS GN&C
The Russian equivalent of the GPS system is
Aerodynamic drag or _______ _______ can be used for slowing spacecraft in orbits around planets with atmospheres, which reduces
the total retrograde thrust needed for orbit insertion
The _____ gradient force is used to desaturate the momentum exchange devices (CMGs, Gyrodynes) on the ISS
Pointing calculations and control operations are needed for the ISS ________, _________ and solar arrays