SPST201 quiz 6

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School

American Public University *

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Course

201

Subject

Mechanical Engineering

Date

Apr 3, 2024

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pdf

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Uploaded by 32denny

Quiz 6 - Results Attempt 1 of 1 Written Jan 8, 2024 7:38 PM - Jan 8, 2024 8:03 PM Attempt Feedback Attempt Score 100 / 100 - 100 % Overall Grade (Highest Attempt) 100 / 100 - 100 % Quiz 6 Question 1 10 / 10 points Open-loop control systems, such as the heating system described above, are in cars, planes, spacecraft, and even the human body. They are extremely useful because, unlike closed-loop systems, they can make a system do what we want even in the face of random environmental inputs. True False Question 2 10 / 10 points What loads affecting a spacecraft during launch is of the most concern to engineers? Along which axis is it felt by the spacecraft? , A perfect score. If desired, schedule a meeting with me via email or Microsoft Teams to go over this assignment. Make sure you know how to get the correct answer for every problem. Axial loads caused by launch acceleration produce a compressive force on the vehicle and spacecraft through its longitudinal axis. AKA "g-loads" or "g-force".

Question 3 10 / 10 points ___ disturbance torques___ Question 4 10 / 10 points ___ Direct___ ___ Alternating___ Question 5 10 / 10 points Which type of sensors are the most widely used spacecraft attitude sensors? Question 6 10 / 10 points What are disturbance torques and how do they affect a spacecraft? Which ones do spacecraft designers worry about most? Question 7 10 / 10 points Figure skaters change their moments of inertia to vary their rate of spin. For the same total angular momentum, they will spin faster by bringing their arms in (lower moment of inertia) and slower by extending their arms (higher moment of inertia). Over time, if we do nothing, environmental effects called will drive a spacecraft away from its original attitude. Current is either or Earth Sun Star Optical Disturbance Torques are very small environmental effects that, over time, could affect a spacecraft's attitude and rotate even very large spacecraft. The following are the four main disturbance torques: gravity gradient solar-radiation pressure Earth's magnetic field atmospheric drag Atmospheric drag would be the biggest worry to spacecraft designers as it will cause a spacecrafts orbit to reduce to the point where the spacecraft will be on a collision course with Earth and burn up upon re-entry.

True False Question 8 10 / 10 points What type of device changes angular momentum by absorbing energy. Question 9 10 / 10 points What are the three main passive attitude actuators used on spacecraft? Question 10 10 / 10 points ___ Batteries___ ___ Fuel Cells___ Done Damper Thruster Magnetic torquer Momentum wheels The three main passive attitude actuators on a spacecraft are: Gravity gradient stabilization Spin stabilization Dampers Two types of chemical-energy systems are and .

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