patrickfleith/astro-mcq huggingface dataset:
Why is electric propulsion system more efficent than chemical propulsion?

A. Because of the recombination of ions and electrons to form neutral atoms.
B. It does not generate heat.
C. It produces a higher exhaust velocity.
D. Because of the production of electrodynamics shock waves at the exhaust.

Answer: C. It produces a higher exhaust velocity.
In the process of Orbit insertion what does MECO refer to?

A. It does not mean anything relevant
B. Main Engine Cut-Off
C. Micro-Elliptic Catapult Orbit

Answer: B. Main Engine Cut-Off
Which of the following statements are true?

A. LVLH is an inertial coordinate system
B. LVLH stands for Local Vertical, Local Horizontal.
C. LVLH is a coordinate system
D. In the LVLH system, the z-axis points towards the center of the Earth
E. LVLH is a french luxury clothing brand

Answer: B. LVLH stands for Local Vertical, Local Horizontal.
C. LVLH is a coordinate system
D. In the LVLH system, the z-axis points towards the center of the Earth
How does a magnetic torquer work ?

A. The needle of a compass presses on the thruster button to correctly orient the spacecraft
B. A coil is wrapped around an elongated rod. An electrical current runs through the the coil generating a magnetic field which has the tendency to align itself with Earth's magnetic field
C. Permanent magnets are placed at strategic places in the spacecraft, keeping it correctly oriented

Answer: B. A coil is wrapped around an elongated rod. An electrical current runs through the the coil generating a magnetic field which has the tendency to align itself with Earth's magnetic field
Solar arrays should be oriented towards the Sun with a very low accuracy. The angle Theta from the normal of the solar array to the Sun, however, is directly linked to the power generated. Why is the requirement the pointing of the solar arrays to the Sun so loose?

A. The power generated is proportional to sine of Theta
B. The individual solar cells can points each towards the exact direction of the sun
C. The power generated is proportional to the cosine of Theta
D. We cannot point a higher precision

Answer: C. The power generated is proportional to the cosine of Theta
Select all propositons that applies to attitude maneuvers with thrusters

A. A minimum of 12 thrusters are needed to have pure rotations
B. It can be used to desaturate other attitude maneuver systems
C. All thrusters systems need to have a ignition system
D. It is the most precise technique
E. 6 thrusters are needed to have pure rotations

Answer: A. A minimum of 12 thrusters are needed to have pure rotations
B. It can be used to desaturate other attitude maneuver systems
What is the fundamental principle that is used when working with rotation wheels?

A. Conservation of momentum
B. Conservation of angular momentum
C. Freedom
D. Conservation of electric charge

Answer: B. Conservation of angular momentum
What was the main power source of the Space Shuttle?

A. Radioisotope Thermoelectric Generators (RTG)
B. Fuel cells
C. Solar arrays
D. Astronaut bicycle ergometer with a generator
E. Hamsters running in a wheel

Answer: B. Fuel cells
A tether deployed from the Space Shuttle with a passive satellite at the end can be used as ...

A. Dipole antenna
B. Electrical Generator
C. Electrical motor
D. Space elevator

Answer: B. Electrical Generator
C. Electrical motor
Which effect dominates the forces on a tethered systems?

A. Collision with other spacecraft
B. Drag disturbances
C. Radiation pressure
D. Gravity gradient

Answer: D. Gravity gradient
What elements were part of selected configuration of the Space Shuttle? (Select all that applies)

A. 3 main engines
B. Two solid rocket boosters
C. An external tank
D. A capsule
E. A third stage
F. An orbiter

Answer: A. 3 main engines
B. Two solid rocket boosters
C. An external tank
F. An orbiter
During which year the Shuttle approach and landing tests took place?

A. 1974
B. 1975
C. 1977
D. 1978
E. 1976

Answer: C. 1977
Up to how many crew-members could participate in Space Shuttle Missions?

A. 2
B. 5
C. 10
D. 11
E. 7

Answer: E. 7
Which abbreviations correspond to real Space Shuttle Missions? (Select all that applies)

A. STS-118
B. STS-1
C. STS-75
D. STS-51L
E. STS-137
F. STS-432

Answer: A. STS-118
B. STS-1
C. STS-75
D. STS-51L
What changes did occur after the Challenger accident? (Select all that applies)

A. The Shuttle was not used by the Department of Defense or for commercial flights
B. Nothing
C. The Launch and Entry Suit was introduced
D. Crew to the ISS were sent only with Soyuz spacecraft
E. The design of some components of the Space Shuttle Transportation System was modified

Answer: A. The Shuttle was not used by the Department of Defense or for commercial flights
C. The Launch and Entry Suit was introduced
E. The design of some components of the Space Shuttle Transportation System was modified
When did the ISS start to be assembled?

A. 2011
B. 1995
C. 1998
D. 2001

Answer: C. 1998
Which of the following vehicles were able to bring crews to the ISS, until 2011? (Select all that applies)

A. Space Shuttle
B. Dragon
C. Progress
D. Soyuz
E. Shenzhou

Answer: A. Space Shuttle
D. Soyuz
What year did the first spacewalk take place?

A. 1962
B. 1963
C. 1965
D. 1964

Answer: C. 1965
What new item was introduced in Apollo 15 to explore the Moon?

A. The spacesuits featured cold gas thrusters to fly small distances
B. A second, scientific, deck to the LEM
C. A Lunar Roving Vehicle
D. A tent-like structure to analyze boulders

Answer: C. A Lunar Roving Vehicle
Which of the following is NOT a branch within the European Cooperation for Space Standardization (ECSS) system?

A. Configuration and information management branch (D-branch)
B. Policy branch (P-branch)
C. System description branch (S-branch)
D. Environmental Sustainability branch (E-branch)

Answer: D. Environmental Sustainability branch (E-branch)
Which ECSS standard series focuses specifically on the product assurance aspects of space projects?

A. E-branch
B. S-branch
C. Q-branch
D. P-branch

Answer: C. Q-branch
The South Atlantic Anomaly (SAA) is an area where the Earth's inner Van Allen radiation belt comes closest to the Earth's surface. What does it lead to?

A. A decreased flux of energetic particles.
B. An increased flux of energetic particles.
C. A high number of auroras.
D. A screening from sun light.

Answer: B. An increased flux of energetic particles.
What might be the effect of the impact of a cosmic ray with the onboard electronics? (More than one answer possible)

A. Create single event latchups.
B. Cause the loss of performance of the system.
C. Change the position of the satellite.
D. Create single event upsets.

Answer: A. Create single event latchups.
B. Cause the loss of performance of the system.
D. Create single event upsets.
What causes the difference between the spectral irradiance at the top of the atmosphere and at sea level?

A. The passage of airplanes
B. The presence of water in the atmosphere
C. The presence of CO2
D. The high albedo (about 0.9) at the poles

Answer: B. The presence of water in the atmosphere
C. The presence of CO2
A probe is leaving the vicinity of Earth to fly to Mercury. Where will the solar panels generate the most power?

A. Mid-flight from the Earth to Mercury.
B. In the vicinity of Mercury.
C. The distance to the Sun does not matter.
D. In the vicinity of Earth.

Answer: B. In the vicinity of Mercury.
The Earth receives an almost constant flux from the Sun of S = 1361 W/m^2. Which of the following is correct?

A. The Earth is in constant shadow due to the multitude of satellites that orbit, such that it is in thermal equilibrium.
B. The Earth is in thermal equilibrium because some of the heat received is reflected back to space and the Earth radiates away energy, mostly in the IR.
C. The Earth reflects most of the energy received and is kept in its thermal equilibrium by the heat source in its core.
D. All the energy received is funnelled to the core of the Earth to keep it at a constant temperature.

Answer: B. The Earth is in thermal equilibrium because some of the heat received is reflected back to space and the Earth radiates away energy, mostly in the IR.
The exterior of a satellite must be covered with a coating. What would be the best choice such that the temperature of the satellite is the lowest possible?

A. White Epoxy (alpha = 0.248, epsilon = 0.924)
B. Gold (alpha = 0.299, epsilon = 0.023)
C. Aluminum (alpha = 0.379, epsilon = 0.0346)
D. Titanium (alpha = 0.448, epsilon = 0.129)

Answer: A. White Epoxy (alpha = 0.248, epsilon = 0.924)
Which modulation method can have a combination of 2 bits per symbol, a code rate of 0.5 and a spectral efficiency of about 1.0

A. QPSK
B. 16-PSK
C. 8-PSK
D. BPSK

Answer: A. QPSK
Which of the following statements are true about Precipitation Losses for Communication Link Analysis?

A. precipitation losses attenuates RF signals by absorption
B. Geographic databases of rainfall are needed for link analysis
C. precipitation losses attenuates RF signals by scattering (depolarization)
D. precipitation losses are inversely proportional to the humidity in the atmosphere

Answer: A. precipitation losses attenuates RF signals by absorption
B. Geographic databases of rainfall are needed for link analysis
C. precipitation losses attenuates RF signals by scattering (depolarization)
Which of the following influence the total power at the receive amplifier in communication link analyses?

A. mu, the Standard gravitational parameter
B. Ltx, the transmitter pointing losses
C. Ls, the Free-Space Losses
D. Na, the avogadro number
E. EIRP, the Equivalent Isotropic Radiated Power
F. Lin, the input losses to the receiver

Answer: B. Ltx, the transmitter pointing losses
C. Ls, the Free-Space Losses
E. EIRP, the Equivalent Isotropic Radiated Power
F. Lin, the input losses to the receiver
In spacecraft link analysis which is the name used to refer to the signal transmitted from end users (for instance military troops) to the satellite?

A. Return downlink
B. Forward downlink
C. Forward uplink
D. Return uplink

Answer: D. Return uplink
What does an engineer means when she say that "the link closes" in communication link analysis?

A. The energy received by the receiving antenna is strictly equal to the emitted energy (outputting the emitter's amplifier)
B. The difference between the power-to-noise ratio and the detection threshold is negative
C. The link margin is negative
D. The communication is finished and there are no more signal passing through the communication chain
E. The difference between the power-to-noise ratio and the detection threshold is positive

Answer: E. The difference between the power-to-noise ratio and the detection threshold is positive
Which satellite band in the electromagnetic spectrum correspond to the highest frequencies?

A. Ka-band
B. C-band
C. Q-band
D. V-band

Answer: D. V-band
Which of the following satellite band is associated with its correct frequency range?

A. Ka-band (18 to 30 GHz)
B. Q-band (2 to 4 GHz)
C. S-band (7 to 11 GHz)
D. Ku-band (11 to 18 GHz)
E. V-band (1 to 2 Gz)
F. C-band (4 to 7 GHz)

Answer: A. Ka-band (18 to 30 GHz)
D. Ku-band (11 to 18 GHz)
F. C-band (4 to 7 GHz)
Why are Decibels used for communication links analyses?

A. Because link analyses involves calculations with numbers that may differ by many orders of magnitude, decibel is simpler, faster and less error-prone.
B. Because of Aristote
C. This is a standard introduced by German scientist in Huntsville, Alabama, during Rocket Engine Fire test and was kept for legacy purpose and now introduced in the ECSS
D. In hommage of George Mikari Decibels, the inventor of the mechanical speaker

Answer: A. Because link analyses involves calculations with numbers that may differ by many orders of magnitude, decibel is simpler, faster and less error-prone.
What is the decibel equivalent of a 135 W amplifier output power relative to a 1 W reference?

A. 23.4
B. 18.2
C. 21.3
D. 16.0

Answer: C. 21.3
How do you express the antenna gain G as a function of the antenna directivity D and various losses L?

A. G = D^2 / L
B. G = (D - L) / L
C. G = D - L
D. G = D / L

Answer: C. G = D - L
What does A refer to in the formula G = etha * (4*pi / lambda^2 ) * A for communication link analyses

A. A relates to the absorptivity of the emitting medium (dimensionless)
B. A to the antenna volume (m^3)
C. A relates to the physical size of the antenna aperture (m^2)

Answer: C. A relates to the physical size of the antenna aperture (m^2)
How do you compute theta (in degrees), the half-power beamwidth in link analyses?

A. Theta = - k*frequency, k is a tablulated constant
B. You cannot, you need to measure it
C. Theta = 21 / (frequency * Diameter)
D. Theta = frequency / Diameter

Answer: C. Theta = 21 / (frequency * Diameter)
Which is a major contribution to the antenna pointing error on-board satellite?

A. thermal distortions
B. fixed misalignment
C. atmospheric residual drag

Answer: A. thermal distortions
What does typical design allow for maximum satellite antennas pointing errors?

A. Usually around 10% of the beamwidth, so 0.1 degree for 1 degree beamwidth
B. Usually up to 50% of the beamwidth because it is sized to account for that loss
C. Usually maximum 1% of the beamwidth, because beyond 1% the power-to-noise ratio decays exponentially minus infinity

Answer: A. Usually around 10% of the beamwidth, so 0.1 degree for 1 degree beamwidth
Who is not a European Astronaut?

A. Christina Koch
B. Samantha Cristoforetti
C. Jeremy Hansen
D. Thomas Pesquet

Answer: A. Christina Koch
C. Jeremy Hansen
What is the key difference between a jet engine and a liquid rocket engine?

A. The liquid rocket engine has to carry the oxidizer
B. The jet engine produce a long flamme tail after combustion
C. The jet engine is in general more expensive

Answer: A. The liquid rocket engine has to carry the oxidizer
How do satellite communication missions usually cover irregular areas such as the United States, without providing bandwidth to unwanted areas (oceans, prohibited areas)?

A. Utilising higher frequency bands
B. Using shaped beam reflector antennas
C. Increasing satellite altitude
D. Encrypting the signal

Answer: B. Using shaped beam reflector antennas
Assuming that D_ideal is the ideal antenna maximum directivity and A_theta is the coverage area in deg^2: Which of the following is a valid formula expressing the maximum directivity achievable for an ideal antenna that covers a small solid angle?

A. D_ideal = 46.15 - 10 * log(A_theta)
B. D_ideal = A_theta / log(A_theta)
C. D_ideal = 10 * log (A_theta)
D. D_ideal = exp(-A_theta)

Answer: A. D_ideal = 46.15 - 10 * log(A_theta)
In space communication link analyses, the ideal directivity calculations do not include antenna radiated efficiency, which is a measure of the power being radiated outside of the desired coverage area. What is the typical range of antenna efficiencies to adjust the ideal directivity?

A. 98 to 99.5%
B. 55 to 75%
C. 80 to 99%
D. 20 to 40%

Answer: B. 55 to 75%
For ground or satellite antennas, which of the following are typical contributing components to the noise temperature?

A. noise temperature that originates high energy ionizing particles deposited energy hitting the antenna structure
B. noise temperature that originates from the thermally radiated energy of objects that appear within the antenna's field of view
C. noise temperature that originates from the delta-phi (smalled boresight angle possible) product with the Earth reflected magnetic field when crossing of the south atlantic anomaly (SAA)
D. noise temperature that originates from the temperature of the antenna feed structure and transmission losses within the antenna and feed assembly itself

Answer: B. noise temperature that originates from the thermally radiated energy of objects that appear within the antenna's field of view
D. noise temperature that originates from the temperature of the antenna feed structure and transmission losses within the antenna and feed assembly itself
What are realistic mission objectives for a missions to Mars?

A. Geological and topological study to understand the historical Mars-Earth collision which led to the creation of Earth's Moon.
B. Oild fields scoutting for future super tanker missions
C. ISRU Technology Demonstration
D. Search for scientific evidence for past life on Mars

Answer: C. ISRU Technology Demonstration
D. Search for scientific evidence for past life on Mars
How long would a typical human crewed mission to Mars last (only the duration of the trip to reach Mars) for conjunction-type missions?

A. more than 7 years
B. 3 to 4 months
C. 3 to 4 years
D. 6 to 9 months

Answer: D. 6 to 9 months
How are the two types chemical compounds of bipropellant propulsion systems called?

A. igniter and oxidizer
B. fuel and oxidizer
C. Igniter and fuel

Answer: B. fuel and oxidizer
Which of the following rocket engine(s) is / were manufactured by "Aerojet" ?

A. MONARC-445
B. CHT-20
C. MR-111C

Answer: C. MR-111C
Select all the combinations of propulsion system and applications that are typical among the following?

A. Liquid monopropellant for attitude control
B. Liquid bipropellant for orbit insertion
C. Electric propulsion for orbit maintenance and maneuvering
D. Cold Gas propulsion for orbit insertion
E. Liquid monopropellant for orbit insertion
F. Solid propulsion for orbit insertion

Answer: A. Liquid monopropellant for attitude control
B. Liquid bipropellant for orbit insertion
C. Electric propulsion for orbit maintenance and maneuvering
F. Solid propulsion for orbit insertion
What is the typical range of specific impulse for liquid monopropellant systems?

A. 200 - 235s
B. 500 - 3000s
C. 45 - 75s
D. 274 - 467s

Answer: A. 200 - 235s
Select all the advantages of monopropellant hydrazine propulsion systems over bipropellants propulsion systems?

A. lower toxicity
B. system simplicity
C. capability to restart
D. long term storability
E. higher specific impulse

Answer: B. system simplicity
C. capability to restart
D. long term storability
How does the combustion takes place for hydrazine monoprop system?

A. Hydrazine ignites spontaneous in contact of an hydrogen isotope, typically deuterium
B. Hydrazine decomposes on a micro-fluidic chip, typically made of palladium enriched carbon nanotubes in a sillicon wafer
C. Hydrazine decomposes on a catalyst material, typically iridium
D. Hydrazine ignites spontaneous in presence of an high-voltage electric discharge, typically 20,000 - 30,000 Volts

Answer: C. Hydrazine decomposes on a catalyst material, typically iridium
What is the name of the nozzle cooling technique, sometimes using in expander cycles, where one of the propellant (usually the fuel but not always) passes around the nozzle to cool it?

A. Film cooling
B. Ablative cooling
C. Regenerative cooling

Answer: C. Regenerative cooling
What does ablative cooling in rocket engine propulsion systems refer to?

A. chamber walls made of ablative material which decomposes into gas when heat up, hence acting as a coolant
B. combustion-generated heat is conducted through the chamber walls and rejected through radiation
C. the heat is absorbed by a thin film coating made of ablatium

Answer: A. chamber walls made of ablative material which decomposes into gas when heat up, hence acting as a coolant
What does AOCS usually refer to in Astronautics?

A. Attitude and Orbit Control System
B. Aerodynamic Optimization for Crew Safety
C. Astronomical Observation and Calculation System
D. Advanced Orbital Communication Satellite

Answer: A. Attitude and Orbit Control System
In the LVLH coordinate system that is often used for AOCS, what is the direction of each axis ofr a spacecraft on orbit around the Earth?

A. X towards the center of the Earth, Y towards the rear of the spacecraft, Z towards the north of the orbit
B. X towards the spacecraft velocity vector, Y towards the south of the orbit, Z towards the center of the Earth
C. X towards the Noth of the orbit, Y towards the center of the Earth, Z towards the spacecraft velocity vector

Answer: B. X towards the spacecraft velocity vector, Y towards the south of the orbit, Z towards the center of the Earth
ISS and Space Shuttle euler sequence was Pitch, Yaw, Roll. This is difference from most spacecraft. Which Euler sequence do spacecrafts in general?

A. Roll Yaw Pitch (RYP)
B. Roll Pitch Yaw (RPY)
C. Yaw Pitch Roll (YPR)
D. Yaw Roll Pitch (YRP)

Answer: C. Yaw Pitch Roll (YPR)
How it is possible to maintain a certain orientation by spinning a spacecraft?

A. Due to the electron spin
B. Due to the gyroscopic effect
C. Due to the rotational speed being waved

Answer: B. Due to the gyroscopic effect
How is it possible to use gravity gradient for attitude control?

A. For an elongated object, the gravity force at the bottom of the object is greater than the force at the top
B. For a spherical rotating object, the gravity at the bottom of the sphere is greater than the gravity at the top
C. For an elongated object, the gravity force at the top of the object is greater than the force at the bottom
D. For a spherical rotating object, the gravity gradient originates from the fluid forces momentum in the intern structure.

Answer: A. For an elongated object, the gravity force at the bottom of the object is greater than the force at the top
Which of the following is the primary factor determine the voltage of a solar array?

A. The number of cells connected in series to form a string
B. The mounting structure of the solar cell
C. The temperature of the environment where the solar array is in
D. The solar cell thickness

Answer: A. The number of cells connected in series to form a string
Which of the following time point is used to size a satellite photovoltaic system?

A. Average life power requirements plus a 10 to 20 margin
B. Beginning-of-life power requirements
C. End-of-life power requirements

Answer: C. End-of-life power requirements
Which of the following are the lower costs cells that could be in use for satellite solar arrays?

A. Thin film amorphous Silicon cells
B. Gallium-Arsenide Triple Junction cells
C. Indium Phosphide cells

Answer: A. Thin film amorphous Silicon cells
Which of the following rechargeable battery technologies used for satellite has the higher energy density?

A. Li-ion
B. Ni-H2
C. Ni-Cd

Answer: A. Li-ion
Assuming a similar lifetime, and temperature maintained range, which of the following orbit would enable to use secondary batteries with a higher depth of discharge?

A. Geostationary Orbit mission
B. Low-Earth Equatorial Orbit mission
C. Sun-Synchronous Polar Orbit mission

Answer: A. Geostationary Orbit mission
Which of the following are typical ranges of load input power requirements in satellite engineering?

A. Normal Steady State Voltage Range: 25 to 21 V DC
B. Normal Steady State Voltage Range: 5 to 7 V DC
C. Nominal Ripple 1 V peak to peak
D. Max Current 60 Amp
E. Normal Steady State Voltage Range: 150 to 220 V DC

Answer: A. Normal Steady State Voltage Range: 25 to 21 V DC
C. Nominal Ripple 1 V peak to peak
Which are the most common power bus control techniques used in satellite electrical power subsystems?

A. Alternating Current Frequency Adjustment (ACFA)
B. Voltage Multiplication Regulation (VMR)
C. Capacitive Load Stabilization (CLS)
D. Peak Power Tracker (PPT)
E. Direct Energy Transfer (DET)

Answer: D. Peak Power Tracker (PPT)
E. Direct Energy Transfer (DET)
Which of the following buck-boost derived regulator is the most complex among the following?

A. Flyback
B. Full Bridge Regulator
C. Two-switch Forward

Answer: B. Full Bridge Regulator
Which technique used on spacecraft power regulators (buck-boost) enables to further enhance their efficiency?

A. Resonant Mode Switching
B. Voltage Ripple Reduction
C. Continuous Current Calibration

Answer: A. Resonant Mode Switching
Which of the following power source in spacecraft design usually require storage in case of Eclipse?

A. Radioistope Thermoelectric Generator
B. Solar Photovoltaic
C. Solar Thermal Dynamic
D. Fuell cells
E. Nuclear reactor

Answer: B. Solar Photovoltaic
C. Solar Thermal Dynamic