dataset update

astro-mcqa.csv

@@ -108,3 +108,48 @@ The exterior of a satellite must be covered with a coating. What would be the be
 "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","['BPSK', 'QPSK', '8-PSK', '16-PSK']","[0, 1, 0, 0]",,True,caf7a503-ce34-4d2e-a11a-a8eec2b04dbc
 Which of the following statements are true about Precipitation Losses for Communication Link Analysis?,"['precipitation losses attenuates RF signals by absorption', 'precipitation losses attenuates RF signals by scattering (depolarization)', 'Geographic databases of rainfall are needed for link analysis', 'precipitation losses are inversely proportional to the humidity in the atmosphere']","[1, 1, 1, 0]","Precipitation in the form of rain and wet snow attenuates RF signals through both absorption and scattering (depolarization). Precipitation-induced losses are dependent upon the product of a rate-dependent attenuation coefficient and the path length that the RF signals are required to traverse through rainfall regions within the atmosphere. Because losses are a function of the concentration of water in the atmosphere, precipitation-induced losses are heavily dependent upon a geographic and seasonal variation in weather. To provide a means for predicting rain precipitation effects, the ITU has created a geographic database of rainfall rates. This helps for link analysis.",True,61719260-46e9-444f-875e-8ea04e07f2bf
 Which of the following influence the total power at the receive amplifier in communication link analyses?,"['EIRP, the Equivalent Isotropic Radiated Power', 'mu, the Standard gravitational parameter', 'Ls, the Free-Space Losses', 'Lin, the input losses to the receiver', 'Ltx, the transmitter pointing losses', 'Na, the avogadro number']","[1, 0, 1, 1, 1, 0]","The total power at the receive amplifier can be expressed as C = EIRP + Gr - Ls - Latm - Lprec - Lin - Ltx - Lrx where EIRP is the Equivalent Isotropic Radiated Power, Gr is the gain of the receive antenna, Ls are the free-space losses, Latm and Lprec are the losses due to the atmosphere and precipitation, Lin the input losses to the receiver, Ltx the transmitter pointing losses, and Lrx the depointing losses of the receiver. The standard gravitational parameter has to do with orbital mechanics but not with communication link analysis and the avogadro number is used in chemistry, not in this context.",True,8a4c5031-a489-4d16-95b6-1049aa4806a3
+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?,"['Forward uplink', 'Forward downlink', 'Return downlink', 'Return uplink']","[0, 0, 0, 1]","Forward communications links carry information toward user terminals, while return communications links carry information away from user terminals. Both forward and return links include uplinks and downlinks",True,2af4081d-5cf9-4a96-8177-f47711c45929
+"What does an engineer means when she say that ""the link closes"" in communication link analysis?","['The communication is finished and there are no more signal passing through the communication chain', 'The difference between the power-to-noise ratio and the detection threshold is positive', 'The difference between the power-to-noise ratio and the detection threshold is negative', ""The energy received by the receiving antenna is strictly equal to the emitted energy (outputting the emitter's amplifier)"", 'The link margin is negative']","[0, 1, 0, 0, 0]","The difference between the power-to-noise ratio and tabulated detection thresholds refer to a parameter called the link margin. When the link margin is positive, the received signal can be detected, and the link is said to ""close"". When it is negative however the signal cannot be detected and the link does not close.",True,a82da0e7-861e-420a-9cec-97be967adbc0
+Which satellite band in the electromagnetic spectrum correspond to the highest frequencies?,"['C-band', 'V-band', 'Ka-band', 'Q-band']","[0, 1, 0, 0]","V-band, mostly used for inter-satellite links uses frequency between 40 GHz and 75 GHz, then Q-band (30-40 GHz), then are Ka-band (18 to 30 GHz). C-band are of much lower frequencies, in the range of 4 to 7 GHz.",True,2e40b8b7-9830-4de0-b220-d77ad8c90abf
+Which of the following satellite band is associated with its correct frequency range?,"['Ka-band (18 to 30 GHz)', 'Ku-band (11 to 18 GHz)', 'S-band (7 to 11 GHz)', 'C-band (4 to 7 GHz)', 'Q-band (2 to 4 GHz)', 'V-band (1 to 2 Gz)']","[1, 1, 0, 1, 0, 0]","S-band frequencies are within 2 to 4 GHz, Q-band frequencies are within 30 to 40 GHz (much higher than those reported), and V-band are even higher frequencies, above 40 GHz. It is L-band which correspond to frequencies between 1 and 2 GHz.",True,e55ec36c-b9b5-45fe-8136-5d52273b54bd
+True or False: an electromagnetic wave to that is RHCP means it is right-handed circular polarised and the electric field vector rotates anticlockwise as viewed from the direction of propagation?,"['True', 'False']","[0, 1]",It False because RHCP means it is right-handed circular polarised and the electric field vector rotates clockwise (not anticlockwise) as viewed from the direction of propagation.,True,c2afbc6a-6128-49e9-b339-1ed9933da5a0
+Why are Decibels used for communication links analyses?,"['In hommage of George Mikari Decibels, the inventor of the mechanical speaker', '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', 'Because link analyses involves calculations with numbers that may differ by many orders of magnitude, decibel is simpler, faster and less error-prone.', 'Because of Aristote']","[0, 0, 1, 0]",,True,c41b75d1-8c13-49d1-ab68-ddf74eb73d52
+What is the decibel equivalent of a 135 W amplifier output power relative to a 1 W reference?,"['16.0', '18.2', '21.3', '23.4']","[0, 0, 1, 0]",The power in Decibels is given by P(dB) = 10 * LOG10( P / Pref ) = 10 * LOG10( 135 / 1 ) = 21.3,True,7aec6699-a608-4ed4-8140-446f0d5117dd
+How do you express the antenna gain G as a function of the antenna directivity D and various losses L?,"['G = D / L', 'G = D^2 / L', 'G = (D - L) / L', 'G = D - L']","[0, 0, 0, 1]","The total amplification factor of an antenna is given by its gain G, a value that includes both the focusing effect of the antenna (directivity D), which is a mesure of the antenna's ability to concentrate energy in a given direction, and various losses (including ohmic transmission-line losses, L for example). The formula is G = D - L",True,d1553f22-46fe-4dd8-9c35-a1df88727d49
+What does A refer to in the formula G = etha * (4*pi / lambda^2 ) * A for communication link analyses,"['A relates to the absorptivity of the emitting medium (dimensionless)', 'A relates to the physical size of the antenna aperture (m^2)', 'A to the antenna volume (m^3)']","[0, 1, 0]",,True,604dfbb9-035f-4144-968e-4fc8259362e6
+"How do you compute theta (in degrees), the half-power beamwidth in link analyses?","['You cannot, you need to measure it', 'Theta = frequency / Diameter', 'Theta = - k*frequency, k is a tablulated constant', 'Theta = 21 / (frequency * Diameter)']","[0, 0, 0, 1]",,True,883be593-9c9c-4437-a718-a0699882cc4c
+Which is a major contribution to the antenna pointing error on-board satellite?,"['thermal distortions', 'atmospheric residual drag', 'fixed misalignment']","[1, 0, 0]","Atmospheric drag is negligible and fixed misalignment is usually mitigated on-ground and static. However, a source for variable pointing error is related to thermal distortion that results from variable heating of different antenna and spacecraft structures, changing with as the orientation of the satellite and its antennas changes with respect to the Sun, Earth, and other satellite structures like solar panels and other antennas?",True,b774f04e-e3a3-43a1-ab0b-d9bf87639636
+What does typical design allow for maximum satellite antennas pointing errors?,"['Usually up to 50% of the beamwidth because it is sized to account for that loss', 'Usually around 10% of the beamwidth, so 0.1 degree for 1 degree beamwidth', 'Usually maximum 1% of the beamwidth, because beyond 1% the power-to-noise ratio decays exponentially minus infinity']","[0, 1, 0]",,True,d7b25114-55fc-4143-bb47-9196a2a31f46
+Who is not a European Astronaut?,"['Thomas Pesquet', 'Christina Koch', 'Jeremy Hansen', 'Samantha Cristoforetti']","[0, 1, 1, 0]",,True,7b251f74-511d-4057-8ed3-decd500f6bb6
+What is the key difference between a jet engine and a liquid rocket engine?,"['The jet engine is in general more expensive', 'The liquid rocket engine has to carry the oxidizer', 'The jet engine produce a long flamme tail after combustion']","[0, 1, 0]","The difference between a jet engine and a rocket engine, the jet engine only needs to carry its own fuel. A rocket, on the other hand, has to carry not only its own fuel but also the oxidizer, which in most cases is oxygen, either a compressed gas or liquid oxygen.",True,ae4e517f-c4a6-440c-98ff-c3d8d11faf09
+"How do satellite communication missions usually cover irregular areas such as the United States, without providing bandwidth to unwanted areas (oceans, prohibited areas)?","['Increasing satellite altitude', 'Utilising higher frequency bands', 'Encrypting the signal', 'Using shaped beam reflector antennas']","[0, 0, 0, 1]","Increasing the altitude would actually broaden the signal. Higher frequency bandas can offer more focused beams, but don't inherently prevent signal spill-over into unwanted areas. The key is the shape and direction of the beam, not the frequency. Finally, encrypting the signal does not prevent it from being broadcast over unwanted area, it only controls who can access the content of the signal.",True,c2a98060-6a75-4353-9d4a-2e157218c1d0
+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?,"['D_ideal = 10 * log (A_theta)', 'D_ideal = exp(-A_theta)', 'D_ideal = A_theta / log(A_theta)', 'D_ideal = 46.15 - 10 * log(A_theta)']","[0, 0, 0, 1]",This provides a first level approximation for the link equation.,True,2a970ab4-5fd5-4e03-8e66-abaa2094b2cf
+"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?","['20 to 40%', '55 to 75%', '80 to 99%', '98 to 99.5%']","[0, 1, 0, 0]",,True,33c67e43-0041-4b8f-b867-37165c71c612
+"For ground or satellite antennas, which of the following are typical contributing components to the noise temperature?","[""noise temperature that originates from the thermally radiated energy of objects that appear within the antenna's field of view"", 'noise temperature that originates from the temperature of the antenna feed structure and transmission losses within the antenna and feed assembly itself', 'noise temperature that originates high energy ionizing particles deposited energy hitting the antenna structure', '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)']","[1, 1, 0, 0]","noise temperature that originates high energy ionising particles deposited energy hitting the antenna structure is negligible and the following ""noise temperature that originates from the delta-phi (smallest bore-sight angle possible) product with the Earth reflected magnetic field when crossing of the South Atlantic Anomaly (SAA)"" is not a concept used or reference in space mission engineering.",True,c41bef86-8e11-4f1d-a082-abbcecf64bd4
+What are realistic mission objectives for a missions to Mars?,"['ISRU Technology Demonstration', ""Geological and topological study to understand the historical Mars-Earth collision which led to the creation of Earth's Moon."", 'Oild fields scoutting for future super tanker missions', 'Search for scientific evidence for past life on Mars']","[1, 0, 0, 1]",,True,815136a9-3969-44c6-87d5-8bcea3f9517c
+How long would a typical human crewed mission to Mars last (only the duration of the trip to reach Mars) for conjunction-type missions?,"['3 to 4 months', '6 to 9 months', '3 to 4 years', 'more than 7 years']","[0, 1, 0, 0]",,True,cc48db84-1b81-4670-a195-076dee267592
+How are the two types chemical compounds of bipropellant propulsion systems called?,"['Igniter and fuel', 'igniter and oxidizer', 'fuel and oxidizer']","[0, 0, 1]",,True,73bf0237-afac-4dd9-a330-d8fcb3580379
+"Which of the following rocket engine(s) is / were manufactured by ""Aerojet"" ?","['MONARC-445', 'MR-111C', 'CHT-20']","[0, 1, 0]",The MR-111C is a flight proven monopropellant hydrazine thruster.,True,64fc0fa7-43af-41d6-b8c4-268ba0c928c8
+"Having stages in space launchers is advantageous because it disposes the the mass of the expended stage (tank, engine, etc...). But are there single stage launchers that are operational as of today in 2024 capable of launching a payload to Low Earth Orbit?","['Yes', 'No']","[0, 1]",,True,41456ac5-fe9b-4178-9e48-70deaca2a5b1
+Select all the combinations of propulsion system and applications that are typical among the following?,"['Cold Gas propulsion for orbit insertion', 'Solid propulsion for orbit insertion', 'Liquid monopropellant for orbit insertion', 'Liquid monopropellant for attitude control', 'Electric propulsion for orbit maintenance and maneuvering', 'Liquid bipropellant for orbit insertion']","[0, 1, 0, 1, 1, 1]",,True,ea7c422b-60f6-4178-9732-0d615939c26f
+What is the typical range of specific impulse for liquid monopropellant systems?,"['45 - 75s', '200 - 235s', '274 - 467s', '500 - 3000s']","[0, 1, 0, 0]",,True,3f9f6c75-740b-4c5f-a010-231506efad98
+Select all the advantages of monopropellant hydrazine propulsion systems over bipropellants propulsion systems?,"['system simplicity', 'long term storability', 'capability to restart', 'higher specific impulse', 'lower toxicity']","[1, 1, 1, 0, 0]","Hydrazine monopropellant systems have lower Isp (max 230s) not higher than most bipropellants systems. Also hydrazine toxicity poses several challenges, and research is being conducted to find alternatives which are safer to handle.",True,beefd301-4e93-4e57-923b-3d992f6e8030
+How does the combustion takes place for hydrazine monoprop system?,"['Hydrazine ignites spontaneous in contact of an hydrogen isotope, typically deuterium', 'Hydrazine decomposes on a micro-fluidic chip, typically made of palladium enriched carbon nanotubes in a sillicon wafer', 'Hydrazine ignites spontaneous in presence of an high-voltage electric discharge, typically 20,000 - 30,000 Volts', 'Hydrazine decomposes on a catalyst material, typically iridium']","[0, 0, 0, 1]",,True,2870f350-5488-40da-bd0c-e026b991b01f
+"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?","['Regenerative cooling', 'Ablative cooling', 'Film cooling']","[1, 0, 0]",,True,1a348c80-de10-43bc-ba82-d74ad7fd1f69
+What does ablative cooling in rocket engine propulsion systems refer to?,"['chamber walls made of ablative material which decomposes into gas when heat up, hence acting as a coolant', 'combustion-generated heat is conducted through the chamber walls and rejected through radiation', 'the heat is absorbed by a thin film coating made of ablatium']","[1, 0, 0]",,True,ebd8e218-ba8f-482c-b7e1-6ee1eb7c92ec
+What does AOCS usually refer to in Astronautics?,"['Astronomical Observation and Calculation System', 'Advanced Orbital Communication Satellite', 'Aerodynamic Optimization for Crew Safety', 'Attitude and Orbit Control System']","[0, 0, 0, 1]",,True,19af499b-7a42-4a72-b393-e63bb4fd6e5c
+Which axis of the coordinate system for the ISS AOCS is used in the direction of the velocity vector?,"['+X (roll)', '+X (pitch)', '+X (yaw)', '-X (roll)', '-X (pitch)', '-X (yaw)']","[0, 0, 0, 0, 0, 0]",The choice of the ISS fixed coordinate system is pretty much like in aviation where we have the forward portion of ISS oriented toward the velocity vector and that's a + X axis. X is also correspond to the roll.,True,07b3bd15-13d5-45ad-b0cc-9a64d5214561
+"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?","['X towards the center of the Earth, Y towards the rear of the spacecraft, Z towards the north of the orbit', 'X towards the Noth of the orbit, Y towards the center of the Earth, Z towards the spacecraft velocity vector', 'X towards the spacecraft velocity vector, Y towards the south of the orbit, Z towards the center of the Earth']","[0, 0, 1]",,True,70710915-a079-49fd-874a-28d9470489ea
+"ISS and Space Shuttle euler sequence was Pitch, Yaw, Roll. This is difference from most spacecraft. Which Euler sequence do spacecrafts in general?","['Yaw Roll Pitch (YRP)', 'Yaw Pitch Roll (YPR)', 'Roll Pitch Yaw (RPY)', 'Roll Yaw Pitch (RYP)']","[0, 1, 0, 0]",,True,e904a2e2-67c6-4da6-820e-1861b040d617
+How it is possible to maintain a certain orientation by spinning a spacecraft?,"['Due to the electron spin', 'Due to the gyroscopic effect', 'Due to the rotational speed being waved']","[0, 1, 0]",,True,c2bd96c1-08db-4bb3-bdc0-67097d6f174c
+How is it possible to use gravity gradient for attitude control?,"['For an elongated object, the gravity force at the bottom of the object is greater than the force at the top', 'For an elongated object, the gravity force at the top of the object is greater than the force at the bottom', 'For a spherical rotating object, the gravity at the bottom of the sphere is greater than the gravity at the top', 'For a spherical rotating object, the gravity gradient originates from the fluid forces momentum in the intern structure.']","[1, 0, 0, 0]",,True,b185c125-a603-4e68-97bf-796ee0dd929a
+Which of the following is the primary factor determine the voltage of a solar array?,"['The temperature of the environment where the solar array is in', 'The solar cell thickness', 'The number of cells connected in series to form a string', 'The mounting structure of the solar cell']","[0, 0, 1, 0]",,True,57f57993-5f84-46b7-82ab-37aba7f12d70
+Which of the following time point is used to size a satellite photovoltaic system?,"['Beginning-of-life power requirements', 'Average life power requirements plus a 10 to 20 margin', 'End-of-life power requirements']","[0, 0, 1]","This is because power requirement have to be met, even at end-of-life otherwise the satellite would not be able to operate nominally at towards the end of its mission. This results in the system often being oversized for BOL requirements and can cause power problems if not taken care of.",True,ca57a7ff-3145-4c26-ad77-1e8b1ce2fcb1
+Which of the following are the lower costs cells that could be in use for satellite solar arrays?,"['Thin film amorphous Silicon cells', 'Gallium-Arsenide Triple Junction cells', 'Indium Phosphide cells']","[1, 0, 0]",,True,848d888b-d844-46ad-a5db-7b9fbaf9cb93
+Which of the following rechargeable battery technologies used for satellite has the higher energy density?,"['Li-ion', 'Ni-Cd', 'Ni-H2']","[1, 0, 0]","Ni-Cd has about 30 Wh/kg, Ni-H2 has about 60 Wh/kg and Li-ion more than 125 Wh/kg energy storage density",True,f84011f6-edb0-4748-ba0d-c5a01d1bee78
+"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?","['Low-Earth Equatorial Orbit mission', 'Sun-Synchronous Polar Orbit mission', 'Geostationary Orbit mission']","[0, 0, 1]","Geostationary satellite experience less frequent eclipse than Low-Earth orbiting missing, reducing the number of charge/discharge cycle on the batteries. Relaxing the number of charge/discharge requirement enables usually to increase the depth-of-discharge.",True,4efab579-4b0a-4647-9dff-4aaaf6f12713
+Which of the following are typical ranges of load input power requirements in satellite engineering?,"['Normal Steady State Voltage Range: 5 to 7 V DC', 'Normal Steady State Voltage Range: 25 to 21 V DC', 'Normal Steady State Voltage Range: 150 to 220 V DC', 'Max Current 60 Amp', 'Nominal Ripple 1 V peak to peak']","[0, 1, 0, 0, 1]",Typical max current is often around 15 Amp (even though not always!),True,a95ff8d7-d775-4602-a2b9-52aa613af262
+Which are the most common power bus control techniques used in satellite electrical power subsystems?,"['Alternating Current Frequency Adjustment (ACFA)', 'Voltage Multiplication Regulation (VMR)', 'Capacitive Load Stabilization (CLS)', 'Direct Energy Transfer (DET)', 'Peak Power Tracker (PPT)']","[0, 0, 0, 1, 1]",,True,7bff3a67-9181-48dd-811b-48ca49851e30
+Which of the following buck-boost derived regulator is the most complex among the following?,"['Full Bridge Regulator', 'Flyback', 'Two-switch Forward']","[1, 0, 0]","From least complex to most complex are the flyback, single switch forward, two switch forward, push-pull, and full-bridge regulators",True,ea3c5ee5-1439-4e00-9555-026fc3c8837f
+Which technique used on spacecraft power regulators (buck-boost) enables to further enhance their efficiency?,"['Resonant Mode Switching', 'Continuous Current Calibration', 'Voltage Ripple Reduction']","[1, 0, 0]",,True,dda35b83-c23f-4682-b89c-b4d217366785
+Which of the following power source in spacecraft design usually require storage in case of Eclipse?,"['Fuell cells', 'Nuclear reactor', 'Radioistope Thermoelectric Generator', 'Solar Thermal Dynamic', 'Solar Photovoltaic']","[0, 0, 0, 1, 1]",Both solar thermal dynamic and solar photovoltaic do not generate power during eclipse so storage is require to keep the satellite powered on.,True,8d14f358-de2e-46fa-8eb2-26edb2eee900