火箭喷管为什么做成拉瓦尔喷管（先收窄后扩张）的形状？
Why is a rocket nozzle shaped like a converging-diverging (de Laval) nozzle?
燃气在喉部被加速到音速，之后在扩张段继续膨胀加速到超音速，把热压高效转化为向前喷出的高速气流，从而获得更大推力。
Gas reaches the speed of sound at the throat and then expands in the diverging section to supersonic speed, efficiently converting pressure into a fast forward jet for greater thrust.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航空航天 #喷管 #超音速
火箭上的 POGO 振动是怎么产生的，为什么它能危及整枚箭？
What causes rocket pogo oscillation, and why can it endanger an entire vehicle?
POGO 是结构与推进系统构成的闭环耦合：箭体纵向弹性振动使推进剂管路入口压力波动，泵入口压力变化引起推力脉动，推力脉动又反过来激励箭体纵向模态，若相位形成正反馈，振幅可在几秒内急剧增长。土星五号第一级和双子星-泰坦飞行中都出现过明显纵向振荡，严重时会损坏结构、破坏发动机或让乘员无法操作。典型抑制手段是在氧化剂或燃料管路上加装充气蓄压器（POGO 抑制器），改变管路的等效柔度与谐振频率，把推进系统响应与结构模态解耦。
Pogo is a closed loop between structure and propulsion: longitudinal elastic vibration modulates propellant pressure at the pump inlet, that inlet variation modulates thrust, and the thrust pulsation re-excites the longitudinal mode, so amplitude can grow explosively within seconds when the phase relationship is regenerative. Saturn V first-stage and Gemini-Titan flights both showed pronounced longitudinal oscillation, which at high amplitude can damage structure, wreck engines or leave the crew unable to operate controls. The standard fix is a gas-filled accumulator in the oxidizer or fuel feedline that retunes the line's effective compliance and resonance, decoupling propulsion response from the structural mode.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#POGO振动 #结构-推进耦合 #蓄压器抑制
飞船着陆时，为什么有时用降落伞、有时用反推火箭？
Why do spacecraft use parachutes for landing in some cases but retro-rockets in others?
降落伞靠大气阻力减速，只适用于有稠密大气的行星（如地球、火星）；在没有大气或需要精准软着陆的地方（如月球），只能用反推火箭向下喷气来减速。
Parachutes rely on atmospheric drag, so they work only where there is thick air like Earth or Mars; with no atmosphere or for precise soft landings such as on the Moon, retro-rockets firing downward are required.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航空航天 #着陆 #减速
什么是超音速激波，它对飞机有何影响？
What is a supersonic shock wave and how does it affect aircraft?
当物体速度超过音速时，前方的压力扰动无法及时散开，会叠加形成突然的压强、温度和密度跳变的激波。激波带来强烈的波阻和气动加热，并要求机体结构承受额外载荷。
When an object exceeds the speed of sound, pressure disturbances ahead cannot disperse in time and pile up into a shock wave with abrupt jumps in pressure, temperature, and density. Shock waves cause strong wave drag and aerodynamic heating and demand extra structural strength.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#激波 #超音速 #波阻
什么是气动加热，高超音速飞行时为何机身前缘温度急剧上升？
What is aerodynamic heating and why do leading edges get extremely hot at hypersonic speed?
高超音速下，飞行器前方空气被强烈压缩且粘性摩擦把动能转化为热能，边界层温度随马赫数平方量级升高。最尖锐的前缘驻点处气流几乎停滞，动能全部转为热能，因此温度最高。
At hypersonic speed, compressed and viscous air converts kinetic energy to heat, with boundary-layer temperature rising roughly with Mach squared. At the sharp leading-edge stagnation point the flow nearly stops, dumping all kinetic energy into heat, so it gets hottest there.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Anderson，《高超声速与高温气体动力学》（第2版）
Anderson, 'Hypersonic and High-Temperature Gas Dynamics' (2nd ed.)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL1993330W：Hypersonic and high-tem
#气动加热 #高超音速 #激波
火箭发动机的“分级燃烧循环”为什么比简单燃气发生器循环效率更高，代价是什么？
Why is a staged-combustion rocket cycle more efficient than a simple gas-generator cycle, and what is the cost?
燃气发生器把部分推进剂烧完就排掉，白白损失能量；分级燃烧把所有富燃燃气都送回主燃烧室充分燃烧，比冲更高。代价是极高温高压的预燃室和涡轮，结构复杂、制造苛刻。
A gas generator burns some propellant just to dump it, wasting energy; staged combustion sends all fuel-rich gas back to the main chamber to burn fully, raising specific impulse. The cost is very hot, high-pressure preburners and turbines—complex and demanding to build.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#分级燃烧 #燃气发生器 #比冲
探测器去火星时为什么要先"绕远路"而不是直线飞过去？
Why do Mars probes take a long elliptical route instead of flying straight there?
关闭发动机后的探测器只在太阳引力下飞行，轨迹是以太阳为焦点的椭圆轨道。霍曼转移取一个近日点在地球轨道、远日点在火星轨道的椭圆：第一次点火在近地轨道加速进入转移椭圆，抵达远日点后再点火把轨道圆化成火星轨道。虽然是绕远路，但这两次点火所需的速度增量总和最小，能省下大量燃料。代价是飞行时间长达6到9个月，而且发射窗口每26个月才出现一次，因为地球与火星的相对位置必须合适。
Once its engines shut off, a probe flies only under solar gravity along an ellipse with the Sun at one focus. A Hohmann transfer picks an ellipse whose perihelion touches Earth's orbit and aphelion touches Mars': the first burn accelerates the probe onto the ellipse, and at aphelion a second burn circularizes it into Mars orbit. It is the long way around, but the sum of the two burns' velocity changes (delta-v) is the minimum possible, saving enormous fuel. The cost is 6-9 months of flight time, and launch windows recur only every 26 months because Earth and Mars must be in the right relative positions.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#霍曼转移 #轨道力学 #变轨
飞船以每秒7.6公里的速度再入大气层，为什么没有被烧成灰烬？
Re-entering at 7.6 km/s, why doesn't a spacecraft burn to ash?
再入时的极端热量主要不是来自摩擦，而是激波压缩：飞行器以高超音速挤压前方空气，弓形激波后的空气被绝热压缩到几千摄氏度，高温气体再对飞船表面加热。航天飞机的陶瓷隔热瓦靠极低的热导率把热量挡在外面；载人飞船则用烧蚀热防护——酚醛树脂等材料表面熔化、气化时吸热并带走热量，烧蚀层自身不断"牺牲"以保护内部。从水星、阿波罗到神舟都采用烧蚀方案，它简单可靠，只是不能重复使用。
The extreme heat of re-entry comes mainly not from friction but from shock compression: at hypersonic speed the vehicle shoves air ahead of it, and behind the bow shock the air is adiabatically compressed to thousands of degrees, then heats the surface. The Space Shuttle's silica tiles block heat with very low thermal conductivity; crew capsules instead use ablative shielding — phenolic resin chars, melts, and vaporizes, absorbing and carrying heat away while the ablator sacrifices itself to protect the interior. From Mercury and Apollo to Shenzhou, capsules chose ablation: simple and reliable, though not reusable.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Anderson，《高超声速与高温气体动力学》（第2版）
Anderson, 'Hypersonic and High-Temperature Gas Dynamics' (2nd ed.)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL1993330W：Hypersonic and high-tem
#再入 #烧蚀热防护 #激波
什么是“气动弹性”，为什么飞机机翼在高速时既要够硬又不能太硬？
What is aeroelasticity, and why must a wing at high speed be stiff yet not too stiff?
气动弹性研究气动力与结构柔度的耦合：太软会颤振发散，太硬则重且把载荷硬传给机身。设计师在重量、刚度和气动效率间找平衡，避开危险的共振频率。
Aeroelasticity studies coupling of aerodynamic force and structural flexibility: too soft invites flutter divergence, too stiff adds weight and harsh load transfer. Designers balance weight, stiffness and efficiency while avoiding dangerous resonant frequencies.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
Bisplinghoff、Ashley & Halfman，《气动弹性力学》
Bisplinghoff, Ashley & Halfman, 'Aeroelasticity'
#气动弹性 #颤振 #刚度
喷气式发动机是怎样产生推力的？
How does a jet engine produce thrust?
发动机吸入空气，压缩后与燃料燃烧膨胀，从尾部高速喷出；根据反作用力，向后喷出的气体把飞机向前推，这和火箭、划船是一个道理。
It sucks in air, compresses it, burns fuel to expand the gas, and blasts it out the back at high speed; the reaction pushes the plane forward, the same principle as a rocket or rowing.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Hill & Peterson，《推进的力学与热力学》（第2版）
Hill & Peterson, 'Mechanics and Thermodynamics of Propulsion' (2nd ed.)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL4616004W：Mechanics and thermodyn
#航空航天 #喷气发动机 #推力
旅行者号飞了二百多亿公里，信号为什么还能传回地球？
How can Voyager's signal still reach Earth from over 20 billion kilometers away?
深空通信靠窄波束射电和极高的接收灵敏度。旅行者号以约8千兆赫的X波段发射约20瓦信号，信号按距离平方衰减，到达地球时功率已低至约10的负19次方瓦，但NASA直径70米的大天线把零星光子一点点收集起来，再靠信道编码纠错把信噪比极低的信号"救"回来。由于单程信号要飞二十多个小时，地面还必须用深空测控网（DSN）分布在三大洲的天线接力跟踪。
Deep-space links use narrow radio beams and extreme receiver sensitivity. Voyager transmits about 20 watts at X-band near 8 GHz; the signal fades as the square of distance and arrives at Earth at roughly 1e-19 watts, yet NASA's 70-meter antennas accumulate those few photons, and channel coding and error correction recover data from a signal far below the noise floor. With a one-way light time of over twenty hours, ground stations must also hand the spacecraft over across the three Deep Space Network (DSN) sites as Earth rotates.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Clarke 1945（地球静止轨道）；Wertz
Clarke (1945, geostationary orbit); Wertz, Space Mission Analysis
#深空通信 #射电 #深空测控网
离子推进器的推力只有几十毫牛，为什么深空任务还偏爱它？
Ion thrusters produce only tens of millinewtons of thrust, so why do deep-space missions favour them?
电推进用电场把氙等工质加速到 20–40 km/s 的排气速度，比化学火箭高一个数量级，按齐奥尔科夫斯基公式，获得同样速度增量所需的推进剂质量因此大幅减少，比冲可达 3000 s 以上。推力虽小，却能连续工作数千小时乃至数年，把微小加速度累积成几公里每秒的速度增量，非常适合无阻力环境下的深空巡航与卫星位置保持。代价是必须携带大功率太阳能电池阵和电源处理单元，加速缓慢、无法用于快速逃逸机动，栅极溅射侵蚀还限制寿命。
Electric propulsion accelerates xenon or similar propellant electrostatically to exhaust speeds of 20–40 km/s, an order of magnitude above chemical rockets, so by the Tsiolkovsky equation the propellant mass for a given velocity change drops sharply and specific impulse exceeds 3000 s. Thrust is tiny but can run for thousands of hours or years, accumulating small accelerations into several km/s of delta-v, which suits drag-free deep-space cruise and satellite station keeping. The costs are large solar arrays and power processing units, slow acceleration unusable for quick escape manoeuvres, and grid erosion by ion sputtering limiting operating life.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Goebel 与 Katz，《Fundamentals of Electric Propulsion: Ion and Hall Thrusters》（JPL/Wiley，2008）
Goebel & Katz, 'Fundamentals of Electric Propulsion: Ion and Hall Thrusters' (JPL/Wiley, 2008)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9780470429273 (2008)
#电推进 #比冲 #齐奥尔科夫斯基公式
喷气发动机和火箭发动机有什么不同？
What is the difference between a jet engine and a rocket engine?
喷气发动机从大气中吸入空气作为氧化剂来燃烧燃料，因此只能在有空气处工作。火箭发动机自带氧化剂，不依赖空气，所以可用于太空飞行。
A jet engine draws air from the atmosphere as oxidizer to burn fuel, so it only works where air exists. A rocket carries its own oxidizer and does not depend on air, enabling it to operate in space.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#喷气 #火箭 #氧化
卫星之间怎么“打电话”（星间链路），为什么有了它能组成全球星座而不依赖地面站？
How do satellites 'call' each other (inter-satellite links), and why lets them form a global constellation without ground stations?
卫星用激光或微波直接互相对接通信，数据在太空里一跳跳转发，不必每颗都连地面。这样即使地面站少、极地海洋也能联网，延时更低、覆盖更稳。
Satellites link directly by laser or microwave and relay data hop-by-hop in space without each touching ground. Even with few ground stations, polar oceans get connected, with lower latency and steadier coverage.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《十万个为什么》第六版航空与航天分册,少年儿童出版社,2013
Ten Thousand Whys: Aviation and Aerospace volume, 6th ed., Juvenile and Children Publishing House, 2013
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-7-5324-9328-9 · 核验依据 2 ISBN 9787532493289
#星间链路 #星座 #激光通信
国际空间站为什么不会掉下来，它的轨道速度是多少量级？
Why doesn't the ISS fall, and what order of orbital speed does it have?
空间站以约每秒 7.7 公里的第一宇宙速度绕地球做圆周运动，地球引力恰好提供向心力，所以它不断下落却又始终错过地面。要维持轨道需要偶尔点火抵消大气阻力带来的减速。
The ISS orbits at about 7.7 km/s, the speed where Earth's gravity exactly supplies the centripetal force, so it keeps falling but forever misses the ground. Small thruster burns counteract drag to hold the orbit.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Curtis，《轨道力学》（第4版）
Curtis, 'Orbital Mechanics for Engineering Students' (4th ed.)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787030253231（豆瓣书目条目: 轨道力学）
#轨道 #向心力 #空间站
空间站里为什么是微重力而不是零重力？
Why is the space station microgravity rather than zero gravity?
空间站其实在绕地球自由落体，处于持续下落的轨道中，内部物体相对漂浮，但仍有微小残余加速度，所以叫微重力。
The station is in continuous free-fall orbit, so objects float inside, but tiny residual accelerations remain, hence micro rather than true zero gravity.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航天 #微重力
火箭在没有空气的太空里，靠什么来改变方向？
In airless space, what does a rocket use to steer and change direction?
火箭靠姿控推力器或小喷口喷出气体产生反作用力来转向，原理和主发动机一样都来自牛顿第三定律：向后喷，自身就向反方向受力。
Rockets use small thrusters or gimbaled nozzles that eject gas to create reaction forces; like the main engine, this follows Newton's third law: push mass one way, the craft is pushed the other.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航空航天 #火箭 #姿态控制
返回舱最后靠什么减速着陆？
What finally slows a reentry capsule for landing?
再入后依次用减速伞、稳定伞和主降落伞大幅降低下降速度，部分型号再配合反推火箭或气囊在触地瞬间进一步缓冲。
After reentry it deploys drogue, stabilization and main parachutes to slow descent, sometimes with retro-rockets or airbags for final cushioning.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Currey，《Aircraft Landing Gear Design: Principles and Practices》（AIAA，1988）
Currey, 'Aircraft Landing Gear Design: Principles and Practices' (AIAA, 1988)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9780930403416 (1988)
#航天 #着陆
飞机驾驶舱的人因工程设计为什么强调注意力分配和信息显示？
Why does cockpit human-factors design place such emphasis on attention allocation and information display?
驾驶舱人因工程的目标是让飞行员在复杂任务下快速准确获取信息并作出决策，避免因显示混乱或操作不便造成人为差错。设计要点包括仪表信息按重要性分级布置、主飞行显示器保持直观一致、报警按紧急程度分层、控制按钮形状位置符合肌肉记忆（形状编码），并用冗余显示减少误读。研究表明相当比例的事故源于人机界面设计不当引发的失误，因此FAA等机构把人为因素纳入适航审定的重要内容。
Cockpit human-factors engineering aims to let pilots acquire information and make decisions quickly and accurately under heavy workload, preventing errors caused by confusing displays or awkward controls. Design essentials include grouping instruments by importance, keeping the primary flight display intuitive and consistent, tiering alerts by urgency, giving controls shape and location coding that match muscle memory, and providing redundant display paths to reduce misreading. A large share of accidents traces to human-machine interface failures, which is why agencies such as the FAA make human factors a key part of airworthiness certification.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
《人机交互》（清华大学出版社）
Sweller, Ayres & Kalyuga, Cognitive Load Theory, Springer
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL21308956W：Cognitive Load Theory（
#人因工程 #驾驶舱 #人机界面
火箭为什么大多采用多级设计，而不是造一根超长单级火箭？
Why do rockets use multiple stages instead of one very long single stage?
火箭大部分质量是燃料和空油箱，带着用不上的空壳飞到终点很浪费。多级设计在每级燃料烧完后抛掉空壳，让剩余部分用更轻的重量继续加速，从而提高最终速度和运载效率。
Most rocket mass is fuel and empty tanks, so hauling spent stages is wasteful. Multistage rockets drop empty tanks after each burn, letting the rest accelerate with less mass and reach higher speed and efficiency.
难度 进阶 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#火箭 #多级 #质量比
火箭在真空中没有空气可"推"，为什么还能加速？
With no air to push against in space, how can a rocket still accelerate?
火箭靠动量守恒获得推力，不依赖任何外部介质。燃料在燃烧室内反应生成高温高压燃气，经喷管加速后高速喷出，喷出的气体带走向后的动量；根据动量守恒，火箭必然获得等大反向的动量增量，于是向前加速。推力等于每秒喷出的质量乘以排气速度，喷管做成先收敛后扩张的形状，正是为了把燃气加速到超音速、最大化排气速度。
A rocket accelerates by conserving momentum, needing no external medium. Fuel reacts in the chamber into hot high-pressure gas, which the nozzle accelerates and ejects rearward; the expelled gas carries backward momentum, and momentum conservation forces the rocket to gain an equal and opposite forward momentum. Thrust equals the mass flow rate times the exhaust velocity, and the convergent-divergent nozzle exists precisely to push the gas past the speed of sound and maximize that velocity.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#动量守恒 #火箭推进 #喷管
什么是攻角，攻角过大会为什么导致失速？
What is angle of attack and why does too much cause stall?
攻角是机翼弦线与来流的夹角，适当增大攻角能提升升力。但超过临界值后，上表面气流分离、湍流剧增，升力骤降而阻力猛升，飞机便失速下坠。
Angle of attack is the angle between the wing chord and the airflow; moderate increase raises lift. Past a critical value the upper flow separates into turbulence, lift collapses and drag spikes, so the aircraft stalls.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Anderson，《空气动力学基础》（第6版）
Anderson, 'Fundamentals of Aerodynamics' (6th ed.)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787516504413（豆瓣书目条目: 空气动力学基础）
#攻角 #失速 #气流分离
为什么航天器返回地球时要防热大底而不是普通外壳？
Why does a spacecraft need a heat shield rather than a normal shell on return?
返回时飞船以极高速度冲入大气层，空气被剧烈压缩产生上千度的高温。防热大底用烧蚀或隔热材料把热量挡在外面并随表层烧蚀带走热量，保护舱内人员和设备。
On reentry the craft slams into the atmosphere at huge speed, compressing air to over a thousand degrees. The heat shield uses ablative or insulating material to block heat and carry it away as the surface burns, protecting the cabin.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Anderson，《高超声速与高温气体动力学》（第2版）
Anderson, 'Hypersonic and High-Temperature Gas Dynamics' (2nd ed.)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL1993330W：Hypersonic and high-tem
#返回舱 #防热 #再入
什么是伯努利原理在飞行中的应用？
What is the application of Bernoulli's principle in flight?
伯努利原理指出流体速度越大压强越小，机翼正是利用上下表面流速差产生压强差形成升力。虽然升力还来自机翼对气流的下偏作用，但伯努利效应是核心解释之一。
Bernoulli's principle states that faster fluid has lower pressure, and a wing exploits the speed difference between its surfaces to create a pressure difference and thus lift. Although lift also comes from the wing deflecting air downward, the Bernoulli effect is a core explanation.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Anderson，《空气动力学基础》（第6版）
Anderson, 'Fundamentals of Aerodynamics' (6th ed.)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787516504413（豆瓣书目条目: 空气动力学基础）
#伯努利 #升力 #压强
什么是第一宇宙速度？
What is the first cosmic velocity?
第一宇宙速度是物体绕地球做圆周轨道运动所需的最小速度，约为每秒7.9公里。达到这个速度，物体就能成为地球卫星而不落回地面。
The first cosmic velocity is the minimum speed needed for an object to orbit Earth in a circular path, about 7.9 kilometers per second. At this speed an object becomes an Earth satellite instead of falling back down.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#宇宙速度 #轨道 #环绕
什么是黑匣子，它有什么用？
What is a black box and what is it for?
黑匣子是飞机上的飞行数据记录器和驾驶舱语音记录器，通常涂成醒目的橙色。它能在坠毁后耐高温、抗冲击，帮助调查人员还原事故原因。
A black box is an aircraft's flight data recorder and cockpit voice recorder, usually painted bright orange. It survives heat and impact after a crash, helping investigators reconstruct what happened.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#黑匣子 #飞行记录 #安全
空间站上的氧气和水是从哪里来的？
Where do oxygen and water on a space station come from?
空间站在轨无法补给大气，必须循环再生。氧气主要靠电解水制得，同时副产氢气；二氧化碳由分子筛吸附捕获后，与氢气在萨巴蒂耶反应器中合成水和甲烷，水再送回电解，形成氧-氢-水闭合循环。尿液和冷凝水经蒸馏、反渗透净化后变成饮用水。只有食品无法再生，靠货运飞船定期补给。这套环境控制与生命保障系统让空间站的水自给率达到90%以上。
In orbit a station cannot import air, so it must recycle. Oxygen comes mainly from electrolyzing water, which also yields hydrogen; carbon dioxide is captured by molecular sieves and reacted with that hydrogen in Sabatier reactors to make water and methane, and the water returns to electrolysis — a closed oxygen-hydrogen-water loop. Urine and condensed moisture are distilled and reverse-osmosed into drinking water. Only food cannot be regenerated and arrives by cargo ship. This Environmental Control and Life Support System gives the station over 90% water self-sufficiency.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#生命保障 #电解水 #空间站
宇航员在太空里呼吸的氧气是从哪里来的？
Where do astronauts get the oxygen they breathe in space?
飞船里带着氧气罐，还会用机器把宇航员呼出的二氧化碳和水变成新鲜氧气，就像在太空里种了一台会造空气的魔法盒子。
The spacecraft carries oxygen tanks and runs machines that turn the carbon dioxide and water the crew exhale back into fresh oxygen, like a magic box that makes air.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：本题原挂出处与答案内容不符，已撤回；具体书目待补，暂不展示来源。
本题原挂出处与答案内容不符，已撤回；具体书目待补。
Previous citation withdrawn as unsupported for this answer; a specific source is pending.
#航空航天 #生命保障 #氧气
为什么火箭点火后会有大量白雾？
Why is there lots of white mist when a rocket ignites?
那层白雾大多是极冷的液氧或燃料泄漏后遇热空气凝结成的小水珠，也有部分是喷水降温产生的水蒸气。它不是燃料本身，而是水汽形成的云。
The white cloud is mostly tiny water droplets from super-cold liquid oxygen or fuel condensing in warm air, plus steam from water sprayed to cool the pad. It's water vapor, not the fuel itself.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Huzel & Huang，《液体推进剂火箭发动机现代设计》（NASA SP-125）
Huzel & Huang, 'Modern Engineering for Design of Liquid-Propellant Rocket Engines' (NASA SP-125)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL27313820W：Modern Engineering for
#火箭 #白雾 #冷凝
飞机为什么能飞起来？
Why can an airplane fly?
飞机机翼上表面弯曲、下表面较平，气流经过时机翼上方流速更快、压强更低，从而产生向上的升力。更准确地说，机翼的迎角与环量使气流被向下偏转，根据牛顿第三定律产生反作用升力；当升力超过飞机重力时，飞机就能离地升空。
An airplane wing is curved on top and flatter below, so air moves faster over the top and creates lower pressure there, producing upward lift. More precisely, the wing's angle of attack and the circulation around it deflect the airflow downward; by Newton's third law this produces a reaction force. When lift exceeds the plane's weight, the aircraft can leave the ground.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Anderson《空气动力学基础》（Fundamentals of Aerodynamics）第5版,Wiley,2017
J. D. Anderson Jr., Fundamentals of Aerodynamics, 5th ed., Wiley, 2017
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787516504413（豆瓣书目条目: 空气动力学基础）
#升力 #机翼 #伯努利
载人飞船顶部的发射逃逸系统，要在多短的时间里把乘员带离故障火箭？
How quickly must a crewed spacecraft's launch abort system pull the crew away from a failing rocket?
逃逸系统必须在探测到异常后不到一秒内点火，固体逃逸发动机在两三秒内产生数十吨推力，把乘员舱以大约 7–10g 的加速度拉离数百米以上，随后抛掉塔架、展开降落伞完成海上或陆上着陆。之所以这么急，是因为液体火箭一旦发生爆燃，火球扩展只需几秒，而低空逃逸还必须留出足够高度让降落伞充分张开。1983 年联盟 T-10-1 在发射台起火时逃逸系统成功救出两名航天员，是这套设计最直接的实战验证。
An abort system must ignite within a fraction of a second of detecting failure, with solid motors delivering tens of tonnes of thrust for two or three seconds to accelerate the capsule away at roughly 7–10g and several hundred metres clear before the tower is jettisoned and parachutes deploy for a water or land landing. Such urgency exists because a liquid rocket deflagration expands into a fireball within seconds, and a low-altitude abort must still leave enough altitude for canopies to inflate. The 1983 Soyuz T-10-1 pad fire, where the escape system saved both crew members, remains the concept's clearest practical demonstration.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#发射逃逸系统 #载人航天安全 #固体逃逸发动机
卫星为什么不会掉下来？
Why don't satellites fall down?
卫星以很高的速度绕地球做圆周运动，地球的引力恰好提供它转弯所需的向心力。由于高空空气极其稀薄，几乎没有阻力让卫星慢下来，所以它能长期停留在轨道上。
A satellite moves around Earth at high speed so that Earth's gravity exactly provides the centripetal force needed to curve its path. Because the upper atmosphere is extremely thin, almost no drag slows it down, so it stays in orbit for a long time.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#卫星 #轨道 #向心力
火箭发射时为什么先笔直上升，之后又慢慢倾斜？
Why do rockets go straight up at launch and then tilt over?
先垂直上升是为了尽快穿过稠密、阻力大的低层大气；之后倾斜是为了获得绕地球飞行所需的高速水平方向，最终进入轨道。
Going straight up first quickly clears the dense, drag-heavy lower atmosphere; then it tilts to build the horizontal speed needed to orbit the Earth.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航空航天 #发射 #轨道
什么是音障？
What is the sound barrier?
音障是飞机接近音速时遇到的空气阻力急剧增大的现象，曾被认为难以突破。现代飞机通过后掠翼和强劲发动机可以超过音速，即超音速飞行。
The sound barrier is the sharp rise in aerodynamic drag an aircraft meets as it approaches the speed of sound, once thought impossible to break. Modern planes with swept wings and powerful engines can exceed the speed of sound in supersonic flight.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#音障 #音速 #超音速
火箭靠什么推进？
What propels a rocket?
火箭依靠向后高速喷出气体，根据作用力与反作用力原理获得向前的推力。它自带燃料和氧化剂，因此不需要空气也能在太空中工作。
A rocket is propelled by ejecting gas backward at high speed, gaining forward thrust by Newton's action-reaction principle. It carries both fuel and oxidizer, so it works in space where there is no air.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#火箭 #推力 #反作用力
火箭整流罩是干什么的？
What is a rocket fairing for?
整流罩在发射初期包裹并保护卫星等有效载荷，使其免受气动加热与声振损伤，飞出稠密大气层后抛掉以减轻重量。
The fairing encloses and protects the payload from aerodynamic heating and vibration during ascent, then is jettisoned after leaving the dense atmosphere.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航天 #整流罩
卫星主要靠什么供电？
What mainly powers a satellite?
大多数卫星展开太阳能帆板将太阳光转为电能，并配蓄电池在阴影期（如地影）继续供电，少数深空探测器用放射性同位素电源。
Most satellites deploy solar arrays and store energy in batteries for eclipse periods; a few deep-space probes use radioisotope power instead.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Sutton & Biblarz,《Rocket Propulsion Elements》第9版,Wiley,2016
G. P. Sutton and O. Biblarz, Rocket Propulsion Elements, 9th ed., Wiley, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9780665590955 (2002)
#航天 #供电