开普勒第三定律说明了什么？
What does Kepler's third law state?
它指出行星（或卫星）轨道周期的平方与轨道半长轴的立方成正比，意味着离中心天体越远，公转越慢、周期越长。
It states the square of the orbital period is proportional to the cube of the semi-major axis, so farther objects orbit more slowly with longer periods.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Bate, Mueller & White《天体力学基础》；NASA 轨道力学；开普勒定律
Bate, Mueller & White, Fundamentals of Astrodynamics; NASA orbital mechanics; Kepler's laws
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL7217951W：Fundamentals of astrody
#航天 #轨道力学
空间交会对接难在哪里？
What is hard about space rendezvous and docking?
两航天器要在轨道上把相对速度降到接近零并精确对齐接口，靠雷达、激光与视觉引导，任何偏差都可能导致碰撞，对接机构还要缓冲吸收能量。
Two craft must null their relative velocity and align ports in orbit using radar, lidar and vision; any error risks collision, and the docking ring must absorb energy.
难度 专业 · 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 #交会对接
霍曼转移为什么最省燃料？
Why is a Hohmann transfer the most fuel-efficient?
它在两个共面圆轨道间用两段切向脉冲（先加速到转移椭圆、再在圆轨道上加速圆化），仅用两个冲量完成，是能量最优的轨道变换。
Between two coplanar circular orbits it uses just two tangential burns, onto a transfer ellipse and then circularizing, making it the minimum-energy transfer.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Bate, Mueller & White《天体力学基础》；NASA 轨道力学；开普勒定律
Bate, Mueller & White, Fundamentals of Astrodynamics; NASA orbital mechanics; Kepler's laws
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL7217951W：Fundamentals of astrody
#航天 #轨道力学
第二宇宙速度是多少，意义是什么？
What is the second cosmic velocity and its meaning?
约11.2 km/s，是物体摆脱地球引力束缚、飞离地球所需的最小速度，也称逃逸速度。
About 11.2 km/s, the minimum speed to escape Earth's gravity entirely, also called escape velocity.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Bate, Mueller & White《天体力学基础》；NASA 轨道力学；开普勒定律
Bate, Mueller & White, Fundamentals of Astrodynamics; NASA orbital mechanics; Kepler's laws
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL7217951W：Fundamentals of astrody
#航天 #宇宙速度
第一宇宙速度是多少？
What is the first cosmic velocity?
约7.9 km/s，是物体在地球表面附近绕地球做匀速圆周运动所需的最小速度，也是近地轨道的环绕速度。
About 7.9 km/s, the speed needed to orbit Earth near its surface, the circular orbital velocity in low Earth orbit.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Bate, Mueller & White《天体力学基础》；NASA 轨道力学；开普勒定律
Bate, Mueller & White, Fundamentals of Astrodynamics; NASA orbital mechanics; Kepler's laws
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL7217951W：Fundamentals of astrody
#航天 #宇宙速度