The first cosmic speed (V1) spacecraft as the earth's surface along the circular motion must have the speed, also known as speed around. The first two speed of the universe another name: the smallest space launch speed, maximum speed of the spacecraft. In a number of issues that when a spacecraft to the speed of the universe in the first run, it shows that the spacecraft is operating along the Earth's surface. In accordance with the mechanical theory can be calculated V1 = 7.9 km / sec. Spacecraft from the ground a few hundred kilometers above the surface of the high-altitude operation of the spacecraft in the face of gravity on the ground than when it is smaller, so the speed of slightly less than V1.
第二宇宙速度(V2) when the spacecraft in the first over of the universe V1 speed up to a certain value, it will be out of the earth's gravitational field around the sun as a man-made planet, the speed is called第二宇宙速度, also known as escape Speed. In accordance with the mechanical theory can be calculated第二宇宙速度V2 = 11.2 km / sec. As the gravity of the earth the moon has not yet exceeded the scope of it from the ground to launch lunar spacecraft, the initial rate of not less than 10.848 km / s can be.
The third speed of the universe (V3) from the Earth's surface to launch the spacecraft, flying out of the solar system, the vast roaming in the Milky Way need Minimum speed, the speed of the universe is called the third. In accordance with the mechanical theory of the universe can be calculated in the third speed V3 = 16.7 km / sec. It should be noted that this is to choose the speed of the spacecraft orbit the Earth and the revolution speed in the same direction when the calculated value of the V3; if not the direction, speed requirements will be GREater than 16.7 km / s by. It can be said that the speed of the spacecraft is free of the Earth and even the sun's gravitational the only factor, only the speed rockets can break through the universe.
The fourth speed of the universe (V4) of a speed of the universe, objects are expected to have 110 ~ 120km / s speed, you can enter Hewaixingxi out of the Milky Way, known as the pace of the fourth rate of the universe.
As the spacecraft in the Earth's dense atmosphere other than the extremely high vacuum space similar to the natural movement of celestial bodies flying, the first spacecraft to look for the realization of Air and the labor-saving means of delivery.
Does carry a rocket combustion agents, with antioxidants that can fly in space. But to break free of Earth's gravity and fly out to overcome the air resistance of the Earth, single-stage rockets can also be used STEP-ROCKETS relay, one level to speed up the end of the universe to reach the speed of the numerical requirements.
Modern arrows from the launch vehicle body structure, power plants, guidance and control systems, telemetry systems, testing outside the system, security and other self-destructive system constitutes an additional, on all levels between the level inter-agency connectivity, and separation, the spacecraft mounted on the end of the The location of the rocket to the top level by the end of grade separation and institutions linked to the rocket; outside the spacecraft equipped with a fairing, in order to launch the initial phase of the protection of the spacecraft.
The launch vehicle technology indicators, including the carrying capacity, precision orbit, rockets of different weights in the spacecraft's reliability and adaptability. And the weight of the spacecraft orbit, the rocket needed to provide energy and speed varies, with a variety of track between the speed of a certain relationship. If the spacecraft into a 185 km high circular orbit required speed of 7.8 km / s; spacecraft into the 1,000 km high circular orbit required speed of 8.3 km / s; spacecraft Into the geosynchronous transfer orbit speed of 10.25 kilometers requirements / s; spacecraft to detect the speed of the solar system requirements for 12 to 20 km / s, and so on. To this day, the Rockets can only rely on breakthroughs in the speed of the universe, the realization of the ideals of human space flight.
第二宇宙速度(V2) when the spacecraft in the first over of the universe V1 speed up to a certain value, it will be out of the earth's gravitational field around the sun as a man-made planet, the speed is called第二宇宙速度, also known as escape Speed. In accordance with the mechanical theory can be calculated第二宇宙速度V2 = 11.2 km / sec. As the gravity of the earth the moon has not yet exceeded the scope of it from the ground to launch lunar spacecraft, the initial rate of not less than 10.848 km / s can be.
The third speed of the universe (V3) from the Earth's surface to launch the spacecraft, flying out of the solar system, the vast roaming in the Milky Way need Minimum speed, the speed of the universe is called the third. In accordance with the mechanical theory of the universe can be calculated in the third speed V3 = 16.7 km / sec. It should be noted that this is to choose the speed of the spacecraft orbit the Earth and the revolution speed in the same direction when the calculated value of the V3; if not the direction, speed requirements will be GREater than 16.7 km / s by. It can be said that the speed of the spacecraft is free of the Earth and even the sun's gravitational the only factor, only the speed rockets can break through the universe.
The fourth speed of the universe (V4) of a speed of the universe, objects are expected to have 110 ~ 120km / s speed, you can enter Hewaixingxi out of the Milky Way, known as the pace of the fourth rate of the universe.
As the spacecraft in the Earth's dense atmosphere other than the extremely high vacuum space similar to the natural movement of celestial bodies flying, the first spacecraft to look for the realization of Air and the labor-saving means of delivery.
Does carry a rocket combustion agents, with antioxidants that can fly in space. But to break free of Earth's gravity and fly out to overcome the air resistance of the Earth, single-stage rockets can also be used STEP-ROCKETS relay, one level to speed up the end of the universe to reach the speed of the numerical requirements.
Modern arrows from the launch vehicle body structure, power plants, guidance and control systems, telemetry systems, testing outside the system, security and other self-destructive system constitutes an additional, on all levels between the level inter-agency connectivity, and separation, the spacecraft mounted on the end of the The location of the rocket to the top level by the end of grade separation and institutions linked to the rocket; outside the spacecraft equipped with a fairing, in order to launch the initial phase of the protection of the spacecraft.
The launch vehicle technology indicators, including the carrying capacity, precision orbit, rockets of different weights in the spacecraft's reliability and adaptability. And the weight of the spacecraft orbit, the rocket needed to provide energy and speed varies, with a variety of track between the speed of a certain relationship. If the spacecraft into a 185 km high circular orbit required speed of 7.8 km / s; spacecraft into the 1,000 km high circular orbit required speed of 8.3 km / s; spacecraft Into the geosynchronous transfer orbit speed of 10.25 kilometers requirements / s; spacecraft to detect the speed of the solar system requirements for 12 to 20 km / s, and so on. To this day, the Rockets can only rely on breakthroughs in the speed of the universe, the realization of the ideals of human space flight.
第一宇宙速度（V1） 航天器沿地球表面作圆周运动时必须具备的速度，也叫环绕速度。第一宇宙速度两个别称：航天器最小发射速度、航天器最大运行速度。在一些问题中说，当某航天器以第一宇宙速度运行，则说明该航天器是沿着地球表面运行的。按照力学理论可以计算出V1＝7．9公里／秒。航天器在距离地面表面数百公里以上的高空运行，地面对航天器引力比在地面时要小，故其速度也略小于V1。
第二宇宙速度（V2）当航天器超过第一宇宙速度V1达到一定值时，它就会脱离地球的引力场而成为围绕太阳运行的人造行星，这个速度就叫做第二宇宙速度，亦称逃逸速度。按照力学理论可以计算出第二宇宙速度V2＝11．2公里／秒。由于月球还未超出地球引力的范围，故从地面发射探月航天器，其初始速度不小于10．848公里／秒即可。
第三宇宙速度（V3）从地球表面发射航天器，飞出太阳系，到浩瀚的银河系中漫游所需要的最小速度，就叫做第三宇宙速度。按照力学理论可以计算出第三宇宙速度V3＝16．7公里／秒。需要注意的是，这是选择航天器入轨速度与地球公转速度方向一致时计算出的V3值；如果方向不一致，所需速度就要大于16．7公里／秒了。可以说，航天器的速度是挣脱地球乃至太阳引力的惟一要素，目前只有火箭才能突破宇宙速度。
第四宇宙速度（V4）宇宙速度的一级，预计物体具有110~120km/s的速度时，就可以脱离银河系而进入河外星系，这个速度叫做第四宇宙速度。
由于航天器在地球稠密大气层以外极高真空的宇宙空间以类似自然天体的运动规律飞行，所以实现航天首先要寻找不依赖空气而又省力的运载工具。
火箭本身既携有燃烧剂，又带有氧化剂，能够在太空中飞行。但要挣脱地球引力和克服空气阻力飞出地球，单级火箭还做不到，必须用多级火箭接力，逐级加速，最终才能达到宇宙速度要求的数值。
现代运载火箭由箭体结构、动力装置、制导和控制系统、遥测系统、外测系统、安全自毁和其他附加系统构成，各级之间靠级间段和分离机构连接，航天器装在末级火箭的顶端位置，通过分离机构与末级火箭相连；航天器外面装有整流罩，以便在发射初始阶段保护航天器。
运载火箭的技术指标，包括运载能力、入轨精度、火箭对不同重量的航天器的适应能力和可靠性。航天器的重量和轨道不同，所需火箭提供的能量和速度也各不相同，各种轨道与速度之间有一定的对应关系。如把航天器送入185公里高的圆形轨道运行所需的速度为7．8公里／秒；航天器进入1000公里高的圆形轨道运行所需速度为8．3公里／秒；航天器进入地球同步转移轨道运行所需速度为10．25公里／秒；航天器探测太阳系所需速度为12～20公里／秒等。直到今天，只有依靠火箭才能突破宇宙速度，实现人类飞天的理想。
第二宇宙速度（V2）当航天器超过第一宇宙速度V1达到一定值时，它就会脱离地球的引力场而成为围绕太阳运行的人造行星，这个速度就叫做第二宇宙速度，亦称逃逸速度。按照力学理论可以计算出第二宇宙速度V2＝11．2公里／秒。由于月球还未超出地球引力的范围，故从地面发射探月航天器，其初始速度不小于10．848公里／秒即可。
第三宇宙速度（V3）从地球表面发射航天器，飞出太阳系，到浩瀚的银河系中漫游所需要的最小速度，就叫做第三宇宙速度。按照力学理论可以计算出第三宇宙速度V3＝16．7公里／秒。需要注意的是，这是选择航天器入轨速度与地球公转速度方向一致时计算出的V3值；如果方向不一致，所需速度就要大于16．7公里／秒了。可以说，航天器的速度是挣脱地球乃至太阳引力的惟一要素，目前只有火箭才能突破宇宙速度。
第四宇宙速度（V4）宇宙速度的一级，预计物体具有110~120km/s的速度时，就可以脱离银河系而进入河外星系，这个速度叫做第四宇宙速度。
由于航天器在地球稠密大气层以外极高真空的宇宙空间以类似自然天体的运动规律飞行，所以实现航天首先要寻找不依赖空气而又省力的运载工具。
火箭本身既携有燃烧剂，又带有氧化剂，能够在太空中飞行。但要挣脱地球引力和克服空气阻力飞出地球，单级火箭还做不到，必须用多级火箭接力，逐级加速，最终才能达到宇宙速度要求的数值。
现代运载火箭由箭体结构、动力装置、制导和控制系统、遥测系统、外测系统、安全自毁和其他附加系统构成，各级之间靠级间段和分离机构连接，航天器装在末级火箭的顶端位置，通过分离机构与末级火箭相连；航天器外面装有整流罩，以便在发射初始阶段保护航天器。
运载火箭的技术指标，包括运载能力、入轨精度、火箭对不同重量的航天器的适应能力和可靠性。航天器的重量和轨道不同，所需火箭提供的能量和速度也各不相同，各种轨道与速度之间有一定的对应关系。如把航天器送入185公里高的圆形轨道运行所需的速度为7．8公里／秒；航天器进入1000公里高的圆形轨道运行所需速度为8．3公里／秒；航天器进入地球同步转移轨道运行所需速度为10．25公里／秒；航天器探测太阳系所需速度为12～20公里／秒等。直到今天，只有依靠火箭才能突破宇宙速度，实现人类飞天的理想。
