Space balloon

Hot air balloon has a long history in China. It is called Sky Lantern or Kongming Lantern. Joseph Needham, a famous scholar, also pointed out that Mongols used dragon lanterns to transmit signals in the Linitz Battle of 124 1 year.

Helicopter is mainly composed of airframe, lift (including rotor and tail rotor), power and transmission system and airborne flight equipment. The rotor is generally driven by a turboshaft engine or a piston engine through a mechanical transmission system consisting of a transmission shaft and a reducer, and can also be driven by the reaction force generated by the jet from the tip of the blade. At present, there are mechanically driven single-rotor helicopters and double-rotor helicopters in actual use, of which single-rotor helicopters have the largest number.

The maximum speed of a helicopter can reach more than 300km/h, the dive limit speed is nearly 400km/h, the use ceiling can reach 6000m (the world record is 12450m), and the general range can reach about 600 ~ 800 km. The range of internal and external auxiliary fuel tanks can reach more than 2000 kilometers. Helicopters have different takeoff weights according to different needs. At present, the largest heavy helicopter put into use in the world is the Russian Mi -26 (with a maximum takeoff weight of 56t and a payload of 20t).

The outstanding feature of helicopter is that it can do low altitude (a few meters above the ground), low speed (starting from hovering) and the nose direction remains unchanged, especially suitable for small-area vertical take-off and landing. Because of these characteristics, it has broad uses and development prospects. In the military field, it has been widely used in ground attack, aircraft take-off and landing, weapons delivery, logistics support, battlefield rescue, reconnaissance patrol, command and control, communication, anti-submarine mine clearance, electronic countermeasures and so on. Used for short-distance transportation, medical rescue, disaster relief and lifesaving, emergency rescue, lifting equipment, geological exploration, forest protection and fire fighting, aerial photography, etc. The transportation of people and materials between offshore oil wells and bases is an important aspect of civil use.

At present, compared with airplanes, helicopters have higher vibration and noise levels, greater maintenance workload, higher use cost, lower speed and shorter flight range. The future development direction of helicopters is to improve these aspects.

An airship is a lighter-than-air aircraft. The biggest difference between an airship and a balloon is that it has a device to propel and control the flight state. The airship consists of a huge streamlined hull, a pod under the hull, a tail surface for stable control and a propulsion device. The airbag of the hull is filled with buoyancy gas (hydrogen or helium) whose density is lower than that of air, so as to generate buoyancy and lift the airship off. Pods are used for people to ride and load goods. The tail surface is used to control and maintain the stability of heading and pitching.

Fighter refers to a military aircraft that is mainly used to protect our air superiority and destroy the enemy's ability to use air superiority. It is characterized by excellent flight performance, flexibility and strong firepower; Modern advanced fighters are equipped with all kinds of search and aiming fire control equipment, which can attack all air targets around the clock.

The space shuttle is a manned spacecraft, which takes off vertically and lands horizontally. It is launched into space by a rocket engine, can run in orbit, can go back and forth between the earth's surface and near-earth orbit, and can be partially reused. It consists of three parts: orbiter, solid fuel booster rocket and external tank.