The V-2 (German: Vergeltungswaffe 2, lit.'Retaliation Weapon 2'), with the technical name Aggregat 4 (A4), was the worlds first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was developed during the Second World War in Nazi Germany as a "vengeance weapon" and assigned to attack Allied cities as retaliation for the Allied bombings against German cities. The V-2 rocket also became the first artificial object to travel into space by crossing the Krmn line (edge of space) with the vertical launch of MW 18014 on 20 June 1944.Research into military use of long-range rockets began when the graduate studies of Wernher von Braun attracted the attention of the Wehrmacht. A series of prototypes culminated in the A-4, which went to war as the V-2. Beginning in September 1944, over 3,000 V-2s were launched by the Nazi Wehrmacht against Allied targets, first London and later Antwerp and Lige. According to a 2011 BBC documentary, the attacks from V-2s resulted in the deaths of an estimated 9,000 civilians and military personnel, and a further 12,000 forced laborers and Nazi concentration camps prisoners died as a result of their forced participation in the production of the weapons.The rockets travelled at supersonic speed, impacted without audible warning, and proved unstoppable, as no effective defense existed. Teams from the Allied forcesthe United States, the United Kingdom, and the Soviet Unionraced to seize key Nazi manufacturing facilities, procure the Nazis' missile technology, and capture the V-2s launching sites. Von Braun and over 100 key V-2 personnel surrendered to the Americans, and many of the original V-2 team ended up working at the Redstone Arsenal. The US also captured enough V-2 hardware to build approximately 80 of the missiles. The Soviets gained possession of the V-2 manufacturing facilities after the war, re-established V-2 production, and moved it to the Soviet Union.

Spaceflight (or space flight) is an application of astronautics to fly spacecraft into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such as satellites in orbit around Earth, but also includes space probes for flights beyond Earth orbit. Such spaceflight operates either by telerobotic or autonomous control. The more complex human spaceflight has been pursued soon after the first orbital satellites and has reached the Moon and permanent human presence in space around Earth, particularly with the use of space stations. Human spaceflight programs include the Soyuz, Shenzhou, the past Apollo Moon landing and the Space Shuttle programs, with currently the International Space Station as the main destination of human spaceflight missions while China's Tiangong Space Station is under construction.

Spaceflight is used for placing in Earth's orbit communications satellites, reconnaissance satellites, Earth observation satellites, but also for space exploration such as space observatories and space probes, or even for space tourism.

Spaceflight can be achieved with different types of launch systems, conventionally by rocket launching, which provide the initial thrust to overcome the force of gravity and propel a spacecraft from the surface of the Earth. Once in space, the motion of a spacecraft—both when unpropelled and when under propulsion—is covered by the area of study called astrodynamics.

Some spacecraft remain in space practically indefinitely, which has created the issue of space pollution in the form of light pollution and space junk, which is a hazard to spaceflight. Otherwise spacecraft are terminated by atmospheric reentry, in which they disintegrate, or if they do not, their reentry is mostly controlled to safely reach a surface by landing or impacting, often being dumped in the oceanic spacecraft cemetery. As such spacecraft have been the subject of some space traffic management.