Orbital spaceflightAn orbital spaceflight (or orbital flight) is a spaceflight in which a spacecraft is placed on a trajectory where it could remain in space for at least one orbit. To do this around the Earth, it must be on a free trajectory which has an altitude at perigee (altitude at closest approach) around ; this is the boundary of space as defined by NASA, the US Air Force and the FAA. To remain in orbit at this altitude requires an orbital speed of ~7.8 km/s. Orbital speed is slower for higher orbits, but attaining them requires greater delta-v.
Tsiolkovsky rocket equationThe classical rocket equation, or ideal rocket equation is a mathematical equation that describes the motion of vehicles that follow the basic principle of a rocket: a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity can thereby move due to the conservation of momentum. It is credited to the Russian scientist Konstantin Tsiolkovsky (Константи́н Эдуа́рдович Циолко́вский) who independently derived it and published it in 1903, although it had been independently derived and published by the British mathematician William Moore in 1810, and later published in a separate book in 1813.
SpaceXSpace Exploration Technologies Corp., doing business as SpaceX, is an American spacecraft manufacturer, launch service provider and satellite communications company headquartered in Hawthorne, California. The company was founded in 2002 by Elon Musk with the goal of reducing space transportation costs and to colonize Mars. The company manufactures the Falcon 9, Falcon Heavy and Starship heavy-lift launch vehicles, the Cargo Dragon and Crew Dragon spacecraft, the Starlink mega-constellation satellite and rocket engines.
Sounding rocketA sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to launch instruments from 48 to 145 km (30 to 90 miles) above the surface of the Earth, the altitude generally between weather balloons and satellites; the maximum altitude for balloons is about 40 km (25 miles) and the minimum for satellites is approximately 121 km (75 miles).
Expendable launch systemAn expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are either destroyed during reentry or discarded in space. ELVs typically consist of several rocket stages that are discarded sequentially as their fuel is exhausted and the vehicle gains altitude and speed. As of 2022, most satellites and human spacecraft are currently launched on ELVs. ELVs are simpler in design than reusable launch systems and therefore may have a lower production cost.
Saturn VSaturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, had three stages, and was powered with liquid fuel. It was flown from 1967 to 1973. It was used for nine crewed flights to the Moon, and to launch Skylab, the first American space station. As of 2023, the Saturn V remains the only launch vehicle to carry humans beyond low Earth orbit (LEO).
Operation PaperclipOperation Paperclip was a secret United States intelligence program in which more than 1,600 German scientists, engineers, and technicians were taken from the former Nazi Germany to the U.S. for government employment after the end of World War II in Europe, between 1945 and 1959. Conducted by the Joint Intelligence Objectives Agency (JIOA), it was largely carried out by special agents of the U.S. Army's Counterintelligence Corps (CIC). Many of these personnel were former members and some were former leaders of the Nazi Party.
Liquid-propellant rocketA liquid-propellant rocket or liquid rocket utilizes a rocket engine that uses liquid propellants. Gaseous propellants may also be used but are not common because of their low density and difficulty with common pumping methods. Liquids are desirable because they have a reasonably high density and high specific impulse (Isp). This allows the volume of the propellant tanks to be relatively low.
ScramjetA scramjet (supersonic combustion ramjet) is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully before combustion (hence ramjet), but whereas a ramjet decelerates the air to subsonic velocities before combustion using shock cones, a scramjet has no shock cone and slows the airflow using shockwaves produced by its ignition source in place of a shock cone.
Reusable launch vehicleA reusable launch vehicle has parts that can be recovered and reflown, while carrying payloads from the surface to outer space. Rocket stages are the most common launch vehicle parts aimed for reuse. Smaller parts such as rocket engines and boosters can also be reused, though reusable spacecraft may be launched on top of an expendable launch vehicle. Reusable launch vehicles do not need to make these parts for each launch, therefore reducing its launch cost significantly.
