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Retrorocket
A retrorocket (short for ''retrograde rocket'') is a rocket engine providing thrust opposing the motion of a vehicle, thereby causing it to decelerate. They have mostly been used in spacecraft, with more limited use in short-runway aircraft landing. New uses are emerging since 2010 for retro-thrust rockets in reusable launch systems. History Rockets were fitted to the nose of some models of the DFS 230, a World War II German Military glider. This enabled the aircraft to land in more confined areas than would otherwise be possible during an airborne assault. Another World War II development was the British Hajile project, initiated by the British Admiralty's Directorate of Miscellaneous Weapons Development. Originally a request from the British Army as a method to drop heavy equipment or vehicles from aircraft flying at high speeds and altitudes, the project turned out to be a huge disaster and was largely forgotten after the war. Although some of the tests turned out to be suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Mercury
Project Mercury was the first human spaceflight program of the United States, running from 1958 through 1963. An early highlight of the Space Race, its goal was to put a man into Earth orbit and return him safely, ideally before the Soviet Union. Taken over from the US Air Force by the newly created civilian space agency NASA, it conducted 20 uncrewed developmental flights (some using animals), and six successful flights by astronauts. The program, which took its name from Roman mythology, cost $ (adjusted for inflation). The astronauts were collectively known as the "Mercury Seven", and each spacecraft was given a name ending with a "7" by its pilot. The Space Race began with the 1957 launch of the Soviet satellite Sputnik 1. This came as a shock to the American public, and led to the creation of NASA to expedite existing US space exploration efforts, and place most of them under civilian control. After the successful launch of the Explorer 1 satellite in 1958, crewed spacef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reusable Launch System
A reusable launch vehicle have 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. However, these benefits are diminished by the cost of recovery and refurbishment. Reusable launch vehicles may contain additional avionics and propellant, making them heavier than their expendable counterparts. Reused parts may need to enter the atmosphere and navigate through it, so they are often equipped with heat shields, grid fins, and other flight control surfaces. By modifying their shape, spaceplanes can leverage aviation mechanics to aid in its recovery, such as gliding or lift. In the atmosphere, par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hajile
Hajile was an experimental project developed by the British Admiralty's Directorate of Miscellaneous Weapons Development (DMWD) during the final years of Second World War for slowing the landing of air-dropped supplies with retrorockets. Development The project was initiated by a request from the Army for a method of dropping heavy equipment and vehicles from aircraft at high speed, retaining the materiel's terminal velocity for as long as possible in order to minimise drift and damage from anti-aircraft gun batteries. It was further required that the materiel suffer only minimal or no damage from landing, and once dropped be ready to deploy within minutes. The high falling speed ruled out parachutes, so the DMWD came up with the idea of loading the drops onto a platform surrounded with cordite rockets. These would fire at the last instant to decelerate the materiel to a safe landing speed. The initial test produced the project's codename; as the rockets' exhaust engulfed the appar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Assisted Descent
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, airfoils, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity. Rockets for military and recreational uses date back to at least 13th-century China. Significant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Orbit Insertion
In astronomy, lunar orbit (also known as a selenocentric orbit) is the orbit of an object around the Moon. As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by spacecraft around the Moon. The altitude at apoapsis (point farthest from the center of attraction) for a lunar orbit is known as apolune, apocynthion, or aposelene, while the periapsis (point closest to the center of attraction) is known as perilune, pericynthion, or periselene, from names or epithets of the moon goddess. Lunar orbit insertion (LOI) is the adjustment to achieve lunar orbit, as undertaken by Apollo spacecraft for example. Low lunar orbit (LLO) are orbits below altitude. They have a period of about 2 hours. They are of particular interest in exploration of the Moon, but suffer from gravitational perturbation effects that make most unstable, and leave only a few orbital inclinations possible for indefinite ''frozen orbits'', useful for long-term stays in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo Lunar Module
The Apollo Lunar Module (LM ), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed spacecraft to operate exclusively in the airless vacuum of space, and remains the only crewed vehicle to land anywhere beyond Earth. Structurally and aerodynamically incapable of flight through Earth's atmosphere, the two-stage lunar module was ferried to lunar orbit attached to the Apollo command and service module (CSM), about twice its mass. Its crew of two flew the complete lunar module from lunar orbit to the Moon's surface. During takeoff, the spent descent stage was used as a launch pad for the ascent stage which then flew back to the command module, after which it was also discarded. Overseen by Grumman, the LM's development was plagued with problems that delayed its first uncrewed flight by about ten months and its first crewed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Descent Propulsion System
The descent propulsion system (DPS - pronounced 'dips') or lunar module descent engine (LMDE), internal designation VTR-10, is a variable-throttle hypergolic rocket engine invented by Gerard W. Elverum Jr. and developed by Space Technology Laboratories (TRW) for use in the Apollo Lunar Module descent stage. It used Aerozine 50 fuel and dinitrogen tetroxide () oxidizer. This engine used a pintle injector, which paved the way for other engines to use similar designs. Requirements The propulsion system for the descent stage of the lunar module was designed to transfer the vehicle, containing two crewmen, from a circular lunar parking orbit to an elliptical descent orbit with a pericynthion of , then provide a powered descent to the lunar surface, with hover time above the lunar surface to select the exact landing site. To accomplish these maneuvers, a propulsion system was developed that used hypergolic propellants and a gimballed pressure-fed ablative cooled engine that was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-IC
The S-IC (pronounced S-one-C) was the first stage of the American Saturn V rocket. The S-IC stage was manufactured by the Boeing Company. Like the first stages of most rockets, most of its mass of more than at launch was propellant, in this case RP-1 rocket fuel and liquid oxygen (LOX) oxidizer. It was tall and in diameter, and provided of thrust to get the rocket through the first of ascent. The stage had five F-1 engines in a quincunx arrangement. The center engine was fixed in position, while the four outer engines could be hydraulically gimballed to control the rocket. Manufacturing The Boeing Co. was awarded the contract to manufacture the S-IC on December 15, 1961. By this time the general design of the stage had been decided on by the engineers at the Marshall Space Flight Center (MSFC). The main place of manufacture was the Michoud Assembly Facility, New Orleans. Wind tunnel testing took place in Seattle and the machining of the tools needed to build the stages at W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-II
The S-II (pronounced "S-two") was the second stage of the Saturn V rocket. It was built by North American Aviation. Using liquid hydrogen (LH2) and liquid oxygen (LOX) it had five J-2 engines in a quincunx pattern. The second stage accelerated the Saturn V through the upper atmosphere with of thrust. History The beginning of the S-II came in December 1959 when a committee recommended the design and construction of a high-thrust, liquid hydrogen fueled engine. The contract for this engine was given to Rocketdyne and it would be later called the J-2. At the same time the S-II stage design began to take shape. Initially it was to have four J-2 engines and be in length and in diameter. In 1961 the Marshall Space Flight Center began the process to find the contractor to build the stage. Out of the 30 aerospace companies invited to a conference where the initial requirements were laid out, only seven submitted proposals a month later. Three of these were eliminated after their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturn V
Saturn 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, with multistage rocket, three stages, and powered with liquid-propellant rocket, 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. the Saturn V remains the only launch vehicle to carry humans beyond low Earth orbit (LEO). Saturn V holds records for the heaviest payload launched and largest payload capacity to low Earth orbit: , which included the third stage and unburned propellant needed to send the Apollo command and service module and Apollo Lunar Module, Lunar Module to the Moon. The largest production model of the Saturn (rocket family), Saturn family of rockets, the Saturn V was designed under the direction of Wernher von Braun at the Marshall Space Flight Center in Huntsville, Alabama; the lead contractor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Entry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass (ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic speed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development. The first ( STS-1) of four orbital test flights occurred in 1981, leading to operational flights (STS-5) beginning in 1982. Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. They launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST), conducted science experiments in orbit, participated in the Shuttle-''Mir'' program with Russia, and participated in construction and servicing of the International Space Station (ISS). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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