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Ullage Motor
Ullage motors (also known as ullage engines or ullage rockets) are relatively small, independently fueled rocket engines that may be fired prior to main engine ignition, when the vehicle is in a zero-g situation. The resulting acceleration causes liquid in the rocket's main tanks to settle towards the aft end, ensuring uninterrupted flow to the fuel and oxidizer pumps. Description Cryogenic-liquid-fueled rockets keep their propellants in insulated tanks. These tanks are never completely filled to allow for expansion. In micro-gravity conditions the cryogenic liquids are without a free surface existing in a slushy state between solid, liquid, and gas. In this mixed state, ullage gases may be sucked into the engines, which is undesirable, as it displaces useful propellant, reduces efficiency, and may damage the engines. Small rocket engines, called "ullage motors", are sometimes used to settle the propellant prior to the main engine ignition to allow the formation of a temporary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturn V Third Stage Ullage (APS) Motor
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; however, with its larger volume, Saturn is over 95 times more massive. Saturn's interior is most likely composed of a core of iron–nickel and rock (silicon and oxygen compounds). Its core is surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium, and finally, a gaseous outer layer. Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere. An electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is weaker than Earth's, but which has a magnetic moment 580 times that of Earth due to Saturn's larger size. Saturn's magnetic field strength is around one-twentieth of Jupiter's. The outer atmosphere is ge ... [...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 LH2, liquid hydrogen (LH2) and liquid oxygen (LOX) it had five J-2 (rocket engine), 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 (rocket engine), 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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload ( spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are classified by their orbital payload capacity, ranging from small-, medium-, heavy- to super-heavy li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molniya (rocket)
The Molniya (russian: Молния, meaning "lightning"), GRAU Index 8K78, was a modification of the well-known R-7 Semyorka rocket and had four stages. The 8K78 resulted from a crash program by the Korolev Bureau to develop a booster for launching planetary probes. A larger third stage was added along with a fourth stage ( Blok L) that was designed to fire in-orbit to send the payload out of LEO. The basic R-7 core was also structurally strengthened and given more powerful engines. A rushed development produced multiple malfunctions of the upper stages, which led to its being replaced by the improved Molniya-M in 1964, but there were enough 8K78s left to continue flying them into 1967.The Soyuz Launch Vehicle: The Two Lives of an Engineering Triumph By Christian Lardier, Stefan Barensky, page 156 The Molniya also carried early Venera probes to Venus. Molniya (E6) was a minor revision adapted for launch of some Luna series space probes. Characteristics * Length: 43.440 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo 13
Apollo 13 (April 1117, 1970) was the seventh crewed mission in the Apollo space program and the third meant to land on the Moon. The craft was launched from Kennedy Space Center on April 11, 1970, but the lunar landing was aborted after an oxygen tank in the service module (SM) failed two days into the mission. The crew instead looped around the Moon and returned safely to Earth on April 17. The mission was commanded by Jim Lovell, with Jack Swigert as command module (CM) pilot and Fred Haise as Lunar Module (LM) pilot. Swigert was a late replacement for Ken Mattingly, who was grounded after exposure to rubella. A routine stir of an oxygen tank ignited damaged wire insulation inside it, causing an explosion that vented the contents of both of the SM's oxygen tanks to space. Without oxygen, needed for breathing and for generating electric power, the SM's propulsion and life support systems could not operate. The CM's systems had to be shut down to conserve i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Return Trajectory
In orbital mechanics, a free-return trajectory is a trajectory of a spacecraft traveling away from a primary body (for example, the Earth) where gravity due to a secondary body (for example, the Moon) causes the spacecraft to return to the primary body without propulsion (hence the term ''free''). Many free-return trajectories are designed to intersect the atmosphere; however, periodic versions exist which pass the moon and Earth at constant periapsis, which have been proposed for cyclers. Earth–Moon The first spacecraft to use a free-return trajectory was the Soviet Luna 3 mission in October 1959. It used the Moon's gravity to send it back towards the Earth so that the photographs it had taken of the far side of the Moon could be downloaded by radio. Symmetrical free-return trajectories were studied by Arthur Schwaniger of NASA in 1963 with reference to the Earth–Moon system. He studied cases in which the trajectory at some point crosses at a right angle the line going ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jim Lovell
James Arthur Lovell Jr. (; born March 25, 1928) is an American retired astronaut, naval aviator, test pilot and mechanical engineer. In 1968, as command module pilot of Apollo 8, he became, with Frank Borman and William Anders, one of the first three astronauts to fly to and orbit the Moon. He then commanded the Apollo 13 lunar mission in 1970 which, after a critical failure en route, circled the Moon and returned safely to Earth. A graduate of the United States Naval Academy in Annapolis, Maryland, in the class of 1952, Lovell flew F2H Banshee night fighters. This included a Western Pacific deployment aboard the aircraft carrier . In January 1958, he entered a six-month test pilot training course at the Naval Air Test Center at Naval Air Station Patuxent River, Maryland, with Class 20 and graduated at the top the class. He was then assigned to Electronics Test, working with radar, and in 1960 he became the McDonnell Douglas F-4 Phantom II program manager. The following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 cre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Control System
A reaction control system (RCS) is a spacecraft system that uses thrusters to provide attitude control and translation. Alternatively, reaction wheels are used for attitude control. Use of diverted engine thrust to provide stable attitude control of a short-or-vertical takeoff and landing aircraft below conventional winged flight speeds, such as with the Harrier "jump jet", may also be referred to as a reaction control system. Reaction control systems are capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow control of rotation ( roll, pitch, and yaw). Reaction control systems often use combinations of large and small ( vernier) thrusters, to allow different levels of response. Uses Spacecraft reaction control systems are used for: * attitude control during different stages of a mission; * station keeping in orbit; * close maneuvering during docking procedures; * c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-IVB
The S-IVB (pronounced "S-four-B") was the third stage on the Saturn V and second stage on the Saturn IB launch vehicles. Built by the Douglas Aircraft Company, it had one J-2 rocket engine. For lunar missions it was fired twice: first for Earth orbit insertion after second stage cutoff, and then for translunar injection (TLI). History The S-IVB evolved from the upper stage of the Saturn I rocket, the S-IV, and was the first stage of the Saturn V to be designed. The S-IV used a cluster of six engines but used the same fuels as the S-IVB – liquid hydrogen and liquid oxygen. It was also originally meant to be the fourth stage of a planned rocket called the C-4, hence the name S-IV. Eleven companies submitted proposals for being the lead contractor on the stage by the deadline of 29 February 1960. NASA administrator T. Keith Glennan decided on 19 April that Douglas Aircraft Company would be awarded the contract. Convair had come a close second but Glennan did not want to monopol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturn V Rocket
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 three stages, and 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. 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 Lunar Module to the Moon. The largest production model of the 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 contractors were Boeing, North American Aviation, Douglas Aircraft Company, and IBM. A total of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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