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Saturn C-5N
The Saturn C-5N was a conceptual successor to the Saturn V launch vehicle which would have had a nuclear thermal third stage instead of the S-IVB used on the Saturn V. This one change would have increased the payload of the standard Saturn V to Low Earth orbit from 118,000 kg to 155,000 kg. The conceptual Saturn C-5N was designed as an evolutionary successor to the Saturn V, intended for the planned crewed mission to Mars by 1980, it would have cut crewed transit times to Mars to about 4 months, instead of the 8–9 months of chemical rocket engines. However the Mars mission, along with all work related to the evolutionary successors of the Saturn V, was cancelled in 1972-3 by the Nixon Administration. ''The Plum Brook Reactor Facility'', pp. 68, 73, 76, 101, 116, 129. The ground testing of ... [...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] |
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 pad, launch pads, supported by a missile launch control center, 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 spaceflight, 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 spaceflight, 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-propellant rocket, solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NERVA
Nerva (; originally Marcus Cocceius Nerva; 8 November 30 – 27 January 98) was Roman emperor from 96 to 98. Nerva became emperor when aged almost 66, after a lifetime of imperial service under Nero and the succeeding rulers of the Flavian dynasty. Under Nero, he was a member of the imperial entourage and played a vital part in exposing the Pisonian conspiracy of 65. Later, as a loyalist to the Flavians, he attained consulships in 71 and 90 during the reigns of Vespasian and Domitian, respectively. On 18 September 96, Domitian was assassinated in a palace conspiracy involving members of the Praetorian Guard and several of his freedmen. On the same day, Nerva was declared emperor by the Roman Senate. As the new ruler of the Roman Empire, he vowed to restore liberties which had been curtailed during the autocratic government of Domitian. Nerva's brief reign was marred by financial difficulties and his inability to assert his authority over the Roman army. A revolt by the Praeto ... [...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), 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 Saturn C-4, 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 G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. The term ''LEO region'' is also used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. All crewed space stations to date have been within LEO. From 1968 to 1972, the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, no human spaceflights have been beyond LEO. Defining characteristics A wide variety of sources define LEO in terms of altitude. The altitude of an object in an elliptic orbit can vary significantly along the orbit. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturn MLV
The Saturn MLV was a proposed concept family of rockets, intended as a follow-on to the Saturn V. MLV stands for "Modified Launch Vehicle". Vehicle configurations representative of several alternative uprating methods were specified by the Marshall Space Flight Center for initial studies. Proposed modifications # Thrust uprating and modifying of the five F-1 rocket engines used in the first S-IC stage, and corresponding increases in propellant tank capacities. # Addition of a sixth F-1 engine in the S-IC stage, as an alternative to engine uprating, plus increased propellant capacities. # Use of solid rocket boosters derived from the Titan IIIC vehicle. # Additional J-2 engines in the S-II stage, ~131 s increased upper stage propellant capacities. # Improved or advanced upper stage engines, such as the HG-3, plus increased propellant capacities. The baseline Saturn MLV would incorporate these changes from the Saturn V vehicle. The Saturn IC first stage would have been s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Crewed Mars Mission Plans
This list of crewed Mars mission plans is a listing of concept studies for a crewed mission to Mars during the 20th and 21st centuries. It is limited to studies done with engineering and scientific knowledge about the capabilities of then current technology, typically for high-budget space agencies like NASA. Mission profiles include crewed flybys, crewed landers, or other types of Mars system encounter strategies. Concepts Many mission concepts for expeditions to Mars were proposed in the late 20th century. David Portree's history volume ''Humans to Mars: Fifty Years of Mission Planning, 1950–2000'' discusses many of these.David S. F. Portree, ''Humans to Mars: Fifty Years of Mission Planning, 1950 – 2000,'' NASA Monographs in Aerospace History Series, Number 21, February 2001. Available aNASA SP-2001-4521 Portree notes that every 26 Earth months a lower energy Earth to Mars transfer opportunity opens, so missions typically coincide with one of these windows. In addition, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nixon Administration
Richard Nixon's tenure as the List of presidents of the United States, 37th president of the United States began with First inauguration of Richard Nixon, his first inauguration on January 20, 1969, and ended when he resigned on August 9, 1974, in the face of Impeachment process against Richard Nixon, almost certain impeachment because of the Watergate Scandal and resigned, the only U.S. president ever to do so. He was succeeded by Gerald Ford, whom he 1973 United States vice presidential confirmation, had appointed Vice President of the United States, vice president after Spiro Agnew became embroiled in a separate corruption scandal and was forced to resign. Nixon, a prominent member of the Republican Party (United States), Republican Party from California who previously served as vice president under Dwight D. Eisenhower, took office following the 1968 United States presidential election, 1968 presidential election, in which he defeated Hubert Humphrey, the then-incumbent vice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Thermal Rocket
A nuclear thermal rocket (NTR) is a type of thermal rocket where the heat from a nuclear reaction, often nuclear fission, replaces the chemical energy of the propellants in a chemical rocket. In an NTR, a working fluid, usually liquid hydrogen, is heated to a high temperature in a nuclear reactor and then expands through a rocket nozzle to create thrust. The external nuclear heat source theoretically allows a higher effective exhaust velocity and is expected to double or triple payload capacity compared to chemical propellants that store energy internally. NTRs have been proposed as a spacecraft propulsion technology, with the earliest ground tests occurring in 1955. The United States maintained an NTR development program through 1973 when it was shut down for various reasons, for example to focus on Space Shuttle development. Although more than ten reactors of varying power output have been built and tested, , no nuclear thermal rocket has flown. Whereas all early applicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Timberwind
Project Timberwind aimed to develop nuclear thermal rockets. Initial funding by the Strategic Defense Initiative ("Star Wars") from 1987 through 1991 totaled $139 million (then-year). The proposed rocket was later expanded into a larger design after the project was transferred to the Air Force Space Nuclear Thermal Propulsion (SNTP) program. The program underwent an audit in 1992 due to security concerns raised by Steven Aftergood. This special access program, highly classified program provided the motivation for starting the Federation of American Scientists#Government_Secrecy, FAS Government Secrecy project. Convicted spy Stewart Nozette was found to be on the master access list for the TIMBER WIND project. Advances in high-temperature metals, computer modelling and nuclear engineering in general resulted in dramatically improved performance. Whereas the NERVA engine was projected to weigh about 6803 kg, the final SNTP offered just over 1/3 the thrust from an engine of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
