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David Y. Oh
David Y. Oh is an American spacecraft systems engineer and expert in electric propulsion. Dr. Oh currently works at the Jet Propulsion Laboratory (JPL) as the NASA Psyche mission chief engineer. Prior to this role he served as the Project Systems Engineering Manager for Psyche. He was also the cross-cutting phase lead and lead flight director for the NASA Mars Science Laboratory mission ( Curiosity Mars rover) and was recognized in popular media for living on Mars time with his family during the month following the landing of the Curiosity rover. Early life and education David Oh was raised in Birmingham, Alabama and graduated from Indian Springs School in 1987. He attended the Massachusetts Institute of Technology where he earned Bachelors of Science degrees in Aeronautics and Astronautics (1991) and in Humanities, Music (1991). He went on to earn both a master's degree (1993) and a Doctor of Science degree (1997) in Aeronautics and Astronautics from MIT. For his doctoral t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerospace Engineering
Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is similar, but deals with the electronics side of aerospace engineering. "Aeronautical engineering" was the original term for the field. As flight technology advanced to include vehicles operating in outer space, the broader term "aerospace engineering" has come into use. Aerospace engineering, particularly the astronautics branch, is often colloquially referred to as "rocket science". Overview Flight vehicles are subjected to demanding conditions such as those caused by changes in atmospheric pressure and temperature, with structural loads applied upon vehicle components. Consequently, they are usually the products of various technological and engineering disciplines including aerodynamics, Air propulsion, avionics, materials science, stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle-in-cell
In plasma physics, the particle-in-cell (PIC) method refers to a technique used to solve a certain class of partial differential equations. In this method, individual particles (or fluid elements) in a Lagrangian frame are tracked in continuous phase space, whereas moments of the distribution such as densities and currents are computed simultaneously on Eulerian (stationary) mesh points. PIC methods were already in use as early as 1955, even before the first Fortran compilers were available. The method gained popularity for plasma simulation in the late 1950s and early 1960s by Buneman, Dawson, Hockney, Birdsall, Morse and others. In plasma physics applications, the method amounts to following the trajectories of charged particles in self-consistent electromagnetic (or electrostatic) fields computed on a fixed mesh. Technical aspects For many types of problems, the classical PIC method invented by Buneman, Dawson, Hockney, Birdsall, Morse and others is relatively intuitiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Recovery And Interior Laboratory
The Gravity Recovery and Interior Laboratory (GRAIL) was an American lunar science mission in NASA's Discovery Program which used high-quality gravitational field mapping of the Moon to determine its interior structure. The two small spacecraft GRAIL A (Ebb) and GRAIL B (Flow) were launched on 10 September 2011 aboard a single launch vehicle: the most-powerful configuration of a Delta II, the 7920H-10. GRAIL A separated from the rocket about nine minutes after launch, GRAIL B followed about eight minutes later. They arrived at their orbits around the Moon 25 hours apart. The first probe entered orbit on 31 December 2011 and the second followed on 1 January 2012. The two spacecraft impacted the Lunar surface on December 17, 2012. Overview Maria Zuber of the Massachusetts Institute of Technology was GRAIL's principal investigator. NASA's Jet Propulsion Laboratory managed the project. NASA budgeted US$496 million for the program to include spacecraft and instrument development, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary Orbit
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitude above Earth's equator ( in radius from Earth's center) and following the direction of Earth's rotation. An object in such an orbit has an orbital period equal to Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky. The concept of a geostationary orbit was popularised by the science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, and the first satellite to be placed in this kind of orbit was launched in 1963. Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them but can be pointed permanently at the position in the sky where the sat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Maneuver
In spaceflight, an orbital maneuver (otherwise known as a burn) is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth (for example those in orbits around the Sun) an orbital maneuver is called a ''deep-space maneuver (DSM)''. The rest of the flight, especially in a transfer orbit, is called ''coasting''. General Rocket equation The Tsiolkovsky rocket equation, or ideal rocket equation is an equation that is useful for considering vehicles that follow the basic principle of a rocket: where a device that can apply acceleration to itself (a thrust) by expelling part of its mass with high speed and moving due to the conservation of momentum. Specifically, it is a mathematical equation that relates the delta-v (the maximum change of speed of the rocket if no other external forces act) with the effective exhaust velocity and the initial and final mass of a rocket (or other reaction engine.) For any such maneuver (or journey involvin ... [...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] |
SPT-140
SPT-140 is a solar-powered Hall-effect ion thruster, part of the SPT-family of thrusters. SPT stands for ''Stationary Plasma Thruster''. Like other members of the SPT series, it creates a stream of electrically charged xenon ions accelerated by an electric field and confined by a magnetic field. The thruster is manufactured by the Russian OKB Fakel, who collaborated during development with NASA's Glenn Research Center, Space Systems Loral, and Pratt & Whitney beginning in the late 1980s. It was first tested at the Plasmadynamics and Electric Propulsion Laboratory in 1997. In 2002, it was tested as a 3.5 kW unit by the United States Air Force as part of its Integrated High Payoff Rocket Propulsion Technology program. In 2023, the thruster was launched aboard NASA's Psyche spacecraft. Specifications See also * PPS-1350 * SPT-100 SPT-100 is a Hall-effect ion thruster, part of the SPT-family of thrusters. SPT stands for ''Stationary Plasma Thruster''. It creates a stream of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPT-100
SPT-100 is a Hall-effect ion thruster, part of the SPT-family of thrusters. SPT stands for ''Stationary Plasma Thruster''. It creates a stream of electrically charged xenon ions accelerated by an electric field and confined by a magnetic field. The thruster is manufactured by Russian OKB Fakel, and was first launched onboard Gals-1 satellite in 1994. In 2003 Fakel debuted a second generation of the thruster, called SPT-100B, and in 2011 it presented further upgrades in SPT-100M prototypes. As of 2011 SPT-100 thrusters were used in 18 Russian and 14 foreign spacecraft, including IPSTAR-II, Telstar-8 and Ekspress A and AM constellations. Specifications See also * PPS-1350 PPS-1350 is a Hall-effect thruster, a kind of ion propulsion system for spacecraft. It was used in the SMART-1 mission to the moon and one geostationary satellites: Inmarsat-4A F4. It creates a stream of electrically charged xenon ions acceler ... Stationary plasma thrusters¼ˆPDF) References {{Reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SSL 1300
The SSL 1300, previously the LS-1300 and the FS-1300, is a satellite bus produced by Maxar Technologies. Total broadcast power ranges from 5 to 25 kW, and the platform can accommodate from 12 to 150 transponders. The SSL 1300 is a modular platform and Maxar Technologies no longer reports designators for sub-versions, such as: 1300E, 1300HL, 1300S, 1300X. First available in the late 1980s, the SSL 1300 platform underwent revision multiple times over its design life, all the while remaining a popular communications platform. The earliest models provided 5,000 RF watts of transmitter power, weighed 5,500 kg, and required a 4-meter diameter launch fairing. Newer models provide double that, approximately 10,000 RF watts of transmitter power, weigh 6,700 kg, and require a 5-meter diameter launch fairing. SSL stated that they would use electric propulsion for North-South station keeping for the first time on the MBSat in 2004. The subsystem was supplied by International S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Systems/Loral
SSL, formerly Space Systems/Loral, LLC (SS/L), of Palo Alto, California, is a wholly owned manufacturing subsidiary of Maxar Technologies. SSL designs and builds satellites and space systems for a wide variety of government and commercial customers. Its products include high-powered direct-to-home broadcast satellites, commercial weather satellites, digital audio radio satellites, Earth observation satellites and spot-beam satellites for data networking applications. History The company was founded as the Western Development Laboratories (WDL) of Philco (Philco-Ford since 1966). The Space Systems Division was made a stand-alone Division of Aeronutronic/Ford Aerospace/ and was acquired by Loral Corp. in 1990 for $715 million from Ford Motor Company, and renamed Space Systems/Loral. All other divisions of Ford Aerospace including Western Development Labs now located in San Jose were also acquired by Loral at that time. In 2012 Space Systems/Loral was acquired by the Canadia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
