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Aerodynamic Braking
Aerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit (apoapsis) by flying the vehicle through the atmosphere at the low point of the orbit (periapsis). The resulting drag slows the spacecraft. Aerobraking is used when a spacecraft requires a low orbit after arriving at a body with an atmosphere, as it requires less fuel than using propulsion to slow down. Method When an interplanetary vehicle arrives at its destination, it must reduce its velocity to achieve orbit or to land. To reach a low, near-circular orbit around a body with substantial gravity (as is required for many scientific studies), the required velocity changes can be on the order of kilometers per second. Using propulsion, the rocket equation dictates that a large fraction of the spacecraft mass must consist of fuel. This reduces the science payload and/or requires a large and expensive rocket. Provided the target body has an atmosphere, aerobraking can be used to reduce fuel re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRO Aerobrake
MRO or Mro may refer to: People * Mru (other), peoples and languages also known as Mro * Mary Rambaran-Olm, Canadian literary historian Locations * Hood Aerodrome (IATA code MRO), near Masterton, New Zealand * Marlborough (other), some cities named Marlborough use MRO as an abbreviation * Magdalena Ridge Observatory, a multi-use astronomical observatory near Socorro, New Mexico, United States * Morradoo railway station, Melbourne * Murchison Radio-astronomy Observatory in outback Western Australia, one of the Square Kilometre Array core sites Companies * Hokuriku Broadcasting Company, also known as MRO, a broadcasting station in Ishikawa Prefecture, Japan * Marathon Oil Corporation, listed on the New York Stock Exchange as MRO * Melrose Industries, listed on the London Stock Exchange as MRO * MRO Software, a software company best known for its Maximo maintenance management system Organisations * Middlesex Record Office, former historical organisa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Month
A month is a unit of time, used with calendars, that is approximately as long as a natural phase cycle of the Moon; the words ''month'' and ''Moon'' are cognates. The traditional concept of months arose with the cycle of Moon phases; such lunar months ("lunations") are Lunar month#Synodic month, synodic months and last approximately 29.53 days, making for roughly 12.37 such months in one Earth year. From excavated tally sticks, researchers have deduced that people counted days in relation to the Moon's phases as early as the Paleolithic age. Synodic months, based on the Moon's orbital period with respect to the Earth–Sun line, are still the basis of many calendars today and are used to divide the year. Calendars that developed from the Roman calendar system, such as the internationally used Gregorian calendar, divide the year into 12 months, each of which lasts between 28 and 31 days. The names of the months were Anglicized from various Latin names and events important to Rome, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kalman Filter
In statistics and control theory, Kalman filtering (also known as linear quadratic estimation) is an algorithm that uses a series of measurements observed over time, including statistical noise and other inaccuracies, to produce estimates of unknown variables that tend to be more accurate than those based on a single measurement, by estimating a joint probability distribution over the variables for each time-step. The filter is constructed as a mean squared error minimiser, but an alternative derivation of the filter is also provided showing how the filter relates to maximum likelihood statistics. The filter is named after Rudolf E. Kálmán. Kalman filtering has numerous technological applications. A common application is for guidance, navigation, and control of vehicles, particularly aircraft, spacecraft and ships Dynamic positioning, positioned dynamically. Furthermore, Kalman filtering is much applied in time series analysis tasks such as signal processing and econometrics. K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moriba Jah
Moriba Kemessia Jah CorrFRSE (born 1971) is an American space scientist and aerospace engineer who describes himself as a "space environmentalist". Jah is adamant finding solution to the accumulating garbage in space. He specializes in orbit determination and prediction, especially as related to space situational awareness and space traffic monitoring. He is currently a full professor of Aerospace Engineering and Engineering Mechanics at the University of Texas at Austin, a position he attained in 2024, and a National Geographic Explorer. Jah has co-founded Privateer Space x Orbital Insight, GaiaVerse, and Moriba Jah Universal. His work now broadly focuses on decision intelligence to improve the stewardship of the planet and beyond. In 2024, Privateer Space acquired Orbital Insight, a satellite imagery analytics company, following Series A Funding. Jah has authored a number of academic papers, including ''Entropy-based approach for uncertainty propagation of nonlinear dynamic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Observer
The ''Mars Observer'' spacecraft, also known as the ''Mars Geoscience/Climatology Orbiter'', was a Robotic spacecraft, robotic space probe launched by NASA on September 25, 1992, to study the Martian surface, atmosphere, climate and magnetic field. On August 21, 1993, during the interplanetary cruise phase, communication with the spacecraft was lost, three days prior to the probe's orbital insertion. Attempts to re-establish communications with the spacecraft were unsuccessful. Mission background History In 1984, a high priority mission to Mars was set forth by the Solar System Exploration Committee. Then titled the ''Mars Geoscience/Climatology Orbiter'', the Martian orbiter was planned to expand on the information already gathered by the Viking program. Preliminary mission goals expected the probe to provide planetary magnetic field data, detection of certain spectral line signatures of minerals on the surface, images of the surface at 1 meter/pixel and global elevation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), with the third being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newton (unit)
The newton (symbol: N) is the unit of force in the International System of Units (SI). Expressed in terms of SI base units, it is 1 kg⋅m/s2, the force that accelerates a mass of one kilogram at one metre per second squared. The unit is named after Isaac Newton in recognition of his work on classical mechanics, specifically his second law of motion. Definition A newton is defined as 1 kg⋅m/s2 (it is a named derived unit defined in terms of the SI base units). One newton is, therefore, the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by one metre per second every second. In 1946, the General Conference on Weights and Measures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount need ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force
In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitude (mathematics), magnitude and Direction (geometry, geography), direction of a force are both important, force is a Euclidean vector, vector quantity. The SI unit of force is the newton (unit), newton (N), and force is often represented by the symbol . Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include Elasticity (physics), elastic, frictional, Normal force, contact or "normal" forces, and gravity, gravitational. The rotational version of force is torque, which produces angular acceleration, changes in the rotational speed of an object. In an extended body, each part applies forces on the adjacent pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Reconnaissance Orbiter
The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on August 12, 2005, at 11:43 UTC and reached Mars on March 10, 2006, at 21:24 UTC. In November 2006, after six months of aerobraking, it entered its final science orbit and began its primary science phase. Mission objectives include observing the climate of Mars, investigating geologic forces, providing reconnaissance of future landing sites, and relaying data from surface missions back to Earth. To support these objectives, the ''MRO'' carries different scientific instruments, including three cameras, two spectrometers and a subsurface radar. As of July 29, 2023, the ''MRO'' has returned over 450 terabits of data, helped choose safe landing sites for NASA's Mars landers, discovered pure water ice in new craters and further evidence that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerocapture
Aerocapture is an Orbital maneuver, orbital transfer maneuver in which a spacecraft uses aerodynamic drag force from a single pass through a planetary atmosphere to decelerate and achieve orbit insertion. Aerocapture uses a planet's or moon's atmosphere to accomplish a quick, near-propellantless orbit insertion maneuver to place a spacecraft in its science orbit. The aerocapture maneuver starts as the spacecraft enters the atmosphere of the target body from an interplanetary approach trajectory. The aerodynamic drag generated as the vehicle descends into the atmosphere slows the spacecraft. After the spacecraft slows enough to be captured by the planet, it exits the atmosphere and executes a small propulsive burn at the first apoapsis to raise the periapsis outside the atmosphere. Additional small burns may be required to correct apoapsis and inclination targeting errors before the initial science orbit is established. Compared to conventional propulsive orbit insertion, this nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Reentry
Atmospheric entry (sometimes listed as Vimpact or Ventry) 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. Atmospheric entry may be ''uncontrolled entry,'' as in the entry of astronomical objects, space debris, or bolides. It may be ''controlled entry'' (or ''reentry'') of a spacecraft that can be navigated or follow a predetermined course. Methods for controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience Drag (physics), 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. Objects have reentered with speeds ranging from 7.8&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat
In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, atomic, or molecular particles, or small surface irregularities, as distinct from the macroscopic modes of energy transfer, which are thermodynamic work and transfer of matter. For a closed system (transfer of matter excluded), the heat involved in a process is the difference in internal energy between the final and initial states of a system, after subtracting the work done in the process. For a closed system, this is the formulation of the first law of thermodynamics. Calorimetry is measurement of quantity of energy transferred as heat by its effect on the states of interacting bodies, for example, by the amount of ice melted or by change in temperature of a body. In the International System of Units (SI), the unit of measurement for he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
