Image Aerocapture.svg thumb right 500px The five steps of an aerocaptureAerocapture is a technique used to reduce velocity of a spacecraft, arriving at a celestial body with a hyperbolic trajectory , in order to bring it in an orbit with an eccentricity orbit eccentricity of less than 1. ref cite conference title The aerocapture vehicle mission design concept author Cruz, MI conference Conference on Advanced Technology for Future Space Systems, Hampton, Va. date May 8 10, 1979 booktitle Technical Papers. A79 34701 14 12 location New York publisher American Institute of Aeronautics and Astronautics pages 195 201 volume 1 url http adsabs.harvard.edu abs 1979atfs.conf..195C ref It uses the drag created by the atmosphere of the celestial body to decelerate. Only one pass in the atmosphere is required by this technique, in contrast with aerobraking . However, this approach requires significant thermal protection and precision closed loop guidance during the maneuver. This level of control authority .... In practice Aerocapture has not yet been tried on a planetary mission, but the Skip reentry re entry skip by Zond 6 and Zond 7 upon lunar return were aerocapture maneuvers, since they turned ... the perigee after the aerocapture, the resulting orbit still intersected the atmosphere, and re entry occurred at the next perigee. Aerocapture was originally planned for the Mars Odyssey orbiter, ref ... archive nasa casi.ntrs.nasa.gov 20050207424 2005207086.pdf title Assessing the Relative Risk of Aerocapture ... 2005 ref Aerocapture has been proposed and analyzed for arrival at Saturn s moon Titan moon Titan . ref cite journal title Aerocapture simulation and performance for the Titan Explorer mission author ... Aerocapture within fiction can be read in Arthur C. Clarke s novel 2010 Odyssey Two , in which two spacecraft one Russian, one Chinese both use aerocapture in Jupiter s atmosphere to shed their excess ... spacecraft undergoes aerocapture in the film incorrectly called aerobraking , which is demonstrated ... more details
An aerogravity assist , or AGA , is a spacecraft maneuver designed to change velocity when arriving at a body with an atmosphere . A pure gravity assist uses only the gravity of a body to change the direction of the spacecraft trajectory. The change in direction is limited by the mass of the body, and how closely it can be approached. An aerogravity assist uses a closer approach to the planet, dipping into the atmosphere, so the spacecraft can also use lift force aerodynamic lift to further curve the trajectory. This enables the spacecraft to deflect through a larger angle, resulting in a higher delta v change in velocity . This in turn allows a shorter travel time, a larger payload fraction of the spacecraft, or a smaller spacecraft for a given payload. The related techniques of aerocapture , aerobraking , and atmospheric re entry also attempt to use the body s atmosphere to help reduce propulsion requirements. In an aerogravity assist, however, the goal is not to use the atmosphere to slow the spacecraft down, but instead use it to achieve a larger change in direction. Aerogravity assists are so far theoretical and have not yet been used. See also Aerocapture Aerobraking Atmospheric reentry References cite conference title Hypersonic maneuvering to provide planetary gravity assist author McDonald, Angus D., Randolph, James E. booktitle AIAA 1990 539, 28th Aerospace Sciences Meeting location Reno, NV date Jan 8 11,1990 cite journal doi 10.1016 0094 5765 94 00195 R title Aerogravity assist trajectories to the outer planets author Sims, JA and Longuski, JM and Patel, MR journal Acta Astronautica volume 35 pages 297 297 year 1995 publisher Pergamon Press Category Spaceflight Category Space technology Category Spacecraft propulsion ... more details
aerodynamic decelerators , ballute , expandable terminal decelerators , and aerocapture inflatable .... ref http metnet.fmi.fi index.pp?id 49 MetNet EDLS ref Martian air can also be used for aerocapture ... more details
for the Mars Sample Return mission. Mars aerocapture demonstrator , to further develop ... aerocapture, solar electric propulsion and soft landing to be launched in 2018. ref Compare http ... aerocapture , solar electric propulsion and soft landing formerly envisaged as a smaller ... aerocapture, solar electric propulsion and soft landing formerly envisaged as a smaller Arrow class ... more details
Refimprove date June 2011 Asteroid capture can happen when an asteroid approaches a large planetary body . Typically asteroids that approach close enough to a planet are thrown out into space or impact the body. In rarer instances, the asteroid is captured in orbit around the planet ref http www.earthsky.org faq asteroids accretion ref . This is possible with any planetary body given the right conditions. Detailed explanation Asteroid capture happens when an asteroid has enough velocity to keep missing the planet it is falling towards but not enough velocity to escape orbit, in other words, when it reaches a stable orbit around it. Asteroids have natural properties that may lend themselves to be captured. The properties of an asteroid that are most significant to this process are its mass and relative velocity to the planet in question. The mass of the planet is also a key variable, as is the trajectory of the asteroid. An asteroid with too much velocity will pass by the planet with a hyperbolic orbit , shooting it out into space. Asteroids that do not have enough velocity will fall into the planet in an impact event . Any trajectory which has a lower relative velocity compared to the escape velocity which changes with distance will result in either capture or impact. Asteroid capture by Earth The earth moon system creates a particularly unstable situation whereby the orbit of the asteroid is destabilized. However, with the right orbital stabilization techniques, it may be possible to keep an asteroid in orbit above the earth. Effecting capture Spontaneous capture relates to a method whereby an asteroid s velocity is not changed and it is captured by the planet. fact date April 2012 Aerocapture relates to a method of slowing down an object, which could theoretically be an asteroid. It involves slowing down the asteroid with the atmosphere of the planet. Problems The problems surrounding causing a man made capture scenario are many. These stem from the fact that we d ... more details
reentry or aerocapture . Simulations of the Mars Reconnaissance Orbiter aerobraking use a force ... Bot generated title ref Related methods Aerocapture is a related but more extreme method in which ... nasa casi.ntrs.nasa.gov 20050207424 2005207086.pdf title Assessing the Relative Risk of Aerocapture ... Spaceflight Aerocapture Skip reentry Lithobraking Notes Reflist References http mars.jpl.nasa.gov ... more details
Image F 111F dropping high drag bombs.jpg thumb 250px Ballute on freefall bombs File 20110430 BurbleFence 000.svg thumb 250px Sketch of ballute components A ballute a portmanteau combining balloon and parachute was invented by Goodyear Tire and Rubber Company Goodyear in 1958. It is a parachute braking device that is optimized for use at high altitudes and high supersonic velocities. The original ballute was a cone shaped balloon with a toroid al burble fence fitted around its widest point. The burble fence is an inflated toroidal structure on a ballute intended to ensure flow separation. ref http ntrs.nasa.gov archive nasa casi.ntrs.nasa.gov 19690017080 1969017080.pdf ref This stabilizes the ballute as it deccelerates through different flow regimes from supersonic to subsonic . The ballute is either inflated by a gas generator, or by air forced into the structure by ram air inlets. Ballutes have also been proposed in stacked toroidal and tension cone form factors, in additional to the more standard isotensoid ballute. ref name ss2011 Applications The ballute has been used as a retarding device for freefall gravity bomb bombs dropped from aircraft. It was used as part of the escape equipment for the Project Gemini Gemini spacecraft. ref www.hq.nasa.gov office pao History SP 4203 ch8 4.htm ref It has been proposed for use during aerocapture and aerobraking . ref name as20111224 cite web title Reentry System CubeSat Recovery System url http www.andrews space.com content main.php?mainsection Mjc2 year 2008 publisher Andrews Space accessdate 2011 12 24 ref Extended designs using inflatable tension cone ballute technology have been proposed for Nanosatellite NanoSat deorbit and recovery of low mass convert 1.5 kg satellite s from low Earth orbit . ref name ss2011 cite web title NanoSat Deorbit and Recovery System DRS to Enable New Missions url http www.andrews space.com brochures Publications AndrewsSpace SmallSat2011 NanosatelliteDeorbitandRecovery.pdf work conference p ... more details
Refimprove date December 2009 Orbit insertion is the spaceflight operation of adjusting a spacecraft s momentum to allow for entry into a stable orbit around a planet , moon , or other celestial body. ref cite web url http library.thinkquest.org 03oct 02144 spacecraft orbit.htm Thinkquest.org title Orbital Insertion ref This maneuver involves either deceleration from a speed in excess of the respective body s escape velocity , or acceleration to it from a lower speed. Deceleration The first kind of orbit insertion is used when capturing into orbit around a celestial body other than Earth, owing to the excess speed of interplanetary transfer orbits relative to their destination orbits. This shedding of excess velocity is typically achieved via a rocket firing known as an orbit insertion burn. For such a maneuver, the spacecraft s engine thrusts in its direction of travel for a specified duration to slow its velocity relative to the target body enough to enter into orbit. ref cite web url http www.astronomy.com link.aspx? id 8d44e60f 5911 4e5a ae09 158e39ad8655 Astronomy.com title MESSENGER poised for Mercury orbit insertion ref Another technique, used when the destination body has a tangible atmosphere, is called aerobraking , which uses the friction of atmospheric drag to slow a spacecraft. Generally aerobraking is used to circularize a highly elliptical capture orbit while minimizing the use of on board fuel. To date, only a handful of aerocapture maneuvers have been attempted by NASA. ref cite web url http trs new.jpl.nasa.gov dspace bitstream 2014 17918 1 99 1368.pdf jpl.nasa.gov title AEROBRAKING AT VENUS AND MARS A COMPARISON OF THE MAGELLAN AND MARS GLOBAL SURVEYOR AEROBRAKING PHASES ref Acceleration The second type of orbit insertion is used for newly launched satellite s and other spacecraft. The majority of space launch vehicle s used today can only launch a payload into a very narrow range of orbits. The angle relative to the equator and maximum altitude o ... more details
Dablink For the cancelled 1990s NASA Neptune Orbiter, see Mariner Mark II Neptune Orbiter was a proposed NASA unmanned planetary spacecraft to explore the planet Neptune . It was envisioned that it would be launched sometime around 2016 and take 8 to 12 years to reach the planet however, http solarsystem.nasa.gov missions future1.cfm NASA s website no longer lists any possible launch date. The Neptune Orbiter was designed to answer many questions that still surround the planet. Its main mission was to study Neptune s atmosphere and weather, its ring system, and its moons, particularly Triton moon Triton . The California Institute of Technology proposed one mission plan, while the University of Idaho and Boeing proposed an alternative approach. Citation needed date August 2009 Mission Summary and Status Neptune Orbiter s primary mission was to go into orbit and perform scientific analysis on the planet. The mission was first picked up from NASA in 2005. It was expected to use a launch rocket similar to the Delta IV rocket Delta IV or Atlas V . The orbiter s trajectory was to use one Venus gravity assist, and a Jupiter gravity assist before arriving at Neptune. The length of time from launch until Neptune arrival was estimated to be 10.25 years. One early proposed idea for the mission included a Uranus fly by, although the fly by was deemed unnecessary and was scratched off the schedule. Citation needed date August 2009 Just prior to arriving, the orbiter would release its two atmospheric probes which will transmit data before aerocapture . Then, it would begin Neptune Orbit Insertion by aerocapture. After adjusting its orbit to its regular science orbit, the orbiter would carry out studies of Neptune, its rings, atmospheric weather & climate, and satellites. The main phase of the science operations would take as long as 3 to 5 years with an extended mission phase lasting 3 more years. Citation needed date August 2009 In 2008, the mission was removed from http solarsy ... more details
Use mdy dates date March 2011 Year dab 2018 Year nav 2018 C21 year in topic 2018 Roman numerals MMXVIII will be a common year starting on Monday common year starting on a Monday in the Gregorian calendar . It is the 2018th year of Common Era also called Anno Domini , the 18th of the 3rd millennium and the 21st century and the 9th of the 2010s . In 2018, the 10 years bonds opened by many countries to face the GFC will start to expire. Predicted and scheduled events February February 9 February 25 &ndash 2018 Winter Olympics to be held in Pyeongchang , South Korea . June June 8 July 8 &ndash 2018 FIFA World Cup to be held in Russia . July July 27 &ndash Mars will make its closest approach to Earth since 2003 . It will not be as close as the 2003 opposition. July 30 &ndash NASA s Solar Probe Plus will be launched. ref http solarprobe.jhuapl.edu index.php ref Date unknown The US missile defense complex in Poland Reformulated Obama administration project US missile defense complex in Poland will be operational. ref http www.neurope.eu article us missile defence shield be poland 2018 ref The James Webb Space Telescope JWST is likely to be launched no earlier than 2018. It is intended as a successor to the Hubble Space Telescope HST , which was launched in 1990. The Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter London Convention , which prevents sea dumping, expires. Researchers and investors in space elevator technology hope to start funding the construction of the first elevator by 2031. ref Boyle, A Cosmic Log MSNBC, 10 October 2006 ref Aurora Programme Aerocapture and soft landing technology demonstrator for Mars. The Helium Centennial Time Columns Monument is expected to be opened 50 years after the time capsule was locked in 1968 . According to futurist Ray Kurzweil , by 2018 there will be a drug that lets you eat whatever you want without gaining weight. ref cite news first John last Tierney authorlink coauthors title The Fut ... more details
This is an alphabetical list of articles pertaining specifically to aerospace engineering . For a broad overview of engineering, see List of engineering topics . For biographies, see List of engineers . compactTOC8 side yes nobreak yes A Ablative laser propulsion Absolute value Acceleration Action physics Action Advanced Space Vision System Aeroacoustics Aerobrake Aerobraking Aerocapture Aerodynamics Aeroelasticity Aeronautical abbreviations Aeronautics Aerospace engineering Aerospike engine Aerostat Aft crossing trajectory Aileron Air augmented rocket Aircraft Aircraft flight control systems Aircraft flight mechanics Airlock Airship Alcubierre drive Angle of attack Angular momentum Angular velocity Antimatter rocket Apsis Arcjet rocket Areal velocity ARP4761 Astrodynamics Atmospheric reentry Attitude control Avionics B Balloon aircraft Balloon Ballute Beam powered propulsion Bernoulli s equation Bi elliptic transfer Big dumb booster Bipropellant rocket Bleed air Booster rocket Breakthrough Propulsion Physics Program Buoyancy Bussard ramjet Brianna Mears C Canard aeronautics Canard Centennial challenges Center of gravity Center of mass Center of pressure fluid mechanics Center of pressure Chord aircraft Chord Collimated light Compressibility Computational fluid dynamics Computing Control engineering Conservation of momentum Crew Exploration Vehicle Critical mach Centrifugal compressor D De Laval nozzle Deflection engineering Deflection Delta v Delta v budget Density Derivative Digital Datcom Displacement vector DO 178B DO 254 Drag physics Drag coefficient Drag equation Dual mode propulsion rocket Delta wing E Earth s atmosphere Electrostatic ion thruster Elliptic partial differential equation Energy Engineering Engineering economics Enstrophy Equation of motion Euler angles European Space Agency Expander cycle rocket F Field Emission Electric Propulsion Fixed wing aircraft Flight controls disambiguation Flight controls Flight dynamics Floatstick Fluid Fluid dynamics ... more details
title A comparison of aerobraking and aerocapture vehicles for interplanetary missions booktitle AIAA ... , and at least one Venus mission, Magellan probe Magellan . Aerocapture is a much more aggressive ... in orbit, then at least one more propulsive maneuver is required after aerocapture otherwise the low point of the resulting orbit will remain in the atmosphere, resulting in eventual re entry. Aerocapture ... 7 upon lunar return were aerocapture maneuvers, since they turned a hyperbolic orbit into an elliptical orbit. On these missions, since there was no attempt to raise the perigee after the aerocapture ... more details
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