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 requires either the production of significant lift, or relatively large attitude control thrusters. 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 a hyperbolic orbit into an elliptical orbit. On these missions, since there was no attempt to raise the perigee after the aerocapture, the resulting orbit still intersected the atmosphere, and re entry occurred at the next perigee. 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 ... 4951.pdf ref In fiction 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 ... in which only a Russian spacecraft undergoes aerocapture in the film incorrectly called aerobraking ... more details
Summary The five steps of an aerocapture. Author SIgMA group, Universit de Sherbrooke. Licensing GFDL self with disclaimers migration relicense ... 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
for the Mars Sample Return mission. Mars aerocapture demonstrator , to further develop the technologies ... mission seems to have been revised into an expanded mission to demonstrate aerobraking aerocapture ... A technology demonstrator for aerobraking aerocapture , solar electric propulsion and soft landing ... mission with NASA 2018? A technology demonstrator for aerobraking aerocapture, solar electric propulsion ... more details
Image F 111F dropping high drag bombs.jpg thumb 250px Ballute on freefall bombs 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. It is either inflated by a gas generator, or by air forced into the structure by ram air inlets. Ballutes have also been proposed in toroidal form. 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. It has been proposed for use during aerocapture and aerobraking . Fictional references Ballutes are seen in the film 2010 film 2010 . They are used by the spaceship Alexei Leonov for an aerobraking manoeuvre around the planet Jupiter to enter orbit about the moon Io. In the animated Gundam series, ballutes are used for ships or mobile suits to re enter Earth s atmosphere. External links http esapub.esrin.esa.it bulletin bullet103 marraffa103.pdf http www.parachutehistory.com other ballute.html Andrews Space http www.andrews space.com content main.php?subsection MjA4 Ballute Rentry Technology and http www.andrews space.com images videos Ballute.wmv simulation video Category Spacecraft components fr Ballute lt Baliutas ja ... more details
Asteroid capture can happen when an asteroid comes into close contact with 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. 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. 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 . Earth Asteroid Capture 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. Aerocapture relates to a method of slowing down an object, which could theoretically be an asteroid. It would require slowing down the asteroid with the atmosphere of the nearby planet. Problems The problems surrounding causing a man made capture scenario are many. These stem from the fact that we do not have enough detailed information on the orbital elements of our solar system. Even the slightest variations in estimates for planetary velocity and mass can cause multiple earth radii of change in the asteroid deflection. References reflist DEFAULTSORT Asteroid ... 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 . California Institute of Technology proposed one mission plan, while 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 that of the Delta IV rocket Delta IV or Atlas V rocket. 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 s ... more details
Use mdy dates date March 2011 Year dab 2018 Year nav 2018 C21 year in topic NOTOC 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 . Predicted and scheduled events January 1 &ndash Estonia takes over the Presidency of the Council of the European Union from the United Kingdom . June 8 &ndash July 8 &ndash 2018 FIFA World Cup . July 1 &ndash Bulgaria takes over the Presidency of the Council of the European Union from Estonia . July 27 &ndash Mars will make its closest approach to Earth since 2003. It will not be as close as the 2003 opposition. October 31 &ndash Unless adequate alternatives are developed, cheques will be phased out in the UK. ref http news.bbc.co.uk 1 hi 8414341.stm ref Date unknown 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 International nuclear fusion project ITER is expected to be completed. 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 Future Is Now? Pretty Soon, at Least url http www.nytimes.com 2008 06 03 science 03tier.html work New York Times publisher date 2008 06 03 accessdate ref Expected completion of the Copenhagen City Circle Line The Giant Magellan Telescope will be completed. The European Extrem ... more details
Image Skip reentry trajectory.svg thumb 400px Atmospheric entry trajectory illustrating the basic phases of flight in a skip reentry. Skip reentry is a Atmospheric reentry reentry technique involving one or more successive skips off the atmosphere to achieve greater entry range or to slow the spacecraft before final entry, which helps to dissipate the huge amount of heat that is usually generated on faster descents. The range modulation made possible by skip entry allows a spacecraft to reach a wider landing area, or to reach a designated landing point from a wider range of possible entry times, which is especially important in abort situations. Like aerocapture , skip reentry requires precise guidance. An overly shallow entry angle will result in the spacecraft retaining too much of its velocity, possibly escaping into space permanently if this is more than escape velocity . An overly steep entry, on the other hand, results in more intense heating and stress that could exceed the design limits of the spacecraft, potentially destroying it. The basic concept is to clip the atmosphere at such an angle that the craft is pushed back out into space, conceptually similar to a pebble skipping across the surface of a lake. Each time, the craft s velocity is reduced so that it can eventually drop into the atmosphere at a low suborbital velocity. In theory, any craft could perform skip re entry as it does not require much lift, but in practice it requires precise guidance. Although the space shuttle is capable of skip reentry, NASA has carried it out only in computer simulations Scott Horowitz, NASA interview, Jan. 25, 2007 . It is unclear how thermal shielding would fare under the rapid heating, cooling and reheating. In theory STS 107 might have survived if a skip trajectory had been attempted giving more time for heat dissipation but this cannot be proven. Skip entry was first imagined in the 1930s, when a suborbital skipping trajectory was planned for the German Silbervog ... more details
reentry or aerocapture . Simulations of the Mars Reconnaissance Orbiter aerobraking use a force ... around Mars Bot generated title ref Related methods Aerocapture is a related but more extreme method ... 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 C Canard aeronautics Canard Centennial challenges Center of gravity Center of mass 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 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 Fluid mechanics Fluid statics Force Freefall G Gas generato ... more details
Hoffman title A comparison of aerobraking and aerocapture vehicles for interplanetary missions booktitle ... Venus mission, Magellan probe Magellan . Aerocapture is a much more aggressive manoeuver, converting ... 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 has not yet been ... 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, the resulting ... more details
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