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Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. However, most spacecraft today are propelled by exhausting a gas from the back/rear of the vehicle at very high speed through a supersonic de Laval nozzle. This sort of engine is called a rocket engine. All current spacecraft use chemical rockets (bipropellant or solid-fuel) for launch, though some (such as the Pegasus rocket and SpaceShipOne) have used air-breathing engines on their first stage. Most satellites have simple reliable chemical thrusters (often monopropellant rockets) or resistojet rockets for orbital station-keeping and some use momentum wheels for attitude control. Soviet bloc satellites have used electric propulsion for decades, and newer Western geo-orbiting spacecraft are starting to use them for north-south stationkeeping. Interplanetary vehicles mostly use chemical rockets as well, although a few have experimentally used ion thrusters (a form of electric propulsion) to great success. From Wikipedia under the
GNU Free Documentation License  originlab.com 398px x 456px | 9.90kB [source page] the first graph the top X and right Y axes were enabled for the layer Finally several text labels and arrows were again included Figure 2 Origin s Plot Details dialog box showing the Fill Area Under Curve check box  grin.hq.nasa.gov 954px x 1420px | 1400.00kB [source page] Image KSC 97PC 903 606x407 JPG 253 KBytes 1420x954 JPG 1 429 KBytes 2840x1907 JPG 6 750 KBytes  conferences.esa.int 693px x 695px | 16.40kB [source page] The conference will take place at the European Space Research and Technology Centre estec noordwijk located on the North Sea coast about 35 km 20 miles south of Amsterdam Airport see access map 60K Major car rental companies and some local ones have offices at Amsterdam Airport To get to ESTEC by car exit Amsterdam Airport and take the A4 motorway highway From Yahoo Image Search: "Spacecraft propulsion"  news.google.com Tulsa World He presided over important robotic space missions including the launches of the Magellan spacecraft to Venus and the Galileo mission to Jupiter. ... and more » news.google.com Aviation Week One approach to the problem is the Space Tracking and Surveillance System satellite, which uses infrared sensors on two spacecraft to track missiles. ... and more » news.google.com Space Fellowship Credit: NASA The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 8, 2009. The view was acquired at a distance of ... Cassini Does New Flyby Around Titan The Saturnine moon was investigated on ... Softpedia all 12 news articles » From Google News Search: "Spacecraft propulsion" I wonder if humans will ever try a steam powered spacecraft, with compressed steam as a propulsion system? Q. I wouldn't be suprised. Asked by dark_hellbent_king - Thu Jan 11 05:26:17 2007 - - 6 Answers - 0 Comments A. Unlikely - it would be very inefficient. Just for fun, read Poul Anderson's short story "The Makeshift Rocket" - it's about a beer powered spaceship. Answered by Iridflare - Thu Jan 11 06:16:15 2007 Physicists, help me understand inertia in vaccuums? Q. In particular, how is it possible for a spacecraft using rocket propulsion to change direction, accelerate or decelerate in a vaccuum? Doesn't the vaccuum just absorb all the thrust the engine can produce, since there's no atmosphere for the thrust to push against? Or does the thrust push against the craft? I may have just answered my own question (equal and opposite reaction, eh?) but I'd like to hear some explanations from people more learned than I. What is it I'm not understanding about vaccuums? Thanks! Asked by Forty 7 - Wed Apr 2 16:53:45 2008 - - 4 Answers - 0 Comments A. Uuuuhhh... excuse me but Alcari is wrong. Rocket engines push against the craft into which they have been built. Now for directional control. The rocket's thrusters are moveable and can change the direction of the exhaust gasses within a small but significant radius. Space capsules have small thrusters mounted at strategic points in the craft. Delta Acceleration is accomplished by controlling the amount of fuel the engines receive. Deceleration is accomplished by turning the rocket 180 degrees and powering up the thrusters. Remember, a vacuum is essentially nothing... no atmosphere and therefore no air pressure, no wind resistance, just the occasional hydrogen atom to collide with. I've tried to simplify these answers for clarity… [cont.] Answered by dickn2000a - Wed Apr 2 17:26:11 2008 Can Man send manned or unmanned spacecrafts far out into Space?
Q. During the the Cold War and the Vietnam War the US government was being funded by the making and the selling of drugs. Now, that people have gotten wise to this scheme they've decided to come up with another...Space Travel? Just the other day I learned that when NASA sent a radio signal, traveling at the speed of light(186,000m/sec), to the spacecraft Voyager supposedly orbiting Neptune, it took 4hrs. First question came to mind was how long did it take for the spacecraft itself to reach Neptune. So, I did the math. First the distance and speed: 14,400/sec(4hrs) times 186,000mph/sec(speed of light)=2,678,400,000 miles. I don't know the speed of the aircraft as it traveled through space, but I do know it was launched Sept. 5, 1977( The… [cont.] Asked by Jimmy E - Wed Jan 6 08:35:30 2010 - - 6 Answers - 0 Comments From Yahoo Answer Search: "Spacecraft propulsion" |
