shun Posted March 17, 2004 #1 Share Posted March 17, 2004 (edited) I do not know if this belongs here, but I replied to Govt. Conspiracy board. Maybe it goes here! The actual Lunar Excursion Module (LEM) required around 11.5 minutes to descend from the Lunar Module (mothership), to the surface of the moon. From an orbit of 60 nauticle miles, they throttled the rockets to move closer in. Next is the braking phase. It is gradual, and saves on fuel. They then approached the surface like an airport. That is called a "highgate" position. Then, they correct for landing, pilot visibilty, and manual control, if needed. That is the "lowgate" phase. The rockets had around 10,000 pounds of thrust, but I do not know what the various missions carried, with Lunar Rovers, but that figure might cover it. The control was computerized, but could be flown manually. The actual LEMs had what is called "hypergolic" propellant. DiNitrogen Tetroxide and AeroZine 50 (50% Hydrazine, 50% Unsymmetrical Dimethyl Hydrazine) were kept in helium pressurized tanks. If you combine them, stand back! They feed into a chamber, and generate a thrust exhaust. No ignition mechanism to fail. LEMs had to ascend, go into orbital insertion, and dock with the main ship, back up at 60 n. miles. Gyroscopes and hydraulic servos kept the LEM's gimbaled rockets correcting despite attitude. If the vehicle pitched, the engines kept firing vertically. The test vehicles had H2O2 thrust rockets. Something like 5 test vehicles, 3 crashes. Back up rockets for emergency included. Research vehicle could go into VTOL mode (verticle), attain 200 ft. while moving forward 400 ft. in eight seconds. Training the astronauts in these vehicles reminds me of the saying "flying by the seat of your pants". http://www.dfrc.nasa.gov/Gallery/Movie/LLR.../EM-0019-01.mpg http://www.dfrc.nasa.gov/Gallery/Movie/LLR.../EM-0019-02.mpg Edited March 17, 2004 by shun Link to comment Share on other sites More sharing options...
shun Posted March 17, 2004 Author #2 Share Posted March 17, 2004 (edited) This was because Nethius said he liked the response about the Lunar Lander. So here is a general view of the events as they unfolded. First, a little clip. Launched on July 16, 1969, Apollo 11 was the third U.S. manned mission to the Moon. They carried a plaque on the leg of the LEM- "We Came In Peace For All Mankind". On the way- Buzz Aldrin http://www.hq.nasa.gov/office/pao/History/...BuzzInEagle.mov Buzz Aldrin, day before descent, in lunar command module. He wears a fire proof suit. http://www.hq.nasa.gov/office/pao/History/...s11-36-5390.jpg Panning the shot http://www.hq.nasa.gov/office/pao/History/...s11-5389-90.jpg Want to hold the monitor unit together really well? Use duck tape! Niel Armstrong. http://www.hq.nasa.gov/office/pao/History/...S11-36-5385.jpg View from lunar orbit, west of crater 308. http://www.hq.nasa.gov/office/pao/History/...S11-41-6121.jpg Looking up, they caught an earthrise. This was after a dozen orbits, in the control module. http://www.hq.nasa.gov/office/pao/History/...S11-44-6547.jpg Some neat math. As seen from the Moon, the angular diameter of Earth, in the first picture is about 1.9 degrees (width of index finger is one degree, your fist held out is about 10*, your fingers spread are around 20*). Between the times these pictures are taken, the Earth rises about 0.37 diameters (about 0.7 degrees) and, with lunar orbital period of two hours for the Apollo 11 control module, the interval between these can be estimated as 14 seconds. Second image. http://www.hq.nasa.gov/office/pao/History/...S11-44-6549.jpg Finally. Can you guess where the North Pole is? http://www.hq.nasa.gov/office/pao/History/...S11-44-6559.jpg This is where you undock, and your landing gear is looked at by your friend back in the main ship, and he says, "You are all set! Your landing gear is down and locked in position." The wrap on the landing quads prevents thermal damage from the exahust plume, upon touchdown. http://www.hq.nasa.gov/office/pao/History/...s11-44-6574.jpg http://www.hq.nasa.gov/office/pao/History/...S11-44-6581.jpg Lander in descent. http://www.hq.nasa.gov/office/pao/History/...S11-37-5445.jpg Over Sea of Tranquility. They eventually landed in the middle of this area. http://www.hq.nasa.gov/office/pao/History/...S11-37-5447.jpg Closing in, over craters known as 216 and 217. http://www.hq.nasa.gov/office/pao/History/...s11-40-5844.jpg Circling from above, waiting for rendevoux from surface. http://www.hq.nasa.gov/office/pao/History/...S11-44-6609.jpg Returning after 22 hours, with about two hours actual time working outside the on the surface. Approach of "Eagle". http://www.hq.nasa.gov/office/pao/History/...s11-44-6626.jpg Closing. http://www.hq.nasa.gov/office/pao/History/...s11-44-6642.jpg Neil Armstrong back inside. http://www.hq.nasa.gov/office/pao/History/...s11-37-5528.jpg Goin' Home. http://www.hq.nasa.gov/office/pao/History/...s11-44-6667.jpg Edited March 18, 2004 by shun Link to comment Share on other sites More sharing options...
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