lazerq3 0 #1 September 30, 2003 I need to find out the angle of the space shuttle when it leaves the atmosphere and then the rentry...!!! Iread heard that the rentry is like 2.5 Degrees but does anyone know for sure orhave a link..I cant find it anywhere!!! jasonFreedom of speech includes volume Quote Share this post Link to post Share on other sites
Jimbo 0 #2 September 30, 2003 Your mama is an astronaut! - Jim"Like" - The modern day comma Good bye, my friends. You are missed. Quote Share this post Link to post Share on other sites
PhillyKev 0 #3 September 30, 2003 Quote Your mama is an astronaut! - Jim WMCJ Take that back, say my mama ain't no astronaut! Quote Share this post Link to post Share on other sites
lazerq3 0 #4 September 30, 2003 QuoteYour mama is an astronaut! Yeah but she doesnt know either jasonFreedom of speech includes volume Quote Share this post Link to post Share on other sites
billvon 2,409 #5 September 30, 2003 > I need to find out the angle of the space shuttle when it leaves the >atmosphere and then the rentry...!!! Angle compared to what? Absolute datum? Angle of attack? And where do you define the edge of the atmosphere? During launch, the shuttle is initially at a vertical pitch angle. It transitions quickly to a slight over-vertical (i.e. nose down) attitude due to thrust vector considerations; the main engines are not directly "below" the vehicle's center of gravity, and there is therefore a difference between pitch attitude and thrust vector. As it climbs it pitches further and further over. By the time MECO occurs it is pitched over past the horizontal a bit; this is for orbital insertion purposes and due to that center of gravity offset. Note that the thrust vector, the orbiter pitch attitude, and velocity vector are NOT the same at that point. Another way to think about this is that when MECO occurs the astronauts are looking at the earth upside down, and from their perspective are actually pointed slightly back _towards_ the planet. During reentry, the "atmospheric interface" is usually defined to be 400,000 feet. At that point the orbiter is pitched about 40 degrees nose-up; this is primarily to better deal with reentry heating. It holds that via the RCS until around 180,000 feet, at which point it begins to pitch nose-down in preparation for normally controlled gliding flight. By the time it gets to 150,000 feet, reentry heating stops being the primary issue in pitch attitude control. Angle of attack never gets to less than about 5 degrees; it's not a very efficient glider. Quote Share this post Link to post Share on other sites
lazerq3 0 #6 September 30, 2003 Holy shit!!!! Thanks Bill!!!!... But now let me ask this ... so from your reading would it be safe to say that during take off the angle of attack is more important for orbit insertion or getting through the atmosphere (outer) without heating up or a little of both... jasonFreedom of speech includes volume Quote Share this post Link to post Share on other sites
freeflygoddess 0 #7 September 30, 2003 You guys need girls...really... Quote Share this post Link to post Share on other sites
lazerq3 0 #8 September 30, 2003 QuoteYou guys need girls...really... What can I say...... "I'm married with children"! jasonFreedom of speech includes volume Quote Share this post Link to post Share on other sites
Jimbo 0 #9 September 30, 2003 QuoteTake that back, say my mama ain't no astronaut! Your mama wasn't no astronaut, your mama's too dumb to be an astronaut! One of the greatest movies ever, ever. - Jim"Like" - The modern day comma Good bye, my friends. You are missed. Quote Share this post Link to post Share on other sites
billvon 2,409 #10 September 30, 2003 >would it be safe to say that during take off the angle of attack is > more important for orbit insertion or getting through the > atmosphere (outer) without heating up or a little of both... 99% of the planning for the 'angle of attack' (really pitch angle, thrust angle and trajectory) is to get the shuttle into orbit with minumum fuel usage. It's just barely able to reach orbit as it is. However, the system does do a few things to reduce aerodynamic loads near max-Q, or period of highest dynamic load: 1. It throttles the main engines back (the SRB's can't be throttled) 2. It basically "slips" the whole assembly a bit to change the wing's angle of attack a little, at the expense of maintaining a perfect trajectory 3. It plays with the body flap and elevons to reduce stress on the wings After the period of max-Q, air pressure drops off rapidly, the engines are throttled back up and the trajectory is optimized for orbital insertion. Quote Share this post Link to post Share on other sites
billvon 2,409 #11 September 30, 2003 >You guys need girls...really... Amy says it turns her on when I start talking technical. Go figure. Quote Share this post Link to post Share on other sites
