Archive-name: space/schedule Last-modified: $Date: 93/04/01 14:39:23 $  SPACE SHUTTLE ANSWERS, LAUNCH SCHEDULES, TV COVERAGE      SHUTTLE LAUNCHINGS AND LANDINGS; SCHEDULES AND HOW TO SEE THEM      Shuttle operations are discussed in the Usenet group sci.space.shuttle,     and Ken Hollis (gandalf@pro-electric.cts.com) posts a compressed version     of the shuttle manifest (launch dates and other information)     periodically there. The manifest is also available from the Ames SPACE     archive in SPACE/FAQ/manifest. The portion of his manifest formerly     included in this FAQ has been removed; please refer to his posting or     the archived copy. For the most up to date information on upcoming     missions, call (407) 867-INFO (867-4636) at Kennedy Space Center.      Official NASA shuttle status reports are posted to sci.space.news     frequently.       WHY DOES THE SHUTTLE ROLL JUST AFTER LIFTOFF?      The following answer and translation are provided by Ken Jenks     (kjenks@gothamcity.jsc.nasa.gov).      The "Ascent Guidance and Flight Control Training Manual," ASC G&C 2102,     says:  	"During the vertical rise phase, the launch pad attitude is 	commanded until an I-loaded V(rel) sufficient to assure launch tower 	clearance is achieved. Then, the tilt maneuver (roll program) 	orients the vehicle to a heads down attitude required to generate a 	negative q-alpha, which in turn alleviates structural loading. Other 	advantages with this attitude are performance gain, decreased abort 	maneuver complexity, improved S-band look angles, and crew view of 	the horizon. The tilt maneuver is also required to start gaining 	downrange velocity to achieve the main engine cutoff (MECO) target 	in second stage."      This really is a good answer, but it's couched in NASA jargon. I'll try     to interpret.      1)	We wait until the Shuttle clears the tower before rolling.      2)	Then, we roll the Shuttle around so that the angle of attack 	between the wind caused by passage through the atmosphere (the 	"relative wind") and the chord of the wings (the imaginary line 	between the leading edge and the trailing edge) is a slightly 	negative angle ("a negative q-alpha").	This causes a little bit of 	"downward" force (toward the belly of the Orbiter, or the +Z 	direction) and this force "alleviates structural loading." 	We have to be careful about those wings -- they're about the 	most "delicate" part of the vehicle.      3)	The new attitude (after the roll) also allows us to carry more 	mass to orbit, or to achieve a higher orbit with the same mass, or 	to change the orbit to a higher or lower inclination than would be 	the case if we didn't roll ("performance gain").      4)	The new attitude allows the crew to fly a less complicated 	flight path if they had to execute one of the more dangerous abort 	maneuvers, the Return To Launch Site ("decreased abort maneuver 	complexity").      5)	The new attitude improves the ability for ground-based radio 	antennae to have a good line-of-sight signal with the S-band radio 	antennae on the Orbiter ("improved S-band look angles").      6)	The new attitude allows the crew to see the horizon, which is a 	helpful (but not mandatory) part of piloting any flying machine.      7)	The new attitude orients the Shuttle so that the body is 	more nearly parallel with the ground, and the nose to the east 	(usually).  This allows the thrust from the engines to add velocity 	in the correct direction to eventually achieve orbit.  Remember: 	velocity is a vector quantity made of both speed and direction. 	The Shuttle has to have a large horizontal component to its 	velocity and a very small vertical component to attain orbit.      This all begs the question, "Why isn't the launch pad oriented to give     this nice attitude to begin with?  Why does the Shuttle need to roll to     achieve that attitude?"  The answer is that the pads were leftovers     from the Apollo days.  The Shuttle straddles two flame trenches -- one     for the Solid Rocket Motor exhaust, one for the Space Shuttle Main     Engine exhaust.  (You can see the effects of this on any daytime     launch.  The SRM exhaust is dirty gray garbage, and the SSME exhaust is     fluffy white steam.  Watch for the difference between the "top"     [Orbiter side] and the "bottom" [External Tank side] of the stack.) The     access tower and other support and service structure are all oriented     basically the same way they were for the Saturn V's.  (A side note: the     Saturn V's also had a roll program.  Don't ask me why -- I'm a Shuttle     guy.)      I checked with a buddy in Ascent Dynamics.	He added that the "roll     maneuver" is really a maneuver in all three axes: roll, pitch and yaw.     The roll component of that maneuver is performed for the reasons     stated.  The pitch component controls loading on the wings by keeping     the angle of attack (q-alpha) within a tight tolerance.  The yaw     component is used to determine the orbital inclination.  The total     maneuver is really expressed as a "quaternion," a grad-level-math     concept for combining all three rotation matrices in one four-element     array.       HOW TO RECEIVE THE NASA TV CHANNEL, NASA SELECT      NASA SELECT is broadcast by satellite. If you have access to a satellite     dish, you can find SELECT on Satcom F2R, Transponder 13, C-Band, 72     degrees West Longitude, Audio 6.8, Frequency 3960 MHz. F2R is stationed     over the Atlantic, and is increasingly difficult to receive from     California and points west. During events of special interest (e.g.     shuttle missions), SELECT is sometimes broadcast on a second satellite     for these viewers.      If you can't get a satellite feed, some cable operators carry SELECT.     It's worth asking if yours doesn't.      The SELECT schedule is found in the NASA Headline News which is     frequently posted to sci.space.news. Generally it carries press     conferences, briefings by NASA officials, and live coverage of shuttle     missions and planetary encounters. SELECT has recently begun carrying     much more secondary material (associated with SPACELINK) when missions     are not being covered.       AMATEUR RADIO FREQUENCIES FOR SHUTTLE MISSIONS      The following are believed to rebroadcast space shuttle mission audio:  	W6FXN  - Los Angeles 	K6MF   - Ames Research Center, Mountain View, California 	WA3NAN - Goddard Space Flight Center (GSFC), Greenbelt, Maryland. 	W5RRR  - Johnson Space Center (JSC), Houston, Texas 	W6VIO  - Jet Propulsion Laboratory (JPL), Pasadena, California. 	W1AW Voice Bulletins  	Station    VHF	   10m	   15m	   20m	  40m	 80m 	------	 ------  ------  ------  ------  -----	----- 	W6FXN	 145.46 	K6MF	 145.585			 7.165	3.840 	WA3NAN	 147.45  28.650  21.395  14.295  7.185	3.860 	W5RRR	 146.64  28.400  21.350  14.280  7.227	3.850 	W6VIO	 224.04		 21.340  14.270 	W6VIO	 224.04		 21.280  14.282  7.165	3.840 	W1AW		 28.590  21.390  14.290  7.290	3.990      W5RRR transmits mission audio on 146.64, a special event station on the     other frequencies supplying Keplerian Elements and mission information.      W1AW also transmits on 147.555, 18.160. No mission audio but they     transmit voice bulletins at 0245 and 0545 UTC.      Frequencies in the 10-20m bands require USB and frequencies in the 40     and 80m bands LSB. Use FM for the VHF frequencies.      [This item was most recently updated courtesy of Gary Morris     (g@telesoft.com, KK6YB, N5QWC)]       SOLID ROCKET BOOSTER FUEL COMPOSITION      Reference: "Shuttle Flight Operations Manual" Volume 8B - Solid Rocket     Booster Systems, NASA Document JSC-12770      Propellant Composition (percent)      Ammonium perchlorate (oxidizer)			69.6     Aluminum						16     Iron Oxide (burn rate catalyst)			0.4     Polybutadiene-acrilic acid-acrylonitrile (a rubber) 12.04     Epoxy curing agent					1.96      End reference      Comment: The aluminum, rubber, and epoxy all burn with the oxidizer.