henry@utzoo.UUCP (Henry Spencer) (02/05/86)
> Can anyone explain why during assent the orbiter flies upside-down?
As I understand it, it's simply so that the tank and SRB's don't block
line-of-sight for radio communications between the orbiter and the ground.
--
Henry Spencer @ U of Toronto Zoology
{allegra,ihnp4,linus,decvax}!utzoo!henryspock@iham1.UUCP (Ed Weiss) (02/07/86)
In article <6357@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) writes: > > Can anyone explain why during assent the orbiter flies upside-down? > > As I understand it, it's simply so that the tank and SRB's don't block > line-of-sight for radio communications between the orbiter and the ground. > -- > Henry Spencer @ U of Toronto Zoology > {allegra,ihnp4,linus,decvax}!utzoo!henry But, why the role? Why doesn't it just fly straight onto its back? -- Ed Weiss ihnp4!iham1!spock --> Live Long and Prosper <--
lmc@cisden.UUCP (Lyle McElhaney) (02/09/86)
> > > Can anyone explain why during assent the orbiter flies upside-down? > > > > As I understand it, it's simply so that the tank and SRB's don't block > > line-of-sight for radio communications between the orbiter and the ground. > > But, why the role? Why doesn't it just fly straight onto its back? The initial orientation of the shuttle (roll, or vertical axis) is defined by the high radius turns in the lane from the VAB to the launch pad. The crawlers cannot turn easily, and so straight-on approaches to the pad are made, and the pads were designed with this in mind. Also, Kennedy supports launch azimuths of from 35 degrees (northeast) to 120 degrees (southeast), so some kind of roll manuever would be required in most flights anyway before pitch over. Lyle McElhaney ...hao!cisden!lmc
brent@poseidon.UUCP (Brent P. Callaghan) (02/10/86)
>In article <6357@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) writes: >> > Can anyone explain why during assent the orbiter flies upside-down? >> >> As I understand it, it's simply so that the tank and SRB's don't block >> line-of-sight for radio communications between the orbiter and the ground. >> -- >> Henry Spencer @ U of Toronto Zoology >> {allegra,ihnp4,linus,decvax}!utzoo!henry > >But, why the role? Why doesn't it just fly straight onto its back? >-- The roll is initiated once the tower is clear to put the launch vehicle on the correct azimuth for the desired orbital plane. It is much easier to do it this way than to have some kind of turntable launch pad. -- Made in New Zealand --> Brent Callaghan AT&T Information Systems, Lincroft, NJ {ihnp4|mtuxo|pegasus}!poseidon!brent (201) 576-3475
henry@utzoo.UUCP (Henry Spencer) (02/20/86)
> > As I understand it, it's simply so that the tank and SRB's don't block > > line-of-sight for radio communications between the orbiter and the ground. > > But, why the role? Why doesn't it just fly straight onto its back? The attitude at launch is constrained by the structure of the launch site. Things like the flame trenches were originally set up for the Saturn V, and rebuilding the pads totally for the shuttle wasn't thought reasonable. So the shuttle lifts off in an attitude that's different from what's wanted in flight. Hence the roll. Incidentally, it has nothing to do with getting the thrust line to pass through the center of gravity, since that depends on which way the nozzles point *with respect to the vehicle* and has nothing to do with attitude. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
dave@quest.UUCP (David Messer) (03/06/86)
> > > As I understand it, it's simply so that the tank and SRB's don't block > > > line-of-sight for radio communications between the orbiter and the ground. > > > > But, why the role? Why doesn't it just fly straight onto its back? > > The attitude at launch is constrained by the structure of the launch site. > Things like the flame trenches were originally set up for the Saturn V, > and rebuilding the pads totally for the shuttle wasn't thought reasonable. > So the shuttle lifts off in an attitude that's different from what's wanted > in flight. Hence the roll. Also, if you think back to the Apollo days, you will notice that the Saturn launches also had a roll program. Apollo also flew upside-down. -- +-----------------------------------+----------------------------------+ | Disclaimer: | David Messer | | I'm always right and I never lie. | | | My company knows this and agrees | UUCP: ...ihnp4!quest!dave | | with everything I say. | FIDO: 14/415 (Sysop) | +-----------------------------------+----------------------------------+
desj@brahms.BERKELEY.EDU (David desJardins) (03/10/86)
In article <367@quest.UUCP> dave@quest.UUCP (David Messer) writes: > >Also, if you think back to the Apollo days, you will notice that >the Saturn launches also had a roll program. Apollo also flew >upside-down. > All right, you've got me interested. How can a cylindrical rocket fly upside-down?? -- David desJardins
bl@hplabsb.UUCP (Bruce T. Lowerre) (03/26/86)
> In article <367@quest.UUCP> dave@quest.UUCP (David Messer) writes: > > > >Also, if you think back to the Apollo days, you will notice that > >the Saturn launches also had a roll program. Apollo also flew > >upside-down. > > > All right, you've got me interested. How can a cylindrical > rocket fly upside-down?? > > -- David desJardins Easy, put the hot end at the top. :-)
dbb@aicchi.UUCP (Burch) (03/29/86)
In article <3367@hplabsb.UUCP> bl@hplabsb.UUCP (Bruce T. Lowerre) writes: >> In article <367@quest.UUCP> dave@quest.UUCP (David Messer) writes: >> > >> >Also, if you think back to the Apollo days, you will notice that >> >the Saturn launches also had a roll program. Apollo also flew >> >upside-down. >> > >> All right, you've got me interested. How can a cylindrical >> rocket fly upside-down?? >> >> -- David desJardins > >Easy, put the hot end at the top. :-) Really, they did not so much roll as spin.... Gyroscope-wise for stability. -- -David B. (Ben) Burch Analyst's International Corp. Chicago Branch (ihnp4!aicchi!dbb) "Argue for your limitations, and they are yours"