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#11
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Ares1-X failure - new information
Derek Lyons wrote:
Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? I realise this may require some planning, such as ensuring whatever connections to the tower are placed accordingly (as well as placing the payload (Orion) in such a way that its door faces the access arm). So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? |
#12
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Ares1-X failure - new information
John Doe wrote:
Derek Lyons wrote: Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? I realise this may require some planning, such as ensuring whatever connections to the tower are placed accordingly (as well as placing the payload (Orion) in such a way that its door faces the access arm). So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? Because you have various and sundry connections between the vehicle and the launch pad that can't be moved without extensive renovations to the pad and extensive design changes to the vehicles - for each and every flight. It's much easier to roll. D. -- Touch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
#13
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Ares1-X failure - new information
John Doe wrote:
Derek Lyons wrote: Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? I realise this may require some planning, such as ensuring whatever connections to the tower are placed accordingly (as well as placing the payload (Orion) in such a way that its door faces the access arm). So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? That's what I do, orient it straight east with the proper roll preset, and then all you have to deal with is the pitch and the pitch rate. I like to have pitch, pitch rate, altitude, velocity, acceleration and elapsed time numerically on my HUD, as well as the usual visual pitch and momentum vector targets. Of course, with a SINGLE high efficiency closed combustion cycle regeneratively cooled high performance space shuttle main engine for propulsion, you have to load the stack up with payload and use big hydrocarbon boosters in order to prevent exceeding your acceleration limits, and roll control is a definite problem that has to be dealt with, otherwise you might indeed spin out of control after you lose the boosters and really start to haul ass. That's why there are pairs of outboard ground started OMS engines idling along as roll control, and ready to do long deep throttling fuel settling and scavenging burns too, and orbital tweaking and final circularization. Once you achieve orbit and docking you just react or burn off your residual fuel to boost the tank farm, and let the space port workers handle to pesky details of dealing with the tank, payload and engines. Engine into the nosecone and back to the ocean for quick pickup, and the tank gets added to your vast orbiting space port and star trek vessels. Excess fuel quickly burnt off for electricity and heat, and then you drink and grow plants so that you don't need billion dollar resupply. Those SRBs are gonna set us back another couple of decades again. Unless you use them with a decent reusable hydrogen core, they just won't work. The canceled the Saturn V for a reason, and they didn't even use SRBs. |
#14
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Ares1-X failure - new information
Derek Lyons wrote:
John Doe wrote: Derek Lyons wrote: Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? I realise this may require some planning, such as ensuring whatever connections to the tower are placed accordingly (as well as placing the payload (Orion) in such a way that its door faces the access arm). So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? Because you have various and sundry connections between the vehicle and the launch pad that can't be moved without extensive renovations to the pad and extensive design changes to the vehicles - for each and every flight. It's much easier to roll. D. Right. The SRB hold-down post configuration is not symmetric, either. Structural considerations will dictate LV placement on the pad, dynamic considerations will dictate LV flight attitude. The difference between the two dictates the roll required. Simple as that. |
#15
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Ares1-X failure - new information
On Nov 1, 2:37*am, John Doe wrote:
.. But for a symetrically round rocket, why would it need to rotate 90° ? What does that achieve ? Why not place it in the right orientation on the pad to begin with if it needs to be in a specific roll orientation ? Guidance system and Cockpit orientation. |
#17
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Ares1-X failure - new information
On Nov 2, 12:28�pm, Me wrote:
On Nov 1, 2:37�am, John Doe wrote: . But for a symetrically round rocket, why would it need to rotate 90� ? What does that achieve ? Why not place it in the right orientation on the pad to begin with if it needs to be in a specific roll orientation ? Guidance system and Cockpit orientation. doesnt the shuttle fly a dogleg manuver to avoid overflying land areas in some cases? |
#18
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Ares1-X failure - new information
On Sun, 01 Nov 2009 14:57:46 -0500, John Doe wrote:
Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? In the case of the lunar missions, that orientation will change as the Earth/Moon angle changes. So if you have to delay launch a month because of a glitch or an astronaut is exposed to the measles, you'd have to roll back to the VAB, destack the vehicle, restack at the new orientation, and then roll back to the pad. A roll at liftoff just needs the updated azimuth loaded into software. So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? It would require an all-new SRB design, and Ares I was chosen specifically to avoid this. (Sure, the SRB is different, but it fundamentally isn't that different. Its the same diameter with the same MLP mounts as the Shuttle-version.) You do know that Titan II (Gemini), Saturn IB (Apollo), and Saturn V (Apollo) all rolled too, right? Easier to build the pad to be easiest for ground crews and let the vehicle roll after liftoff, since the vehicle has to be able to roll for stablization and guidance anyway. Brian |
#19
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Ares1-X failure - new information
On Nov 1, 4:05*pm, kT wrote:
John Doe wrote: Derek Lyons wrote: Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. *Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. *This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? I realise this may require some planning, such as ensuring whatever connections to the tower are placed accordingly (as well as placing the payload (Orion) in such a way that its door faces the access arm). So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? That's what I do, orient it straight east with the proper roll preset, and then all you have to deal with is the pitch and the pitch rate. I like to have pitch, pitch rate, altitude, velocity, acceleration and elapsed time numerically on my HUD, as well as the usual visual pitch and momentum vector targets. Of course, with a SINGLE high efficiency closed combustion cycle regeneratively cooled high performance space shuttle main engine for propulsion, you have to load the stack up with payload and use big hydrocarbon boosters in order to prevent exceeding your acceleration limits, and roll control is a definite problem that has to be dealt with, otherwise you might indeed spin out of control after you lose the boosters and really start to haul ass. That's why there are pairs of outboard ground started OMS engines idling along as roll control, and ready to do long deep throttling fuel settling and scavenging burns too, and orbital tweaking and final circularization. Once you achieve orbit and docking you just react or burn off your residual fuel to boost the tank farm, and let the space port workers handle to pesky details of dealing with the tank, payload and engines. Engine into the nosecone and back to the ocean for quick pickup, and the tank gets added to your vast orbiting space port and star trek vessels. Excess fuel quickly burnt off for electricity and heat, and then you drink and grow plants so that you don't need billion dollar resupply. Those SRBs are gonna set us back another couple of decades again. Unless you use them with a decent reusable hydrogen core, they just won't work. The canceled the Saturn V for a reason, and they didn't even use SRBs. Saturn V was a Zionist Nazi accomplishment that's still more advanced and more reliable than anything since, not to mention environmentally greener. ~ BG |
#20
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Ares1-X failure - new information
On Nov 3, 1:56*am, BradGuth wrote:
On Nov 1, 4:05*pm, kT wrote: John Doe wrote: Derek Lyons wrote: Because the pad is fixed - while a vehicle launched from it may depart on any number of different azimuths. *Therefore the vehicle rolls to align the vehicles various axes with the with the trajectory. *This also helps ensure communications with the vehicle as various antenna are pointed in the proper direction. Since this is a round cylinder, why not just place the rocket on the pad in the right roll orientation to begin with ? I realise this may require some planning, such as ensuring whatever connections to the tower are placed accordingly (as well as placing the payload (Orion) in such a way that its door faces the access arm). So , what is the reason they couldn't orient the rocket on the pad to remove the need for a 90° roll ? That's what I do, orient it straight east with the proper roll preset, and then all you have to deal with is the pitch and the pitch rate. I like to have pitch, pitch rate, altitude, velocity, acceleration and elapsed time numerically on my HUD, as well as the usual visual pitch and momentum vector targets. Of course, with a SINGLE high efficiency closed combustion cycle regeneratively cooled high performance space shuttle main engine for propulsion, you have to load the stack up with payload and use big hydrocarbon boosters in order to prevent exceeding your acceleration limits, and roll control is a definite problem that has to be dealt with, otherwise you might indeed spin out of control after you lose the boosters and really start to haul ass. That's why there are pairs of outboard ground started OMS engines idling along as roll control, and ready to do long deep throttling fuel settling and scavenging burns too, and orbital tweaking and final circularization. Once you achieve orbit and docking you just react or burn off your residual fuel to boost the tank farm, and let the space port workers handle to pesky details of dealing with the tank, payload and engines. Engine into the nosecone and back to the ocean for quick pickup, and the tank gets added to your vast orbiting space port and star trek vessels. Excess fuel quickly burnt off for electricity and heat, and then you drink and grow plants so that you don't need billion dollar resupply. Those SRBs are gonna set us back another couple of decades again. Unless you use them with a decent reusable hydrogen core, they just won't work.. The canceled the Saturn V for a reason, and they didn't even use SRBs. Saturn V was a Zionist Nazi accomplishment that's still more advanced and more reliable than anything since, not to mention environmentally greener. *~ BG "Zionist Nazi" That's quite a combination! Bob Clark |
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