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Hi, I have a question about orbit.
Assume we are going from Earth to an inner planet, like Venus, Mercury for example, and we will be using a Hohmann trasfer, I am trying to figure out at which point we need to apply some small corrections(or called Trajectory maneuver correction in some books if I am correct), and also what cause the satellite to drift away from its interplanetary orbit. I guess it might be something do to with the rotating Earth as it will influence the orbit of the satellite but not sure about it. |
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Use Eulers numerical calculation for multibody newtonium dynamics,
Do a trial launch and then use newtons apprimation to bring the the bodies close, then transfer to the two body problem and recaculate an capture trajerctory including a powered period (called a burn), then do the classic solution of landing on the planet by a short burn to bring the trajectory to a path intesecting the surface (you may need radar to be sure) and do the zero height at zero velocity, this also done using newtons approximation, the non linear (Parablic) verson (rung cut) is actually no better because the number of calutations in machine cycles for the parabilic opproximation is higher than euler for the same precisuion so there is no advantage. we use it in our 4- metric for hyperpsce trajectories our discs are a bit faster at 10,000 c but it the same really. The last few meter you look out the window and listen for the bonk as the undecarage bonks agast the red hot rocks on venus, you will need rocksill insulation about ten yards think and a big heat pump with a huge fins to glow at 600 degrees to keep cool and get out as soon as possible otherwise you will turn into charcoal. Maia got quite good at it but the banged her into a nut house because the brits think venus is a litle light put there by god for us to decorate the night, dont come to brit europe cause you wont get out and the brits are swarming for war. Look out there is bible babbler about keep yer powder dry and fire on warning, no quater and no negotion dont let any go with their heads stuck on. wrote in message ps.com... Hi, I have a question about orbit. Assume we are going from Earth to an inner planet, like Venus, Mercury for example, and we will be using a Hohmann trasfer, I am trying to figure out at which point we need to apply some small corrections(or called Trajectory maneuver correction in some books if I am correct), and also what cause the satellite to drift away from its interplanetary orbit. I guess it might be something do to with the rotating Earth as it will influence the orbit of the satellite but not sure about it. |
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On Mon, 04 Jun 2007 21:45:11 GMT, James wrote:
Maia got quite good at it but the banged her into a nut house because the brits think venus is a litle light put there by god for us to decorate the night, dont come to brit europe cause you wont get out and the brits are swarming for war. I'll have a pint of whatever he's drinking! -- .................................................. ......................... .. never trust a man who, when left alone ...... Pete Lynch . .. in a room with a tea cosy ...... Marlow, England . .. doesn't try it on (Billy Connolly) ..................................... |
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On Jun 4, 10:45 pm, "James" James@James$$Domain.$$ wrote:
Use Eulers numerical calculation for multibody newtonium dynamics, Do a trial launch and then use newtons apprimation to bring the the bodies close, then transfer to the two body problem and recaculate an capture trajerctory including a powered period (called a burn), then do the classic solution of landing on the planet by a short burn to bring the trajectory to a path intesecting the surface (you may need radar to be sure) and do the zero height at zero velocity, this also done using newtons approximation, the non linear (Parablic) verson (rung cut) is actually no better because the number of calutations in machine cycles for the parabilic opproximation is higher than euler for the same precisuion so there is no advantage. we use it in our 4- metric for hyperpsce trajectories our discs are a bit faster at 10,000 c but it the same really. The last few meter you look out the window and listen for the bonk as the undecarage bonks agast the red hot rocks on venus, you will need rocksill insulation about ten yards think and a big heat pump with a huge fins to glow at 600 degrees to keep cool and get out as soon as possible otherwise you will turn into charcoal. Maia got quite good at it but the banged her into a nut house because the brits think venus is a litle light put there by god for us to decorate the night, dont come to brit europe cause you wont get out and the brits are swarming for war. Look out there is bible babbler about keep yer powder dry and fire on warning, no quater and no negotion dont let any go with their heads stuck on. wrote in message ps.com... Hi, I have a question about orbit. Assume we are going from Earth to an inner planet, like Venus, Mercury for example, and we will be using a Hohmann trasfer, I am trying to figure out at which point we need to apply some small corrections(or called Trajectory maneuver correction in some books if I am correct), and also what cause the satellite to drift away from its interplanetary orbit. I guess it might be something do to with the rotating Earth as it will influence the orbit of the satellite but not sure about it.- Hide quoted text - - Show quoted text - Thanks for you reply James. I am still a bit confused though, I have tried to calculate the velocity changed required at the beginning of the Hohmann transfer and also calculated the velocity required when it reaches the Mercury lets say, to allow the satellite to be captured by the Mercury, I just dont know at which point during the half Hohmann transfer I need to make some small corrections to keep the satellite in the Hohmann orbit, and I also dont know what cause the satellite to drift away. |
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"Nicholas" wrote in message
oups.com... On Jun 4, 10:45 pm, "James" James@James$$Domain.$$ wrote: Use Eulers numerical calculation for multibody newtonium dynamics, Do a trial launch and then use newtons apprimation to bring the the bodies close, then transfer to the two body problem and recaculate an capture trajerctory including a powered period (called a burn), then do the classic solution of landing on the planet by a short burn to bring the trajectory to a path intesecting the surface (you may need radar to be sure) and do the zero height at zero velocity, this also done using newtons approximation, the non linear (Parablic) verson (rung cut) is actually no better because the number of calutations in machine cycles for the parabilic opproximation is higher than euler for the same precisuion so there is no advantage. we use it in our 4- metric for hyperpsce trajectories our discs are a bit faster at 10,000 c but it the same really. The last few meter you look out the window and listen for the bonk as the undecarage bonks agast the red hot rocks on venus, you will need rocksill insulation about ten yards think and a big heat pump with a huge fins to glow at 600 degrees to keep cool and get out as soon as possible otherwise you will turn into charcoal. Maia got quite good at it but the banged her into a nut house because the brits think venus is a litle light put there by god for us to decorate the night, dont come to brit europe cause you wont get out and the brits are swarming for war. Look out there is bible babbler about keep yer powder dry and fire on warning, no quater and no negotion dont let any go with their heads stuck on. wrote in message ps.com... Hi, I have a question about orbit. Assume we are going from Earth to an inner planet, like Venus, Mercury for example, and we will be using a Hohmann trasfer, I am trying to figure out at which point we need to apply some small corrections(or called Trajectory maneuver correction in some books if I am correct), and also what cause the satellite to drift away from its interplanetary orbit. I guess it might be something do to with the rotating Earth as it will influence the orbit of the satellite but not sure about it.- Hide quoted text - - Show quoted text - Thanks for you reply James. I am still a bit confused though, I have tried to calculate the velocity changed required at the beginning of the Hohmann transfer and also calculated the velocity required when it reaches the Mercury lets say, to allow the satellite to be captured by the Mercury, I just dont know at which point during the half Hohmann transfer I need to make some small corrections to keep the satellite in the Hohmann orbit, and I also dont know what cause the satellite to drift away. If our rocket engines were perfect to 7-8 decimal places, providing exactly the amount of thrust predicted and with a throat nozzle vector exactly as the engineers designed, with radar-guided or inertially-guided launches being perfect with zero error, mid-course corrections would never be necessary. Mid-course corrections are required due to small errors in the initial trajectory that gradually build up. Launches involve vector changes of many km/sec. A few cm/sec of drift or speed differential can add up over a year, say, to hundreds or thousands of km at the destination. And there is also drift due to outgassing from the spacecraft, radiation pressure, etc. Corrections are not made early in the journey because you can't measure exactly the amount of drift off the nominal course. And if you wait until you are closing in on the target you may need a longer burn and do not have enough fuel. So a mid-course correction relies on waiting until the drift off the required course can be measured accurately (usually via radio-doppler methods), then acting in good time to apply a small amount of thrust to bring the spacecraft back on course to arrive at the destination exactly as planned. If fuel is a primary consideration then the adjustment is made as soon as measurements make it practicable, and sometimes a second fine tuning is required later, which includes correcting for the "unpredictables". -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) |
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I am still a bit confused though, ...
Oh come on, this isn't exactly rocket science ! Sorry, couldn't resist it. Pete K |
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On Jun 6, 5:10 am, "Joey" wrote:
I am still a bit confused though, ... Oh come on, this isn't exactly rocket science ! Sorry, couldn't resist it. Pete K Then offer up the fully interactive 3D orbital simulator, and be done with it. - "whoever controls the past, controls the future" / George Orwell - Brad Guth |
#8
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On Jun 4, 2:45 pm, "James" James@James$$Domain.$$ wrote:
Use Eulers numerical calculation for multibody newtonium dynamics, Do a trial launch and then use newtons apprimation to bring the the bodies close, then transfer to the two body problem and recaculate an capture trajerctory including a powered period (called a burn), then do the classic solution of landing on the planet by a short burn to bring the trajectory to a path intesecting the surface (you may need radar to be sure) and do the zero height at zero velocity, this also done using newtons approximation, the non linear (Parablic) verson (rung cut) is actually no better because the number of calutations in machine cycles for the parabilic opproximation is higher than euler for the same precisuion so there is no advantage. we use it in our 4- metric for hyperpsce trajectories our discs are a bit faster at 10,000 c but it the same really. The last few meter you look out the window and listen for the bonk as the undecarage bonks agast the red hot rocks on venus, you will need rocksill insulation about ten yards think and a big heat pump with a huge fins to glow at 600 degrees to keep cool and get out as soon as possible otherwise you will turn into charcoal. Maia got quite good at it but the banged her into a nut house because the brits think venus is a litle light put there by god for us to decorate the night, dont come to brit europe cause you wont get out and the brits are swarming for war. Look out there is bible babbler about keep yer powder dry and fire on warning, no quater and no negotion dont let any go with their heads stuck on. wrote in message ps.com... Hi, I have a question about orbit. Assume we are going from Earth to an inner planet, like Venus, Mercury for example, and we will be using a Hohmann trasfer, I am trying to figure out at which point we need to apply some small corrections(or called Trajectory maneuver correction in some books if I am correct), and also what cause the satellite to drift away from its interplanetary orbit. I guess it might be something do to with the rotating Earth as it will influence the orbit of the satellite but not sure about it.- Hide quoted text - - Show quoted text - Is that what British Zions actually think of Venus? - "whoever controls the past, controls the future" / George Orwell - Brad Guth |
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