Orbits - Revision history

Farred: /* References */

2012-04-24T17:11:26Z

References

Farred: fix typo

2012-04-24T16:18:13Z

fix typo

76.92.86.210: /* References */

2012-04-24T01:32:53Z

References

76.92.86.210: /* References */

2012-04-24T01:31:11Z

References

Cfrjlr: replace Transportation with Space Transport

2007-06-10T15:29:49Z

replace Transportation with Space Transport

Jriley: reformat add references

2007-05-28T12:56:20Z

reformat add references

Sdsds: /* The Moon is Gravitationally very Lumpy */ curst -> crust

2007-04-03T04:13:38Z

The Moon is Gravitationally very Lumpy: curst -> crust

Jarogers2001: removed category colonization

2007-03-18T05:01:29Z

removed category colonization

Jriley at 22:17, 8 March 2007

2007-03-08T22:17:39Z

Cfrjlr: Kepler

2007-03-08T14:10:06Z

Kepler

@@ Line 45: / Line 45: @@
 ===References===
-−
-[http://science.nasa.gov/science-news/science-at-nasa/2006/30nov_highorbit/|"A New Paradigm for Lunar Orbits"]
+[http://web.archive.org Go to WayBackMachine], enter <nowiki>http://science.nasa.gov/headlines/y2006/30nov_highorbit.htm</nowiki> in the take me back window, click the take me back button, and choose 1 December 2006 for the article ''A New Paradigm for Lunar Orbits''.
-−
 [http://adsabs.harvard.edu/abs/2005AdSpR..36..552D|"Numerical study of low-cost alternative orbits around the Moon" Melo, Winter, Neto]

@@ Line 20: / Line 20: @@
 * Mass Concentrations (Masscon) in the Mares
 * The Near Side crust being ½ the thickness of the Far Side crust
-* A mass deficiency in the South Pole Aitken Basin (which were we are going)
+* A mass deficiency in the South Pole Aitken Basin (which is where we are going)
 ==Result on Lunar Orbits==

@@ Line 46: / Line 46: @@
 ===References===
-[http://science.nasa.gov/science-news/science-at-nasa/2006/30nov_highorbit/ |"A New Paradigm for Lunar Orbits"]
+[http://science.nasa.gov/science-news/science-at-nasa/2006/30nov_highorbit/|"A New Paradigm for Lunar Orbits"]
 [http://adsabs.harvard.edu/abs/2005AdSpR..36..552D|"Numerical study of low-cost alternative orbits around the Moon" Melo, Winter, Neto]

@@ Line 46: / Line 46: @@
 ===References===
-[http://science.nasa.gov/headlines/y2006/30nov_highorbit.htm|"A New Paradigm for Lunar Orbits"]
+[http://science.nasa.gov/science-news/science-at-nasa/2006/30nov_highorbit/ |"A New Paradigm for Lunar Orbits"]
 [http://adsabs.harvard.edu/abs/2005AdSpR..36..552D|"Numerical study of low-cost alternative orbits around the Moon" Melo, Winter, Neto]

@@ Line 56: / Line 56: @@
 [[Category:Physics]]
 [[Category:Suborbital]]
-[[Category:Transportation]]
+[[Category:Space Transport]]
 [[Category:Spacecraft]]

@@ Line 1: / Line 1: @@
-==Orbits to and Around the Moon==
+{|align=right
 The motion of one body about another body due to gravity, is known as an Orbit. [[Orbits]] are described by a body of theory called "[[Orbital Dynamics]]".   [[Kepler]] discovered that in [[Newtonian]] [[Physics]], which ignore [[Einstein]]'s theories of [[relativity]], orbits are [[elliptical]] in shape, at least for the simple case of one body orbiting another body without any influence from any third body.   [[Kepler's Laws]] are three [[equations]] which describe elliptical orbits, and still hold true today.
-===The Moon is Gravitationally very Lumpy===
+==The Moon is Gravitationally very Lumpy==
 The Moon is both out of round and does not have a symmetric distribution of mass.  The result is that low lunar orbits are not stable for long time periods.  For example, the Apollo Command modules would have drifted out of reach for the returning Lunar Lander in only a few days.
@@ Line 15: / Line 22: @@
 * A mass deficiency in the South Pole Aitken Basin (which were we are going)
-===Result on Lunar Orbits===
+==Result on Lunar Orbits==
 If you need a long term stable lunar orbit, either you have to maintain considerable altitude or you have to choose from a limited number of low orbits that happen to balance out the lumps.  There are about five angles to the lunar equator that have long term orbits.  One of these is in the high 80 degrees of inclination and is attractive for polar work.
@@ Line 24: / Line 31: @@
-===A Trip to the Moon===
+==A Trip to the Moon==
 The factors controlling the choice of a path from the Earth to the Moon are very different for manned and unmanned vehicles.  In all cases, a lunar polar site takes a little more delta V, and therefore rocket fuel, than an equatorial site.
-====Unmanned:====
+===Unmanned:===
 Usually for unmanned vehicles, you are simply trying for the most mass delivered to the Moon for a given type of rocket launched from a specific Earth port.  Often you trade off time in transit for additional mass delivered.  The transit time may be a few extra days or even weeks longer than manned flights.  If an ion drive transfer rocket is used, this trip could take months.  The launch windows for this type of trip are wide open.
-====Manned:====
+===Manned:===
 The safest route is to fly first to an orbit near the International Space Station (ISS).  You do not plan to stop, but if you have an emergency you could reach the station.  You then have a problem.  ISS has a high orbit inclination so that it can be reached from Russian launch sites.  This is a poor orbit to use for lunar transfer as it takes a lot of fuel to take out the inclination.  One workable solution is to next fly to the Earth-Moon Lagrange Point 2 (L2).  At this point the gravity of the two bodies is nearly balanced and you can make a burn of reasonable size to move you on your way to a near lunar polar orbit.  Your path will look like a large figure 8 that is twisted at the cross-over point.   This transfer path takes more time and fuel and has fewer and shorter launch windows than more direct methods.
 ----

@@ Line 1: / Line 1: @@
 ==Orbits to and Around the Moon==
@@ Line 41: / Line 40: @@
 ----
 [[Category:Missions]]
 [[Category:Mission Plans]]

← Older revision		Revision as of 22:17, 8 March 2007
Line 1:		Line 1:

−	'''The motion of one body about another body due to gravity, is known as an Orbit. [[Orbits]] are described by a body of theory called "[[Orbital Dynamics]]". [[Kepler]] discovered that in [[Newtonian]] [[Physics]], which ignore [[Einstein]]'s theories of [[relativity]], orbits are [[elliptical]] in shape, at least for the simple case of one body orbiting another body without any influence from any third body. [[Kepler's Laws]] are three [[equations]] which describe elliptical orbits, and still hold true today.'''

	==Orbits to and Around the Moon==		==Orbits to and Around the Moon==
		+
		+	=== General Theory of Orbits===
		+	The motion of one body about another body due to gravity, is known as an Orbit. [[Orbits]] are described by a body of theory called "[[Orbital Dynamics]]". [[Kepler]] discovered that in [[Newtonian]] [[Physics]], which ignore [[Einstein]]'s theories of [[relativity]], orbits are [[elliptical]] in shape, at least for the simple case of one body orbiting another body without any influence from any third body. [[Kepler's Laws]] are three [[equations]] which describe elliptical orbits, and still hold true today.

	===The Moon is Gravitationally very Lumpy===		===The Moon is Gravitationally very Lumpy===

← Older revision		Revision as of 14:10, 8 March 2007
Line 1:		Line 1:
−	'''The motion of one body about another body due to gravity, is known as an Orbit. [[Orbits]] are ~~desribed~~ by a body of theory called "[[Orbital Dynamics]]". [[Kepler]] discovered that in [[Newtonian]] [[Physics]], which ignore [[Einstein]]'s theories of [[relativity]], orbits are [[~~ellipitical~~]] in shape, at least for the simple case of one body orbiting another body without any influence from any third body. [[Kepler's Laws]] are three [[equations]] which describe elliptical orbits, and still hold true today.'''	+
		+	'''The motion of one body about another body due to gravity, is known as an Orbit. [[Orbits]] are described by a body of theory called "[[Orbital Dynamics]]". [[Kepler]] discovered that in [[Newtonian]] [[Physics]], which ignore [[Einstein]]'s theories of [[relativity]], orbits are [[elliptical]] in shape, at least for the simple case of one body orbiting another body without any influence from any third body. [[Kepler's Laws]] are three [[equations]] which describe elliptical orbits, and still hold true today.'''

	==Orbits to and Around the Moon==		==Orbits to and Around the Moon==