Momentum from GTO - Revision history

Strangelv: 9 revisions imported

2019-04-08T14:44:16Z

9 revisions imported

Jburk: Created page with "There are many upper stages in geosynchronous transfer orbit (GTO), at perigee they have a velocity of about 10.5 kilometres per second, although this reduces gradually over y..."

2018-06-27T05:50:44Z

Created page with "There are many upper stages in geosynchronous transfer orbit (GTO), at perigee they have a velocity of about 10.5 kilometres per second, although this reduces gradually over y..."

Exoplatz.org>Sysop: Reverting to Lunarpedia version of 6 February 2007

2014-07-06T09:22:01Z

Reverting to Lunarpedia version of 6 February 2007

Exoplatz.org>Sysop: 7 revisions: importing surviving older versions of articles from Lunarpedia

2014-07-06T06:11:05Z

7 revisions: importing surviving older versions of articles from Lunarpedia

Exoplatz.org>Farred: Undo revision 17735 by Farred (talk) restoring old version now that the Exoplatz link is clean

2012-07-07T16:06:16Z

Undo revision 17735 by Farred (talk) restoring old version now that the Exoplatz link is clean

Exoplatz.org>Farred: removing link that caused problems, adding see also section

2012-05-12T06:27:39Z

removing link that caused problems, adding see also section

Exoplatz.org>Strangelv: {{Goto space}}

2007-05-30T03:24:59Z

Exoplatz.org>Strangelv: tagged with Move2space

2007-03-29T05:06:59Z

tagged with Move2space

Exoplatz.org>Geoffrey.landis: added link to tether

2007-02-06T22:06:47Z

added link to tether

Exoplatz.org>Strangelv: added cleanup tag

2007-01-04T19:28:35Z

added cleanup tag

← Older revision		Revision as of 09:22, 6 July 2014
Line 1:		Line 1:
−	{{~~Goto space~~}}	+	There are many upper stages in geosynchronous transfer orbit (GTO), at perigee
		+	they have a velocity of about 10.5 kilometres per second, although this
		+	reduces gradually over years as they slowly decay.
		+
		+	If a suborbital vehicle could attach a [[tether]] to one of these stages at
		+	perigee, it could be towed most of the way into orbit.
		+
		+	To get into LEO requires 7 km/sec.
		+
		+	If the payload and the stage are equal mass, then the payload would be
		+	accelerated by 5 km/sec and the GTO stage would be decelerated the same
		+	amount.
		+
		+	Accelerating by 5 km/sec requires about 50 G acceleration for ten seconds,
		+	which would traverse a distance of 25 kilometres (the length of tether
		+	required).
		+
		+	Alternative profile would factor by ten, e.g. 500 G for one second,
		+	traverses 2.5 kilometres (shorter length of tether but higher stress).
		+
		+	The tether would be on a spool with a controlled resistance (e.g. friction
		+	brake, or dashpot, or E-M brake) to soften the initial jerk at contact,
		+	then, pay out the tether at the right rate to control the acceleration to
		+	the planned profile.
		+
		+	The practicalities of attaching a cable to an object moving at 10.5 km/sec
		+	are daunting. In this profile the suborbital vehicle would already need to boost itself to 2 km/sec, as the 5 km/sec is not enough to reach orbit. Therefore the relative speed would be 8.5 km/sec (2km/sec less).
		+	<br>
		+	<br>
		+	Capture perhaps via a light weight structure made of a 3-D web of kevlar
		+	strands (or something stronger), like a large bullet proof vest in which the
		+	GTO stage becomes embedded. Size, maybe a few hundreds metres across. The
		+	webbing could be within an inflatable sphere a few hundred metres diameter,
		+	or alternatively shaped as a tetrahedron for simplicity of geometry.
		+	<br>
		+	The mechanics of high speed collisions are difficult to analyze. At such
		+	speeds, the flexibility of the strands become irrelevant, they behave more
		+	like solid bars. The stage would be severely damaged, one would need to
		+	devise a configuration which would not shred the GTO stage into a zillion
		+	fragments. The kevlar strands would probably be stronger than the stage
		+	material.
		+	<br>
		+	Wikipedia reports that some remarkable new developments are emerging for new
		+	materials being used in bullet proof vests.
		+	<br>
		+	http://en.wikipedia.org/wiki/Bulletproof_vest
		+	<br>
		+	Researchers in the U.S. and separately in the Hebrew University are on their
		+	way to create artificial spider silk that will be super strong, yet light
		+	and flexible.
		+	<br>
		+	American company ApNano have developed a nanocomposite based on Tungsten
		+	Disulfide able to withstand shocks generated by a steel projectile traveling
		+	at velocities of up to 1.5 km/second. During the tests, the material proved
		+	to be so strong that after the impact the samples remained essentially
		+	unmarred. Under isostatic pressure tests it is stable up to at least 350
		+	tons/cm².
		+	<br>
		+	Most upper stages are composed of Aluminum alloys (softer than steel), with
		+	some graphite composites.
		+	<br>
		+
		+
		+	{{cleanup}}
		+	[[Category:Transportation]]
		+	[[Category:Components]]
		+	[[Category:Hardware Plans]]

← Older revision		Revision as of 16:06, 7 July 2012
Line 1:		Line 1:
−	{{~~Move2space~~}}	+	{{Goto space}}
−	~~There are many upper stages in geosynchronous transfer orbit (GTO), at perigee~~
−	~~they have a velocity of about 10.5 kilometres per second, although this~~
−	~~reduces gradually over years as they slowly decay.~~
−
−	~~If a suborbital vehicle could attach a [[tether]] to one of these stages at~~
−	~~perigee, it could be towed most of the way into orbit.~~
−
−	~~To get into LEO requires 7 km/sec.~~
−
−	~~If the payload and the stage are equal mass, then the payload would be~~
−	~~accelerated by 5 km/sec and the GTO stage would be decelerated the same~~
−	~~amount.~~
−
−	~~Accelerating by 5 km/sec requires about 50 G acceleration for ten seconds,~~
−	~~which would traverse a distance of 25 kilometres (the length of tether~~
−	~~required).~~
−
−	~~Alternative profile would factor by ten, e.g. 500 G for one second,~~
−	~~traverses 2.5 kilometres (shorter length of tether but higher stress).~~
−
−	~~The tether would be on a spool with a controlled resistance (e.g. friction~~
−	~~brake, or dashpot, or E-M brake) to soften the initial jerk at contact,~~
−	~~then, pay out the tether at the right rate to control the acceleration to~~
−	~~the planned profile.~~
−
−	~~The practicalities of attaching a cable to an object moving at 10.5 km/sec~~
−	are daunting. In this profile the suborbital vehicle would already need to boost itself to 2 km/sec, as the 5 km/sec is not enough to reach orbit. Therefore the relative speed would be 8.5 km/sec (2km/sec less).
−	~~<br>~~
−	~~<br>~~
−	~~Capture perhaps via a light weight structure made of a 3-D web of kevlar~~
−	~~strands (or something stronger), like a large bullet proof vest in which the~~
−	~~GTO stage becomes embedded. Size, maybe a few hundreds metres across. The~~
−	~~webbing could be within an inflatable sphere a few hundred metres diameter,~~
−	~~or alternatively shaped as a tetrahedron for simplicity of geometry.~~
−	~~<br>~~
−	~~The mechanics of high speed collisions are difficult to analyze. At such~~
−	~~speeds, the flexibility of the strands become irrelevant, they behave more~~
−	~~like solid bars. The stage would be severely damaged, one would need to~~
−	~~devise a configuration which would not shred the GTO stage into a zillion~~
−	~~fragments. The kevlar strands would probably be stronger than the stage~~
−	~~material.~~
−	~~<br>~~
−	~~Wikipedia reports that some remarkable new developments are emerging for new~~
−	~~materials being used in bullet proof vests.~~
−	~~<br>~~
−	~~http://en.wikipedia.org/wiki/Bulletproof_vest~~
−	~~<br>~~
−	~~Researchers in the U.S. and separately in the Hebrew University are on their~~
−	~~way to create artificial spider silk that will be super strong, yet light~~
−	~~and flexible.~~
−	~~<br>~~
−	~~American company ApNano have developed a nanocomposite based on Tungsten~~
−	~~Disulfide able to withstand shocks generated by a steel projectile traveling~~
−	~~at velocities of up to 1.5 km/second. During the tests, the material proved~~
−	~~to be so strong that after the impact the samples remained essentially~~
−	~~unmarred. Under isostatic pressure tests it is stable up to at least 350~~
−	~~tons/cm².~~
−	~~<br>~~
−	~~Most upper stages are composed of Aluminum alloys (softer than steel), with~~
−	~~some graphite composites.~~
−	~~<br>~~
−
−	~~==See Also==~~
−	*[[List of Propulsion Systems]]
−
−	~~{{cleanup}}~~
−	~~[[Category:Transportation]]~~
−	~~[[Category:Components]]~~
−	~~[[Category:Hardware Plans]]~~

← Older revision		Revision as of 06:27, 12 May 2012
Line 1:		Line 1:
−	{{~~Goto space~~}}	+	{{Move2space}}
		+	There are many upper stages in geosynchronous transfer orbit (GTO), at perigee
		+	they have a velocity of about 10.5 kilometres per second, although this
		+	reduces gradually over years as they slowly decay.
		+
		+	If a suborbital vehicle could attach a [[tether]] to one of these stages at
		+	perigee, it could be towed most of the way into orbit.
		+
		+	To get into LEO requires 7 km/sec.
		+
		+	If the payload and the stage are equal mass, then the payload would be
		+	accelerated by 5 km/sec and the GTO stage would be decelerated the same
		+	amount.
		+
		+	Accelerating by 5 km/sec requires about 50 G acceleration for ten seconds,
		+	which would traverse a distance of 25 kilometres (the length of tether
		+	required).
		+
		+	Alternative profile would factor by ten, e.g. 500 G for one second,
		+	traverses 2.5 kilometres (shorter length of tether but higher stress).
		+
		+	The tether would be on a spool with a controlled resistance (e.g. friction
		+	brake, or dashpot, or E-M brake) to soften the initial jerk at contact,
		+	then, pay out the tether at the right rate to control the acceleration to
		+	the planned profile.
		+
		+	The practicalities of attaching a cable to an object moving at 10.5 km/sec
		+	are daunting. In this profile the suborbital vehicle would already need to boost itself to 2 km/sec, as the 5 km/sec is not enough to reach orbit. Therefore the relative speed would be 8.5 km/sec (2km/sec less).
		+	<br>
		+	<br>
		+	Capture perhaps via a light weight structure made of a 3-D web of kevlar
		+	strands (or something stronger), like a large bullet proof vest in which the
		+	GTO stage becomes embedded. Size, maybe a few hundreds metres across. The
		+	webbing could be within an inflatable sphere a few hundred metres diameter,
		+	or alternatively shaped as a tetrahedron for simplicity of geometry.
		+	<br>
		+	The mechanics of high speed collisions are difficult to analyze. At such
		+	speeds, the flexibility of the strands become irrelevant, they behave more
		+	like solid bars. The stage would be severely damaged, one would need to
		+	devise a configuration which would not shred the GTO stage into a zillion
		+	fragments. The kevlar strands would probably be stronger than the stage
		+	material.
		+	<br>
		+	Wikipedia reports that some remarkable new developments are emerging for new
		+	materials being used in bullet proof vests.
		+	<br>
		+	http://en.wikipedia.org/wiki/Bulletproof_vest
		+	<br>
		+	Researchers in the U.S. and separately in the Hebrew University are on their
		+	way to create artificial spider silk that will be super strong, yet light
		+	and flexible.
		+	<br>
		+	American company ApNano have developed a nanocomposite based on Tungsten
		+	Disulfide able to withstand shocks generated by a steel projectile traveling
		+	at velocities of up to 1.5 km/second. During the tests, the material proved
		+	to be so strong that after the impact the samples remained essentially
		+	unmarred. Under isostatic pressure tests it is stable up to at least 350
		+	tons/cm².
		+	<br>
		+	Most upper stages are composed of Aluminum alloys (softer than steel), with
		+	some graphite composites.
		+	<br>
		+
		+	==See Also==
		+	*[[List of Propulsion Systems]]
		+
		+	{{cleanup}}
		+	[[Category:Transportation]]
		+	[[Category:Components]]
		+	[[Category:Hardware Plans]]

← Older revision		Revision as of 03:24, 30 May 2007
Line 1:		Line 1:
−	{{~~Move2space~~}}	+	{{Goto space}}
−	~~There are many upper stages in geosynchronous transfer orbit (GTO), at perigee~~
−	~~they have a velocity of about 10.5 kilometres per second, although this~~
−	~~reduces gradually over years as they slowly decay.~~
−
−	~~If a suborbital vehicle could attach a [[tether]] to one of these stages at~~
−	~~perigee, it could be towed most of the way into orbit.~~
−
−	~~To get into LEO requires 7 km/sec.~~
−
−	~~If the payload and the stage are equal mass, then the payload would be~~
−	~~accelerated by 5 km/sec and the GTO stage would be decelerated the same~~
−	~~amount.~~
−
−	~~Accelerating by 5 km/sec requires about 50 G acceleration for ten seconds,~~
−	~~which would traverse a distance of 25 kilometres (the length of tether~~
−	~~required).~~
−
−	~~Alternative profile would factor by ten, e.g. 500 G for one second,~~
−	~~traverses 2.5 kilometres (shorter length of tether but higher stress).~~
−
−	~~The tether would be on a spool with a controlled resistance (e.g. friction~~
−	~~brake, or dashpot, or E-M brake) to soften the initial jerk at contact,~~
−	~~then, pay out the tether at the right rate to control the acceleration to~~
−	~~the planned profile.~~
−
−	~~The practicalities of attaching a cable to an object moving at 10.5 km/sec~~
−	are daunting. In this profile the suborbital vehicle would already need to boost itself to 2 km/sec, as the 5 km/sec is not enough to reach orbit. Therefore the relative speed would be 8.5 km/sec (2km/sec less).
−	~~<br>~~
−	~~<br>~~
−	~~Capture perhaps via a light weight structure made of a 3-D web of kevlar~~
−	~~strands (or something stronger), like a large bullet proof vest in which the~~
−	~~GTO stage becomes embedded. Size, maybe a few hundreds metres across. The~~
−	~~webbing could be within an inflatable sphere a few hundred metres diameter,~~
−	~~or alternatively shaped as a tetrahedron for simplicity of geometry.~~
−	~~<br>~~
−	~~The mechanics of high speed collisions are difficult to analyze. At such~~
−	~~speeds, the flexibility of the strands become irrelevant, they behave more~~
−	~~like solid bars. The stage would be severely damaged, one would need to~~
−	~~devise a configuration which would not shred the GTO stage into a zillion~~
−	~~fragments. The kevlar strands would probably be stronger than the stage~~
−	~~material.~~
−	~~<br>~~
−	~~Wikipedia reports that some remarkable new developments are emerging for new~~
−	~~materials being used in bullet proof vests.~~
−	~~<br>~~
−	~~http://en.wikipedia.org/wiki/Bulletproof_vest~~
−	~~<br>~~
−	~~Researchers in the U.S. and separately in the Hebrew University are on their~~
−	~~way to create artificial spider silk that will be super strong, yet light~~
−	~~and flexible.~~
−	~~<br>~~
−	~~American company ApNano have developed a nanocomposite based on Tungsten~~
−	~~Disulfide able to withstand shocks generated by a steel projectile traveling~~
−	~~at velocities of up to 1.5 km/second. During the tests, the material proved~~
−	~~to be so strong that after the impact the samples remained essentially~~
−	~~unmarred. Under isostatic pressure tests it is stable up to at least 350~~
−	~~tons/cm².~~
−	~~<br>~~
−	~~Most upper stages are composed of Aluminum alloys (softer than steel), with~~
−	~~some graphite composites.~~
−	~~<br>~~
−
−
−	~~{{cleanup}}~~
−	~~[[Category:Transportation]]~~
−	~~[[Category:Components]]~~
−	~~[[Category:Hardware Plans]]~~

← Older revision		Revision as of 05:06, 29 March 2007
Line 1:		Line 1:
		+	{{Move2space}}
	There are many upper stages in geosynchronous transfer orbit (GTO), at perigee		There are many upper stages in geosynchronous transfer orbit (GTO), at perigee
	they have a velocity of about 10.5 kilometres per second, although this		they have a velocity of about 10.5 kilometres per second, although this

@@ Line 3: / Line 3: @@
 reduces gradually over years as they slowly decay.
-If a suborbital vehicle could attach a tether to one of these stages at
+If a suborbital vehicle could attach a [[tether]] to one of these stages at
 perigee, it could be towed most of the way into orbit.

@@ Line 61: / Line 61: @@
 <br>
 [[Category:Transportation]]
 [[Category:Components]]
 [[Category:Hardware Plans]]