Aerobraking - Revision history

Michel Lamontagne at 14:32, 27 August 2021

2021-08-27T14:32:36Z

← Older revision		Revision as of 15:32, 27 August 2021
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	Aerobraking is a technique used by mission scientists to reduce the height of spacecraft orbits by allowing atmospheric drag to slow the spacecraft's velocity. Often the [[solar panel\|solar panels]] onboard orbiters can be used to maximize and control the amount of drag applied to the craft. This technique will ultimately minimize the requirement for the use of [[propellant\|propellants]] (to slow the craft down), thereby optimizing cost effectiveness.		Aerobraking is an [[Astronautics\|astronautical]] technique used by mission scientists to reduce the height of spacecraft orbits by allowing atmospheric drag to slow the spacecraft's velocity. Often the [[solar panel\|solar panels]] onboard orbiters can be used to maximize and control the amount of drag applied to the craft. This technique will ultimately minimize the requirement for the use of [[propellant\|propellants]] (to slow the craft down), thereby optimizing cost effectiveness.

	This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.		This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.
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	The images show orbits determined by the NASA Ames research center trajectory planner tool<ref>NASA Ames Research Center, "Trajectory Browser", web tool. https://trajbrowser.arc.nasa.gov/traj_browser.php?maxMag=25&maxOCC=4&chk_target_list=on&target_list=mars%0D%0A&mission_class=oneway&mission_type=flyby&LD1=2020&LD2=2030&maxDT=200&DTunit=days&maxDV=5&min=DT&wdw_width=-1&submit=Search#a_load_results</ref>.		The images show orbits determined by the NASA Ames research center trajectory planner tool<ref>NASA Ames Research Center, "Trajectory Browser", web tool. https://trajbrowser.arc.nasa.gov/traj_browser.php?maxMag=25&maxOCC=4&chk_target_list=on&target_list=mars%0D%0A&mission_class=oneway&mission_type=flyby&LD1=2020&LD2=2030&maxDT=200&DTunit=days&maxDV=5&min=DT&wdw_width=-1&submit=Search#a_load_results</ref>.

	== References ==		==References==
	[[category:Spaceflight science]]		[[category:Spaceflight science]]
			<references />

Olawlor: Add a paragraph of technical details from the 1990 MSFC paper on Mars aerocapture.

2020-08-09T01:14:27Z

Add a paragraph of technical details from the 1990 MSFC paper on Mars aerocapture.

← Older revision		Revision as of 02:14, 9 August 2020
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	===Aerocapture===		===Aerocapture===
	Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere. Aerocapture can subject a vehicle to very high accelerations, and for future manned mission will require very precise attitude controls for the vehicles.		Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere. Aerocapture can subject a vehicle to very high accelerations, and for future manned mission will require very precise attitude controls for the vehicles.

			For example, in a typical manned Mars mission concept, using aerobraking cuts the initial vehicle mass in half<ref>Braun, Powell, Hartung, "The effect of interplanetary trajectory options on a manned Mars aerobrake configuration
			," 1990 NASA Marshall Technical Report. https://ntrs.nasa.gov/citations/19900016720</ref> compared to purely propulsive capture, even including the mass of a large heatshield required for aerobraking. This is because aerobraking can scrub off several km/s of arrival velocity per aerobraking pass without using propellant. However, high arrival velocities can impose significant radiative and convective heating loads on the heatshield, and sustained accelerations on the crew of as much as 5g for several minutes. A typical Mars aerobraking atmosphere entry corridor has a periapsis of 40-50km and a height tolerance of less than 5km, requiring accurate navigation and aerodynamic control.

	Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.		Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.
	[[File:244 days.jpg\|thumb\|600x600px\|Typical Mars rendez-vous trajectory. 244 days to Mars, with the same deltaV than an aerocapture mission, but less risk.]]		[[File:244 days.jpg\|thumb\|600x600px\|Typical Mars rendez-vous trajectory. 244 days to Mars, with the same deltaV than an aerocapture mission, but less risk.]]
	This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are ~~lost~~. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.		This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are left on an elliptical solar orbit that may not approach any planet for centuries. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.

	The images show orbits ~~determines~~ by the NASA Ames research center trajectory planner tool<ref>https://trajbrowser.arc.nasa.gov/traj_browser.php?maxMag=25&maxOCC=4&chk_target_list=on&target_list=mars%0D%0A&mission_class=oneway&mission_type=flyby&LD1=2020&LD2=2030&maxDT=200&DTunit=days&maxDV=5&min=DT&wdw_width=-1&submit=Search#a_load_results</ref>.		The images show orbits determined by the NASA Ames research center trajectory planner tool<ref>NASA Ames Research Center, "Trajectory Browser", web tool. https://trajbrowser.arc.nasa.gov/traj_browser.php?maxMag=25&maxOCC=4&chk_target_list=on&target_list=mars%0D%0A&mission_class=oneway&mission_type=flyby&LD1=2020&LD2=2030&maxDT=200&DTunit=days&maxDV=5&min=DT&wdw_width=-1&submit=Search#a_load_results</ref>.

	== References ==		== References ==
	[[category:Spaceflight science]]		[[category:Spaceflight science]]

Michel Lamontagne at 05:14, 29 July 2019

2019-07-29T05:14:17Z

← Older revision		Revision as of 06:14, 29 July 2019
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	[[File:244 days.jpg\|thumb\|600x600px\|Typical Mars rendez-vous trajectory. 244 days to Mars, with the same deltaV than an aerocapture mission, but less risk.]]		[[File:244 days.jpg\|thumb\|600x600px\|Typical Mars rendez-vous trajectory. 244 days to Mars, with the same deltaV than an aerocapture mission, but less risk.]]
	This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are lost. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.		This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are lost. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.

			The images show orbits determines by the NASA Ames research center trajectory planner tool<ref>https://trajbrowser.arc.nasa.gov/traj_browser.php?maxMag=25&maxOCC=4&chk_target_list=on&target_list=mars%0D%0A&mission_class=oneway&mission_type=flyby&LD1=2020&LD2=2030&maxDT=200&DTunit=days&maxDV=5&min=DT&wdw_width=-1&submit=Search#a_load_results</ref>.

			== References ==
	[[category:Spaceflight science]]		[[category:Spaceflight science]]

Michel Lamontagne at 05:07, 29 July 2019

2019-07-29T05:07:29Z

← Older revision		Revision as of 06:07, 29 July 2019
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	Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.		Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.
			[[File:244 days.jpg\|thumb\|600x600px\|Typical Mars rendez-vous trajectory. 244 days to Mars, with the same deltaV than an aerocapture mission, but less risk.]]
	This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are lost. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.		This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are lost. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.
	[[category:Spaceflight science]]		[[category:Spaceflight science]]

Michel Lamontagne at 04:56, 29 July 2019

2019-07-29T04:56:20Z

← Older revision		Revision as of 05:56, 29 July 2019
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	This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.		This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.
	[[File:128days.jpg\|thumb\|600x600px\|This screen capture shows the NASA trajectory planner for a flyby mission of 128 days to Mars in 2022. The flyby is transformed into a ~~capture~~ by aerocapture in the Martian atmosphere.]]		[[File:128days.jpg\|thumb\|600x600px\|This screen capture shows the NASA trajectory planner for a flyby mission of 128 days to Mars in 2022. The flyby could be transformed into a transit by aerocapture in the Martian atmosphere.]]

	===Aerocapture===		===Aerocapture===

Michel Lamontagne at 04:55, 29 July 2019

2019-07-29T04:55:17Z

← Older revision		Revision as of 05:55, 29 July 2019
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	Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.		Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.

			This type of orbit is much more dangerous than the Hohmann transfer orbit, as it requires a successful capture or the vehicle and crew are lost. The return velocity of Apollo was about 11 km/s, so the 9 km/s relative speed shown in the illustration should be manageable.
	[[category:Spaceflight science]]		[[category:Spaceflight science]]

Michel Lamontagne at 04:45, 29 July 2019

2019-07-29T04:45:18Z

← Older revision		Revision as of 05:45, 29 July 2019
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	[[File:96 days to Mars.jpg\|thumb\|600x600px\|Screen shot of the NASA trajectory planner for a flyby transfer to Mars in 96 days. The Flyby is transformed into a capture by using aerocapture in the Martian atmosphere.]]
	Aerobraking is a technique used by mission scientists to reduce the height of spacecraft orbits by allowing atmospheric drag to slow the spacecraft's velocity. Often the [[solar panel\|solar panels]] onboard orbiters can be used to maximize and control the amount of drag applied to the craft. This technique will ultimately minimize the requirement for the use of [[propellant\|propellants]] (to slow the craft down), thereby optimizing cost effectiveness.		Aerobraking is a technique used by mission scientists to reduce the height of spacecraft orbits by allowing atmospheric drag to slow the spacecraft's velocity. Often the [[solar panel\|solar panels]] onboard orbiters can be used to maximize and control the amount of drag applied to the craft. This technique will ultimately minimize the requirement for the use of [[propellant\|propellants]] (to slow the craft down), thereby optimizing cost effectiveness.

	This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.		This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.
			[[File:128days.jpg\|thumb\|600x600px\|This screen capture shows the NASA trajectory planner for a flyby mission of 128 days to Mars in 2022. The flyby is transformed into a capture by aerocapture in the Martian atmosphere.]]

	===Aerocapture===		===Aerocapture===
	Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere. Aerocapture can subject a vehicle to very high accelerations, and for future manned mission will require very precise attitude controls for the vehicles.		Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere. Aerocapture can subject a vehicle to very high accelerations, and for future manned mission will require very precise attitude controls for the vehicles.

	Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months for a Hohmann transfer orbit to four months ~~or even less~~.		Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months, 270 days, for a Hohmann transfer orbit to about four months (128 days). This would reduce radiation doses by over 60% compared to the Hohmann transfer. This trajectory uses 4.62 km/s of deltaV. SpaceX Starship is designed for about 6 km/s of deltaV.
	[[category:Spaceflight science]]		[[category:Spaceflight science]]

Michel Lamontagne at 04:33, 29 July 2019

2019-07-29T04:33:08Z

← Older revision		Revision as of 05:33, 29 July 2019
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			[[File:96 days to Mars.jpg\|thumb\|600x600px\|Screen shot of the NASA trajectory planner for a flyby transfer to Mars in 96 days. The Flyby is transformed into a capture by using aerocapture in the Martian atmosphere.]]
	Aerobraking is a technique used by mission scientists to reduce the height of spacecraft orbits by allowing atmospheric drag to slow the spacecraft's velocity. Often the [[solar panel\|solar panels]] onboard orbiters can be used to maximize and control the amount of drag applied to the craft. This technique will ultimately minimize the requirement for the use of [[propellant\|propellants]] (to slow the craft down), thereby optimizing cost effectiveness.		Aerobraking is a technique used by mission scientists to reduce the height of spacecraft orbits by allowing atmospheric drag to slow the spacecraft's velocity. Often the [[solar panel\|solar panels]] onboard orbiters can be used to maximize and control the amount of drag applied to the craft. This technique will ultimately minimize the requirement for the use of [[propellant\|propellants]] (to slow the craft down), thereby optimizing cost effectiveness.

Michel Lamontagne: /* Aerocapture */

2019-07-20T20:06:39Z

Aerocapture

← Older revision		Revision as of 21:06, 20 July 2019
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	===Aerocapture===		===Aerocapture===
	Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere.		Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere. Aerocapture can subject a vehicle to very high accelerations, and for future manned mission will require very precise attitude controls for the vehicles.

			Aerocapture can be used to shorten travel times between Earth and Mars, as well as with other planetary bodies in the solar system with atmospheres. The time of travel to Mars, for a similar deltaV expense, can be reduced from nine months for a Hohmann transfer orbit to four months or even less.
	[[category:Spaceflight science]]		[[category:Spaceflight science]]

Michel Lamontagne at 20:00, 20 July 2019

2019-07-20T20:00:48Z

← Older revision		Revision as of 21:00, 20 July 2019
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	This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.		This technique was used to great effect on missions such as the [[ExoMars Trace Gas Orbiter]] in 2017, [[Mars Reconnaissance Orbiter]] in 2006 and [[Mars Odyssey]] in 2001, and is standard practice when spacecraft are being inserted into orbit or when a reduction in velocity is required.

	=== Aerocapture ===		===Aerocapture===
	Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to descent and entry into the atmosphere.		Aerocapture is a subcategory of aerobraking. Atmospheric drag is used to reduce velocity to a point the vehicle can enter a stable orbit with a minimum or no propellant burn. Aerocapture can be the prelude to [[Landing on Mars\|descent and entry]] into the atmosphere.
	[[category:Spaceflight science]]		[[category:Spaceflight science]]