Atmospheric Reentry - Revision history

reskin: /* Methods */

2019-11-25T22:11:30Z

Methods

← Older revision		Revision as of 22:11, 25 November 2019
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	None of the E, W,or P-series aerospace vehicles are designed for true areobraking. In the case of MRO (Mars Reconnaissance Orbiter) It took 6 months to decelerate to orbital velocity.		None of the E, W,or P-series aerospace vehicles are designed for true areobraking. In the case of MRO (Mars Reconnaissance Orbiter) It took 6 months to decelerate to orbital velocity.

	*Thrust/Lift/Drag (Modified ~~Areobraking~~)		*Thrust/Lift/Drag (Modified Aerobraking)
	The ships in Rise use [[Refined_Fuel\|Iagreous]] fuel, For all practical purposes a pilot at orbital speed could use [[TVM]] set it to 0.5km/sec and let the ship use the engines to try and maintain that 0.5km/sec total speed all the way down to about 30km altitude and then transition over to normal flight.		The ships in Rise use [[Refined_Fuel\|Iagreous]] fuel, For all practical purposes a pilot at orbital speed could use [[TVM]] set it to 0.5km/sec and let the ship use the engines to try and maintain that 0.5km/sec total speed all the way down to about 30km altitude and then transition over to normal flight.

rana: /* Points to Remember */

2019-11-15T20:28:51Z

Points to Remember

← Older revision		Revision as of 20:28, 15 November 2019
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	===Points to Remember===		===Points to Remember===
	[[Image:caution.png\|right]]		[[Image:caution.png\|right]]
	* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk over-stressing the air frame and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.		* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk over-stressing the air frame and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards (F9) and use a little positive pitch to reduce your rate of descent.
	* Do NOT roll inverted!		* Do NOT roll inverted!
	* If you are going to overshoot, no problem. Stop maneuvering and level out, ride the [[lift]] and begin your descent again when you are ready.		* If you are going to overshoot, no problem. Stop maneuvering and level out, ride the [[lift]] and begin your descent again when you are ready.

reskin at 20:11, 15 November 2019

2019-11-15T20:11:15Z

← Older revision		Revision as of 20:11, 15 November 2019
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	==Methods==		==Methods==
	* [https://en.wikipedia.org/wiki/Aerobraking Aerobraking] --- [https://mars.nasa.gov/mro/mission/timeline/mtaerobraking/ Example of NASA using Aerobraking to enter Mars orbit]		* [https://en.wikipedia.org/wiki/Aerobraking Aerobraking] --- [https://mars.nasa.gov/mro/mission/timeline/mtaerobraking/ Example of NASA using Aerobraking to enter Mars orbit]
	None of the E,W,or P series are designed for true areobraking. In the case of MRO (Mars Reconnaissance Orbiter) It took 6 months to decelerate to orbital velocity.		None of the E, W,or P-series aerospace vehicles are designed for true areobraking. In the case of MRO (Mars Reconnaissance Orbiter) It took 6 months to decelerate to orbital velocity.

	*Thrust/Lift/Drag (Modified Areobraking)		*Thrust/Lift/Drag (Modified Areobraking)
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	===Normal re-entry attitude===		===Normal re-entry attitude===
	This entire discussion is ~~base~~ on the assumption that you are wings level, nose pointed in the direction of travel, and all of this is lined up with your desired destination.		This entire discussion is based on the assumption that you are wings level, nose pointed in the direction of travel, and all of this is lined up with your desired destination.

	===Deciding When To Drop===		===Deciding When To Drop===
	A heavy ship ~~take longer,~~ more time, and distance to decelerate. This entire lesson is based on an acceleration of 1.2 [[G]] in the vacuum of space.		A heavy ship takes more time and distance to decelerate. This entire lesson is based on an acceleration of 1.2 [[G]] in the vacuum of space.
	<br />		<br />
	First you must understand that the [[atmosphere]] has no measurable effect on your vessel until you descend below about 95-85km [[MSL]] assuming normal orbital speeds. Since you are not yet in the [[atmosphere]] you can not use the air to slow or generate lift.		First you must understand that the [[atmosphere]] has no measurable effect on your vessel until you descend below about 95-85km [[MSL]] assuming normal orbital speeds. Since you are not yet in the [[atmosphere]] you can not use the air to slow or generate lift.
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	REMEMBER it is NOT your FORWARD speed that will kill you IT IS your RATE OF DESCENT		REMEMBER it is NOT your FORWARD speed that will kill you IT IS your RATE OF DESCENT
	<br />		<br />
	The faster you change the ~~out side~~ air pressure the faster the drag changes. Higher drag, higher deceleration rate. 5km/sec at 100km altitude no problem. 5Km/sec at 70km you might as well drive in to a brick wall.		The faster you change the outside air pressure the faster the drag changes. Higher drag, higher deceleration rate. 5km/sec at 100km altitude no problem. 5Km/sec at 70km you might as well drive in to a brick wall.
	<br />		<br />
	===Slowing Down===		===Slowing Down===

rana at 20:07, 15 November 2019

2019-11-15T20:07:01Z

← Older revision		Revision as of 20:07, 15 November 2019
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	==Methods==		==Methods==
	~~The preferrable method for atmospheric reentry is the '''drag''' method~~. ~~The drag method (not~~ to ~~be confused with ''aerobraking'') saves fuel~~, ~~compared to~~ the ~~direct use~~ of ~~[[thrust]]~~ (~~see [[TVM]]~~).		* [https://en.wikipedia.org/wiki/Aerobraking Aerobraking] --- [https://mars.nasa.gov/mro/mission/timeline/mtaerobraking/ Example of NASA using Aerobraking to enter Mars orbit]
			None of the E,W,or P series are designed for true areobraking. In the case of MRO (Mars Reconnaissance Orbiter) It took 6 months to decelerate to orbital velocity.

	For ~~this methodology,~~ the ~~following assumptions are made.~~..		*Thrust/Lift/Drag (Modified Areobraking)
			The ships in Rise use [[Refined_Fuel\|Iagreous]] fuel, For all practical purposes a pilot at orbital speed could use [[TVM]] set it to 0.5km/sec and let the ship use the engines to try and maintain that 0.5km/sec total speed all the way down to about 30km altitude and then transition over to normal flight.

	*~~You are flying between 100-120 [[kilometer\|km]]~~ [[~~MSL~~]]		*[[TVM]]
	*You are travelling at roughly 5.~~6km/s~~		TVM will get you down safe but it will literally fight lift, drag, gravity all the way down trying to get and maintain the set speed you put in.
	*You are ~~not carrying cargo (which changes~~ the ~~distance at which you start to slow down dramatically)~~
			===Normal re-entry attitude===
			This entire discussion is base on the assumption that you are wings level, nose pointed in the direction of travel, and all of this is lined up with your desired destination.

	===Deciding When To Drop===		===Deciding When To Drop===
	First you must understand that the [[atmosphere]] has no effect on your vessel until you descend below about ~~70km~~ [[MSL]] assuming normal orbital speeds. Since you are not yet in the [[atmosphere]] you can not use the air to ~~brake~~.		A heavy ship take longer, more time, and distance to decelerate. This entire lesson is based on an acceleration of 1.2 [[G]] in the vacuum of space.
			<br />
	If you are ~~travelling~~ at the ~~specified~~ speed and altitude, you will start to ~~descend~~ at around ~~1500km~~ from your target. ~~Aim~~ to ~~be hitting the atmosphere~~ at ~~between 850~~-~~1000km from your~~ target.		First you must understand that the [[atmosphere]] has no measurable effect on your vessel until you descend below about 95-85km [[MSL]] assuming normal orbital speeds. Since you are not yet in the [[atmosphere]] you can not use the air to slow or generate lift.
			<br />
	~~The best way~~ to ~~descend~~ in ~~a controlled fashion is to first zero out your [[trim]] and~~ use ~~your vertical thrusters (~~F8/F9~~). In order~~ to ~~do this starting using~~ your ~~roof mounted thrusters to push yourself into a descent~~. ~~A sensible descent speed when going~~ down ~~to meet~~ the ~~[[atmosphere]] is about 300m/s~~		If you are traveling at the orbital speed, or just under, and at 100-120 km altitude, you will start to using reverse thrust at around 1500-1300 km from your target. Use the up thrust (F9) to hold your ship above 100km till your ground speed is about 3km/sec.
			<br />
	~~If you sense you are going~~ to ~~overshoot~~ your ~~target because you are too high think about increasing that~~ rate of descent ~~to about 500m/s~~.		With luck and or practice you will end up at about 2.5-3 km/sec as the target get to about 12-15 degrees nose down. Lower your nose to 15 degrees down. KEEP the engines in reverse but use the F8/F9 to help keep your direction of travel lined up with your nose. You will see some aerodynamic heating and plasma effects. As you generate more and more lift you will stop using the up and down thrust and start pitching the nose up and down to adjust your rate of descent.
			<br />
	~~It is important that you do not let that descent rate increase above 600m~~/~~s or you are at high risk of burning up the [[atmosphere]].~~		<br />
			REMEMBER it is NOT your FORWARD speed that will kill you IT IS your RATE OF DESCENT
	REMEMBER it is NOT your FORWARD speed that will kill you IT IS your RATE OF DESCENT		<br />
			The faster you change the out side air pressure the faster the drag changes. Higher drag, higher deceleration rate. 5km/sec at 100km altitude no problem. 5Km/sec at 70km you might as well drive in to a brick wall.
	~~===Meeting~~ the ~~Atmosphere===~~		<br />
	~~At about 850-1000km, you are just starting enter~~ the ~~[[atmosphere]] and you are now starting to pick up [[airspeed]]~~. ~~You will notice your speed both [[velocity]] and [[ground speed]] will start to decrease ever rapidly as you descend~~.

	~~At this point you need to make sure your wings are level with the [[artificial horizon\|horizon]] and your [[pitch]] is~~ no ~~more than -5°~~. ~~When~~ you ~~are more confident and want to slow down faster feel free to go in nose first. But it is dangerous and I don't recommend it until you know what you are doing. You are aiming to go~~ in ~~"belly first" so-~~to~~-speak.~~

	~~The two main [[instruments]] you need to pay close attention to now are your [[VSI]] and your [[acceleration\|J]] which is on the left [[MFD]]~~.

	===Slowing Down===		===Slowing Down===
	~~You will also notice that as~~ you ~~descend and slow your rate of descent will start~~ to ~~decrease and head towards a positive rate of climb. This means that you are now picking up [[lift]] from the oncoming air, and at~~ your ~~current speed that [[lift]] is so powerful it is pushing~~ you ~~right back up!~~		If you kept close to your ideal 15 degree down you will end up close to 30km and at 0.5 km a sec.
			If you made it down safely to where you are now flying like an airplane. WELL DONE and CONGRATULATIONS! You just completed your first safe operational reentry!! Go and get a drink and celebrate!!!
	There is a way to combat this and keep your rate of descent constant or to your desire... by rolling 90° left or right you can maintain the descent rate that you wish to hold. I suggest that you alternate your roll left and right at intervals so that you do not drift too far off course.

	~~It is IMPORTANT that you DO NOT roll [[inverted_flight\|inverted]], this~~ will ~~cause your rate of descent to increase VERY rapidly and you are very likely to burn~~ up!

	All the while during your rolls and manuvers keep watching that [[acceleration\|J]] number on the left [[MFD]], this is how many Gs of [[acceleration]]/decceleration your are pulling from below your vessel. I advise that you do not allow this to ~~get further than ±5km/s or your will be injured~~ and parts of your ship will begin to break away. The same goes for [[acceleration\|K]] which is the force in Gs from the front of your vessel although you can let this get up to about 12G I DON'T advise it unless you know what you are doing.

	As you reach about 3km/s [[ground speed]] look at your distance from you target... if you sense you are falling short, roll level and point your vessel at the [[artificial horizon\|horizon]], this will reduce the level of slowing that is being placed on your ship, do not be concerned if you start to gain altitude due to [[lift]], and do not try to fight where the air is taking you with [[pitch]] too much. Y ou can then glide a bit further a then try to lose some more altitude when you feel you are at ~~a good distance.~~.~~. I would say you want to aim to be about 350-450km away from your target before continuing~~ a ~~descent and brake from 3km/s.~~

	~~Once you are down to about 1km/s you can start thinking about using your ptch controls to gently ease the [[velocity vector]] down towards your [[target vector]]~~. ~~Your ship will continue to slow gently from here and you can apply power as and when you feel it is neccesary.~~

	If you made it down safely WELL DONE and CONGRATULATIONS! You just completed your first safe operational reentry!! Go and get a drink and celebrate!!!

	===Points to Remember===		===Points to Remember===
	[[Image:caution.png\|right]]		[[Image:caution.png\|right]]
	* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk ~~overstressing~~ the ~~airframe~~ and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.		* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk over-stressing the air frame and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.
	* Do NOT roll inverted!		* Do NOT roll inverted!
	* If you are going to overshoot, no problem. Stop ~~manuvering~~ and level out, ride the [[lift]] and begin your descent again when you are ready.		* If you are going to overshoot, no problem. Stop maneuvering and level out, ride the [[lift]] and begin your descent again when you are ready.
	* Do NOT scramble to get on target in your first few attempts if you overshoot or come short SO WHAT?!?! The main thing is you need to be in one piece to be pleased with what you just acheived, you can work on getting on target with practice... safely!! Getting on target is not to promote expansion of your e-genitals!		* Do NOT scramble to get on target in your first few attempts if you overshoot or come short SO WHAT?!?! The main thing is you need to be in one piece to be pleased with what you just acheived, you can work on getting on target with practice... safely!! Getting on target is not to promote expansion of your e-genitals!
	* Your instruments are your friends, they will show you when danger is approaching, not the window.		* Your instruments are your friends, they will show you when danger is approaching, not the window.

reskin: /* Methods */

2018-05-16T02:08:43Z

Methods

← Older revision		Revision as of 02:08, 16 May 2018
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	==Methods==		==Methods==
	The preferrable method for '''~~atmospheric reentry~~''' ~~is the [[drag]]~~ method. The [[drag]] method (not to be confused with ''aerobraking'') saves fuel, compared to the direct use of [[thrust]] (see [[TVM]]).		The preferrable method for atmospheric reentry is the '''drag''' method. The drag method (not to be confused with ''aerobraking'') saves fuel, compared to the direct use of [[thrust]] (see [[TVM]]).

	For this methodology, the following assumptions are made...		For this methodology, the following assumptions are made...
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	*You are not carrying cargo (which changes the distance at which you start to slow down dramatically)		*You are not carrying cargo (which changes the distance at which you start to slow down dramatically)

	===Deciding ~~when to drop~~===		===Deciding When To Drop===
	First you must understand that the [[atmosphere]] has no effect on your vessel until you descend below about 70km [[MSL]] assuming normal orbital speeds. Since you are not yet in the [[atmosphere]] you can not use the air to brake.		First you must understand that the [[atmosphere]] has no effect on your vessel until you descend below about 70km [[MSL]] assuming normal orbital speeds. Since you are not yet in the [[atmosphere]] you can not use the air to brake.

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	It is important that you do not let that descent rate increase above 600m/s or you are at high risk of burning up the [[atmosphere]].		It is important that you do not let that descent rate increase above 600m/s or you are at high risk of burning up the [[atmosphere]].

	''REMEMBER it is NOT your FORWARD speed that will kill you IT IS your RATE OF DESCENT''		REMEMBER it is NOT your FORWARD speed that will kill you IT IS your RATE OF DESCENT

	===Meeting the ~~atmosphere~~===		===Meeting the Atmosphere===
	At about 850-1000km, you are just starting enter the [[atmosphere]] and you are now starting to pick up [[airspeed]]. You will notice your speed both [[velocity]] and [[ground speed]] will start to decrease ever rapidly as you descend.		At about 850-1000km, you are just starting enter the [[atmosphere]] and you are now starting to pick up [[airspeed]]. You will notice your speed both [[velocity]] and [[ground speed]] will start to decrease ever rapidly as you descend.

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	The two main [[instruments]] you need to pay close attention to now are your [[VSI]] and your [[acceleration\|J]] which is on the left [[MFD]].		The two main [[instruments]] you need to pay close attention to now are your [[VSI]] and your [[acceleration\|J]] which is on the left [[MFD]].

	===Slowing ~~down~~===		===Slowing Down===
	You will also notice that as you descend and slow your rate of descent will start to decrease and head towards a positive rate of climb. This means that you are now picking up [[lift]] from the oncoming air, and at your current speed that [[lift]] is so powerful it is pushing you right back up!		You will also notice that as you descend and slow your rate of descent will start to decrease and head towards a positive rate of climb. This means that you are now picking up [[lift]] from the oncoming air, and at your current speed that [[lift]] is so powerful it is pushing you right back up!

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	If you made it down safely WELL DONE and CONGRATULATIONS! You just completed your first safe operational reentry!! Go and get a drink and celebrate!!!		If you made it down safely WELL DONE and CONGRATULATIONS! You just completed your first safe operational reentry!! Go and get a drink and celebrate!!!

	===Points to ~~remember~~===		===Points to Remember===
	[[Image:caution.png\|right]]		[[Image:caution.png\|right]]
	* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk overstressing the airframe and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.		* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk overstressing the airframe and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.

reskin at 18:03, 29 April 2018

2018-04-29T18:03:04Z

← Older revision		Revision as of 18:03, 29 April 2018
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	Need further help just ask!		Need further help just ask!

			[[Category:Getting Started]]

reskin: /* Points to remember */

2007-12-03T00:34:01Z

Points to remember

← Older revision		Revision as of 00:34, 3 December 2007
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	===Points to remember===		===Points to remember===
	[[Image:caution.png]]		[[Image:caution.png\|right]]
	* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk overstressing the airframe and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.		* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk overstressing the airframe and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.
	* Do NOT roll inverted!		* Do NOT roll inverted!

reskin: /* Points to remember */

2007-12-03T00:31:05Z

Points to remember

← Older revision		Revision as of 00:31, 3 December 2007
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	===Points to remember===		===Points to remember===
			[[Image:caution.png]]
	* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk overstressing the airframe and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.		* Do NOT fight the [[lift]] being placed on your vessel with pitch or thrusters you will risk overstressing the airframe and losing bits from it, and causing injury or death. However if you need to help slow your descent rate, thrust downwards and use a little positive pitch to reduce your rate of descent.
	* Do NOT roll inverted!		* Do NOT roll inverted!
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	Need further help just ask!		Need further help just ask!

	~~--[[User:stalintc\|stalintc]] 18:29, 28 February 2007 (HKT)stalintc~~

reskin at 04:06, 11 June 2007

2007-06-11T04:06:45Z

← Older revision		Revision as of 04:06, 11 June 2007
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	* Do NOT roll inverted!		* Do NOT roll inverted!
	* If you are going to overshoot, no problem. Stop manuvering and level out, ride the [[lift]] and begin your descent again when you are ready.		* If you are going to overshoot, no problem. Stop manuvering and level out, ride the [[lift]] and begin your descent again when you are ready.
	* Do NOT scramble to get on target in your first few attempts if you overshoot or come short SO WHAT?!?! The main thing is you need to be in one piece to be pleased with what you just acheived, you can work on getting on target with practice... safely!! Getting on target is not to promote expansion of your [[e-genitals]]!		* Do NOT scramble to get on target in your first few attempts if you overshoot or come short SO WHAT?!?! The main thing is you need to be in one piece to be pleased with what you just acheived, you can work on getting on target with practice... safely!! Getting on target is not to promote expansion of your e-genitals!
	* Your instruments are your friends, they will show you when danger is approaching, not the window.		* Your instruments are your friends, they will show you when danger is approaching, not the window.
	* STAY CALM AND DO NOT PANIC!		* STAY CALM AND DO NOT PANIC!

reskin at 05:09, 18 April 2007

2007-04-18T05:09:11Z

← Older revision		Revision as of 05:09, 18 April 2007
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	At about 850-1000km, you are just starting enter the [[atmosphere]] and you are now starting to pick up [[airspeed]]. You will notice your speed both [[velocity]] and [[ground speed]] will start to decrease ever rapidly as you descend.		At about 850-1000km, you are just starting enter the [[atmosphere]] and you are now starting to pick up [[airspeed]]. You will notice your speed both [[velocity]] and [[ground speed]] will start to decrease ever rapidly as you descend.

	At this point you need to make sure your wings are level with the [[horizon]] and your [[pitch]] is no more than -5°. When you are more confident and want to slow down faster feel free to go in nose first. But it is dangerous and I don't recommend it until you know what you are doing. You are aiming to go in "belly first" so-to-speak.		At this point you need to make sure your wings are level with the [[artificial horizon\|horizon]] and your [[pitch]] is no more than -5°. When you are more confident and want to slow down faster feel free to go in nose first. But it is dangerous and I don't recommend it until you know what you are doing. You are aiming to go in "belly first" so-to-speak.

	The two main [[instruments]] you need to pay close attention to now are your [[VSI]] and your [[acceleration\|J]] which is on the left [[MFD]].		The two main [[instruments]] you need to pay close attention to now are your [[VSI]] and your [[acceleration\|J]] which is on the left [[MFD]].