Difference between revisions of "Cheat sheet"

Latest revision as of 20:14, 25 July 2024

Kerbal Space Program rocket scientist's cheat sheet: Delta-v maps, equations and more for your reference so you can get from here to there and back again.

Mathematics

Thrust-to-weight ratio (TWR)

→ See also: Thrust-to-weight ratio

How hard do your engines push UP? That's "thrust".

How hard does gravity pull DOWN? That's "weight".

The ratio of those two is, surprisingly, the "thrust-to-weight" ratio.

If thrust is pushing harder than weight, your rocket goes up! Hooray!

If weight is pulling harder than thrust, your rocket does not go up. Sad!

That's the "thrust-to-weight" ratio, or TWR, in a nutshell.

{\text{TWR}}={\frac {F_{T}}{m\cdot g}}>1

Where:

$F_{T}$ is the thrust of the engines
$m$ the total mass of the craft
$g$ the local gravitational acceleration (usually surface gravity)

If TWR is less than one, then your rocket will not be going into space. You will need more engines, or perhaps MOAR BOOSTERZ!

If TWR is significantly above, say, 2.0, your rocket will ZOOM! But it might ZOOM too hard for your poor Kerbalnauts. Most rockets, straight off the launch pad, will utilize a TWR between 1.5 and 2.0.

Specific Impulse (I_sp)

→ See also: Specific impulse

Specific impulse measures the efficiency of a particular engine. Because this depends on the pressure of a rocket's surroundings, this can change between Sea Level and Vacuum (in space). Most engines are designed for optimal performance either at Sea Level (the big ones that drive your first stage and boosters, which have lots of thrust!) or Vacuum (where they won't burn as much propellant, but can be VERY efficient).

Specific impulse is used in important equations like THE ROCKET EQUATION (see next section) to determine how much oomph (or "delta-vee") you can get out of a given amount of propellant. The higher the specific impulse, the more efficient an engine is!

In real life, specific impulse is governed by things like combustion chamber pressure and propellant energy (hydrogen/oxygen is more efficient than kerosene/oxgyen). Fortunately for Jebediah, our dear Kerbals only have one brand of fuel to worry about.

Delta-v (Δv)

Basic calculation

→ See also: Tutorial:Advanced Rocket Design

Basic calculation of a rocket's Δv. Use the atmospheric and vacuum thrust values for atmospheric and vacuum Δv, respectively.

\Delta {v}=ln\left({\frac {M_{start}}{M_{end}}}\right)\cdot I_{sp}\cdot 9.81{\frac {m}{s^{2}}}

Where:

$\Delta {v}$ is the velocity change possible in m/s
$M_{start}$ is the starting mass in the same unit as $M_{end}$
$M_{end}$ is the end mass in the same unit as $M_{start}$
$I_{sp}$ is the specific impulse of the engine in seconds

True Δv of a stage that crosses from atmosphere to vacuum

Body	Δv_out
Kerbin	2500 m/s
other bodies' data missing

Calculation of a rocket stage's Δv, taking into account transitioning from atmosphere to vacuum. Δv_out is the amount of Δv required to leave a body's atmosphere, not reach orbit. This equation is useful to figure out the actual Δv of a stage that transitions from atmosphere to vacuum.

$\Delta {v}_{T}={\frac {\Delta {v}_{atm}-\Delta {v}_{out}}{\Delta {v}_{atm}}}\cdot \Delta {v}_{vac}+\Delta {v}_{out}$

Maps

Various fan-made maps showing the Δv required to travel to a certain body.

KSP Visual Calculator, online tool that determines delta-v required for multiple checkpoint missions

https://ksp-visual-calculator.blaarkies.com

Subway style Δv map (KSP 1.7.3):

Total Δv values

http://www.skyrender.net/lp/ksp/system_map.png

Δv change values

http://i.imgur.com/duY2S.png

Δv with Phase Angles

http://i.imgur.com/dXT6r7s.png

Precise Total Δv values

http://i.imgur.com/UUU8yCk.png

WAC's Δv Map for KSP 1.0.4

http://i.imgur.com/q0gC9H7.png

Maximum Δv chart

This chart is a quick guide to what engine to use for a single stage interplanetary ship. No matter how much fuel you add you will never reach these ΔV without staging to shed mass or using the slingshot maneuver. (These calculations use a full/empty fuel-tank mass ratio of 9 for all engines except those noted.)

ISP(Vac) (s)	Max Δv (m/s)	Engines	Remarks
250	5249	O-10 "Puff"	Monopropellant (max full/empty mass ratio = 8.5)
290	6249	LV-1R "Spider" 24-77 "Twitch"
300	6464	KR-1x2 "Twin-Boar"
305	6572	CR-7 R.A.P.I.E.R. Mk-55 "Thud"
310	6680	LV-T30 "Reliant" RE-M3 "Mainsail"
315	6787	LV-1 "Ant" KS-25 "Vector" KS-25x4 "Mammoth"
320	6895	48-7S "Spark" LV-T45 "Swivel" RE-I5 "Skipper"
340	7326	KR-2L+ "Rhino" T-1 "Dart"
345	7434	LV-909 "Terrier"
350	7542	RE-L10 "Poodle"
800	17238	LV-N "Nerv"	Mark 1 fuselage tanks, others have differing mass ratios
4200	57099	IX-6315 "Dawn"	Xenon (max full/empty mass ratio = 4.0)

(Version: 1.12.5)

Math examples

TWR

Copy template:

TWR = F / (m * g) > 1

I_sp

When I_sp is the same for all engines in a stage, then the I_sp is equal to a single engine. So six 200 I_sp engines still yields only 200 I_sp.
When I_sp is different for engines in a single stage, then use the following equation:

Equation:

$I_{sp}={\frac {(F_{1}+F_{2}+\dots )}{{\frac {F_{1}}{I_{sp1}}}+{\frac {F_{2}}{I_{sp2}}}+\dots }}$

Simplified:

I_sp = ( F1 + F2 + ... ) / ( ( F1 / I_sp1 ) + ( F2 / I_sp2 ) + ... )

Explained:

I_sp = ( Force of thrust of 1st engine + Force of thrust of 2nd engine...and so on... ) / ( ( Force of thrust of 1st engine / I_sp of 1st engine ) + ( Force of thrust of 2nd engine / I_sp of 2nd engine ) + ...and so on... )

Example:

Two engines, one rated 200 newtons and 120 seconds I_sp ; another engine rated 50 newtons and 200 seconds I_sp.

Isp = (200 newtons + 50 newtons) / ( ( 200 newtons / 120 ) + ( 50 newtons / 200 ) = 130.4347826 seconds I_sp

Δv

For atmospheric Δv value, use atmospheric $I_{sp}$ values.
For vacuum Δv value, use vacuum $I_{sp}$ values.
Use this equation to figure out the Δv per stage:

Equation:

$\Delta {v}=ln\left({\frac {M_{start}}{M_{dry}}}\right)\cdot I_{sp}\cdot 9.81{\frac {m}{s^{2}}}$

Simplified:

Δv = ln ( Mstart / Mdry ) * I_sp * g

Explained:

Δv = ln ( starting mass / dry mass ) X Isp X 9.81

Example:

Single stage rocket that weighs 23 tons when full, 15 tons when fuel is emptied, and engine that outputs 120 seconds I_sp.

Δv = ln ( 23 Tons / 15 Tons ) × 120 seconds I_sp × 9.81m/s² = Total Δv of 503.0152618 m/s

Maximum Δv

Simplified version of the Δv calculation to find the maximum Δv a craft with the given ISP could hope to achieve. This is done by using a magic 0 mass engine and not having a payload.

Equation:

\Delta {v}=21.576745349086\cdot I_{sp}

Simplified:

Δv =21.576745349086 * I_sp

Explained / Examples:

This calculation only uses the mass of the fuel tanks and so the ln ( Mstart / Mdry ) part of the Δv equation has been replaced by a constant as Mstart / Mdry is always 9 (or worse with some fuel tanks) regardless of how many fuel tanks you use.

The following example will use a single stage and fuel tanks in the T-100 to Jumbo 64 range with an engine that outputs 380 seconds I_sp.

Δv = ln ( 18 Tons / 2 Tons ) × 380 seconds I_sp × 9.81m/s² = Maximum Δv of 8199.1632327878 m/s

Δv = 2.1972245773 × 380 seconds I_sp × 9.82m/s² = Maximum Δv of 8199.1632327878 m/s (Replaced the log of mass with a constant as the ratio of total mass to dry mass is constant regardless of the number of tanks used as there is no other mass involved)

Δv = 21.576745349086 × 380 seconds I_sp = Maximum Δv of 8199.1632327878 m/s (Reduced to its most simple form by combining all the constants)

True Δv

How to calculate the Δv of a rocket stage that transitions from Kerbin atmosphere to vacuum.
Assumption: It takes roughly 2500 m/s of Δv to escape Kerbin's atmosphere before vacuum Δv values take over for the stage powering the transition (actual value ranges between 2000 m/s and 3400 m/s depending on ascent). Note that, as of KSP 1.3.1, around 3800 m/s of Δv is required to reach an 80km orbit from the KSC.
Note: This equation is a guess, an approximation, and is not 100% accurate. Per forum user stupid_chris who came up with the equation: "The results will vary a bit depending on your TWR and such, but it should usually be pretty darn accurate."

Equation for Kerbin atmospheric escape:

$\Delta {v}_{T}={\frac {\Delta {v}_{atm}-\Delta {v}_{out}}{\Delta {v}_{atm}}}\cdot \Delta {v}_{vac}+\Delta {v}_{out}$

Simplified:

True Δv = ( ( Δv atm - 2500 ) / Δv atm ) * Δv vac + 2500

Explained:

True Δv = ( ( Total Δv in atmosphere - 2500 m/s) / Total Δv in atmosphere ) X Total Δv in vacuum + 2500

Example:

Single stage with total atmospheric Δv of 5000 m/s, and rated 6000 Δv in vacuum.

Transitional Δv = ( ( 5000 Δv atm - 2500 Δv required to escape Kerbin atmosphere ) / 5000 Δv atm ) X 6000 Δv vac + 2500 Δv required to escape Kerbin atmosphere = Total Δv of 5500 m/s

Difference between revisions of "Cheat sheet"

Latest revision as of 20:14, 25 July 2024

Contents

Mathematics

Thrust-to-weight ratio (TWR)

Specific Impulse (I_sp)

Delta-v (Δv)

Basic calculation

True Δv of a stage that crosses from atmosphere to vacuum

Maps

Maximum Δv chart

Math examples

TWR

I_sp

Δv

Maximum Δv

True Δv

See also

Navigation menu

Personal tools

Namespaces

Variants

Views

More

Search

Navigation

KSP links

Quick access

Languages

Data templates

Tools

@@ Line 1: / Line 1: @@
-=Introduction=
+{{Outdated|
-Kerbal Space Program's Rocket Scientist Cheat Sheet Delta V Maps and Equations for Your Reference So You Can Get From Here to There and Back Again.
+* This page provides false information about the &Delta;v required in planets with atmospheres. A lot of the information on this page has to be either removed or updated.
+* Due to [[Kerbal_Space_Program_Wiki:Migration_problems|migration problems]], The &Delta;v map cannot be updated.
+}}
-==Delta V Maps==
+Kerbal Space Program rocket scientist's '''cheat sheet''': Delta-v maps, equations and more for your reference so you can get from here to there and back again.
-Various maps developed by KSP fans.
-*dV Total Values
+== Mathematics ==
-#http://wiki.kerbalspaceprogram.com/w/images/7/73/KerbinDeltaVMap.png
-#http://www.skyrender.net/lp/ksp/system_map.png
-*dV Change Values
-#http://i.imgur.com/duY2S.png
-==Thrust to Weight Ratio (TWR)==
+=== Thrust-to-weight ratio (TWR) ===
-#This is Newton's Second Law.
-#If ratio is less than 1, you will not lift off the ground.
+{{See also|Thrust-to-weight ratio}}
+How hard do your engines push UP? That's "thrust".
+How hard does gravity pull DOWN? That's "weight".
+The ratio of those two is, surprisingly, the "thrust-to-weight" ratio.
+If thrust is pushing harder than weight, your rocket goes up! Hooray!
+If weight is pulling harder than thrust, your rocket does not go up. Sad!
+That's the "thrust-to-weight" ratio, or TWR, in a nutshell.
+{{Formula|math=\text{TWR} = \frac{F_T}{m \cdot g} > 1|where=* <math>F_T</math> is the thrust of the engines
+* <math>m</math> the total mass of the craft
+* <math>g</math> the local gravitational acceleration (usually surface gravity)}}
+If TWR is less than one, then your rocket will not be going into space. You will need more engines, or perhaps MOAR BOOSTERZ!
+If TWR is significantly above, say, 2.0, your rocket will ZOOM! But it might ZOOM too hard for your poor Kerbalnauts. Most rockets, straight off the launch pad, will utilize a TWR between 1.5 and 2.0.
+=== Specific Impulse (I<sub>sp</sub>) ===
+{{See also|Specific impulse#Multiple engines|Specific impulse}}
+Specific impulse measures the ''efficiency'' of a particular engine. Because this depends on the pressure of a rocket's surroundings, this can change between Sea Level and Vacuum (in space). Most engines are designed for optimal performance either at Sea Level (the big ones that drive your first stage and boosters, which have lots of thrust!) or Vacuum (where they won't burn as much propellant, but can be ''VERY'' efficient).
+Specific impulse is used in important equations like THE ROCKET EQUATION (see next section) to determine how much ''oomph'' (or "delta-vee") you can get out of a given amount of propellant. The higher the specific impulse, the more efficient an engine is!
+In real life, specific impulse is governed by things like combustion chamber pressure and propellant energy (hydrogen/oxygen is more efficient than kerosene/oxgyen). Fortunately for Jebediah, our dear Kerbals only have one brand of fuel to worry about.
+=== Delta-v (&Delta;v) ===
+==== Basic calculation ====
+{{See also|Tutorial:Advanced Rocket Design}}
+Basic calculation of a rocket's &Delta;v. Use the atmospheric and vacuum thrust values for atmospheric and vacuum &Delta;v, respectively.
+{{Formula|math=\Delta{v} = ln\left(\frac{M_{start} }{M_{end} }\right) \cdot I_{sp} \cdot 9.81 \frac{m}{s^2}|where=* <math>\Delta{v}</math> is the velocity change possible in m/s
+* <math>M_{start}</math> is the starting mass in the same unit as <math>M_{end}</math>
+* <math>M_{end}</math> is the end mass in the same unit as <math>M_{start}</math>
+* <math>I_{sp}</math> is the specific impulse of the engine in seconds}}
+==== True &Delta;v of a stage that crosses from atmosphere to vacuum ====
+{| class="wikitable" style="float:left;margin:0.5em;"
+! Body !! &Delta;v<sub>out</sub>
+|-
+| [[Kerbin]] || 2500&nbsp;m/s
+|-
+| colspan="2" | other bodies' data missing
+|}
+Calculation of a rocket stage's &Delta;v, taking into account transitioning from atmosphere to vacuum. &Delta;v<sub>out</sub> is the amount of &Delta;v required to leave a body's atmosphere, ''not'' reach orbit. This equation is useful to figure out the actual &Delta;v of a stage that ''transitions'' from atmosphere to vacuum.
+<math>\Delta{v}_T = \frac{\Delta{v}_{atm} - \Delta{v}_{out}}{\Delta{v}_{atm}} \cdot \Delta{v}_{vac} + \Delta{v}_{out}</math>
+{{clear|left}}
+==== Maps ====
+Various fan-made maps showing the &Delta;v required to travel to a certain body.
+<br /> <br />
+'''KSP Visual Calculator, online tool that determines delta-v required for multiple checkpoint missions'''
+* https://ksp-visual-calculator.blaarkies.com
+[[File:Ksp-visual-calculator-map-dv-preview.jpg|1200px|Delta-v calculator]]
+<br /> <br />
+'''Subway style &Delta;v map ''(KSP 1.7.3)'':'''
+[[File:Subwaydeltavmap1_7_3.png|center|600px|&Delta;v to all bodies in the [[Kerbol System]]]]
+<br /> <br />
+'''Total &Delta;v values'''
+* http://www.skyrender.net/lp/ksp/system_map.png
+<br />
+'''&Delta;v change values'''
+* http://i.imgur.com/duY2S.png
+<br />
+'''&Delta;v with Phase Angles'''
+* http://i.imgur.com/dXT6r7s.png
+<br />
+'''Precise Total &Delta;v values'''
+* http://i.imgur.com/UUU8yCk.png
+<br />
+'''WAC's &Delta;v Map for KSP 1.0.4'''
+* http://i.imgur.com/q0gC9H7.png
+<br />
+==== Maximum &Delta;v chart ====
+:This chart is a quick guide to what engine to use for a single stage interplanetary ship. No matter how much fuel you add you will never reach these &Delta;V without staging to shed mass or using the slingshot maneuver. (These calculations use a full/empty fuel-tank mass ratio of 9 for all engines except those noted.)
+:{| class="wikitable"
+|-
+! ISP(Vac) (s) !! Max &Delta;v (m/s) !! Engines !! Remarks
+|-
+| 250 || 5249 || O-10 "Puff" || Monopropellant (max full/empty mass ratio = 8.5)
+|-
+| 290 || 6249 || LV-1R "Spider" <br /> 24-77 "Twitch" ||
+|-
+| 300 || 6464 || KR-1x2 "Twin-Boar" ||
+|-
+| 305 || 6572 || CR-7 R.A.P.I.E.R. <br /> Mk-55 "Thud" ||
+|-
+| 310 || 6680 || LV-T30 "Reliant" <br /> RE-M3 "Mainsail" ||
+|-
+| 315 || 6787|| LV-1 "Ant" <br /> KS-25 "Vector" <br /> KS-25x4 "Mammoth" ||
+|-
+| 320 || 6895 || 48-7S "Spark" <br /> LV-T45 "Swivel" <br /> RE-I5 "Skipper" ||
+|-
+| 340 || 7326 || KR-2L+ "Rhino" <br /> T-1 "Dart" ||
+|-
+| 345 || 7434 || LV-909 "Terrier" ||
+|-
+| 350 || 7542 || RE-L10 "Poodle" ||
+|-
+| 800 || 17238 || LV-N "Nerv" || Mark 1 fuselage tanks, others have differing mass ratios
+|-
+| 4200 || 57099 || IX-6315 "Dawn" || Xenon (max full/empty mass ratio = 4.0)
+|}
+(Version: 1.12.5)
+== Math examples ==
+=== TWR ===
+*Copy template:
+::'''TWR = F / (m * g) > 1'''
+=== I<sub>sp</sub> ===
+#When I<sub>sp</sub> is the same for all engines in a stage, then the I<sub>sp</sub> is equal to a single engine. So six 200 I<sub>sp</sub> engines still yields only 200 I<sub>sp</sub>.
+#When I<sub>sp</sub> is different for engines in a single stage, then use the following equation:
 *Equation:
-::'''TWR = F / (m * g) > 1'''
+<math>I_{sp} = \frac{(F_1 + F_2 + \dots)}{\frac{F_1}{I_{sp1}} + \frac{F_2}{I_{sp2}} + \dots}</math>
+*Simplified:
+::'''I<sub>sp</sub> = ( F1 + F2 + ... ) / ( ( F1 / I<sub>sp</sub>1 ) + ( F2 / I<sub>sp</sub>2 ) + ... )'''
 *Explained:
-::TWR = Force of Thrust / ( Total Mass X gravity of planet you're on ) > 1
+::I<sub>sp</sub> = ( Force of thrust of 1st engine + Force of thrust of 2nd engine...and so on... ) / ( ( Force of thrust of 1st engine / I<sub>sp</sub> of 1st engine ) + ( Force of thrust of 2nd engine / I<sub>sp</sub> of 2nd engine ) + ...and so on... )
 *Example:
-:200 Newton rocket engine on a 15 ton rocket launching from Kerbin Space Center.
+:Two engines, one rated 200 newtons and 120 seconds I<sub>sp</sub> ; another engine rated 50 newtons and 200 seconds I<sub>sp</sub>.
-:TWR = 200 Newtons / ( 15 Tons total Mass X 9.86 m/s2 ) = 1.36 which is > 1 which means liftoff!
+:Isp = (200 newtons + 50 newtons) / ( ( 200 newtons / 120 ) + ( 50 newtons / 200 ) = 130.4347826 seconds I<sub>sp</sub>
-==Combined Specific Impulse (Isp)==
+=== &Delta;v ===
-#When Isp is the same for all engines in a stage, then the Isp is equal to a single engine. So six 200 Isp engines still yields only 200 Isp.
+#For atmospheric &Delta;v value, use atmospheric <math>I_{sp}</math> values.
-#When Isp is different for engines in a single stage, then use the following equation:
+#For vacuum &Delta;v value, use vacuum <math>I_{sp}</math> values.
+#Use this equation to figure out the &Delta;v per stage:
 *Equation:
-::'''Isp = ( F1 + F2 + ... ) / ( ( F1 / Isp1 ) + ( F2 / Isp2 ) + ... )'''
+<math>\Delta{v} = ln\left(\frac{M_{start}}{M_{dry}}\right) \cdot I_{sp} \cdot 9.81 \frac{m}{s^2}</math>
+*Simplified:
+::'''&Delta;v = ln ( Mstart / Mdry ) * I<sub>sp</sub> * g'''
 *Explained:
-::Isp = ( Force of Thrust of 1st Engine + Force of Thrust of 2nd Engine...and so on... ) / ( ( Force of Thrust of 1st Engine / Isp of 1st Engine ) + ( Force of Thrust of 2nd Engine / Isp of 2nd Engine ) + ...and so on... )
+::&Delta;v = ln ( starting mass / dry mass ) X Isp X 9.81
 *Example:
-:Two engines, one rated 200 Newtons and 120 Specific Impulse; another engine rated 50 Newtons and 200 Specific Impulse.
+:Single stage rocket that weighs 23 tons when full, 15 tons when fuel is emptied, and engine that outputs 120 seconds I<sub>sp</sub>.
-:Isp = (200 Netwons + 50 Newtons) / ( ( 200 Newtons / 120 ) + ( 50 Newtons / 200 ) = 130.89 Specific Impulse
+:&Delta;v = ln ( 23 Tons / 15 Tons ) × 120 seconds I<sub>sp</sub> × 9.81m/s² = Total &Delta;v of 503.0152618 m/s
-==Delta V (dV)==
-#For atmospheric dV value, use atmospheric thrust values.
-#For vacuum dV value, use vacuum thrust values.
-#Use this equation to figure out the dV per stage:
+=== Maximum &Delta;v ===
+:Simplified version of the &Delta;v calculation to find the maximum &Delta;v a craft with the given ISP could hope to achieve. This is done by using a magic 0 mass engine and not having a payload.
 *Equation:
-::'''dV = ln ( Mstart / Mend ) * Isp * g'''
+::<math>\Delta{v} = 21.576745349086 \cdot I_{sp}</math>
-*Explained:
+*Simplified:
-::dV = ln ( Starting Mass / Ending Mass ) X Isp X gravity of planet you're on
+::'''&Delta;v =21.576745349086 * I<sub>sp</sub>'''
-*Example:
+*Explained / Examples:
-:Single Stage Rocket that weighs 23 tons when full, 15 tons when fuel is emptied, and engine that outputs 120 Isp.
+:This calculation only uses the mass of the fuel tanks and so the ln ( Mstart / Mdry ) part of the &Delta;v equation has been replaced by a constant as Mstart / Mdry is always 9 (or worse with some fuel tanks) regardless of how many fuel tanks you use.
-:dV = ln ( 23 Tons / 15 Tons ) X 120 Specific Impulse X 9.86m/s = Total dV of 1803.2 m/s2
+:The following example will use a single stage and fuel tanks in the T-100 to Jumbo 64 range with an engine that outputs 380 seconds I<sub>sp</sub>.
+:&Delta;v = ln ( 18 Tons / 2 Tons ) × 380 seconds I<sub>sp</sub> × 9.81m/s² = Maximum &Delta;v of 8199.1632327878 m/s
+:&Delta;v = 2.1972245773 × 380 seconds I<sub>sp</sub> × 9.82m/s² = Maximum &Delta;v of 8199.1632327878 m/s (Replaced the log of mass with a constant as the ratio of total mass to dry mass is constant regardless of the number of tanks used as there is no other mass involved)
+:&Delta;v = 21.576745349086 × 380 seconds I<sub>sp</sub> = Maximum &Delta;v of 8199.1632327878 m/s (Reduced to its most simple form by combining all the constants)
+=== True &Delta;v ===
+#How to calculate the &Delta;v of a rocket stage that transitions from Kerbin atmosphere to vacuum.
+#Assumption: It takes roughly 2500&nbsp;m/s of &Delta;v to escape Kerbin's atmosphere before vacuum &Delta;v values take over for the stage powering the transition (actual value ranges between 2000&nbsp;m/s and 3400&nbsp;m/s depending on ascent). Note that, as of KSP 1.3.1, around 3800&nbsp;m/s of &Delta;v is required to reach an 80km orbit from the KSC.
+#Note: This equation is a guess, an approximation, and is not 100% accurate. Per forum user stupid_chris who came up with the equation: "The results will vary a bit depending on your TWR and such, but it should usually be pretty darn accurate."
-==Transitional Delta V (dV) aka True dV when launching from Kerbin==
+*Equation for Kerbin atmospheric escape:
-#How to calculate the dV of a rocket stage that transitions from Kerbin atmosphere to vacuum.
+<math>\Delta{v}_T = \frac{\Delta{v}_{atm} - \Delta{v}_{out}}{\Delta{v}_{atm}} \cdot \Delta{v}_{vac} + \Delta{v}_{out}</math>
+{{clear|left}}
-*Equation:
+*Simplified:
-::'''TdV = ( ( dVatm - 1000 ) / dVatm ) * dVvac + 1000'''
+::'''True &Delta;v = ( ( &Delta;v atm - 2500 ) / &Delta;v atm ) * &Delta;v vac + 2500'''
 *Explained:
-::Transitional dV = ( ( Total dV in atmosphere - 1000 m/s2) / Total dV in atmosphere ) X Total dV in vacuum + 1000
+::True &Delta;v = ( ( Total &Delta;v in atmosphere - 2500 m/s) / Total &Delta;v in atmosphere ) X Total &Delta;v in vacuum + 2500
 *Example:
-:Single Stage with total atmospheric dV of 5000 m/s2, and rated 6000 dV in vacuum.
+:Single stage with total atmospheric &Delta;v of 5000 m/s, and rated 6000 &Delta;v in vacuum.
-:Transitional dV = ( ( 5000 dVatm - 1000 dV Required to escape Kerbin atmosphere ) / 5000 dVatm ) X 6000 dVvac + 1000 dV Required to escape Kerbin atmosphere =
+:Transitional &Delta;v = ( ( 5000 &Delta;v atm - 2500 &Delta;v required to escape Kerbin atmosphere ) / 5000 &Delta;v atm ) X 6000 &Delta;v vac + 2500 &Delta;v required to escape Kerbin atmosphere = Total &Delta;v of 5500 m/s
+== See also ==
+* [[Tutorials]]
+* [[Terminology]]
+* [[thread:26220|The Drawing Board: A library of tutorials and other useful information]]