# Questions tagged [delta-v]

Literal meaning is "change in velocity". The quantity has utility in rocketry as measure of the change in velocity that a reaction engine must produce to move into a given trajectory. The rocket equation establishes that the mass ratio of payload to initial mass is an exponential function of delta-v divided by the propellant velocity.

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### Using Mars' inner moon Phobos as a brake

In case of a StarShip (but it could be any other lander), it would arrive a Mars with minimal fuel remaining and it would need to slowdown for reentry, how can it be slowed down for free? Maybe using ...
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### In the context of delta-V budgets, what does C3 = 0 mean? [duplicate]

Wikipedia has the following article on delta-V budgets, which I'm trying to understand. https://en.wikipedia.org/wiki/Delta-v_budget Several times the condition C3 = 0 is included in abbreviations and ...
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### Why is there no difference between a transfer orbit delta-V and a capture orbit delta-V for Earth?

I'm particularly interested in understanding this beautiful solar system delta-v map and concepts on its Wikipedia page. In contrast to other planets there is no Earth Transfer only an Earth Capture/...
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### How feasible is dragging a 1 km asteroid into Mars orbit? (For All Mankind Spoiler Alert)

In the final episode of Season 4, Dev Ayesha, Ed Baldwin and other protagonists hijack the space ship Ranger to drag the wayward Asteroid 2003LC "Goldilocks" into Mars orbit. In terms of the ...
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### NASA GMAT sample script providing deltaV above analytical result when aiming to GEO Height

I am using the GMAT example script available at \samples\Ex_GEOTransfer.script (R2022a) to compute de deltaV from LEO to GEO including change plane maneuver. The problem is that the script seems to be ...
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### At which direction do you apply thrust to perform an inclination change maneuver?

Assume that the vehicle is already at the orbital node. No combined plane changes are included. At which direction is the thrust applied to do an inclination change maneuver? So far, Google hasn't ...
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### How bad is a non-Lagrangian Point orbit?

I am no expert on space physics, just an interested amateur. I've been searching for a few weeks and having a hard time gaining insight on this question. Phrasing the question more specifically: how ...
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### What Δv is needed to reach LEO from a space elevator?

In two recent questions about space elevators, the topic of reaching non-geostationary orbits came up, particularly the popular Low Earth Orbits. This question is simply about how hard exactly it is ...
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### How are Interplanetary Transport Network/Weak Stability Boundary paths calculated?

While reading up a bit online, I found out about Weak Stability Boundaries and the Interplanetary transport network. How is this "path" that traverses the Solar System determined? I am aware ...
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### Why is the value of the Isp of the Rocketdyne J-2 Saturn V engine in my calculation so off?

While calculating the delta V the Saturn V has on its second stage, I wanted to also calculate the Isp of the J2 rockets engines. However, the value difference between my results and the values given ...
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### Delta V required to land and then ascend from the surface of every celestial body

I've been doing some research to figure out how feasible grand tour manned missions to the surface of the moons of each outer planet. This is related: Where can I find a delta v map of landing ...
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### When you burn retrograde, will you reach periapsis sooner or later?

Say you have two spacecraft in identical orbits. Say at a point after apoapsis and before periapsis one of the spacecraft burns retrograde to lower its periapsis, and the other spacecraft does nothing ...
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### Would reaching an elliptical orbit with the same mean altitude as that of a circular orbit require the same amount of fuel?

Would a rocket that wanted to reach an elliptical orbit with a perigee of 100 miles (160 km) and an apogee of 300 miles (480 km) burn the same amount of fuel as a rocket that wanted to attain a ...
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### Going over the Apollo fuel numbers and I have many questions

I was reading through Apollo by the numbers and I noticed the LM descent to the moons surface consumed 17,414kg of fuel out of a total of 18,184kg leaving only 770kg of fuel. But then in the very next ...
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### What is the Delta V from the Moon to Earth Sun L1?

There are various proposals to build infrastructure at Earth/Sun L1 point, such as discussed in this question. From LEO the Delta V cost to L1 is about 3.5 kms or about kg of propellant in LEO for ...
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### How do "halo orbits" save on propellent (delta-v)?

I am trying to understand what advantage the satellite's 'Halo Orbit' has compared to LEO or Geostationary orbits. "Lagrange points have proven to be very useful indeed since a spacecraft can be ...
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### What is the relationship between the radius of the Hill sphere and escape velocity?

I'm currently working on a video game that will make use of a heavily simplified patched-conic model of the Solar System. I was wondering about some discrepancies between my own calculations as well ...
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### At what point did Artemis 1's Orion execute the orbital inclination change for its return transit?

Orion is returning to Earth with a marked orbital inclination compared to its Lunar Distant Retrograde Orbit (DRO). Orbital inclination changes require a great deal of delta-v, and Orion is on a tight ...
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### Why is the Orion capsule using 2 burns to transfer from the moon back to earth instead of one?

I was reading an article about how the Orion capsule just did the first of two burns that it will use to transfer out of its lunar orbit and back to Earth. I understand the phenomenon of a gravity ...
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### Which programs are used to calculate delta V and launch dates to get to other objects?

I have noticed that many people here have used different programs to calculate the launch dates and delta V to get to other planets. For example: https://space.stackexchange.com/a/59585/44505 https://...
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### How much delta V did the V2 have?

The V2 rocket was the first to cross the Karman line. To pass it you need at least 1.4 km\s. How much delta V did the V2 rocket have?
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### What is the difference between a Trans-Mars Injection and a Mars Transfer Orbit?

So I'm using this transfer orbit calculator and when simulating a transfer from LEO to Mars, in the delta-v breakdown, appear two different values: TMI (Trans-Mars Injection), at around 3000 m/s, and ...
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### How could 99942 Apophis, in 2029, be captured and brought into a low Earth orbit?

I'm currently attempting to plan out a mission where, in 2029, during Apophis's close approach to Earth, a rocket is sent up to intercept Apophis and decelerate it, making it orbit the Earth. At it's ...
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### What Delta-V can I gain from very low thrust exit from EML-5 by gravity assist from Earth to Mars?

My vehicle can exit Earth - Moon L-5 point by very low thrust and enter Earth fly-by to Mars. I am not concerned about the time for this maneuver, but say at least 80 days. What Delta-V can be gained ...
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### Could an astronaut with a jump and a "jet pack" "jump" off of the Moon?

The initial naïve question was: "Could an astronaut with a jump and a "jet pack" "jump" off of the Moon?" :) For fun, let's assume the optimal circumstances: Gemini era ...
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### What does ln mean in the Delta V equation?

I am working on a project for school and can't figure out what ln means in the Delta-V equation, as in Δv = VE * ln(ML / ME). I know that Δv is Delta V, VE is ...
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### Delta-v to hit the moon: is reaching Lunar L1 enough?

Lot of questions involve shooting things into the Sun. But there are no aliens on the Sun: they are on the Moon. I want to drop things on them, but since there's lot of them, I can just drop a ...
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### Are there uses for these 'quasi iso-propic' supersynchronous transfer orbits?

In my answer to What are the benefits of supersynchronous transfer orbits? I stumbled upon an interesting outcome when considering the total $\Delta V$ cost from an inclined low altitude parking orbit ...
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### When is the supersynchronous orbit more efficient than a typical Hohmann transfer where inclination change and circularization are simultaneous?

The title essentially explains it all. Some GEO launch vehicles like Proton, which launches from Baikonur at a latitude of 46 degrees, launch into a supersynchronous orbit. So at what point is the ...
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### What are the benefits of supersynchronous transfer orbits?

Some satellites are injected into higher apogee than standard GTO apogee of 35 786 km. Next the satellite then has to increase its perigee ( usually 250 km ) to GEO altitude. Then the apogee has to be ...
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### What is the delta v required for insertion to sun-earth L2?

What is the delta v required to place a satellite in L2 from earth transfer orbit ( Like the James Webb Telescope )? Does orbits closer to L2 different delta v from orbits far from L2?
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### What is the largest single burn plane change maneuver executed in LEO?

Below 2000 km in low Earth orbit (or close to it), what is the largest propulsive plane change from a single burn? Expecting an answer in degrees, a named mission and vehicle executing the burn itself....
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### How is delta-v calculated for an interstellar journey?

Just recently I have been learning about orbital mechanics and I came across the following article: https://blogs.scientificamerican.com/life-unbounded/why-chemical-rockets-and-interstellar-travel-...
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### What is the equation that relates delta v of a rocket to time taken to complete an orbit?

I wanted to see how the delta-v produced by a rocket affects the time it takes to complete a certain orbit. So what is the equation that relates these two quantities?
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### How much delta-v could be saved with a Hohmann-like transfer orbit to the aphelion of Mercury 's orbit instead of its perihelion?

I wrote "Hohmann-like" of course because Mercury's orbit is rather eccentric and has an inclination of 7 ⁰. From this factsheet I've learned that perihelion is at 46 million km and aphelion ...
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### How to convert bi-propellant fuel into Delta-v (for ex., for JWST)

The following news gave the details on the quantity of fuel embarked on JWST: NASA gives green light to fuel the James Webb Telescope. The Webb telescope’s spacecraft bus, built by Northrop Grumman, ...
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### Extended mission options for Juno?

Juno has been given several mission extensions, the last (and most exciting) of which involves close passes to three of the Galilean satellites, also allowing them to trim its orbit every time, and ...
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### Pure orbit inclination changing, why delta v differs between vector and numerical approach?

as said in the title I have different results between numerical en vector approach during inclination changing maneuver. The initial orbit : Perigee radius : 6700 km Eccentricity : 0.7 Inclination : ...
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### Does other orbital parameters change on plane alignment impulsive maneuver?

I work on small application to apply impulsive maneuver on an orbit. I want to align two orbits in the same plane. After the execution of the function, original orbit has the same inclination and ...
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### Understanding g₀ to calculate delta-v

I am trying to calculate the exact delta-v from various existing upper stages with a given payload in a vaccum and in orbit, say LEO. I understand that according to the Tsiolkovsky rocket equation: \...
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### What's wrong with my bielliptic transfer calculation?

I'm trying to calculate the delta-v needed to get from a 200 km circular orbit to a geostationary orbit. GSO is at an altitude of 42164140.1029448 m and at a speed of 3074.6611762 m/s. Because \$\frac{...
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### Orbital Mechanics and Launching into the Sun

Astronomy.com's Here's why we can't just rocket nuclear waste into the sun is an excellent explanation of the delta-V required to launch from Earth orbit into the Sun (30 km/s) vs. to escape from the ...
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### What's the point of characteristic energy?

My understanding of orbital mechanics is that delta-v is the most useful notion of ability to change orbits in space, akin to energy being the most useful notion of the ability to do work. But if ...
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### Penalty for Neutron dog-legging from Wallops to synchronous?

From the April 15, 2021 Everyday Astronaut video A chat with Rocket Lab's CEO Peter Beck about Neutron, Electron recovery and Rocket Lab's future! linked below (mostly from closed captions, small ...
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### What would it take to bring VSS Unity over the Kármán line?

There's been a great deal debate about Virgin Galactic calling 50 miles "space", while most use a 100 km Kármán line definition for the term. VSS Unity has exceeded 89 km altitude on two ...
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### Has there ever been a completely solid fuelled orbital rocket? [duplicate]

Engines and fuel management are very expensive to develop, and for smaller launch providers and space agencies this could prevent them from entering the market. My question is, would the cost savings ...
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### Calculating the delta V budget from Earth to Mercury

Context While verifying a basic computation to compute the required delta V budget to get to Mercury I am experiencing some difficulties in interpreting the number 8650 m/s from Earth intercept to ...
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### Specific impulse and delta-v in Tsiolkovsky's rocket equation

According to Tsiolkovsky's rocket equation, it is possible to calculate the delta-v of a multistage rocket if you know the characteristics of each stage of the rocket. In my case, the only ...
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### How much delta-v does it take to go from one arbitrary orbit to another?

This is, in theory, very basic rocket science. I can't seem to find a solution on here though, so I'm asking in the hopes you'll enlighten me and my amateurish ways. I've got a set of Keplerian ...
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