# 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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### What would be the best course of orbital maneuvers for soft landing an asteroid near the lunar south pole? [duplicate]

Wouldn't it be nice for a colony near the south pole of our Moon to have a nickel-iron asteroid on the surface nearby ! Thousands near-Earth asteroids (NEAs) have been discovered with a diameter up to ...
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### When is it okay or at least helpful to use energy arguments in orbital mechanics?

When faced with energy-based questions about spaceflight we often comment something like orbits are about momentum, not energy and use delta-v math in answers. But in this answer to How big a nuke ...
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### What is delta-v calculated in reference to?

I understand delta-v is literally just the potential change in velocity, but this would obviously differ between air resistance, gravity and many other factors, so what is delta-v calculated in ...
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### How to use specific impulse for multiple stages

I am given a scenario where I need to create a program to give the initial launch mass of a spacecraft that can vary between 4 and 20 stages. I am given that the "specific impulse for all stages is ...
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### Can a Mars orbiter mass only 50 kg?

A press release by the SatRevolution consortium says that it plans to send cubesats "as small as 50 kg" to Mars to "conduct a variety of valuable science." So that means orbiting, not just a flyby ...
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### Launch to orbit delta-v penalty from Venus compared to Earth?

Thinking about the no atmosphere caveat here made me think of Venus, which is the opposite of no atmosphere for solid/rocky bodies in our solar system. Earth's low orbital velocity is about 7.8 km/s. ...
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### Trivial lower bounds for single point mass delta-v problems?

Given two arbitrary elliptic orbits around an ideal single point mass, there will always exist a transfer with the minimal $\Delta v$ required. It's easy to find an upper bound for this ideal ...
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### Delta-v cost of longitudinal plane change correction?

In a recent question, the slow drift of a landing site on a rotating body relative to an orbiter came up. This would sometimes require a plane change correction when one desires to recover the ...
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### What is the optimal inclination change strategy?

Consider a transfer between two circular orbits of similar radius, the only difference being the inclination difference, $\alpha$. What's the minimal $\Delta v$ required to perform this transfer? ...
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### Is it really ~648.69 km/s delta-v to “land” on the surface of the Sun?

According to the following diagram it would require ~648.69 km/s to do all of the intermediate transfers that would land you at or around the sun's surface at perigee. Is this a real number? How would ...
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### Does the Delta v to leave the entire solar system depend on its angle to the ecliptic?

Does the delta-v requirement change depending on the angle a craft is leaving the ecliptic? If a craft were to be leaving only a few degrees above the ecliptic, would it take less delta-v than if a ...
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### How do you plot a porkchop plot like this one?

I was looking around for gravity gradients then got sidetracked by looking at pork-chop plots because they're extremely cool. I'm still struggling to fully understand them, but I did find an ...
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### Can someone help Scott Manley explain this Snoopy-capturing maneuver?

In his recent video Apollo 10's Lunar Module Snoopy Is Lost In Space - Could We Bring it Home? Scott Manley uses some fancy supplemental techniques in KSP to simulate and explain a possible mission to ...
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### How much Delta-V is needed for Orbital Maintenance?

My question is aimed at understanding the how much Delta-V is needed for orbital maintenance for different orbits. Obviously, there still is some residual air resistance that decreases as the orbital ...
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The recently launched Starlink satellites are designed to use their HAL Ion thrusters to seek their own independent orbits, evade collisions, and de-orbit at the end of their lives. That's a lot of ...
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### Is there a general relativistic relativistic rocket equation?

I am not to familiar with rocket equations but I know that if you combine special relativity with classical mechanics you get "c" as a speed limit. Basically the closer you get to "c" the more you ...
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### What are Mass Rate(∆v)/∆v, Mass Rate(Isp)/Isp and time of burn(MR)/MR graphs?

I have some problems about Tsiolkovsky's Rocket Equation and some graphs. Firstly, I didn't get what I can do with Rocket Equation formulas as seen below, Also, what these three graphs try to mean? ...
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### Details about traveling from EM-L2 to SE-L1

Would the optimal time to launch be when the Moon was on the opposite side of the Earth from the Sun? What direction would be optimal leaving EM-L2, radially away from the moon? Is the last line of ...
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### Delta V to get to the Sun-Earth Lagrange Point 1?

For any of these starting positions, GEO, GTO, EM-L2 or EM-L4/5, which would require the least delta-V to get to Sun-Earth L1? How much delta-V would it require? Would this chart help in identifying ...
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### what are various best practices/processes associated with orbit change manoeuvres of LEO / GEO satellites?

Suppose a satellite was supposed to burn X% fuel reduce Y% mass to gain delta V and change to different orbit in time t. But something is faulty with its propulsion system so it's burning more fuel to ...
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### Does it take more energy to get to Venus or to Mars?

Let's assume we use the ideal positions of those planets relative to Earth for launch. And let's assume the spacecraft is launched from the same place on Earth. Also let's assume the goal is to get ...
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### Delta-V to accelerate to/decelerate from .5c

I have a reasonably good understanding of delta-V (from playing KSP). However, I don't have a great understanding of how it works once you start running into the limitations of physics. I know that ...
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### Is there a list of space exploration mission ordered by “size”?

While playing KSP I came to realize how how counter-intuitive distances in space exploration are. Just because a planet is closer doesn't mean it's easier to get to. For example, I used to think ...
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### Does launching to interplanetary space from LEO require the least delta-v?

Based on this chart from wikipedia, (I do not know if I am reading it correctly) This all assumes LEO-Eq LEO to C3/0=3.22 LEO to GEO to C3/0=3.9+1.3=5.2 LEO to EML-1 to C3/0=3.77+0.14=3.91 LEO to ...
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### Delta-v to move from GEO to GEO

To move a satellite in geostationary orbit, 166°55′E, to the antipode, 13° 4' 3.2" W, what delta-V would be needed for this to be accomplished? As for time constraints, I do not know what are the ...
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### Have there been any correlations between rocket size and the delta V it achieves

Have there been any studies that discuss the delta V of the vehicle and compare it to the altitude of operation, or compare it across launchers. If not, what kind of criteria, would one look for ...
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### Is there an absolute limit to single stage ∆V when tank mass is a fixed faction of propellant mass?

Many space exploration fans are familiar with the rocket equation [https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation] $$\Delta V = V_{e} \times ln\frac{M_0}{M_F}$$ where $V_e$ is the exhaust ...
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### What would it cost to bring a 1 gram payload to the CMBR rest frame (i.e. Δv 368 km/s ?)

Suppose we wanted to do a very small experiment in (or very close to) the Cosmic Microwave Background Radiation rest frame, which we are travelling at 368 ± 2 km/s relative to. Without considering the ...
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### How much Delta-V would be required to escape the Gravitational Influence of the Earth without entering orbit?

As impractical as it sounds (and it's definitely impractical) I was wondering what the Delta-V required to leave Earth's influence would look like if we launched "just straight up" into the Earths ...
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### What is the delta-V equivalent to cross the Kármán line in vertical (suborbital) flight?

...or, well, for a typical example - how much delta-V does New Shepard carry? For orbital launches, there's the ~1km/s estimate to overcome drag and gravitational losses on orbital launches; 8km/s of ...
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### How to calculate the delta-v necessary for a suborbital “transfer” of ice from Mars' pole to equator?

I have a big chunk of water ice that needs to go from (say) one of Mars's poles to its equator. Neglecting the atmosphere, how would you calculate the delta-v necessary for this trajectory, and what ...
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### How can I calculate the delta-v correctly, this way does not seem to be correct?

I'm learning about Astrodynamics, and I would like to ask how can I calculate the $\Delta V$ for an interplanetary mission. I used a website for the porkchop plots (http://sdg.aero.upm.es/index.php/...
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### How does the delta v for leaving Earth orbit change in different directions from the Earth?

Inspired by this answer on How to intuitively explain that reaching geostationary orbits consume more Delta V than escape orbits?, which states Move to the edge of the Hill sphere, sit at Earth-...
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### How to intuitively explain that reaching geostationary orbits consume more Delta V than escape orbits?

Studying again orbital maneuvers, I found the following plotting the cost of a Hohmman transfer between coplanar circular orbits (black line), in terms of $\Delta V$ against the orbit ratio $r_f/r_i$. ...
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### How does the delta V to reach and orbit L4 and L5 compare to entering orbit around the Moon?

The L4 and L5 Lagrange points, 60 degrees in front of and behind the Moon in its orbit around Earth, orbit at the same speed as the Moon. But when a spacecraft flies to the Moon, the gravity of the ...
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### Budgeting delta-v for atmospheric drag when orbit is elliptical?

I'm trying to calculate the delta-V budget to maintain a generic elliptical orbit. Looking at the atmospheric drag losses I can only find equations that calculate delta-V loss for circular orbits. ...
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### How can the delta-V be calculated depending on the launch altitude above sea level?

If we assume that we have a given launcher that is able to produce a $\Delta v$ of 10km/s at sea level takeoff, and is able to reach an LEO of 200km above sea level, what LEO altitude would that ...
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### How to calculate if a co-location intercept is possible in a ballistic counter-battery scenario

Let us presume that we have a scenario with ballistic objects. As an example, one object $m_1$ is launched at time $t_0$ from Earth Location $a$ towards Earth Location $b$, both of which are in the ...
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### Why do delta-v and delta-v both use the same term?

As noted in this Wikipedia article, delta-v, used in spacecraft flight dynamics, is a measure of the impulse that is needed to perform a maneuver. However, in general physics (a much longer standing ...
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### What is a High Energy Transfer Orbit and what are some examples of their usage?

In a question about the 6-hour Soyuz / ISS transfer the concept of a High Energy Transfer orbit is discussed. I've heard of Low Energy Transfer Orbits before, which are commonly used on extended ...
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### Reducing transfer time between Mars and Saturn

How would I estimate the transfer time between Mars and Saturn if I have more Delta-V than necessary for a Hohmann transfer?
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### Amount of aerobraking to minimize Delta-V

Say a spacecraft is arriving at Saturn, can aerobrake arbitrarily, and wishes to arrive at Hyperion. How much should it aerobrake (i.e. what should the SMA be after aerocapture) to minimize the Delta-...
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### Delta-V between Titan and other Saturnian moons

Does anyone have a table of the delta-V between Titan escape and other moons of Saturn? If not, could someone provide figures for Hyperion, Phoebe, Iapetus, and Enceladus? Or, more simply, what is the ...
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### Inclination change maneuver [duplicate]

I'm making a spacecraft maneuver from one orbit to another. Firstly, I'm going to change the inclination, therefore, moving to a coplanar orbit. Where is it better to change the inclination, in ...
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### Lambert's problem solution: optimal transfer time

I'm solving the Lambert's problem, and already have written a program, which solves the BVP using Shooting method and computes ...
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### The delta V required for given cordinates intersection on given time

The spacecraft is on a LEO orbit with known keplerian elements. The equation of motion for spacecraft is also known. I have to intersect (just intersect!) the given coordinates $X$, $Y$, $Z$ on near, ...
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### Is bypassing LEO more efficient when launching to Venus or Mars?

According to the table in the Wikipedia article on Hohmann transfer orbits, when traveling to Venus or Mars, the Δv to enter a Hohmann transfer orbit from Earth's orbit is less than the Δv from LEO: ...
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### Are ion thruster trajectories classified as brachistochrones?

Usually, when performing trajectory optimizations for chemical rockets, the limiting factor is the $\Delta v$ budget. That means velocity change is the optimization factor, with things like transfer ...