# Questions tagged [hohmann-transfer]

An orbital maneuver to transfer between two circular orbits consisting of one burn to enter the transfer orbit and one to circularize in the final orbit.

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### Is there a standard 'low orbit' for other solar system bodies?

Is there a standard or convention for what 'counts' as a low orbit for other solar system bodies? I'm currently writing code for computing arbitrary Hohmann/ patched conics transfers, and I am looking ...
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### Are the delta-V requirements for outgoing Hohmann transfer the same as for incoming between two specified semi-major axes?

From a specified circular orbit it is often said that it is easier to go out than in, referring to the fact that achieving escape velocity from a circular orbit takes less delta-V than achieving zero ...
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### Determining the launch period for Hohmann transfer

How do you determine the day of a specific launch? I know there are launch windows but they only refer to the time at which a spacecraft must be launched. For a LEO it is apparently 365 days, but what ...
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### With C3 = 16 km²/sec², How much ∆V is required for the probe to enter a Mars orbit with periapsis at 100 km and Apoapsis at 1000 km?

A Mars probe leaves earth with a Characteristic energy (C3) of 16 km²/sec². How much ∆V is required for the probe to enter a Mars orbit with periapsis at 100 km and Apoapsis at 1000 km?
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### Direction of heliocentric entry velocity for fly-by coming from interplanetary Hohmann transfer?

I'm following Curtis's equation on interplanetary transfers. I'm confused by the direction of the entry Heliocentric velocity for a fly-by. If the assumptions is that orbits are: Coplanar, cofocal ...
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### GMAT: How to do a Hohmann transfer from a larger orbit to a smaller orbit

I've figured out how to do a Hohmann transfer to a larger orbit but can't seem to figure out how to do one back to a smaller orbit (e.g. GEO to random smaller orbit). Any advice would be amazing, ...
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### Hohmann transfer orbit Burn Duration

Hohmann's orbital transfer is explained in theory in terms of instantaneous impulses, but in real life instantaneous impulses do not exist. Finite burn is used instead. How is the burn duration ...
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### Minimum deltaV between two Orbits (re Jonathan McDowell tweet)

In this Tweet Jonathan McDowell estimates the required delta V between an object and a projectile. I have recalculated the ejection velocity of the Kosmos-2543 projectile. The delta-V between Kosmos-...
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### What makes Earth-Mars transfers more non-Hohmann; inclination or eccentricity?

Answers to Why do many Mars missions launch now, if the Hohmann transfer orbit is the most propellant-saving one? and discussions below them made me wonder what makes Earth-Mars transfers more non-...
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### Mars versus the poles of Mercury WRT colonization

From MESSENGER Finds New Evidence for Water Ice at Mercury's Poles : Credits: NASA/John Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and ...
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### Orbital Rendezvous vs Hohmann Transfer

Let's assume that a spaceship (capsule) is about to dock to the ISS the distance between spaceship (capsule) and ISS is 20 meters the relative velocity between the spaceship (capsule) and ISS is ...
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### When doing an interplanetary Hohmann transfer, are additional escape and capture burns necessary in addition to the two Hohmann Transfer burns?

When doing a Hohmann transfer, it takes a burn to change from a low orbit to the Hohmann Transfer Orbit (HTO), and a second burn to change from the HTO to a high orbit. I know how to find the delta-v ...
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### Could we wait for Mars to come to us?

This may be a stupid question but I didn't find much information online about it. The concept is simple, could we launch a vehicle into space from Earth, stop right on Mars trajectory and wait for the ...
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### Mars and back, staying only a few days

This article states that once you arrive at Mars you'll only have a couple of weeks before you'd have to begin a fresh Hohmann transfer back to Earth, otherwise you'll have to hang out on Mars for ...
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### Circular to elliptical orbit delta V requirements

this might be a dumb question, but i've been recently trying to calculate the delta V to deorbit a satellite, and I've run into a problem. Assuming a 400km circular starting orbit(and disregarding ...
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### Forces experienced during transfer orbit

As I understand it, astronauts are weightless because they are in constant free fall around the earth. To get from earth to the moon or earth to mars, spaceships execute a transfer orbit, where they ...
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### Why is Wikipedia's delta-v from the Moon to Mars transfer so much lower than mine?

I tried to write a nice answer to this first question by a new user, but I've crashed and burned. I calculated the escape from the Moon to be about 2,376 m/s which is close to 2.3 km/s shown in the ...
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### Do "partial" Hohmann transfers exist?

I'm doing some research for fiction writing, and I would like to have my plot points comply with known science whenever possible. Regarding orbital transfers, I know that the fastest way from orbit A ...
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### Do satellites inject into a Hohmann transfer orbit in Low Earth Orbit or in Solar orbit?

Lets say we have a satellite wanting to go to Mars. Do satellites such as MAVEN inject into a Hohmann transfer orbit while in Earth's orbit, or do they go out of Earth's Sphere of Influence into solar ...
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### Why is the Chandrayaan lunar insertion so long?

The Chandrayan take 5 earth orbit modifications to reach a translunar trajectory. I thought less orbit modifications should be enough: orbit inclination modification burns to go into a ...
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### What is Buzz Aldrin's T.O.R. plan? How does it work?

Buzz Aldrin is recently quoted in Ars Technical's Buzz Aldrin is looking forward, not back—and he has a plan to bring NASA along: “This T.O.R. plan may be the most important thing I’ve ever done in ...
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### Getting from LEO to a station in geostationary orbit and docking with it using a Hohmann transfer?

How long would it take for a spacecraft with a mass of 30,000 kg, to go from LEO to reach and match the speed of a space station in geostationary orbit so it could dock with the station, using a ...
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### How to find the transfer orbit from a initial circular orbit to a final elliptical orbit

Is a hohmann transfer or bi-elliptical transfer more efficient for this case? How can I find the transfer orbit that conserves the most deltaV? I will be going from a circular Earth centered orbit ...
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### Would a Hohmann transfer within LEO be useful?

Hohmann transfer is often used between a lower LEO orbit and MEO, GTO, GEO or beyond. But if the target is a high altitude within LEO, how would a direct ascent compare to ascent to a lower orbit ...
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### Ratio of low-thrust slow spiral to Hohmann transfer $\Delta V$?

Going from one circular orbit to another, there are tables out there and equations that give the total $\Delta V$ needed for a two or three impulse maneuver scenario. For a very low thrust propulsion ...
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### Hohmann transfer trajectory and "porkchop plot"

The “porkchop plot” for a spacecraft flying from Earth to Mars would show contours of equal characteristic energy against combinations of launch date and arrival date. Assuming the spacecraft has ...
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### Quantitatively, how deep are the stable equilibrium points in GEO? How much delta-v needed to move from one to the other?

This answer discusses a spacecraft in GEO using a two-impulse (circular → elliptical → circular) raise & lower maneuver to move (phase) itself by 180 degrees in longitude then return to synchrony. ...
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### Is it possible to supply 47 tons of payload to the orbit with 5 tons of fuel?

There are 2 orbits: Circular orbit with 200km altitude Circular orbit with 800km altitude The space tug is already on the first orbit. Its dry mass is 960kg, the total mass of fuel is 5250 kg. It ...
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### Is Hohmann transfer the most frequent transfer orbit?

I have to complete a project for a university exam. The task is to design an interplanetary trajectory from Earth to Saturn, and to compare it with a Hohmann transfer to the same planet. I also have ...
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### Why is a Hohmann transfer from an elliptical orbit to a circular one more efficient if done from Perigee?

I was doing some calculations, mainly a Hohmann transfer between the following two orbits... Note my calculations assume 0 perigee argument, 0 inclination and 0 right ascension... Orbit start (400 ...
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### Best heading for Hohmann transfer in real life

Assuming one wants to go from a 400x800 to a 1000x1000 orbit. The solution that require the least D/v is a Hohmann transfer, with one burn at the perigee and one burn at the new apogee (or vice versa)...
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### How to intuitively explain that tri-elliptic transfers are not better than bi-elliptic transfers?

The question How to intuitively explain that reaching geostationary orbits consume more Delta V than escape orbits? includes the graphic below, which illustrates that when transferring between ...
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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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### Mars transfer window frequency

According to this website I drew up a timeline of Mars transfer windows and the time you'd need to stay on Mars before the next return window: Blue to red arrows are Earth to mars transitions, red ...
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### How to calculate mass of fuel for Venus Orbiter

I'm working on a hypothetical constellation of orbiters at Venus for a school project, and I am currently trying to figure out how much fuel I need in the transfer stage. I have already calculated ...
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### How do I calculate wait time to launch?

I want to transfer between two planets using Hohmann transfers and the patched conic approach. However, I am struggling to figure out how long I have to wait at the starting planet (say Uranus) until ...
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### Would a Mars flyby be possible on a transfer orbit from Saturn's moon of Titan to Earth?

So, I am trying to calculate whether a transfer burn from Saturn's moon of Titan to Earth would involve a Mars flyby, assuming I have the burn start on 2 March, 2025 and arrival on 19 March, 2031. ...
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### What's the reasonable "window" in days for a Mars-Earth Hohmann transfer?

As any popular science reader knows, when traveling between Earth and Mars, there's a Hohmann transfer opportunity about every two years (I believe it's every 26 months, specifically). What I've ...
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### From which direction should a spacecraft intercept a target planet's sphere of influence for an inner-to-outer planet trajectory?

Suppose a spacecraft is on an interplanetary Hohmann transfer trajectory from an inner planet to an outer planet. When the spacecraft finally enters the target planet's sphere of influence, which ...
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### Brachistochrone variation for Earth-to-Mars Orbit

Wouldn't a Brachistochrone curve to Mars orbit be a much faster and more efficient way to send personnel and equipment to mars as compared to the Hohmann transfer if we used an Ion engine? The below ...
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### How can Bielliptic transfers be more efficient than Hohmann transfers?

I don't have an exact citation or reference but I remember hearing that in some specific instances, that a bielliptic transfer can be more efficient than Hohmann transfers. The only possible instance ...
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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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### Finding Delta V to circularize orbit after a transfer orbit.

I have been working on calculating all the the delta V needed to fly a rocket from one planet to another. I have worked out the delta V needed to raise the orbit to intercept the second planet, but ...
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### Voyager Earth to Jupiter journey time

Voyager 1 was launched on Sept 5, 1977 and encountered Jupiter March 5, 1979, a journey of less than 2 years. When I try to calculate the trajectory of the probe I assume a Hohmann transfer from ...
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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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### How is 80 to 150 days to Mars possible at 6 km/s TMI Delta V?

Is the data presented on this slide realistic? Here's the slide: Here's the talk at the time the slide is presented, so you can hear what he's saying with it. I can ...
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### Burns for EML-1 to LLO

Wikipedia gives 0.64 or 0.65 km/s for going from LLO to EML-1 or back. I would like to know what the delta v of the specific burns involved are, and if my initial calcs are close, I don't see how ...
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### Thrust and rotation strategy to circularize a standard GTO orbit using ion propulsion?

The previous question How much time does it take to circularize a GTO orbit using ion propulsion? has a good, quantitative answer based on a known delta-v. But I'm wondering how would you actually ...