Questions tagged [orbit]
Questions regarding the mechanics or attributes of objects falling 'around' other objects, thereby orbiting them.
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Which are the current Near-Earth comets that have the closest approach to Venus?
A comment from @planetmaker to this question gives this link to the Minor Planet Centre (MPC) to find a list with Near-Earth comets.
Here's the list with orbits for current comets on that site, but I ...
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160 views
What exactly the orbit accuracy requirement in KSP missions and contracts, and how is it mathematically defined and implemented? [closed]
When playing e.g. the Rosetta mission in Kerbal Space Program (KSP), one of the things one can achieve is called Orbit Accuracy.
Unfortunately, after searching KSP's forums and Wiki I still can not ...
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Is it possible for the exhaust plume of a rocket engine burning retrograde to accelerate an object into an even higher orbit?
A couple weeks back, a debris object was catalogued in a 210x540km orbit following the deorbit burn of the Falcon 9 second stage that launched CRS-22:
Hmm... possible that CRS-22's stage 2 made ...
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1answer
130 views
Has Skyfield or any other SGP4-capable open-source Python package yet wrapped/implemented the new, improved SGP4 (version 8+)?
The first release on Github was in 2014. I have noticed Brandon Rhodes has contributed quite a bit to the Skyfield source code, so I will tag him here and in a comment.
EDIT: I changed the title to ...
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Which institution regulates rocket launches of all countries? [duplicate]
Which institution regulates the rocket launches of all countries? Meaning, suppose a country wants to launch a rocket, where do they have to report it before the actual launch and how far ahead? ...
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1answer
85 views
Do geodesics close on an ellipsoid?
I want to calculate the shortest distance between two points (Point A and Point B) on the ellipsoid surface. For this I need to use geodetic passing through these two points. Well, if I continue this ...
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Is there a name for views of orbital paths that ignore some motions versus those that don't?
Orbital paths of satellites around the Earth are usually shown as conic sections, as are paths of planets around the Sun. In truth, of course, the Earth's satellites are also orbiting the Sun, and the ...
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1answer
105 views
How can I calculate the future position of a satellite orbiting a central body as a function of time using known orbital elements?
Given the position and velocity vectors at one point in an orbit, one can calculate the keplerian elements and thus graph the subsequent orbital path as a circle/ellipse/parabola/hyperbola depending ...
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1answer
49 views
Can we more accurately predict orbits or measure position?
Imagine a satellite of known mass, orbiting the sun outside the Earth-Moon system. Assuming that we made a serious attempt to measure both it's position and attempted to predict it's orbital path, ...
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38 views
Translate/shift ECEF coordinates given certain distance
I have some orbits in ECEF coordinates overlapped at the origin, and I would like to "move" some of them given a certain distance from the original orbit similar to the following picture:
...
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1answer
60 views
Obtaining orbital parameters of a closed orbit given the characteristics of the arrival hyperbolic orbit
According to this paper (page 8) by ESA, given the $v_{inf}$, the right-ascension and the declination of the arrival hyperbolic asymptote, it is possbile to find a loci of pericenters of different ...
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What is the increase in drag by adding a space station module?
Imagine a cylindrical space station module, orbiting at an arbitrary height - the same as the ISS say.
Another identity cylindrical module docks on the end. Real station cross section hasn't changed -...
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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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3answers
84 views
In which Mars orbit, Mars Orbiters are rotating around Mars
Like Earthbound satellites are stationed in the polar orbit or Geosynchronous orbit.
In which orbit related to Mars the Marsbound orbiters are stations?
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Can we determine the position of an artificial satellite using Kepler's parameters?
I have read that an orbit is defined by Kepler's parameters, so is it possible to determine an exact position of an artificial satellite using those parameters?
Forgive me if this is a redundant ...
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Does Tianwen-1 have a near-repeat ground track orbit in order to scan the same general area on each of its low altitude passes?
Though it's not as easy1 to get details on Chinese missions in English, it seems that Tianwen-1 is in a 12,000 x 256 km highly eccentric orbit around Mars, with its hi res cameras able to resolve 0.5 ...
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142 views
Precision in the space navigation [duplicate]
I am curious about the precision NASA and other agencies have in the space navigation.
Are they always accurate to the meter in position they aim for; in mission like the recent rover landing on the ...
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2answers
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What are ISS orbit's sudden falls?
In current (2021) graph from heavens above (https://www.heavens-above.com/IssHeight.aspx) there are sudden falls - more than 1km in many cases and then after other sudden changes, the graphs return on ...
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How to find ECI coordinates for a circular orbit
Suppose a satellite is orbiting Earth in a circular orbit, of which I know the inclination $i$, the right ascension of the ascending node $\Omega$, the semi-major axis $a$ (or orbit radius given that ...
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1answer
169 views
Rocket engine with lowest Isp to reach orbit
Which engine with the lowest possible specific impulse has reached orbit propelling a given rocket? There is a page at Wikipedia that compares orbital engines but some engines are missing Isp value ...
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1answer
181 views
What is the Best position of an object in geostationary orbit relative to the launch site for rendezvous using GTO?
So let's say we have a space station or spacecraft in GEO, and I want to get another spacecraft to it from earth's surface on a direct geostationary transfer orbit, i.e. no waiting about in LEO for ...
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Orbital launches
In the 1950s, many US rockets were capable of reaching the lower limit of LEO altitude. Despite this, no one thought of making the launch vehicle / its payload orbit around earth, even for one ...
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How many time-zone does the ISS cross through during one orbit?
A recent non-answer to an unrelated question stated that the ISS crosses 16 time zones during New Year's Eve, which is obviously incorrect, the actual answer being "around 200".
But this ...
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Are all satellites of all planets in the same plane?
I'm aware of the fact that all planets are almost in the same plane as the Sun and the Earth(ecliptic) plane except Mercury and Pluto(which are more tilted). Are all satellites of all the planets also ...
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Does it count as orbital flight if one reentered the atmosphere due to its drag after about 1 revolution?
Imagine a spacecraft entered an orbit around the Earth whose perigee is low enough into the atmosphere so that it reenters and lands after a revolution, without having to perform a reentry burn. While ...
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How did the Kepler Telescope establish its orbit after third stage burn? (Follow Up)
note: This is a follow-up question based on a discussion under this answer.
The Kepler Telescope was (is) in a heliocentric Earth trailing orbit, but I want to figure out how it was able to reach this ...
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1answer
42 views
Apsis suffix for object orbiting an exoplanet
Is there already an agreed upon apsis suffix for an object orbiting an exoplanet? I don't think it's super likely that there is, as I don't think any moons have been discovered (or at least not at a ...
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2answers
142 views
What's the fastest orbital period for a spacecraft?
I'm not asking about velocity, I'm talking about overall speed. Shortest time from perigee to perigee. This orbit would be a low, circular orbit, but I can't really find any specifics on any world ...
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3answers
254 views
How to plot this orbit?
I have these data for some orbits, without any explanation about meaning of each datum:
...
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1answer
134 views
How many spacecraft orbiting the sun?
How many spacecraft have been sent in a heliocentric orbit in all history?
By this, I mean spacecraft sent to stay in heliocentric orbit.
The satellites orbiting planets or moons don't count.
Related ...
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1answer
116 views
Leaving the ISS orbit
Working on a project of sorts and I can't wrap my head around this at all., have a question regarding leaving the ISS orbit. If, let us say as an example, an astronaut jumped out of a capsule which ...
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Using the Clohessy-Wiltshire equation, what would be the expression for ' r '?
I'm looking for an expression for r. The difficulty I'm facing is simplifying the C-W equation
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When B is directly below A, as shown, what's B’s velocity (in vector notation) relative to A?
Spacecraft A and B are in coplanar circular orbits around the Earth. The orbital radii are as shown in the figure.
(Not looking to use C-W equation. Just the equation describing relative velocity ...
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157 views
(U.S.) What paperwork do civilians need to send items into orbit or beyond?
Are civilians allowed to send objects into orbit, or even leave orbit, like send something to the moon or deep-space? If they can what kind of paperwork/waivers/licenses etc. need to be obtained ...
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Further understanding of a de-orbit burn problem worked on in 2018 [duplicate]
I'm having trouble understanding exactly how calculations in this answer to Calculating a de-orbit burn, is this problem written correctly? were performed.
It’s been a while, but now I’m working on ...
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431 views
When and where on Planet Mars are the Sun's rays the most blueshifted?
Let's say for a moment that the spin of a planet causes the Sun's rays to be blue-shifted in the morning.
As far as I know, redshift occurs in steps of like 2.6 km/s or something like that. We can't ...
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2answers
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General Delta V Calculation for Two-Body-Problem
Problem: Given two orbits (e.g. in the 5 keplerian elements excluding true anomaly) A and B calculate the $\Delta v$ necessary to perform a transfer from A to B using instantaneous burns.
Simple ...
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1answer
71 views
Orbit lifetime of a Nano-Satellite in 350 Km Orbit
I was trying to write a very simple program to calculate orbit life time of a nano-satellite.
I got the atmosphere density as function of altitude from this site.
...
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2answers
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How to determine the delta V required in order for the satellite at pt. A to hit the earth at pt. B?
I'm confused about how would I go about obtaining delta-v in this case. I'm aware of orbital transfers such as bi-elliptical but that is not the answer to this. Kindly help
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1answer
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How to get ISS trajectory information after spaceflight.nasa.gov has been taken offline?
The nasa spaceflight website states that it will soon shut down.
I don't know how long this disclaimer has been there so maybe this is nothing to worry about...
In any case, which different ways do ...
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2answers
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Do I have enough info to find the true anomaly of an orbit?
For a personal coding project, I'm trying to model orbits of satellites around the Earth. I take in some values from a user and use them to determine the shape of the orbit. I want to model the ...
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1k views
Highest apogee of a Soviet/Russian crewed spacecraft?
I wonder which Soviet/Russian crewed spaceflight reached the highest apogee and how high. For America, the highest apogee ever reached is 1,368 kilometers (~ 850 mi) by Gemini 11 (except that America ...
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Lagrange coefficients orbit acceleration
I have an initial position, velocity and acceleration (in x,y,z coordinates) for a certain orbit, and I need to compute the next position, velocity and acceleration after a certain time interval (I ...
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1answer
148 views
Are satellites whose orbits go below 100 km perigee considered having multiple spaceflights?
The International Aviation Federation (FAI) considers the space border at 100 km (330,000 ft) above sea level. So if an orbiting body goes below that altitude and continues its orbit without ...
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2answers
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How were the boundaries of LEO and MEO (or all geocentric orbits) determined?
From my understanding:
Low Earth Orbit is from 100 - 1240 miles.
Medium Earth Orbit is from 1240 - 22246 miles.
High Earth Orbit is from 22246 and above.
What ...
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107 views
Does the Earth's orbiting the Sun influence spacecraft in Earth's orbit?
As I try to comprehend how spacecraft are able to stay in orbit around the Earth I began to think about why the Earth's own orbit around the Sun does not influence spacecraft in Earth's orbit.
I came ...
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1answer
165 views
Map showing which part of geostationary orbit is allocated to which country?
This article (google translated version) says that part of the geostationary orbit is allocated to Hungary (they are talking about 4°W).
Is there a map, which shows me which part of the orbit is ...
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1answer
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Error in Propagating equatorial orbit using GMAT
I propagated an orbit with semi-major axis of 7000km and the rest of the keplerian orbital elements 0 on GMAT. Since the orbit is circular and in the Equatorial plane, it should not change over time. ...
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1answer
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Keplers equation: written in change in eccentric anomaly
I am reviewing the "Fortran Astrodynamics Toolkit (can be found here) and even more specifically at the two body propagation method implemented in this Kepler module for elliptical and circular ...
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1answer
166 views
Why can't I just use dot product angles to get satellite vision of a point on Earth?
Right now I'm using MATLAB and can easily get the ECEF coordinates of the satellite and the point on the Earth. Since ECEF is cartesian, why can't I just rearrange:
$$
r_{es}\cdot r_{ps} = \|r_{es}\| ...
