Questions tagged [orbit]
Questions regarding the mechanics or attributes of objects falling 'around' other objects, thereby orbiting them.
566
questions
1
vote
1
answer
175
views
Why is my C++ code for an orbit propagator wrong?
I tried making an orbit propagator C++ code. Its values seem to be propagating evenly but still I get a straight line orbit instead of an elliptical one. Why?
...
6
votes
1
answer
308
views
How far is the solar system's center of mass from the sun? [duplicate]
We often say that the planets orbit the sun. But, in reality, they orbit the solar system's collective center of mass. How far is that point from the center of the sun?
0
votes
0
answers
96
views
What artificial satellite has the closest stable orbit around the Earth? [closed]
What is the closest Earth orbiting satellite?
What is it's speed
What is it's purpose?
What is it's altitude?
1
vote
1
answer
84
views
How do I correctly convert State Vectors to Orbital Elements to State Vectors at t (sec since epoch) in 2D?
I am following Rene Schwarz' formulas and I've verified my calculations work using the converter by Tony Dunn.
State Vectors to Orbital Elements
Orbital Elements to State Vectors
Convert between ...
- 137
8
votes
3
answers
3k
views
Is escape from earth, hyperbolic in reality?
I have been reading on orbital mechanics and its strewn everywhere that beyond the escape velocity from any orbit around the earth, the trajectory is a hyperbola that approaches V_infinity and with ...
- 83
2
votes
1
answer
209
views
How much energy would be required to launch a 10km x 10km x 10km cube into LEO?
I know this is a bit of a ridiculous scenario, I am just looking for a very conservative estimate as to how much force would be required to get something orders of magnitude bigger and more awkard ...
- 29
2
votes
2
answers
108
views
Were analog cameras been used in orbital space during an EVA after Apollo?
Analog cameras have been used intensively on the Moon and inside orbital space stations or ships.
Were analog cameras ever used during an EVA outside Spacelab, Mir, ISS or Space Shuttle? In zero ...
- 46k
7
votes
2
answers
4k
views
What is the furthest from Earth that a military spacecraft is thought to have been intentionally deployed or moved to?
Space.com's Space Force plans to send a patrol probe out past the moon includes a quote from the new AFResearchLab video Cislunar Highway Patrol System (CHPS).
"Until now, the United States ...
- 148k
5
votes
2
answers
816
views
How can I find the true anomaly of satellites in elliptic orbits?
I want to find the true anomaly of satellites in elliptic orbits. How can I do that with following
information about elliptic orbit:
Altitude, km 543.8832
Period, sec 6114
Eccentricity 0.0727
Semi-...
- 189
6
votes
1
answer
142
views
What type of galactic orbit will the Voyager probes have?
I know that they will eventually get close (within 10,000 light years) of our solar system, but will the orbit be circular or elliptical, around how much eccentricity, what would be a reasonable ...
3
votes
1
answer
131
views
What's the highest latitude for a human spaceflight?
There are obviously many satellites in polar orbits or in orbits that extend to very high latitudes. There are obvious reasons to do this in terms of Earth observations, but there is probabably much ...
- 3,231
1
vote
2
answers
178
views
Could astronauts jump from a spaceship onto a spacestation and how would it be like if yes?
I saw it happen in the videogame Alien:Isolation but not sure how realistic it was. I need help understanding some orbital mechanics for a sci-fi story that I am trying to write.
The scenario I ...
2
votes
1
answer
164
views
How did India get to the Mars?
A few years back ISRO sent their orbiter to the Mars, It is known to be the biggest feat achieved by Indian Space Research Organization over the years.
It special because ISRO manage to pull this out ...
10
votes
2
answers
744
views
Is JWST Halo orbit prograde or retrograde and why?
There is confusion in my mind over the direction of JWST’s halo orbit, depending in the source of graphics.
Observing from the Earth, does JWST orbit clockwise or counterclockwise around the antisolar ...
- 6,410
1
vote
0
answers
112
views
How to make an algorithm that finds time to a true anomaly at epoch?
I am having trouble creating a function that finds the time for an inputed true anomaly when I know my current eccentric and mean anomaly (my equations are in vector form).
Note that I only intend to ...
- 105
3
votes
1
answer
392
views
When calculating the six Keplerian Orbital Parameters, why do we need both Eccentricity AND the Semi-Major Axis? Doesn't one tell you the other?
Perhaps I am misunderstanding elementary math, but....
How is it possible to know the eccentricity of an ellipse (e) but not the semimajor axis (a)?
- 373
1
vote
2
answers
164
views
Is it possible to stay in space without orbiting something?
Like in the movies a spacecraft just stays in someplace without orbiting anything?
This is distinct from geo-synchronous orbit, where the object orbits, but looks like it is standing still from the ...
- 111
5
votes
1
answer
472
views
Is there any website where we can view live orbit of all satellites to scale?
As the question says,
Is there any website or app which has a graphical view of all satellites which are currently in orbit with sizes to scale. An option to view in fast forward is appreciated.
- 2,281
9
votes
1
answer
922
views
Did JWST launch directly into an earth escape trajectory?
My understanding of the JWST trajectory timetable (or the bits that I care about for the purpose of this question) is the following:
Launched by Ariane rocket directly into escape trajectory (from ...
- 472
5
votes
1
answer
1k
views
Is L2 at a distance where the Earth totally eclipses the Sun?
What is the furthest from the Earth that still offers a total eclipse of the Sun? Is L2 inside that distance? (I assume so due the the halo orbit that is planned but perhaps there are numerous other ...
- 51
17
votes
2
answers
3k
views
Why is JWST Launching from French Guiana?
Is the launch from the ESA spaceport because of agreement or an orbital insertion advantage from that facility?
- 171
2
votes
3
answers
274
views
Failing at getting apogee and perigee from TLE
At Celestrak, the current orbit for ISS is currently listed as 423x417 km, but if I'm getting the TLE data from Celestrak and use orb.get_lonlatalt(now) from ...
- 59
20
votes
4
answers
5k
views
Why can't you travel to Mars in a straight line?
I had two questions regarding choosing a path to Mars. Firstly:
I wanted to have a look at the mathematics behind the reason as to why we choose Hohmann's transfer over a journey that is a straight ...
- 459
6
votes
2
answers
1k
views
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?
- 459
4
votes
1
answer
55
views
Software to estimate radiation dose for an orbit
I am searching for a software/method, possibly open-source or free, to estimate the radiation dose for an orbit around earth.
- 430
17
votes
5
answers
5k
views
Why are all trajectories in space a conic sections?
All trajectories available in space: circle, ellipse, parabola, hyperbola, straight line are parts of cone. Why? Does the spacetime have a conic shape?
- 584
4
votes
1
answer
125
views
How to calculate an initial impulse for escape from planet's sphere of influence and lay on a specific orbit around the Sun?
I have a spacecraft parked on orbit around the planet. I want to make interplanetary transfer to another planet. I can find the orbit around the Sun that I can use to move from the end of departure ...
- 584
51
votes
3
answers
9k
views
Shouldn't space junk fall back to Earth on its own? How long will take for a ~1 cm piece of junk in LEO to fall back to Earth on its own for example?
I'm a noob in this subject and know little about space exploration, but I wonder about this every time I read the news:
Wouldn't drag make all space junk fall back to Earth after some time?
I'm ...
- 573
0
votes
2
answers
98
views
How to sort orbital positions in the order of following by spacecraft?
I have an orbiting spacecraft which keplerian elements is known. Also, I have a random-ordered list of true anomalies that represents spacecraft's positions on that orbit.
How to sort this list to get ...
- 584
3
votes
1
answer
161
views
How to calculate the Lagrangian points positions?
I have two bodies, one rotates around another on orbit. For i.e. Earth and Sun or Moon and Earth.
If we know masses, velocity, distance and keplerian elements of orbit, how can we find the positions ...
- 584
0
votes
1
answer
124
views
How to calculate time needed for spacecraft to travel a given number of meters in elliptical orbit or hyperbolic trajectory?
We have elliptical orbit and spacecraft travelling it. I need a formula to calculate a time needed for spacecraft to travel given amount of meters starting from it's current position.
Keplerian ...
- 584
2
votes
1
answer
111
views
How to detect the correct sign of the true anomaly for position prediction (clockwise/counterclockwise rotation)?
I calculated spacecraft's keplerian orbital params from position/velocity using this formulas: https://drive.google.com/file/d/11KhEdFboZCPUjfibtjHaDBWtUTNmJxFA/view?usp=sharing
Then I can predict ...
- 584
7
votes
3
answers
324
views
Is it possible to create a geostationary surveillance telescope?
Is it possible to create a telescope in geostationary orbit, with real-time video from any country or area?
Some applications could be:
Monitoring of burning and deforestation;
Residential/industrial ...
7
votes
2
answers
496
views
Why did Luna 1 enter a heliocentric orbit?
The way I understood it (please correct me if I'm wrong), the easiest (least energy) way to reach the Moon it to put the spacecraft into a highly elliptic geocentric orbit whose apogee reaches the ...
- 192
1
vote
2
answers
156
views
How to correct my real orbit and turn it into predicted ideal orbit?
I want to launch my ship to the purple ellipse orbit. But because of non-ideal world I have non-ideal ship orientation and non-ideal thrust impulse. So, my initial speed is a bit bigger and it's ...
- 584
0
votes
0
answers
79
views
How to correct orbit in case of perturbations? [duplicate]
I predicted the future position of orbital body and sent my spacecraft to that position. But the trajectory of body and spacecraft are changing because of perturbations. So, I need to correct this ...
- 584
0
votes
0
answers
40
views
Arc length between two satellites [duplicate]
When considering two satellites in the same circular orbit, is it correct to say: The arc length between the satellites is...? Is there a more appropriate term when talking about the curved distance ...
- 11
7
votes
1
answer
606
views
List of circular satellite orbits for testing inverse square law of gravity
For a high school activity I am looking for a list of (maybe 10 or so) circular satellite orbit data including radius $r$ or diameter of the orbit and orbital period $T$. Then I want to calculate from ...
- 215
3
votes
2
answers
193
views
Number of satellites needed for global 4-fold coverage as a function of altitude?
I want to estimate how many satellites (and how many number of planes) are needed for achieving a 4-fold global coverage on earth (global coverage with at least 4 satellites in view in each location). ...
- 63
3
votes
2
answers
209
views
How to fly from Earth to Mars if the differences between phase angles is too big for Hohmann transfer but we have fuel for other transfers?
Hohmann transfer is possible when Earth and Mars positions are appropriate for this https://ai-solutions.com/_freeflyeruniversityguide/interplanetary_hohmann_transfe.htm
This happens one time in two ...
- 584
1
vote
1
answer
57
views
Find the Orbital Inclination given all other Elements and a Position on the Ellipse
I'm in a situation where I need to determine an orbit's inclination. At my disposal I have all of the orbit's other Keplerian elements, and I have the vector of a single point on the ellipse. Is ...
- 43
3
votes
4
answers
289
views
How would you calculate a Hohmann transfer going towards the sun?
If you were going from a lower orbit to a higher orbit such as a Earth-Mars transfer, you would use the periapsis of the transfer orbit in the vis-viva equation to calculate the delta V. But if you ...
- 31
2
votes
0
answers
102
views
Calculating TLE, or satellite orbit elements based on angle information (RA and Dec) at multiple epochs
new here.
I am trying to 'determine' orbital elements of a given satellite.
Based on TLE from space-track, or CelesTrak, I observed several satellites resulting in 10 to 20 RA and Dec pairs for each ...
user43913
-1
votes
1
answer
80
views
Eliptical orbit [closed]
If an object revolves around the earth in a perfectly circular path, where the center of the circular path is different from that of the earth, (which means the object is close to earth's surface at ...
- 3,190
1
vote
0
answers
65
views
Is it possible to create a ML (machine learning) model of Spherical harmonics?
Trying to propagate orbits with more than 200 (grade and order) using SH is very slow, is it possible to replicate the SH model using a neural network or something similar achieving faster ...
2
votes
1
answer
156
views
Does the Moon's orbit intersect the Earth's orbit around the Sun?
I know that the Moon's orbital plane makes an angle of 5 degrees with the Earth's orbital plane or the ecliptic. Also, the Moon's orbit intersects the Earth's orbital plane at two nodes - ascending ...
17
votes
3
answers
2k
views
Can you throw a stone into longterm orbit from the surface of a spherical planet if it has lumpy enough gravity?
Could the lumpiness of the gravity of a perfectly spherical but not uniform-density airless planet be exploited to throw a stone into orbit from the surface in such a way that it stays in orbit a long ...
6
votes
3
answers
2k
views
Can an orbit rotate around a non-orthogonal axis?
I'll attempt to draw a mental example, in case images are not kind (if they are kind, you can likely skip this first paragraph). Let us say that the Earth is at it's aphelion (arbitrary choice), and ...
- 61
1
vote
0
answers
69
views
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 ...
- 7,062
1
vote
1
answer
261
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 ...
- 121