Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [orbit]

Questions regarding the mechanics or attributes of objects falling 'around' other objects, thereby orbiting them.

1
vote
1answer
95 views

Astrophysics on “The Martian”

In the movie the martian what was the purpose of the hermes crew in blasting a part of the ship? Was that explosion on the front or back of the ship? After the explosion what happened to the speed ...
3
votes
0answers
84 views

Suggestion for software which allows orbit data generation under different conditions (such as J2, ATM drag etc)

I am an amateur astrophysics enthusiast trying to generate orbit data. What I want to achieve: I want to be able to generate orbits while only considering effects of (J2, J3, atm drag, solar ...
3
votes
1answer
58 views

How to calculate angle in elliptic orbit?

I would like calculate angle in elliptic orbit ZCP at any time, where: Z (position of periapsis), C (center of ellipse), P (current position of planet). I find topic, where is picture (in accepted ...
1
vote
0answers
109 views

Speed needed for the ship to escape Mars, on The Martian movie

Based on the two speeds and altitudes that are presented in the movie: "The Martian" which are respectively 741 m / s and 1350m, 850 m / s and 1843 m I would like to prove with calculations whether or ...
1
vote
0answers
25 views

Orbit class or library or functions [closed]

I am (like a hundred other people, like a thousand other people) trying to make a space flight simulator. I'm not a student. (That said, I found Orbit – space flight sim. It’s excellent.* You ...
5
votes
3answers
116 views

Are sun-synchronous orbits always North to South?

So someone told me that weather satellites orbit from north to south generally because that helps them to obtain a sun-synchronous orbit (his explanation for why this was true was too complicated for ...
4
votes
1answer
161 views

Are we changing Earth's rotation?

Can rockets launching change Earth's rotation, and can going into orbit do the same?
3
votes
1answer
64 views

Ellipse area section from foci

I am wondering how to calculate the area between the 2 red dots towards the bottom and in turn calculate the time elapsed between the right red dot and the green dot at apogee. I figure if I can find ...
2
votes
1answer
46 views

True Anomaly of Circular Orbit

How would you calculate the true anomaly of a circular orbit (e=0)? I'm trying to design an orbit for a mission on STK and so I'm not sure what the eccentric anomaly (in order to calculate true ...
2
votes
0answers
33 views

Compute heliocentric ecliptic coordinates from Kepler's laws

I'm writing a program to compute the heliocentric ecliptic position of planets and asteroids. I want to output rectangular coordinates oriented according to the ecliptic: positive X in the direction ...
2
votes
1answer
75 views

Moon Polar Days And Night

Moon's rotation axis from the orbit plane of earth is about 1.54° tilted. Just like earth because of tilt, do polar regions experience 6 months day and 6 months night? If so, aren't these places ...
1
vote
1answer
64 views

How does lightsail 2 plan to raise its apogee

Lightsail 2 is supposed to be a demonstration flight for solar sail technology. They plan to demonstrate that they can raise the apogee of their satellite using only light pressure on their sail. But ...
2
votes
1answer
127 views

Is it possible to capture geostationary satellites with DSLR?

DSLR is to be mounted on a tripod and pointed at sky with a zoom lens. Would a sufficiently long duration of exposure reveal these non-moving satellites as bright "stars" amongst the streaks caused ...
1
vote
0answers
36 views

How to get true anomaly using subsatellite point (latitude)?

I am working on an application which is using an orbit propagator. I have a satellite which sets its latitude using this orbit propagator. I want to change the latitude of the satellite by a new value,...
4
votes
1answer
74 views

Distribution of satellites by inclination

What is the distribution of Earth orbiting satellites by inclination? In other words, what inclinations are more or less popular? I work with Earth observation myself, where many satellites are Sun-...
2
votes
0answers
65 views

Computing the local orbital frame vector directions and angles of gyroscope direction in the satellite

In the context of the study of a cubesat (little satellite), I am asked to define the local orbital frame and compute the local orbital frame vector directions as a function of time (...
0
votes
2answers
137 views

How to get experiments to space?

How would a person get an experiment done in space? What is the chain of command on something like that? I would like to drop some inflated balloons from space to reenter the atmosphere to see which ...
1
vote
1answer
64 views

How low does OSIRIS REx's record-setting orbiting around Bennu go?

This OSIRISREx tweet says: It's official! I'm in orbit around #asteroid Bennu -- now the smallest body ever orbited by a spacecraft. My snug path around the asteroid also sets a new record for the ...
4
votes
1answer
107 views

What is typical lifetime of GTO rocket stages before reentry?

Most of geostationary satellites are launched at geostationary transfer orbit (GTO) first by rocket's upper stage. Than satellites separate and circularize the orbit by own propulsion. The upper ...
19
votes
2answers
3k views

How far have astronauts been in space?

I just listened to a podcast where it was said that astronauts have only been at most 400 miles from Earth (except for the moon of course in the '60s/'70s). Is this true? I know that the ISS orbits ...
5
votes
1answer
94 views

At what altitude do the effects of atmospheric drag completely disappear?

The spate of K-questions got me thinking: At what point does atmospheric drag disappear1 with the pressure from sunlight, solar wind, or other forces becoming overwhelmingly dominant? I'm guessing it'...
8
votes
1answer
199 views

Deviation of semi-major axis

If I calculate the semi-major axis of Molniya-1T with $a = \sqrt[3]{\dfrac{GM}{n^2}}$ with $n=3.18683728\text{ }d^{-1}$, I get another apoapsis ($a=19505.7$ km) as noted at Heavens Above: apogee ...
1
vote
1answer
62 views

Which orbit around Earth has the least perturbation?

Which orbit around Earth would have the least amount of perturbation from the moon, Sun etc.? Does an orbit exist where in either direction of travel that the perturbation would be the same? The ...
5
votes
4answers
414 views

What could a High Earth Orbit be used for in practice?

I was perusing wikipedia and saw this awesome infographic: Original location of infograhpic: Wikipedia Then it hit me, in all the time I've been browsing space articles and such... I've never ...
4
votes
2answers
72 views

How close will the cubesats be when numerous of them are launched simultaneously?

Checking the onboard video of PSLV C43 gives a feel like the CubeSats are released in very proximity. Does this mean that these CubeSats will be orbiting in such very close proximity through out ...
5
votes
2answers
147 views

What are the advantages of a Molniya orbit over a tundra orbit?

As I understand them, Molniya orbits and tundra orbits are very similar: they are both intended to provide satellite coverage over large latitudes and provide a large apogee dwell time over the large ...
1
vote
1answer
129 views

What is the darkest orbit around Earth?

What orbits around Earth has the least and most sun light exposure? I wondered: When taking pictures either of Earth or otherwise with various telescopes in orbit, does it help to be in Earth's ...
10
votes
6answers
635 views

Is it possible to navigate space travel with no computer?

From launch to land could a person travel in space with only mechanical devices like a sextant? With enough experience what would be the minimum devices needed? Which vehicle currently would be easier ...
4
votes
1answer
112 views

What orbits are popular?

So the two I can think of are the ISS orbit and GEO. Are there any other orbits that consistently have 10+ launches a year? For this question, when I say matching orbit, I mean eccentricity, ...
4
votes
1answer
172 views

Why was Dawn placed into an orbit that would only be stable for “decades”

Last year NASA put Dawn into an orbit around Ceres that Ars Technica said "would remain stable for decades" so as to not contaminate Ceres. Decades are pretty small on the cosmic scale though. Why ...
14
votes
2answers
2k views

Question on giant satellite orbit

So here's a strange question that came up in a class tonight. It is axiomatic that satellites in the same orbit travel at the same speed. But is there some size of satellite whose mass is so great ...
1
vote
0answers
38 views

What would astronauts see if they were in an Earth Moon L1 Lissajous orbit?

Would they be moving fast enough that the change of their position relative to the Earth and the Moon would be perceptible? Or would that change be too slow to notice moment by moment? I take it as ...
2
votes
0answers
58 views

What forces and motion would astronauts experience in a spacecraft in Earth-Moon L1 & L2 Lissajous orbit?

What is the maximum velocity they would experience? Would they be aware of the movement based on the positions of the Earth, Moon, or stars, or would it be too slow to notice? Would they feel any G ...
10
votes
1answer
247 views

What did Karman's original “Karman line” calculations look like?

Looking for the atmospheric parameters (density for example) and vehicle parameters (CL for example) as well as formulae that were used in the original calculation. Primary sources strongly preferred,...
7
votes
2answers
595 views

How would the International Space Station be maintained unmanned?

Russia's lunch to the ISS failed and the crew may have to leave it unmanned. How would the ISS run without a crew? Could some one else take it over or squat in it? https://www.npr.org/2018/10/11/...
6
votes
1answer
272 views

Why are 22N and 440N liquid engines quite common?

One can often spot that liquid apogee engines are 440 N and attitude control systems are 22 N. Is there a reason why the thrusts are proportional? If the engines are scaled for reducing development ...
8
votes
1answer
326 views

How can I calculate the orbital elements from two position vectors and a time difference?

I have two position vectors for my satellite, and I know that the satellite reaches these two positions 15 minutes apart. I know I can find the inclination using linear algebra and my position ...
3
votes
2answers
189 views

Name for point in a satellite's orbit around a planet when the satellite is furthest from the sun

When a satellite is orbiting a planet (which itself is orbiting the sun) there are periodic points when the satellite is closest to and farthest from the sun, once where it is interposed between the ...
10
votes
1answer
379 views

Why do GPS satellites have increasing eccentricity over time?

When comparing GPS, Beidou, Galileo, GLONASS, and potentially other GNSS, we can see that the eccentricities of GPS spacecraft are increasing with time (i.e. apogees increasing and perigees decreasing)...
2
votes
2answers
218 views

What is the shape of a space elevator?

When we think of a space elevator, we might usually think of a purely vertical tower, sticking perpendicular to the surface of the Earth, extending way past the geostationary belt, to the end-mass. ...
2
votes
0answers
50 views

Aerobraking on Mars

I am looking for a calculator or formulas that can be used to calculate the aerobraking on Mars mission. I have found some data on previous Mars flights where aerobraking was used and all my current ...
4
votes
1answer
180 views

How to determine an orbit of a satellite for a collision detection?

I'm trying to validate an collision detector , and for that I'm starting from a pair of initial conditions for a satellite.After that I will use an RK method to integrate . How can I determine a pair ...
3
votes
2answers
172 views

Onboard propagator in satellites SGP or J2

The Earth orbit propagator SGP4 (simplified general perturbation) was developed by NORAD to allow users to generate short-term prediction of satellite positions using two line element sets (TLEs) ...
43
votes
5answers
10k views

Where does space begin on planets without atmospheres?

On Earth the Karman Line is used as the boundary of space, and I believe it is defined as the height where you would have to go faster than orbital speed in order to obtain aerodynamic lift. Therefore ...
2
votes
1answer
56 views

The appropriate reference frame for the interplanetary missions

In the JPL Horizons there are Earth mean equator and ecliptic reference planes. The ecliptic is an apparent path of the Sun's ...
1
vote
0answers
67 views

What is optimum data interval algorithm for Orbit Determination?

I am trying to find Optimum data interval algorithm for orbit determination. Because in Leo, Geo orbit updates the measurement data can be different so that I want to implement an optimum data ...
3
votes
1answer
77 views

Would we be able to see a Space craft transit in Lunar orbit?

If a Apollo type Moon mission happened today would we be able to see it transit in Lunar orbit? I know we can't see the Landing sites of the Apollo but could we see the Command Module and its shadow ...
5
votes
1answer
627 views

Elliptical orbits transformed to “equivalent” circular orbit

I'm trying to transform Mars' elliptical orbit into its circular "equivalent". I understand that if the semi-major axis is used as the radius, and the mean angular rate and period are kept the same, ...
0
votes
0answers
200 views

How can I calculate Mean anomaly from True longitude?

So, I have - TLE data - Reference frame: QMOD - Type: Osculating - Semimajor axis - Eccentricity - Asceding node - ...
5
votes
3answers
295 views

Is a sun-blocking orbit possible?

Is it possible for an orbital "sun shade satellite" to have a geosynchronous equatorial orbit such that it is in an approximately straight line between the Sun and a fixed point on the Earth's ...