The satellites tag has no wiki summary.
11
votes
2answers
190 views
How large can planets or moons appear?
In many artistic impressions or movies there are pictures or scenes where the sky is filled with an enormous moon (as seen from a planet) or vice versa.
I wonder if there is an upper limit to the ...
2
votes
1answer
53 views
Acceleration due to gravity?
I was looking into orbitals and found something I haven't been able to understand.
http://www.math.ubc.ca/~cass/courses/m309-01a/hunter/satelliteOrbits.html
There is a part on the page which states ...
4
votes
1answer
53 views
Gravitational resonances for satellites
I read on the website of European Space Agency that the altitude of Galileo satellites, which is 29600 Km from the center of the Earth, is chosen to avoid gravitational resonances so that station ...
0
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1answer
66 views
Change in speed of a satellite
Suppose there's some satellite orbiting the earth in circular motion. Suppose there's an asteroid that hits the satellite in the same direction as the instant velocity vector of the satellite. The ...
7
votes
1answer
110 views
Cancelling special & general relativistic effects
We know that for a GPS we need to make a correction for both general and special relativity: general relativity predicts that clocks go slower in a higher gravitational field (the clock aboard a GPS ...
5
votes
2answers
80 views
Gravitational potential outside Lagrangian points or Lagrange points
The diagram in Why are L4 and L5 lagrangian points stable? shows that the gravitational potential decreases outside the ring of Lagrange points — this image shows it even more clearly:
If I ...
0
votes
1answer
67 views
Can we make a space elevator/lift?
Is it possible to connect a long rope (excluding the danger of it's breaking) to a geostationary space station and use it to transport food and other necessary item's to the station and then ...
0
votes
2answers
476 views
What is the limit to how many satellites can orbit the earth?
I would like to know how many satellites are physically able to be in place, at the same time, orbiting the earth. Lets ignore which Nations need or use the most satellites (area in space above them) ...
1
vote
4answers
89 views
Constructing an orbital trajectory that quickly returns to its origin
I'm working on a science fiction story that involves two spaceships engaged in combat while in orbit around a planetoid. My original idea called for spaceship A to trick spaceship B into firing a ...
2
votes
1answer
73 views
How does my car acquire satellite signal?
I just got XM radio again after a brief period without it. A customer service rep said that the satellite needs to beam my signal to me in a six minute time window. How exactly does this happen? How ...
3
votes
1answer
96 views
Link between Earth and Mars
I am trying to the calculate the link budget for link between a ground station on Earth (with a particular latitude and longitude) and a rover at a particular location on the surface of Mars, either ...
0
votes
1answer
86 views
Lagrange L4 L5 points and perifocal plane
I have 2 satellites at the L4 and L5 points and these are watching an object. Each satellite provides the angle to the object from its own position from a line parallel to the $\text{x-axis}$ of ...
1
vote
2answers
216 views
What is geostationary orbit radius?
I'm asking this apparently "general reference" question for the simple reason: I was unable to find whether the quoted everywhere "35,786 kilometers (22,236 mi) above the Earth's equator" means ...
3
votes
1answer
70 views
image distortion when taking a picture from space
I'm trying to understand if there is a distortion of an image taken from space (i.e. from a satellite), and if there is, then how to model it mathematically (depending on the angle in which we take ...
3
votes
1answer
109 views
Would two astronauts one in a satellite, one on top of a tower have the same experience?
Imagine two astronauts.
The first is in a satellite in geostationary orbit around the earth.
The second is on top of a 35,786 km tall tower that has been built from the equator to space. This means ...
2
votes
2answers
808 views
how far away can something be from the earth and still be in orbit?
Just as the title asks,
How far away can, say, a satellite be and still be in "orbit" ?
How about for a given velocity?
Fun Facts
200 miles (320 km) up is about the minimum to avoid atmospheric ...
0
votes
0answers
81 views
Is the fuel burn for a satellite launch affected by the position of the moon relative to the launch site?
The gross mass of a satellite rocket is tiny compared to that of Earth, and Luna. Between them, however, the two bodies set up tides in bodies of water which itself is again considerable mass.
At ...
0
votes
1answer
59 views
Why no image of the North or the South Pole Weather? [closed]
I was watching a youtube video which refers to National Geographic and other metereological sources that the US govenrment has banned access to the weather and metereological data of both Poles. What ...
2
votes
1answer
61 views
Raising Altitude by using Magnetic Torquer and Reaction Wheels
Suppose a satellite with a magnetic torquer and reaction wheels.
I wonder if it is possible to use both in such a way that the overall effect would be to raise the satellite's altitude?
7
votes
1answer
30 views
Is There Reddening on Objects Other than the Moon Upon Entry into Earth's Umbra?
With the recent lunar eclipse, for some reason this question came to me: The reason the Moon turns red is that the only appreciable sunlight hitting it when it's in Earth's umbra is refracted through ...
3
votes
0answers
73 views
Parallax Cloud Displacement - Angular Distance from Geostationary Satellite
When observing clouds from a geostationary satellite, they appear displaced because of the parallax effect. The satellite looks at the clouds "at an angle" and it projects them on a point of the earth ...
0
votes
1answer
27 views
Where to get hard historical and trend data related to reentry of satellites like UARS [closed]
NASA is providing very brief updates on the reentry of the UARS satellite. They also published an extensive study of the Re-entry and risk assessment for the NASA Upper Atmosphere Research Satellite ...
6
votes
1answer
35 views
Are there Trojan family or Hilda family satellites locked in Earth's orbit?
Jupiter has many Trojan asteroids located at Lagrangian points L4 and L5 and Hilda asteroids dispersed between points L3, L4, and L5.
Does the Earth have similar satellites? If so, how many?
7
votes
2answers
63 views
What distinguishes a moon from orbiting space debris? Or in other words, when is a satellite “too small” to be a moon?
The Wikipedia article on Natural Satellites doesn't really give an adequate distinction as to what distinguishes a moon from other orbiting bodies. What I am looking for is a classification that ...
8
votes
4answers
254 views
Can a moon have another large body as a satellite, and are there any examples of such?
In my mind, I'm comparing it to the Sun-Earth-Moon system. After all, the Earth is primarily a satellite of the Sun, but the Moon is still gravitationally bound to the Earth. Could something like this ...
2
votes
1answer
789 views
What are the temperatures of objects in Low Earth Orbit (LEO)?
What is the temperature of objects in Low Earth Orbit?
Consider LEO to be 600km to 800km.
11
votes
3answers
2k views
Why are Saturn's rings so thin?
Take a look at this picture (from APOD http://apod.nasa.gov/apod/ap110308.html):
I presume that rocks within rings smash each other. Below the picture there is a note which says that Saturn's rings ...
