Satellite is a generic descriptor for any body that orbits a much larger body. The term commonly refers to objects orbiting planets, like artificial satellites and moons, but it can sometimes also refer to planets, small stars, satellite galaxies, and other objects.
Questions tagged [satellites]
359 questions
71
votes
5 answers
Is there a small enough planet or asteroid you can orbit by jumping?
I just had this idea of orbiting a planet just by jumping and then flying upon it on its orbit kind of like superman. So,
Would it be theoretically possible or is there a chance of that small body to be & remain its unity?
Max Abrahamsson
- 961
50
votes
5 answers
Is it possible to have a geostationary satellite over the poles?
My understanding of orbital mechanics is very limited, but as I understand geostationary satellite, they stay in place by having an orbital speed corresponding to the spot they're orbiting over.
So my basic intuition tells me that it's not possible…
mikl
- 627
44
votes
4 answers
Cooling a satellite
Satellites are isolated systems, the only way for it to transfer body heat to outer space is thermal radiation. There are solar panels, so there is continuous energy flow to inner system. No airflow to transfer the accumulated heat outer space…
inninaro
- 563
41
votes
1 answer
Why is the period of a geostationary satellite not exactly 1440 minutes?
When reading about Astra satellites on Wikipedia (https://en.wikipedia.org/wiki/Astra_1KR), I saw that the period of the Astra 1KR satellite, positioned at 19.2° E, is 1,436.1 minutes (source: NORAD data).
That is 3.9 minutes short of a day (1440…
fbitterlich
- 471
39
votes
6 answers
Why aren't satellites disintegrated even though they orbit earth within earth's Roche Limits?
I was wondering about the Roche limit and its effects on satellites.
Why aren't artificial satellites ripped apart by gravitational tidal forces of the earth?
I think it's due to the satellites being stronger than rocks?
Is this true?
Also, is the…
Sykhow
- 741
34
votes
7 answers
Cause of weightlessness
I'm a first year engineering student who is new to physics, so I apologize if my question is stupid. But in our statics course we are using the book "Engineering mechanics: statics" by R.C. Hibbeler and it contains the following image:
The…
SVolk
- 359
33
votes
3 answers
How do we stabilise satellites so precisely?
Look at the Hubble Ultra Deep Field photo. The stars in it are on the order of 1 arcsecond across. To an order of magnitude, this is $10^{-6}$ radians in a $10\text m$ telescope which was held steady for $10^6$ seconds.
In other words, the velocity…
spraff
- 5,256
29
votes
4 answers
Why doesn't the Moon disrupt the orbits of geostationary satellites?
If a passing star can jostle comets in the Oort Cloud, why doesn't the Moon disrupt the orbits of high-flying satellites?
Or does it? Maybe the satellites need periodic course corrections?
RASx64
- 401
29
votes
8 answers
Why is Microgravity called "Microgravity"?
I find the term "microgravity" to be misleading, how was it coined?
NASA provide this definition:
Microgravity is the condition in which people or objects appear to be
weightless. The effects of microgravity can be seen when astronauts
and objects…
dangerousdave
- 457
29
votes
5 answers
Build a ring around Earth, then remove the supports
What would happen if we decided to build a giant ring that managed to wrap around the whole world, end to end that was supported with pillars all along the ring and then the supports all suddenly removed?
Would the ring float in place? or if it…
Adsy
- 439
25
votes
3 answers
Why don't we put satellites into an orbit where there is (almost) no time dilation/contraction compared to Earth's surface?
Consider:
On this image, if I understand correctly, the time dilation diagram is shown depending on the height for circular orbits. First in low orbit, time slows down relative to the surface due to high speed, but for higher orbits, speed and…
23
votes
3 answers
Why are Saturn's rings so thin?
Take a look at this picture (from APOD https://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 are about 1 km thick.
Is it an explained…
kakaz
- 2,133
13
votes
2 answers
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 apparent size when viewed with the naked eye (no tele…
Jens
- 3,729
12
votes
2 answers
Are there any satellite orbit earth perpendicular to the sun and what is the name of this kind of orbit?
I think we could put satellite to orbit earth in such a way that it always see the sun. Which is orbiting along the path of earth orbiting the sun, like a wheel perpendicular to the sun
I don't know the specific name of this type of orbit so I can't…
Thaina
- 948
11
votes
7 answers
How does a satellite maintain circular orbit?
Given a crewed satellite placed at a distance $r$ from the center of the Earth, with an initial velocity perpendicular to its position vector, the magnitude of the initial velocity that would allow it to maintain a circular orbit of radius $r$…
Larpee
- 211
- 2
- 6