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1answer
66 views

Could an orbiting mass generate power?

If an heavy object (e.g. 10 tons) orbiting around Earth at 370 miles high, is connected with a cable back to Earth, we assumed either Earth is going to pull the mass or vice versa (or it will fall ...
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2answers
34 views

Ground velocity of satellite

I was wondering whether there is a simple formula in order to calculate the ground velocity (the velocity with which the satellite is moving along the planet's surface) on basis of the orbital ...
0
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2answers
31 views

Velocity required for orbit of satellite

I am very confused about orbital velocity for satellite launched from earth. It is states that: $$ v=\sqrt{\frac{GM}{r}} $$ Some says that it is equal to 8000 m/s and some say 3.1 km/s. Please remove ...
6
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1answer
113 views

Why doesn't gravity ruin satellites?

Recently I watched a documentary about Io, a moon around Jupiter. Io has volcanic activity even though it is small and can't retain heat well because gravity from Jupiter and a nearby moon cause it to ...
0
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1answer
28 views

Duration of Satellite orbit in the shadow of the Earth

I want to determine how many minutes a satellite is in a circular orbit around the Earth at about $1000 km$ altitude. I assumed that the Sun-Earth vector lies exactly in the orbital plane of the ...
0
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1answer
33 views

Is “atmospheric geostationary satellite” feasible with current technology?

Meaning by "atmospheric geostationary satellite" a vehicle capable of hovering 30 km above Earth surface, hence insde atmosphere, for unlimited time, making use of air propellers, solar panels and ...
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3answers
86 views

Why aren't there more natural satellites orbiting the Earth than just the Moon?

Considering that there's a lot of debris in space and that impacts fling out rocks into space all the time, why do we only have one large natural satellite - the Moon? Shouldn't there be all kinds of ...
2
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2answers
99 views

Acceleration vector for an object moving in a elliptic trajectory

I am interested in deriving what the radial and tangential components of the acceleration vector should be for an object following an elliptical trajectory centered on the origin, in which the ...
2
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0answers
41 views

Signal strength drop-off from a geosynchronous satellite as a function of angular pointing error

If we have a compact antenna used to communicate with a satellite in geosynchronous orbit somewhere between the $K_u$ and $K_a$ bands of the spectrum (for high broadband applications where we can't ...
2
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2answers
54 views

What may be effect of air friction to the velocity of satellite?

What is the effect of air friction to the velocity of satellite? I have heard satellite's speed increases with air friction. But I'm in confusion how is it possible?
2
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0answers
61 views

If most satellites in orbit were destroyed from debris, would we ever be able to recover?

Suppose enough satellites were destroyed in orbit to cause so much debris from the explosions that a chain reaction destroying other satellites took over to generating more and more debris (even ...
2
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3answers
113 views

How do scientists place satellites into orbit?

How do scientists place satellites into orbit? How do they calculate the gravity acting on the spacecraft in order to generate exact opposite force by means of Kinetic energy to keep the satellite ...
0
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2answers
88 views

How to choose a location for rocket launching?

What's the relation of earth's magnetic equator with satellite launching? How does the nearness of a rocket launching station to the earth's magnetic equator make it an ideal location for scientists ...
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3answers
36 views

about satellite is it possible to get signal from two satellite at a time? [closed]

Is it possible to get signal from two satellites at the same time? If we go far away from a certain country to another, and be able to continue to recieve the same signal?
0
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1answer
44 views

Is it possible to clearly receive weak signal from space?

Imagine there is communication satellite on geostationary orbite. It transmits signal in a defocused beam, "illuminating" whole Earth hemisphere it's floating over. For example, signal is ...
0
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1answer
21 views

Why does angle deviation of a satellite not captured my Mars decreases as the Velocity of the satellite increases?

When a satellite is not captured by a planet, it is moving sufficiently fast. so why is it that the angle deviation of the satellite decreases as its initial velocity increases?
4
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2answers
190 views

Is tripleaxis planet possible?

Imagine. Our solar system. Our sun. Then earth and moon orbiting it. And you have "powers" to create any planet you want, any size, any density, any weight and any velocity. Would it be possible for ...
2
votes
1answer
79 views

What is the constant $K_1$ in these orbital equations?

I want to compute the derivatives of argument of periapsis and longitude of the ascending node of the orbit of a GPS satellite from the following formula. $$\frac{d\Omega}{dt} = -K \cos{i} \\ ...
2
votes
1answer
131 views

How do I convert tangential speed to angular speed in an elliptic orbit?

I am running an animation of a satellite in an elliptic orbit (defined by a parametric equation for $x$ and $y$ as a function of $t$) and want to make sure the spacecraft is traveling at the right ...
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0answers
24 views

Vibrational noise for scientific apparatus on a satellite

Say we're running an experiment on a satellite in some earth orbit. For example, maybe we're imaging something with transmission electron microscope or we're catching atoms in ion traps --- really ...
0
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1answer
127 views

Satellites and gravitation

A satellite with mass $m$ orbits a planet of mass $M$ in a circular path with radius $r$ and velocity $v$. Due to some internal technical failure, the satellite breaks into two, similar parts with ...
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2answers
121 views

Under what conditions, will a projectile motion follow a half circle?

What came to my mind is to throw an object far from the earth with a particular speed equal to $$V_{sat}=\sqrt{\frac{G\times M_{central}}{R}}$$like satellites. However, it would follow a full circle.
1
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3answers
139 views

A satellite in orbit fires it's engines for a short interval. Is the new orbit closer or further away?

A satellite is in a circular orbit when its engines turn on to exert a small force in the direction of the velocity for a short time interval. Is the new orbit further or closer to the Earth? The ...
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2answers
92 views

Is such an orbit possible that allows a satellite on Earth and another on Mars to always be in direct line-of-sight?

If not always, how much "most of the time" could it get? Or would a multi-satellites setup be more suited?
6
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1answer
147 views

When can a natural satellite be in polar orbit around it's primary?

A circular/inclined to the equator/non-polar orbit is typical for natural satellites; apparently a consequence of the energy/velocity requirements. This is applicable to natural satellites around ...
3
votes
1answer
319 views

how does international space station change its orientation?

In what way does the rotating gyroscope help in changing the orientation of the international space station in space ? Is there any other way to change the the orientation of ISS ?
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4answers
2k views

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 ...
3
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0answers
56 views

How to predict Iridium Flare?

I want to find out how to predict Iridium flares, but I don't know where to start. If I know Solar position, Iridium satelites' TLE and it's shape, I need a magnitude(time) function for some place on ...
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2answers
355 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
108 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
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1answer
99 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
195 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 ...
8
votes
1answer
202 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 ...
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votes
2answers
262 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
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1answer
100 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 ...
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2answers
3k 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) ...
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4answers
119 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 ...
1
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2answers
113 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 ...
4
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1answer
117 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
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1answer
144 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 ...
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2answers
2k 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 ...
48
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5answers
3k views

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 ...
3
votes
1answer
82 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 ...
4
votes
1answer
153 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 ...
5
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2answers
1k 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 ...
2
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3answers
161 views

How closely may an artificial satellite orbit Earth without decaying appreciably each orbit?

Just what the title states. An artificial satellite will orbit Earth with some defined angular momentum. An aircraft,on the other hand, relies upon it's engines to provide continuous forward velocity ...
4
votes
1answer
162 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
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1answer
71 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 ...
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1answer
265 views

What is the typical orbital life of an artificial satellite?

The orbit of satellites around Earth eventually decays, or so I read. This is typically caused either by atmospheric drag, or by tides. I would assume most satellites have a limited service life in ...
4
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2answers
368 views

How much thrust would be needed to turn a hobbyist weather balloon into a deep space probe?

I was reading the article Weather Balloon Space Probes that says you can put your own balloon probe at 65,000 ft temporarily. Is it even remotely possible to raise the probe high enough using ...