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Questions tagged [artificial-satellite]

Questions about objects in orbit which are human made, such as communications and GPS satellites, orbital observatories and space stations, and other man-made object in permanent or semi-permanent orbits around the Earth, other celestial objects, aside from the Sun, or even other satellites. Not to be confused with non-orbited man-made objects in space, that are usually referred to as "probes", or simply "spacecraft".

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What kind of liquid propulsion systems do GEO satellites use?

Coming from a question about distances between satellites in GEO, what liquid propulsion systems do a majority of GEO satellites carry to maintain their slot positions? It is easy to find information ...
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1answer
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LEO metric to determine the ground track of a satellite

I'm trying to correlate a behavior on LEO satellites with the position it is over the Earth. The behavior takes place over a period of time. I'm trying to come up with a metric that will identify ...
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How would a satellite powered by RTG be terminated?

How will a satellite powered by RTG be terminated at the end of its life? Is there any set of rules to be followed? What's the general procedure?
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283 views

What will the new Iranian satellites be imaging?

Iran is soon to launch two satellites which will reportedly take images "with a high degree of accuracy of less than 10 meters" (azernews). What will these satellites be imaging?
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Satellite tracking software

I am looking for some software that will help me figure out what different satellites are as I spot them gliding across the sky. I have tried using Stellarium, but I think the satellite package has ...
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1answer
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How is WISE continuing to work without coolant?

In October 2010, the Wide-field Infrared Survey Explorer (WISE) ran out of the coolant it needs for its IR detectors to work, so it's mission ended. In August 2013, NASA powered up WISE again with a ...
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What is the math behind Magnetorquers?

I'm trying to better understand the mathematics behind how torque rods work. I know that even if you have 3 axis of magnetic torquers, in effect there is only 2 axis of control, and I'm trying to ...
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1answer
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To what celestial bodies are GRAIL-like missions planned?

GRAIL recently constructed a complete gravity map of Luna's irregular gravity field. Are similar GRAIL missions on the anvil to any other Celestial bodies as yet? As a corollary (probably opinion-...
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How much power loss does the LLCD suffer in transit?

Space.com writes to say (freeform improved quote): The LLCD (Lunar Laser Communication Demonstration) space terminal is designed to beam data from the moon at a rate six times faster than the best ...
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What is the average cost of satellite construction over the last 10 years? [closed]

In the last 10 years what was the Highest and lowest, construction cost of satellites launched? What are the mean and average costs of satellite construction over the same period? Where "a" ...
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Was the NOAA-N Prime satellite really dropped on the floor?

Recently, Donald.McLean posted this image in The Pod Bay, the site chat room: It's a rather disturbing image once you think about it for more than about half a second. Did it really happen? What ...
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1answer
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How big of a problem is the Lunar eclipse in April 2014 for LADEE?

I've been watching this NASA ScienceCasts video on YouTube (also published on NASA Science), and towards the end the narrator mentiones the end of life for the LADEE (Lunar Atmosphere and Dust ...
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Are satellites able to stream real-time videos about certain parts of Earth's surface?

Are surface-scanning satellites able to show certain parts of Earth's surface real-time? For example, to follow a person who's escaping. Somewhere I heard that these satellites are able to make ...
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1answer
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Does cosmic dust pose a problem for long-term satellites, telescopes and probes?

We have many long-term satellite observatories and probes in outer space way above the Earth's magnetosphere, and some of them progressively cruising out of our Solar system. Off the top of my head, ...
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1answer
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What are the end-of-life options for large classified satellites?

The Delta IV Heavy recently launched NORL-65 to a low Earth orbit. Some of these missions will be in the range of 390 km altitude with circular orbits. Plus, the Delta IV Heavy is a big rocket, with ...
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223 views

Has America launched any satellites for Project Horizon

America has planned to create an army outpost on the Moon. They called it Project Horizon. Did they succeed in that? How many satellites were launched for that project so far?
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Passive attitude stabilization with magnets - are there studies based on actual flight data?

Specifically with the small satellite and cubesat people, there is an rather 'old' idea around: Passive attitude stabilization based on permanent magnets. Schematic of the Earth magnetic field lines ...
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Can solar sail prevent orbital decay?

I can imagine a satellite with a solar sail it rolls when on the night side of Earth, then unrolls near "afternoon", propelled on each past of its "sunset side" of travel. Would such system be a ...
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1answer
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Would magnetic torquers placed in a polar satellite work?

Would magnetic torquers placed in a polar satellite keep the satellite stable? If it would work, would it be very efficient?
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4answers
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What is the oldest artificial satellite still in use?

Wikipedia states that Vanguard I is the oldest artificial satellite still in orbit. What is the oldest that's still in use?
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Would it actually be feasible to drop a nuclear bomb from a satellite?

During the Cold War, one of the main reasons for space exploration was military/propaganda purposes. One of the things that the US was worried about was the prospect of a nuclear bomb being dropped ...
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How does a single rocket place multiple satellites into orbit?

Nowadays, many rockets transport more than one satellite in orbit. But how does a single rocket place multiple satellites into their orbits? Do all rockets which place multiple satellites into orbit ...
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1answer
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Is the first Russian satellite still beeping?

The Russians were the first to launch a satellite into space - and it did one thing: beep. It would send out radio waves of nothing but beeps. Still, it was a huge technological achievement. My ...
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1answer
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Why do coronal mass ejections happen on the Sun? Can they affect artificial satellites?

Recently, the Sun has ejected coronal mass particles towards the Earth at a rate of 3.3 million km per hour. Can these particles affect our artificial satellites' signals, and why coronal mass ...
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Has any satellite proved the hypothesis that the Sun could be used as a gravitational lens?

Has any satellite proved the statement that the Sun's gravity could be used as a magnifying lens, focussing electromagnetic waves of distant galaxies or other celestial objects? Or, is this idea, for ...
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1answer
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Why are satellites and other payloads always placed at the top of rockets?

In all rockets that launch satellites to orbit, the satellite is always placed at the top. Why are payloads always placed at the top of rockets?
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Can spacecraft be made invisible to stations on Earth?

Can spacecraft be made invisible to ground stations? For example, are spy satellites perhaps equipped with stealth technology to prevent radar tracking? Or is it pointless as they can always be ...
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What is the maximum mass of a satellite that can be placed in GEO?

What is the maximum mass of a satellite that can be placed in GEO? Or can satellites of any mass be placed in GEO?
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1answer
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Do long term missions receive insurance coverage?

Wikipedia speaks of satellite insurance. This is restricted as follows: It covers three risks: relaunching the satellite if the launch operation fails; replacing the satellite if it is destroyed,...
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Do all satellites and space probes have high & low gain antennas and what are their functions?

What is the main function of high and low gain antennas? Do all satellites and space probes have high and low gain antennas?
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1answer
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Does the delta v requirement of a rocket to place a satellite in orbit depend on the position of other planets?

Does the necessary delta v given to a satellite (earth orbiting) by the rocket during its launch depend on the positions of other planets? Please justify your answer.
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Why is the life span of a LEO satellite less than that of a GEO satellite?

The average life span of a LEO satellite is approximately 5 years, but the average life span for a GEO satellite is approximately 8 years. Why is this?
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What is the life expectancy of a geosynchronous satellite dependent on?

When a geosynchronous/geostationary satellite is launched, how do its designers calculate its life expectancy? A random sampling of some communication satellites suggest that ~ten years might be the ...
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Does NASA plan to land on Europa?

I recently studied that life may exist on Europa, an icy moon of Jupiter. Does NASA plan to land a spacecraft on Europa to study its environment in the near future?
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Are artificial satellites completely sealed or open to space?

Are artificial satellites such as communication or weather satellites completely sealed or are they open to space? (In either case, why? How are their electronics (un)affected? Presumably they can be ...
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How full is the geostationary belt?

The geostationary ring clearly seen in the above picture looks alarmingly crowded. How full is it? How much space does a satellite in that orbit require to operate safely? Surely, (other) ...
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4answers
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How can the optimal number of satellites in an orbital plane be determined?

How can the optimal number of satellites be determined for a plane of satellites? Specifically, I would like to see how to do this in general, and a specific example worked out, such as the following: ...
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What is the smallest operational artificial satellite?

Miniaturisation has many advantages, and in recent times, nanosatellites, picosatellites, and femosatellite concepts have emerged. The Wikipedia article on miniaturised satellite has some pointers. ...
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Under what circumstances would an object falling out of spacecraft start orbiting that spacecraft?

In one of the short stories of Stanislaw Lem the main character, Ijon Tichy, accidentally drops off a piece of pork out of his spaceship, and this pork becomes a satellite of the spaceship, causing ...
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Which artificial satellites in lunar orbit are currently active?

Most of artificial satellites of the Moon has depleted their batteries, lost communication, been deorbited or impacted the surface after orbital decay. The list doesn't exactly make it clear which ...