# Tag Info

## New answers tagged artificial-satellite

0

The Space Shuttle could have made money as technically it performs very well at delivering large payloads to the ISS (Falcon 9 rockets cost 1.39X more to deliver people and payloads to the ISS according to my table below). The Space Shuttle is probably is not as nimble and adaptable as other smaller systems - both technically and from a pace-of-business ...

2

I second most of what @mefitico said in his excellent answer. Most CubeSat operators even universities will not permit you to operate their satellite. It is a valuable asset, and they don't want anyone just playing with it. Not to mention, often their licenses (e.g. NOAA) has significant restrictions on how they must operate their satellite. You can ...

2

As seen in the photos below from https://terra.nasa.gov/about Terra is reddish, so the answer to Why is Terra reddish? is exactly what you have suspected; because it is wrapped in a thermal protection film that is reddish in color. However, the answer to a more interesting question: Why am I surprised that Terra appears reddish? would have several ...

1

The direction cosine matrix relating the orbit frame and an inertial frame is as followed. Essentially it is a 3-1-3 body-two rotation sequence. I talk about the DCM a little more in detail here (Calculate Argument of periapsis of orbit given focus and two points on ellipse). You will need to know all your orbital parameters in order to calculate this DCM ...

4

This graph shows the common failure modes experienced during the first 100 cubesat missions. Note the large fraction of failed missions that never made contact with the ground after launch; no failure analysis on those. I assume ADC is Attitude Determination and Control, but it doesn't say so in the paper. Source

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There have been projects with this intention, such as OLEV, but actually, this would only allow increasing the life of a satellite from a propellant and orbit maintenance point of view. Theoretically it is possible, but one would expect other systems in the satellite to fail, particularly the battery would loose maximum charge and panels would loose ...

2

This question mixes up a few concepts. First, something being "flight proven" in a cubesat is far different from being "flight proven" in a traditional large spacecraft. It is not being successful in space once that makes a device reliable, but rather the quality control of the production facility and the extensive testing done on ground, both prior to ...

3

I've never heard of a geostationary satellite having magnetic torquers, since the magnetic field is very weak on such high orbits, wheel desaturation is carried out with thrusters. Also, every geostationary satellite I'm aware of uses propulsion for station keeping, so even if any magnetic effect could cause orbit perturbations on them (as does solar ...

2

The short answer is: Unless you are really lucky, your request is unfeasible. The long answer is: If you goal is to get familiar with protocols and data flow, I'd suggest you start studying the CCSDS standards, as they're the usual starting point for telemetry and telecommand formatting. Then, I'd suggest you find some software that will help you get ...

0

A stated in another answer, significant is a relative concept, as it depends on the degree of precision required by the question made. Keplerian orbits, the solution of the inverse square law for a central force or two body problem, are perturb by several much smaller forces that, nevertheless, change the trajectory a bit. Here are the relative strength ...

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When calculating the future orbit of an artificial (Earth) satellite, is the moon's gravity significant or insignificant? It's a great question! Of course everyone's definition of "significant" will be different. Gravity is a long range force, it never goes to zero, and decreases only as $1/r^2$. Nothing blocks it either, so basically everything pulls on ...

2

Referring to your comment to uhoh's answer, in order to get from orbital information to real-world information there are multiple pieces of information you need. First you need to understand that SGP4 will take the TLE and give ephemeral predictions in an inertial frame. This is great if you want to track objects in outer space, but very difficult to track ...

1

Last answer is from 2014. I'll add an answer that will address 2019 and beyond. SpaceBEEs are ¼U (quarter-U) cubesat format with long antennas that extend upon deployment and special radar reflectors that make them more visible. Rather than copy/paste other posts here, I'll refer you to these questions and their answers: How does the SpaceBEEs' ...

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In addition to the sources in @AlexAltair;s answer you can go to https://www.celestrak.com/satcat/search.php and click 'Raw Satcat Data' and save the very large text file, then read the SATCAT Format Documentation Unless you know what year and launch you are looking for, you'll need a spreadsheet, a simple computer program, or a good text editor to look ...

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Now imagine you have a list of satellites, and it tells you one of them should be roughly 'there' (in a particular orbit and position) above the Earth. Those lists of satellites definitely won't tell you anything about the position within the orbit, or much about the orbit at all. Have a second look at those lists. For this question you need Two Line ...

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I think there are several, public and private. Each space-faring country is going to keep its own registry. From googling, I've found the United Nations Register of Objects Launched into Outer Space, which has submissions as of yesterday. The page says States and international intergovernmental organizations that agree to abide by the Convention are ...

5

Yes The orbit you are talking about is one of the Lagrangian Points, the L2 point to be more precise. As a matter of fact, a few satellites are there - and, most relevant to this question, the James Webb Telescope will be placed there. Note that the L2 point is a point of gravitational equilibrium, but isn't actually a stable point. That means that ...

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