Questions tagged [low-earth-orbit]

Questions regarding Low Earth Orbit or LEO, which refers to orbits at an altitude between approximately 160 kilometers / 99 miles and 2,000 kilometers / 1,200 miles.

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6
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99 views

What is Buzz Aldrin's T.O.R. plan? How does it work?

Buzz Aldrin is recently quoted in Ars Technical's Buzz Aldrin is looking forward, not back—and he has a plan to bring NASA along: “This T.O.R. plan may be the most important thing I’ve ever done in ...
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1answer
231 views

Can Astronauts really see firework displays from space?

ISS Expedition 59/60 astronaut Nick Hague tweeted: Sporting our red, white, and blue on @Space_Station!🇺🇸 Planning a “cookout” tonight. Beef patties, corn, blueberry cobbler, and lemonade are all ...
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82 views

How is the proper LEO picked, and, since they are all fairly close, isn't there a lot of debris there?

Some orbits have a clear reason why they are exactly where they are: geostationary orbits and Kepler points, for example. Yet the vast majority of stuff in space is in the LEO range. And my ...
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How can I calculate the azimuth from an earth station to a satellite

I have computed the ecef coordinates of both the user location on the ground, the satellite's ecef coordinates, as well as other inputs such as altitude, lat, long of both satellite and earth station....
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Would it be possible to de-orbit a small object by throwing it with human strength? [duplicate]

If an astronaut went on a spacewalk (say from the ISS), tethered him/herself to a relatively massive object in orbit around the earth (say the ISS), and threw a small object in the direction opposite ...
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1answer
48 views

IRIS Transceiver for LEO Missions?

My professor really wants to know if the IRIS transceiver, which flew on MarCo, will be used in LEO. In fact so much that he doesn't accept "no" for an answer. I have searched for an example but found ...
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What is the longest manned re-entry from Low Earth Orbit ever recorded?

What is the record for the longest amount of time that a manned spacecraft has taken to re-enter from low Earth orbit (LEO)? I would prefer the duration between the beginning of the re-entry burn ...
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1answer
53 views

How frequent do TLEs of LEO satellites change?

I was doing some MATLAB simulations on LEO satellites using TLEs obtained from n2yo websites and I observed that n2yo was displaying a different TLE for the same satellite after a few days. I don't ...
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Is the Starlink array really visible from Earth?

I was browsing YouTube when I came across this video, recorded from a sky gazer who apparently spotted the Starlink satellites. In my lifetime, I haven't seen many satellites in the night skies (maybe ...
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1answer
63 views

Getting from LEO to a station in geostationary orbit and docking with it using a Hohmann transfer?

How long would it take for a spacecraft with a mass of 30,000 kg, to go from LEO to reach and match the speed of a space station in geostationary orbit so it could dock with the station, using a ...
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1answer
56 views

History of multiple-payload launches?

Another question asks why Spirit and Opportunity weren't launched together. My gut response was that multiple-payload launches were less common then than they are today, but I don't actually know if ...
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How fast do optical surfaces get dirty or damaged in space?

These answers: (1, 2) to Do things get dirty in space? mention the Hubble Space Telescope but if I understand correctly refer to the outside of the telescope rather than its optical surfaces. Answers ...
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1answer
50 views

Calculating orbital parameters for given requirements

I'm trying to determine what's the best way to calculate the required orbit for a LEO remote sensing satellite. I understand there exists the trade-off between sensor coverage and sensor accuracy, but ...
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1answer
1k views

How could we transfer large amounts of energy sourced in space to Earth?

At the rate we are using energy, it is inevitable that we will need to source energy from outside of Earth, eg from space. I was wondering how one would transfer this energy from that energy collector ...
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100 views

What if GOCE rolled 90°?

Reading this question: Is GOCE a satellite or aircraft? I wondered what would happen if GOCE rolled 90° in either direction, so that it's solar panels become parallel to Earth's horizon, and then ...
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2k views

Temperature of a satellite orbiting in low Earth orbit

I am working on a project for science fair that involves a deployable component that will not be heated on a CubeSat. I am trying to find data for the skin temperature of a satellite (or the ISS) over ...
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740 views

Can the Right Ascension and Argument of Perigee of a spacecraft's orbit keep varying by themselves with time?

I came across the orbital data for a low Earth orbit spacecraft and one thing which I am not able to understand is why does its Right Ascension of ascending node and Argument of Perigee keep changing ...
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1answer
1k views

How was Skylab's orbit inclination chosen?

As referenced in this question, there were a number of early spaceflight missions at higher inclination than may be expected (given limited payload capability, higher inclination further limits ...
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878 views

Where did Heinlein say “Once you get to Earth orbit, you're halfway to anywhere in the Solar System”?

I know what it means. I've seen delta-V charts. But I don't know if Robert Heinlein wrote this down, or simply said it off-the-cuff to somebody. Variations include: "Reach low orbit, and your ...
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Would a Hohmann transfer within LEO be useful?

Hohmann transfer is often used between a lower LEO orbit and MEO, GTO, GEO or beyond. But if the target is a high altitude within LEO, how would a direct ascent compare to ascent to a lower orbit ...
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1answer
181 views

What is OneWeb's constellation's “progressive pitch” and how does it avoid interference with Ku-band satellites in GEO everywhere on Earth?

The Wikipedia article section OneWeb satellite constellation; Design characteristics tells us: The satellites will operate in the Ku band, communicating in the microwave range of frequencies in the ...
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356 views

How do orbital spacecraft calculate reentry?

For a given spacecraft, in a given LEO orbit, assuming you have all the required data, how do you choose the needed burnout speed and timing (or position in orbit), in order to reach a certain point ...
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Are sun-synchronous orbits always North to South?

So someone told me that weather satellites orbit from north to south generally because that helps them to obtain a sun-synchronous orbit (his explanation for why this was true was too complicated for ...
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81 views

Where was the space station this morning?

Did the space station fly over North Carolina this morning (January 22, 2019) about 6:30am I live in Roxbro NC 27574. I spotted an unusual object in the sky about 140-150 degrees, toward the South ...
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116 views

Could a spacecraft produce lift using sublimating material?

Following this question, could a spacecraft approaching upper atmosphere from very low circular Earth orbit, produce lift to soar propulsively, bleeding speed at constant apoapsis, by sublimating ...
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1answer
86 views

Does launching to interplanetary space from LEO require the least delta-v?

Based on this chart from wikipedia, (I do not know if I am reading it correctly) This all assumes LEO-Eq LEO to C3/0=3.22 LEO to GEO to C3/0=3.9+1.3=5.2 LEO to EML-1 to C3/0=3.77+0.14=3.91 LEO to ...
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1answer
120 views

How long could a spacecraft be attached to ISS?

I've recently noticed how the "Design life, when docked to Space Station" parameter, varies across some of the modern spacecraft that are capable of docking to ISS these days: H-II Transfer Vehicle - ...
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2answers
216 views

Where can I find the TLE of ExseedSat 1, India's first ever private LEO satellite?

On 3rd December 2018, a private Indian company Exseed Space launched it's first ever satellite into space called ExseedSat 1. But I couldn't find the TLE for this satellite. I looked it up on n2yo ...
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1answer
96 views

Atmospheric re-entry speed

What would be the difference in atmospheric re-entry speeds from LEO and GEO, assuming a Hohmman transfer orbit from GEO to re-entry? If I am getting the transfer orbit concept correct?
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1answer
715 views

Calculating the radial, in-track and cross-track distances

I'm computing the relative distances between satellites. The following picture shows the distances, which are considered as risky. What do Radial, In-track and Cross-track mean and why are they ...
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2answers
107 views

Cubesat mass density (kg/U) statistics?

The stuff of which COTS cubesats are made (aluminum, silicon, G10/FR-4, battery) has a density in the ballpark of 2 to 3 (g/cm^3) while vacuum is roughly 0. I'd always figured that cubesats built from ...
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1answer
137 views

Satellites that take advantage of, or require constant availability of sunlight on the spacecraft itself, available in Sun-synchronous orbits?

ditto: "Are there satellites that take advantage of, or require constant availability of sunlight on the spacecraft itself, available in Sun-synchronous orbits?" This question is an offshoot of this ...
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What are the causes of these episodes of faster than average altitude loss by the ISS?

@Cristiano's question No reboosts for the ISS shows the plot below. I don't have the original source. I've added some annotations including four arrows to indicate what looks like short periods (a day ...
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2answers
218 views

How much fuel to maintain VLEO for communication satelites?

A recent answer about communication satellites in VLEO (≤350 km) estimates a useful orbital life of about month without fuel. I.e. Once the vehicle is out of fuel to maintain orbit, THEN it has ...
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1answer
559 views

How low is VLEO? (FCC's newest approval for SpaceX)

Engaget's SpaceX gets FCC approval to deploy thousands more internet satellites says SpaceX's plan to build a global, high-speed wireless internet network using satellites has taken another step ...
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2answers
162 views

How is a satellite constellation launched?

If want 10 satellites chasing each other around the earth (evenly spaced) all one the same plane, these satellites would be evenly distributed around the globe after launch by slightly raise or lower ...
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3answers
2k views

Why are there no LEO satellites in the earth's equatorial plane?

From my elementary school understanding of Satellite orbits, I know that GEO satellites are placed in equatorial plane, MEO satellites are placed in an smaller degree inclined plane while LEO ...
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3answers
204 views

Was Roadster (Starman) seen in Earth orbit, before the long burn to deep space?

Discussion in comments below this answer tend to conclude that 1st stages come back to Earth and so (essentially) all those tumbling rocket body objects in Heavens Above are 2nd stages, though I ...
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Spacecraft-fixed coordinate system

I am working with data from a polar-orbiting satellite (inclination 97 degrees) with limited attitude information. I am trying to define a coordinate system which is fixed with respect to the ...
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How much is LEO worth?

I've seen valuations of the space industry at ~$350bn annually. How much of this is coming from LEO vs MEO/GEO?
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323 views

Did the Soviet Union put an unmanned satellite in “very low orbit”above the Kármán line which used aerodynamic attitude control?

This interesting, archived page https://www.webcitation.org/618QHms8h?url=http://www.fai.org/astronautics/100km.asp which I found in this answer, says: Later in the same decade (or very early in ...
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199 views

What is the speed of ISS relative to ground surface?

Is it 7660 m/s or (7660-460)m/s? If it is the former then the ISS orbits about the Earth at 8120 m/s. I think it should be (7660-460)m/s relative to ground based on this orbital period formula, $$T=...
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370 views

How to calculate azimuth and elevation angles from satellite point of view of a ground station?

How to find azimuth and elevation from satellite of a ground station when yaw, pitch, roll, lat, long position of satellite and lat, long position on ground are given? ...
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Parameters and restrictions of a Single-satellite and Single Ground Station system [closed]

I am designing a ground station system to retrieve data from a single satellite sending at a given bandwidth in LEO, and I am confused of which parameters I have to take into account when designing a ...
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Attitude of the upcoming “Orbital Reflector”; will it result in good visibility?

There's a new (passive solar) orbital reflector, called the Orbital Reflector. While Mayak (Маяк) was a crowdfunded project at Moscow State Mechanical Engineering University and the Humanity Star ...
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2k views

Are there satellites in LEO that can be seen by naked eyes in the daytime?

Are there any satellites in LEO that we can see with naked eyes in the daytime, or any special situations where they might become visible during the day? If there is, how high, and at what ...
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1answer
88 views

Does a LEO mission to study the marine debris exist or is at least planned?

Would a mission to LEO to study and record the amount of marine debris be of use or is someone already doing it?
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79 views

Lighting an area of the Earth Surface from LEO

What does the math look like to calculate the size of an object in LEO that when angeled off the sun, would illuminate a part of the Earth's surface? For example, if I wanted to 'lightup' a square ...
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1answer
196 views

Hyperspectral Imaging from Low Earth Orbit

We're going to be putting a CubeSat into orbit next year and want to use a hyperspectral imaging device onboard. My questions relates to the maths needed to calculate the imaging lens needed to ...
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Split cost of bringing 1 kg to LEO

Historically seen, space logistics prices decrease, as shown here, from $20K/kg to expected 1.7K/kg thanks to reusable rockets. But, how does the cost split look like and vary in detail? i.e. "fuel - ...