Questions tagged [atmospheric-drag]

Questions regarding atmospheric drag which includes the resistance offerd by a moving object in fluid

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37
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4answers
15k views

Effect of atmospheric drag on rocket launches and benefits of high altitude launch sites

What is the approximate influence of atmospheric drag on the cost of rocket launches? Is it beneficial to have launch sites located at higher altitudes? Cape Canaveral is at sea level, but I've ...
15
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2answers
5k views

What is the ISS drag?

ISS constantly loses altitude to air drag and other forces (tidal, electromagnetic). While finding that rate in the sources isn't that hard, with orbital mechanics of altitude loss actually increasing ...
6
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3answers
948 views

Why does Earth's atmospheric density have a big “knee” around 100 km? Is there a good analytical approximation?

I've used a quick very rough approximation of the drop of atmospheric density with altitude in this answer and in this answer by using a single exponential and scale height parameter, but that's not ...
10
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4answers
5k views

Where can I find data for Atmospheric density vs. altitude?

I'm looking for information on atmospheric density in Earth orbit. All the atmospheric density tables and graphs I've found go no higher than 100 km. Definitions like the US Standard Atmosphere don't ...
3
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1answer
4k views

How can I estimate the Coefficient of Drag on a Saturn V rocket, a simulator or some data would be pretty awesome

I'm trying to get some information on this and its proving difficult as the information is usually acquired experimentally from what I've found. A single number at a specific altitude and speed would ...
6
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3answers
2k views

Is aerodynamic lift ever useful in rocket flight?

When a rocket is traveling through an atmosphere, the component of the aerodynamic force in the direction of motion is called drag, and the component perpendicular to that is called lift. Usually a ...
2
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2answers
667 views

Rocket drag and lift based on flight direction - in which frame of reference?

Drag is aerodynamic force component parallel to the direction of motion. Lift is aerodynamic force component perpendicular to the direction of motion. Direction of motion with respect to what? 1) ...
0
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1answer
690 views

How is max Q for the shuttle actually defined?

In this article about max Q https://en.m.wikipedia.org/wiki/Max_Q the shuttle launch is discussed. Since there are four distinct large objects - two boosters, one shuttle and one giant tank - there ...
10
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2answers
1k views

How hard does atmospheric drag push on the ISS? Is it more than one pound?

A comment under this question has me thinking; with it's huge main structure and giant solar panels the ISS presents a very large cross-section to Earth's rarified atmosphere at 400 km altitude. So ...
21
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3answers
15k views

How does skipping off the atmosphere work?

I searched the web and found a couple entries on Wikipedia (Skip reentry & Atmospheric entry) that kind brush at the topic. The article on Stone skipping has some science and physics involved (...
9
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1answer
263 views

What is the closest to Earth you can expect lift from a solar sail?

There is no doubt that a solar sail can move you around the Solar system, and even interstellar, if you're not in a hurry. But it will not get you off the planet. Assuming your ship/satellite is in ...
6
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2answers
793 views

Shear forces between Shuttle, tank, and boosters - what pushes what?

This is the question that I should have asked here. The space shuttle and the two solid rocket boosters (SRBs) are mechanically attached to the giant tank. SRB's, shuttle, and tank all experience ...
13
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2answers
2k views

Re-entry Heat Shield Alternative

Why is it that Controlled Re-entry Vehicles (like the most recent Orion & Dragon) do not use a strong magnetic field during re-entry to "shield" the blunt shaped end from plasma ? Reasoning: ...
4
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1answer
173 views

Did the Space Shuttle crew have to worry about the ionosphere? What relevant training or specific briefings did they receive?

Comments below this answer tell us that the Space Shuttle always remained in Earth's atmosphere. When it visited the Hubble Space Telescope or the ISS or Mir it was still in the thermosphere and ...
4
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1answer
245 views

Why is “Terminator Tape” electrically conductive?

A 230 foot long tape deployed from the satellite Prox-1 greatly reduced how long it took to deorbit. The tape was described as electrically conductive. Was that property intended to help the ...
3
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1answer
151 views

What fraction of Terminator Tape™'s drag comes from interaction with Earth's magnetic field as a function of altitude? Is it ever important?

This answer states that Terminator Tape™ uses the Earth's magnetic field to generate drag to shorten the deorbit time of a spacecraft in LEO. It links to https://sst-soa.arc.nasa.gov/12-passive-...
1
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1answer
143 views

What is Direct Simulation Monte Carlo and why is it a good method for simulating spacecraft drag in VLEO?

Reducing spacecraft drag in Very Low Earth Orbit through shape optimisation J. A. Walsh and L. Berthoud (2017) show simulations calculating drag coefficients for different "nose cone" shapes ...
9
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3answers
4k views

Requesting an in depth explanation of heat created during atmospheric reentry,

What is(are) the root cause(s) of the heat and friction experienced during atmospheric reentry (or initial entry)? I understand that as items descend to earth they experience a force that can ...
7
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1answer
238 views

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 ...
6
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3answers
344 views

How much of a drag is it, orbiting the Earth in a space suit?

An astronaut in a spacesuit travels around the Earth at the same altitude as the ISS. Let's say the astronaut leads the ISS by 1000 meters along the same orbit. After one orbit, how much velocity has ...
5
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1answer
828 views

Can dust be in orbit around a spacecraft which orbits the Earth or Moon?

In the title above, Can dust be in orbit around a spacecraft which orbits the Earth or Moon? let's define "in orbit" to mean gravitationally bound to the spacecraft long enough to go around it a few ...
5
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2answers
195 views

How can a meteor gain energy in an encounter with the Earth even though these answers say it can't?

The question Did a spacecraft ever use an atmosphere to accelerate away from a planet? was unfortunately given five down votes and answered with: Entering the atmosphere introduces drag, which could ...
4
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0answers
151 views

What was the ambient air density was there when/were Starman/Roadster first started playing Bowie's “Life on Mars”

When the Falcon Heavy test flight 2nd stage fairing opened at about 115 km, David Bowie started singing "Life on Mars". Okay, the Tesla Roadster's stereo started playing "Life on Mars", or at least ...
4
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1answer
393 views

How stable is an orbit of 335.9 km?

Spacex has recently begun deployment of its satellite constellation that will provide internet services. In their initial filings with the FCC they propose that they may have over 7,000 VLEO (very low ...
3
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2answers
322 views

North Korean objects 41332 and 41333; how fast are they losing altitude?

I cited objects 41332 and 41333 launched in early 2016 as counterexamples to this answer on my highly down voted and closed but otherwise "perfect" question What regulations, agreements, or other ...
3
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1answer
109 views

How many solar system bodies have “knees” in their atmospheres?

Discussion lead to citing Why does Earth's atmospheric density have a big "knee" around 100 km? Is there a good analytical approximation? who's answer is "monatomic oxygen". ...
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1answer
229 views

Atmospheric drag effect

While propagating the satellite motion faced the strange effect. Without the atmosphere results (x,y,z coordinates in meters and ...
0
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1answer
68 views

What is the difference between “body drag”, “frictional drag” and “pressure drag” for astronaut or aerobot atmospheric locomotion in microgravity?

Complaints below my answer to Would a higher air pressure on the ISS or elsewhere make it easier to “swim” in microgravity? about my spherical-cow estimate of how fast an astronaut can accelerate by &...
16
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1answer
12k views

Why is the Russian approach to the aerodynamics of their rockets different?

Russian rockets look like this: They flare them out at the bottom. With their newest rocket, the Proton, the flared shape is gone but the boosters still have caps that angle in towards the main ...
13
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3answers
903 views

Does it snow in LEO?

How does water spray behave in Low Earth Orbit (LEO), from the side exposed to the Sun to the side in Earth's shadow? Could it be used as means of augmenting atmospheric drag and deorbiting defunct ...
16
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3answers
2k views

How can an *increase* in atmospheric temperature cause an *increase* in the atmospheric mass density?

We often hear that heating Earth's atmosphere from solar activity or CMEs increases the mass density of the atmosphere at a given altitude, causing orbiting spacecraft to lose altitude faster from ...
6
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2answers
4k views

Deorbit time for satellites in LEO

According to Systems and methods for a self-deploying vehicle drag device (US 8616496 B2) patent's background of the invention: The United States Federal Communications Commission (FCC) requires ...
13
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2answers
4k views

How much fuel can SpaceX save by landing the Falcon 9 booster on a barge?

It sounds from the text of this tweet like Elon Musk plans to continue to do barge landings over the long term: "Base is 300 ft by 100 ft, with wings that extend width to 170 ft. Will allow refuel &...
10
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2answers
458 views

Why does in-flight mission abort often ends in ballistic high-g reentry?

I am seeing a lot of references to the “ballistic reentry” mode of the crew return vehicle in relation to the abort during the powered ascent stage. In partiulat, the recent crewed Soyuz MS-10 abort ...
8
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0answers
161 views

Does the kinetic impact of gas particles cause erosion to the surface of objects in orbit?

When satellites or space stations orbit the Earth, they are constantly experiencing a low level of aerodynamic drag from Earth's atmosphere. The ISS needs to be reboosted every few months to account ...
5
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3answers
817 views

Could thermal energy be collected by dragging a thermoconductive device against the outer atmosphere

Atmospheric reentry is notoriously a difficult and HOT endevour. Could this thermal energy be used as an alternative energy source on earth? Could this be used through some sort of orbital charging ...
4
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1answer
972 views

What is the lowest altitude that an ion thruster can be used for station keeping?

What is the lowest altitude that an ion thruster can realistically be used for station keeping before its small amount of thrust is overcome by atmospheric drag? Please state your assumptions such as ...
3
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1answer
6k views

What's the atmospheric drag coefficient of a Falcon 9 at launch (sub-sonic, large fairing)

While I said just a few hours ago that "There's almost no such thing as a dumb question! this one just might sound like one. I'm making some slides about first principles thinking applied to ...
2
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0answers
238 views

Did the Shuttle have a drag penalty for ascent with a negative angle of attack (AOA)?

@OrganicMarble's answer mentions Because the Orbiter wings developed lift at zero angle of attack, the high dynamic pressure portion of ascent had to be flown at a negative angle of attack, close ...
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0answers
153 views

Would Mayak's large solar reflector have produced a stable attitude, or more likely start tumbling or rotating?

update: Answers to Two week mark; has Mayak (Маяк) been spotted yet? Reflector deployed? Astronomy “ruined”? indicate that the reflector did not deploy successfully (more at Mayak, a magnitude -10 (...
21
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2answers
9k views

What is the ideal shape for a rocket?

Obviously there are many factors that go into the design of a rocket. However, to me, many rockets seem very tall and skinny. What I mean is that an ideal rocket would have as little mass used for ...
18
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4answers
8k views

Why are rockets cylindrical?

What are the drag coefficients for a cylinder, a wedge, etc? I know there are other reasons for a rocket to be cylindrical that aren't related to aerodynamics such as efficiency when mixing the ...
9
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1answer
355 views

What is typical lifetime of GTO rocket stages before reentry?

Most of geostationary satellites are launched at geostationary transfer orbit (GTO) first by rocket's upper stage. Than satellites separate and circularize the orbit by own propulsion. The upper ...
8
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1answer
265 views

Which engine worked the hardest to keep the ISS in orbit?

The ISS has spent two decades fighting drag caused by its large size and huge solar panels pushing through the tail-end of Earth's atmosphere only a few hundred kilometers above its surface. Question:...
6
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0answers
397 views

Why is the diameter of the boosters of some launch vehicles smaller than the diameter of their payload fairing?

Whilst watching yesterday's Starliner launch I've noticed how skinny that Centaur (3.1m) looks compared to the CST-100 (4.5m). Looking up the Atlas V I was amazed to find out that it has even larger (...
6
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2answers
319 views

Drawbacks and advantages of two slidable & rotatable control surfaces for BFS sized spaceships

BFS (SpaceX's Big Falcon Spaceship) is in development and has seen between 2016 and 2018 three major design modifications. January 2018 I asked here how BFS planned to manoever during aerobraking. ...
6
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2answers
2k views

Exactly how “Ferrari-like” was GOCE? Was its drag coefficient as low as the car's?

This comment mentions: This relation between drag and mass is taken to a relative (for satellites) extreme in GOCE which I think needed to be close to Earth to accurately sense the changes in gravity,...
6
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2answers
1k views

What is the density of the earth's atmosphere at an altitude of four hundred kilometers?

What is the density of the earth's atmosphere at an altitude of four hundred kilometers? I want to use it to calculate the drag on something in orbit near the ISS. The Jacchia Reference Atmosphere is ...
5
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1answer
189 views

Is the streamlining of a launch vehicle worth the additional fuel required to carry it beyond the Karman line?

Wikipedia writes to say Low Earth Orbit spans the altitude from 160KM above Earth through 2000KM above Earth. Launch vehicles appear to be highly stream-lined. Yet only the first few score KM (as far ...
5
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3answers
1k views

Why does a satellite with a higher mass fall slower?

I was doing simulations in GMAT and I could observe that if I increase the mass of the satellite, the satellite falls slower ... and if I reduce the mass of the satellite, then it falls faster (I only ...