Questions tagged [atmospheric-drag]

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

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0answers
39 views

Can effective thrust in the more dense layers of the atmosphere be considered constant (as approximation)?

I am reading some course material about the 'Thrust load ratio'. It states the following: The thrust load ratio is: $Psi = {T \over Mg}$ $T$ being the effective thrust, equal to the actual (...
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4answers
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Are rockets faster than airplanes?

Rockets are fast. Faster than anything else somebody could fly with - at least intuitively to me. But - airplanes are fast too. A rocket typically flies vertically, an airplane mostly horizontally. ...
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What was the exact nature of the observations of “solar flare activity” that delayed the launch of Vostok 5?

The interesting story of Vostok 5 recounted in Encyclopedia Astronautica's Vostok 5 (linked in comments below this answer) includes the following passage: Vostok 5 was originally planned to go for ...
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1answer
104 views

How do I calculate re-entry velocity when decaying from a circular orbit?

I am trying to find the velocity of an object during re-entry so that I can calculate the peak heat flux but I'm a bit stuck. I know how to find the velocity of the original, circular orbit (300km) ...
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103 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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When do aircraft become solarcraft?

Any body travelling through particles undergoes drag. Any body able to generate lift (for instance spheres cannot generate lift) can generate lift if it undergoes drag. First by assuming one body in ...
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1answer
143 views

Coupling satellites already in orbit reduce drag and debris?

How would 2 or more satellites be joined to reduce atmospheric drag? Could a 3rd satellite tow and join 2 or more satellites that are in similar orbits to prevent Kessler syndrome? At the very least ...
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What would be payload capacity of reusable Falcon 9 if there was no atmosphere on Earth?

Reading this question and answers, I wondered what would happen if there was no atmosphere, everything else being the same on Earth. What would be the payload capacity to LEO of Falcon 9 in reusable ...
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Maximum speed based on atmospheric altitude given maximum temp?

I saw the question Could escape velocity be achieved in the atmosphere? and thought it probably could've been asked better. I'm sure there's an equation to calculate the average heat generated by an ...
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Why not increase contact surface when reentering the atmosphere?

If a craft were to increase the surface area where contact is made with air during reentry, I imagine the heat quantity per area unit would decrease, making the use of (heavy) heat shields less of a ...
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57 views

Reducing the aerodynamic drag of multi-engined rockets: aft wake area

Have there ever been thoughts of reducing the aerodynamic drag that results from the empty space between rocket engines? More precisely, this extremely low-pressure area sucks up ambient air and ...
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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 ...
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Calculating the height and width of a rocket for drag

While messing around with making a little rocket launch simulator, I seem to have hit a slight wall with finding the relevant information in order to calculate the width and height of the rocket for ...
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1answer
204 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 ...
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144 views

At what altitude do the effects of atmospheric drag completely disappear?

The spate of K-questions got me thinking: At what point does atmospheric drag disappear1 with the pressure from sunlight, solar wind, or other forces becoming overwhelmingly dominant? I'm guessing it'...
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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:...
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4answers
148 views

Radioisotope thermoelectric generator behavior on reentry

The RTG has become a major source of power in places where solar power just wont cut it. but there has always been an issue with sending them into space. if the launch fails, radiation comes raining ...
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1answer
170 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 ...
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2answers
240 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. ...
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193 views

Orbital propagation: atmospheric drag

I'm developing the numerical orbital propagator. I've already implemented the Newtonian gravity (Earth, Sun, Moon), Earth harmonics, SRP and relativistic effect. The software is compared with GMAT ...
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373 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 ...
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126 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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431 views

Could I use a satellite as a vehicle for delivering airborne leaflets?

Assuming I have a satellite in a decaying orbit, could I gently release leaflets from my satellite so they were on a near-identical sub-orbital trajectory and have them touch-down safely on the ground ...
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1answer
235 views

When a Saturn V reaches max Q, what fraction of the lengthwise structural load is due to drag rather than acceleration?

Ignoring all other structural loads besides the lengthwise compression of the rocket. This is useful to know when theorizing about whether high altitude launches (e.g. from airplanes) could ...
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How much higher is the wave drag for a spaceplane compared to its induced drag

I'm working on the conceptual design of the path of a suborbital spaceplane and am trying to do basic calculations. I read that wave drag near the sonic barrier can be huge and can impede the flight. ...
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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 ...
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1answer
145 views

GMAT atmosphere

I am using GMAT to propagate satellite motion with Jacchia-Roberts atmosphere model. Here is a formula used from this model which is then used to estimate the variation in drag on a spacecraft due to ...
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3answers
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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 ...
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1answer
162 views

Atmospheric drag effect

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

Drag-only and gravity-only satellite orbit propagation, need help understanding the results

I'm trying to propagate the orbit of an Earth satellite. I've tried my calculation with gravity only (no drag), and also with drag only (no gravity). The gravity-only calculations work fine and ...
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1answer
104 views

Would landing on mars during a storm considerably increase atmospheric drag?

Any chance we could harvest all those dust particles for an significant improvement in aero-breaking capabilities or would it destroy most heat-shields?
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1answer
190 views

Budgeting delta-v for atmospheric drag when orbit is elliptical?

I'm trying to calculate the delta-V budget to maintain a generic elliptical orbit. Looking at the atmospheric drag losses I can only find equations that calculate delta-V loss for circular orbits. ...
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1answer
352 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 ...
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1answer
63 views

Applying secondary orbital perturbation effects

I read about secondary effects which influence on orbit propagation like solar radiation, moon, etc. (https://en.wikipedia.org/wiki/Orbit_modeling). First I calculate position vector Rpqw to object (...
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131 views

Atmospheric drag vs. atmospheric heating. Which occurs first?

If I was in a circular 10km orbit (theoretical) around Earth, what will occur earlier? Will I burn up in atmosphere or be stopped by atmospheric drag?
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1answer
373 views

Modelling SpaceX's lift and drag versus angle of attack and Mach number

I've been trying to find data in the literature that would provide analytical expressions for the relationship between the lift and drag of an object similar in shape and size to the Falcon 9 first-...
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147 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 (...
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5answers
428 views

ISS achieving lift by using it's solar panels

Can the ISS achieve any lift by using it's solar panels as 'wings' against the sparse atmosphere? My understand is they started moving the solar panels into a 'low drag' orientation when on the ...
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0answers
430 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 ...
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1answer
747 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 ...
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1answer
125 views

In what atmospheric densities or pressures have aerobrakings been performed?

How deep have spacecrafts gone into an atmosphere for doing aerobraking for orbital insertion (or as tech demos)? I suppose it is the braking force of the atmosphere that counts, is that closely ...
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1answer
182 views

Atmospheric influences on satellite imagery [closed]

I need to know if there's any relationship between the drag force of any point in LEO with the quantity of particles or something like that that are flying in the air that makes quality of the ...
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4answers
3k 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 ...
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1answer
544 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 ...
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1answer
527 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 ...
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2answers
533 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) ...
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3answers
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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 ...
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1answer
4k 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 ...
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1answer
172 views

Atmospheric drag at 250 km

I was watching the jcsat-14 launch, and I noticed the vehicle was slowly slowing down when 2nd stage engine was off even at 250+km. Is it because of atmospheric drag or pulling force of gravity?
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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 ...