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Questions tagged [lift]

In aeronautics, lift is a component of aerodynamic force that acts perpendicular to drag, and balances the weight of the aircraft against the effects of gravity to achieve flight. In astronautics however, the lift component of a flight of the spacecraft is a force directly negating and greater of the effects of gravity and atmospheric drag on the body of the spacecraft as it gains altitude, a distance between itself and the body it is lifting off from.

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Why is using a space elevator cheaper than rocket power?

Why is rocket power so much less efficient? In both cases you want to lift a given weight a certain height. What does climbing a tether give you that you don't have when using rockets? Wouldn't a ...
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2answers
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Challenging the Kármán line from above

The initial conditions of the thought experiment is (very) LEO / reentry. capsules, space shuttle and other spacecraft can generate lift in upper atmosphere during reentry, in order to reduce ...
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3answers
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What would a “Kármán plane” look like, a bird, or a plane?

If I understand correctly (which I might not), the Kármán line is roughly the altitude where a "Kármán plane's" upward lift force at the orbital velocity for that altitude would be equal in magnitude ...
10
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1answer
992 views

Would an ionocraft have better or worse performance in the upper atmosphere?

The ionocraft produces lift by accelerating ions in the air downward by the use of two meshes held at a large relative voltage difference. With a cursory look at the physical principle, it seems like ...
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1answer
697 views

Just how much can tall skinny rockets bend? (roughly, safely)

Below is a GIF I prepared and used in an earlier question, and the answer seems quite reasonable. With a height to diameter ratio of about 70 m to 3.7 m (nearly 20:1) a weight-conscious design, ...
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1answer
149 views

Grid Fin lift to drag ratio

For a Grid Fin, what would be the most optimal way of finding the lift to drag ratio? I am thinking about comparing lift to drag ratios of square lattice Grid Fins but with different geometrical ...
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3answers
951 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 ...
4
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1answer
120 views

Would an autogyro be a good solution for a space re-entry vehicle?

From what I can imagine, using an autorotative maneuver as a re-entry control method would be a good idea because I believe very high lifts would be generated when relative air speed is high (first re-...
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3answers
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Is the equation showed below the right one for an airplane flying at the Kármán line altitude?

$$\frac{GM_Em}{(R + h)^2} - \frac{ \rho v^2 S C_L}{2} = \frac{mv^2}{R + h}$$ $GM_E$ is Earth's standard gravitational parameter , $R$ is Earth's radius and $h$ the altitude of the airplane above the ...
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2answers
401 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) ...
2
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1answer
266 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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2answers
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Could the $C_L$ of the X-15 be calculated from the flight data near the Kármán line altitude?

The "lift coefficient" $C_L$ can be very different for one specific aircraft at different speeds. According to this article from NASA about the lift coefficient: So it is completely incorrect to ...
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2answers
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Orbital reentry glider with no heat shield

Let's assume a reentry craft designed to not use heat protection like Soyuz or the Space Shuttle, and budget is not an issue. The Concorde max surface temperature was 400 K, so let's use this as a max ...
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Is it correct to use the vis-viva equation when there are two forces acting on the orbiting body? [closed]

Edit: Although this question seems similar to the question "Is it correct to apply the vis-viva equation to an airplane that flies in a straight line", it is different because there the airplane flies ...
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1answer
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Is it correct to apply the vis-viva equation to an airplane that flies in a straight line at the Kármán line?

The vis-viva equation models the motion of an orbiting body and it applies when the only force acting on the body is it's own weight. So is it correct to apply this equation to an airplane that ...
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1answer
94 views

Does an airplane in orbit near the Kármán line altitude, with the air providing lift, ever reach orbital velocity? [duplicate]

The equation for an airplane in orbit with the air providing lift would be: $$\frac{GM_Em}{(R+h)^2} - \frac{\rho(h) v^2 S C_L}{2} = \frac{mv^2}{R+h} $$ $GM_E$ is Earth's standard gravitational ...
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Can the centrifugal force still be ignored as the lift force is a small fraction of the gravitational force at the Kármán line altitude? [duplicate]

The lift force for an airplane is: $$ F_L = 0.5 \rho v^2 S C_L $$ According to this talk page the lift coefficient for a supersonic airplane is: $$ C_L = \frac{4\alpha}{\sqrt{M^2-1}} $$ where $\...
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1answer
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Where does the definition of the Kármán line on Wikipedia come from?

According to Wikipedia's article about the Kármán line: The Kármán line is the altitude where the speed necessary to aerodynamically support the airplane's full weight equals orbital velocity ( ...
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2answers
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Can it be calculated that near the Kármán line the lifting force equals the centrifugal force?

According to Wikipedia about the Kármán line: In the final chapter of his autobiography Kármán adresses the issue of the edge of outer space: ...or 24 miles up. At this altitude and speed, ...
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2answers
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Is the definition of the Kármán line from Wikipedia right? [closed]

Edit: this question is about making clear that the Wikipedia's article about the Kármán line is an interpretation, not the definition ! Why not consider the Kármán line as a curved boundary that ...
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Does a credible Kármán plane reach escape velocity within 1 minute or does it follow the curvature of the Earth? [duplicate]

Edit: This question is no duplicate because here the dropping of the atmospheric density together with the horizontal line, play an important role. Furthermore none of the answers and question ...