Questions tagged [aerodynamics]

the effect on a spacecraft of moving through atmosphere, how its density, pressure, temperature, flow velocity, and viscosity affect a craft, and how lift and drag can be used to modify that.

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14
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1answer
2k views

What are these tiny triangular fins on the Soyuz launcher?

What are the small triangular fins on the lowest part of the boosters of the Soyuz 2.1 rocket? What function do they have? I circled one of them in the upper image here. They are not visible in the ...
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2answers
629 views

Can a reusable electric powered blimp stage for launch possible?

Originally this question asked about using blimps and electricity in replacement of boosters. As written then it was no good and got down votes. I had a few question marks and each question really ...
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0answers
113 views

Max Q vs Prandtl-Meyer Fan

Does Max Q occur before or after the Prandtl–Meyer expansion fan? The shape, nature's way of avoiding a single shock wave (per Wikipedia) is visible on the Apollo launches for example. Apollo 11, ...
13
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1answer
887 views

Purpose of hemisphere under shuttle nose cone (Enterprise)

I noticed a small hemisphere protruding from the dorsal side of the Enterprise space shuttle's nose cone, forward of the front landing gear. I have no clue what its purpose is but am far from an ...
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1answer
3k views

Angle of attack, or displacement angle?

When I hear "angle of attack" or AoA, I think of an airplane. Usually, both the airfoil and the plane itself have a clearly defined 'top' and 'bottom'. In this case, the concept of angle of attack is ...
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 ...
13
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3answers
4k views

How long does Max-Q last?

When watching rocket launches, the commentary or status reports often mention that the vehicle is "passing through Max-Q" - how long does the "passing" take? Is the event instantaneous or is there ...
6
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1answer
287 views

Is the Dragon Mono-Stable?

Re-entry vehicles tend to be either mono-stable (eg soyuz) or bi-stable (apollo) which refers to the orientations in which they're aerodynamically stable. In at least one case, this has proved very ...
0
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1answer
406 views

SpaceX hovering rocket? [duplicate]

How does SpaceX get their rockets to stay vertical when hovering without tips over and eventually crashing into the ground? I don't mean the initial launch. I mean when its coming back down I feel ...
5
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1answer
559 views

Is Martian wind strong enough to produce aerodynamic forces on a spacecraft?

If a spacecraft is entering the Martian atmosphere (say Curiosity rover in a Sky Crane capsule), is the wind strong enough to actually produce forces on the spacecraft? (like you would see during an ...
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3answers
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Why doesn't the Falcon 9 booster use rigid air brakes during landing attempts?

SpaceX's attempts to land involve using the first stage engines to slow the booster down, and use grid fins to perform trajectory adjustments. Parachutes generally aren't rigid and can throw the ...
8
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1answer
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Why are the nose cones of current spacecraft less pointy?

You would think that with the quest for aerodynamic efficiency in current spacecraft that the nose-cones at the pointy end of the launch-vehicle would have a sharp taper, more so for craft that aren't ...
3
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1answer
179 views

Feathering Profile Change for Virgin/TSC/Spaceship Two

We know that the Spaceship One and Spaceship Two designs from Virgin Galactic/The Spaceship Company/Scaled Composites employ feathering for aerobraking and maneuverability. I can't seem to track down ...
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5answers
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Gliding into the atmosphere

The recent question about Cessna reentering from ISS got the answers that all imply a rapid drop. But from what I know, air drag is proportional: to square of airspeed to air density to attack ...
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4answers
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Reason for different "cone angles" of different space capsules?

Here is the Cargo Dragon: And here is the Orion: The "cone" that orion makes has a large opening angle - perhaps about 70 degrees. Meanwhile, the Dragon is almost cylindrical - the opening angle is ...
12
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2answers
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Why is Dragon the only spacecraft that is currently in use to not need a fairing for launch?

Dragon is the only spacecraft I know of currently in use that doesn't need a fairing for launch on top of a rocket. I know there are others in development or in testing like Dragon v2 and CST-100(not ...
18
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1answer
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What control engineering techniques are used for the landing maneuvers of Falcon 9-R?

Which are the main control theories behind the landing maneuvers of the Falcon 9? For the hovering part, as it approaches the landing surface, I guess the inverted pendulum control approaches would do ...
9
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2answers
9k views

Optimal speed per altitude for orbit launch

On Kerbin, rockets have an optimal speed depending on altitude for maximum fuel efficiency, as You can save fuel by being close to your terminal velocity during ascent. Lower velocity wastes delta-...

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