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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Could a helicopter fly on Mars?
Helicopter drones are awesome fun down here on Earth, but what if... we took one to Mars? This sounds like a good question for Randall Munroe. But I read about a proposal to send a helicopter drone (...
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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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What are the pros and cons of Aerospike nosecones?
Some rockets, mainly (only?) ICBMs have Aerospike nosecones
Why are they preferred in lieu of traditional nose cones?
Illustrations:
An aerospike nosecone on a trident ICBM
Video including the ...
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Golfball Dimples on spaceships (and planes)?
The best of us get stupid ideas which run through our heads day in and day out without finding an answer. That's why I came here:
A golf ball has dimples to reduce drag and increase flight distance (...
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Why is Falcon 9's fairing so big?
The Falcon 9 fairing costs millions of dollars. It is 5.2 meters wide while the rocket itself is only 3.7 meters wide. There is no aerodynamic reason that the fairing has to be so big, since Dragon ...
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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 ...
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How would a long pole be transported to space?
Can a long pole or a set of poles be strapped to the out side of a rocket (like a bottle rocket)or on the nose as an external payload without interfering with the aerodynamics of the rocket? How would ...
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Why are the bottom of most stages flat?
When looking for rocket engine images, I noticed that the bottom of the stages are almost flat. That does not seem aerodynamic. I understand this is not a primary concern for upper stages (mainly ...
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Can a reentry be done slowly?
The usual approach to reentry is fast and hot. There's a lot of energy to be lost, and doing it quickly has some advantages: You can dump energy into hypersonic air, and then leave that heat behind ...
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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 ...
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Is this egg-shaped nose cone a good, aerodynamic design?
So Jeff Bezos has recently travelled to space aboard an Amazon-funded rocket, which has an unusual, egg-shaped nose.
However, just about every other rocket I've seen has more of a cone-shaped nose, ...
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How high could Ingenuity fly?
On its 59th flight, Ingenuity achieved a height of 20 meters - twice as high as its maximum height during the original 5 flights that it was designed and expected to last for. In the scheduled 61st ...
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Soyuz Steering during Re-Entry
In this youtube video, it talks about steering Soyuz by changing lift. Why does roll rotation help in changing lift and also helping in cross range steering?
I am looking for an answer from ...
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Is Starship aerodynamically stable when travelling nose first?
Is Starship aerodynamically stable when traveling nose first, or does it require constant gimbaling from the main engines to keep it pointing nose first? Is this part of the explanation for why Space ...
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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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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 ...
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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 ...
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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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Testing flight characteristics before actual flight in model rockets?
I do a lot of scratch design/building of model rockets, but one of the things that I've struggled with is testing the models I come up with.
Some of them are purely intended to be static display ...
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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 ...
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What causes a rocket to be destroyed during launch other than leaking fuel?
There were some famous accidents where rockets launched and just went up into flames. Many had something to do with leaking fuel in some sort.
I want to focus on aerodynamic stress however, like when ...
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Why not jettison the nose-cone from Falcon Heavy side boosters for better control authority?
With February 6th's launch of Falcon Heavy we saw the landing of both side boosters. During the past few weeks and again in the press conference today I've heard over and over about the increased ...
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Why making such a big deal with Max Q?
At each SpaceX launch, they always make some big deal of Max Q which most of the time comes at around 13Km and at a speed of 1700Km.h-1
But on the way back, stage 1 is at this same altitude of 13km at ...
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Would a dimpled heat shield reduce heat transfer during reentry?
Would a large ceramic golfball absorb less heat on reentry than a standard sphere?
From aerospaceweb.org:
The difference in the flowfields around a smooth sphere and a rough, or dimpled, sphere ...
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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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How well would a supersonic aircraft perform in the Martian atmosphere?
I started getting curious about this question during my Flight Test Engineering class. My professor was talking about a part of the International Standard Atmosphere that is a similar pressure to that ...
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How do we control a Reentering Capsule in the denser part of the atmosphere?
My question is: How do we control a Reentering Capsule in the denser part of the atmosphere? How does the aerodynamics of the Reentry vehicle workout?
In other words, how does a reentry module ...
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What is the most aerodynamic Satellite?
From what I understand at least in the lower orbits you want the least amount of drag possible.
My brain is telling me that a long pole or submarine shape satellite orientated to the direction of ...
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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 ...
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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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How does the dynamic pressure evolve during reentry?
During launcher ascent, dynamic pressure evolution is described in this answer for the Saturn V. I suppose this is similar for most launchers.
Given the protections designed for reentry, I suppose ...
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Why might Ingenuity be able to fly faster when it flies higher?
A 2022 March 15 NASA press release says:
A recent software change already on the rotorcraft frees Ingenuity from its previously programmed maximum altitude of 50 feet (15 meters). The altitude gains ...
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Could Space Shuttle's wings be diminished?
From Wikipedia
The crucial factor in the size and shape of the Shuttle orbiter was the requirement that it be able to accommodate the largest planned commercial and military satellites, and have ...
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How hot do the nose cones of fairings actually get on ascent?
I've been reading into aerodynamic heating of rockets, and it's seemingly a rather complicated topic. It's relatively easy to calculate the stagnation temperature at a given mach number, and that is ...
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Why would a significant non-zero angle of attack be an advantage during 1st stage burn?
From videos of both the SES-10 launch shown in @RussellBorogove's question, Cause of apparent plume deflection on SES-10?" and the Block 5 launch Bangabandhu Satellite-1 Mission at ...
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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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How heavy were Perseverance's balance masses?
Perseverance ejected two 70 kg "cruise balance masses" just before it became an airplane,
to move its center of mass off axis and increase its angle of attack from 0° to about 16° to make it ...
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Might Ingenuity tip over?
While Ingenuity patiently waits for its preflight checks to pass, how likely is it that a wind gust could tip it over? How strong and how rare a gust? Those rotors have plenty of area. (Surely NASA ...
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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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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 ...
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What was the actual Q-alpha limit for Saturn/Apollo launches, and what was the typical max Q-alpha?
Organic Marble's answer to a previous question about Apollo abort limits clarified that the figure of concern was the product of dynamic pressure (Q) and angle of attack (alpha), with the 100% level ...
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What is the terminal velocity of SpaceX Starship?
What is the terminal velocity of starship on earth and mars during descent?
Has SpaceX revealed or hinted the values of projected surface area and drag coefficient of the vehicle?
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Upper stage structural loads on ascent?
In another question, this came up:
For example, if a Falcon 9 launches 20 tons of fuel to dock in LEO, how can the same upper stage be used to launch 40 tons of fuel to the same orbit? Doesn't it ...
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What are these circular structures around the rocket?
Youtube video of the Iridium-6/GRACE-FO NASA Launch (Falcon 9 SES-12).
Edit 31 May: Too bad they have changed the content of the video (and still call it 'live'), so that you can no longer see the ...
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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 ...
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How to calculate the lowest possible altitude a satellite can orbit at due to aerodynamic heating if provided with a sufficient propulsion system?
If a satellite is equipped with a propulsion system which is enough for compensating the local drag and maintaining the orbit, then aerodynamic heating would be the limiting factor for attaining the ...
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Do larger less dense objects heat less while entering the atmophere?
When a space craft enters the atmosphere, it gets hot and heat shielding is needed. Do objects with more surface area and less density heat up less then heavier, smaller objects? Could an object with ...
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Is there a mathematical formula to calculate drag force without empirical testing?
Typically people put the interested rocket prototype in a wind tunnel to find out the drag force and use the drag force equation to calculate the drag coefficient of the rocket model. I am wondering ...
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Aerodynamically - can a rocket be over 30 meters in diameter?
The past and current designs of rocket launchers have diameters up to 8-10 meters (Saturn-5, N-1, SLS, BFR), up to 13-14 meters for max cross-section dimension for Space Shuttle and Energia-Buran (...
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Could we achieve aerodynamic and aerostatic lift on the Moon if it had an atmosphere of xenon?
The Moon is not capable of keeping an Earth like atmosphere, nor is it practical to keep satellites in lunar orbit. Which means all transportation and communication would need to be ground based. No ...
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