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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Why does igniting propellant provide more thrust?

My confusion stems from the relationship between thrust and the pressure distribution in the thrust chamber. For a given chamber pressure the wall static pressure along the nozzle is a function of ...
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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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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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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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Do fins with slightly different masses but the same surface area affect the stability of a rocket?

Each of four fins of a rocket are of slightly different masses like( 0.204, 0.2, 0.199 and 0.19 kg). If they have the same surface area, will that severely affect the stability (spin) during flight? I ...
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Lift and Drag of a Model Rocket

Talking about aerodynamic forces in a model rocket, I believe that Lift and Drag are the components of a net force which acts on the Center of pressure. Knowing this, could I affirm that the net ...
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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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4 votes
3 answers
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Merging Shuttle and External Tank to reduce reentry heating

The Space Shuttle needed a high-performance heat shield that caused much grief over it's operational life. Having a large surface area on a reentering vehicle reduces temperatures by causing the ...
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17 votes
4 answers
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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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Up to what Mach/Reynolds numbers will Ingenuity be tested?

From an aerodynamics perspective, velocity alone is insufficient to describe the flow regime experienced during flight. For the Ingenuity helicopter, what specific Mach numbers and Reynolds numbers ...
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Why the max dynamic pressure might not happen at maximum drag instant?

I understand that is that when a rocket accelerates the drag force grows dramatically since the force is related to velocity squared. But, at the same time, the density is decreasing, so the force is ...
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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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2 votes
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How do grid fins actually work? Which aerodynamic mechanism(s) produce the torque on the spacecraft?

I’m trying to model the steering force that grid fins exert on a falcon 9. I know these things are not just grid-shaped fins but actually grids of fins. And each of those fins will experience drag and ...
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9 votes
1 answer
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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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5 votes
2 answers
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Using lasers to reach the Karman line

I've just seen this Anton Petrov video: New Type of Laser Levitation Could Help Us Explore the Mesosphere. It's about this new form of levitation that uses lasers to heat up the air underneath a craft,...
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During space shuttle reentry, why was the sign of GALR based on mach number rather than directly on alpha?

(My apologies if this should go in Aviation.SE instead - I'm not quite certain where questions regarding the behaviour of the shuttle's flight controls during reentry should go.) For flight in ...
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Why are fins located on stage 2 of Iranian rocket Zol Janah?

Iranian launch vehicle Zol-Janah has fin like structure on the second stage of the vehicle. Does aerodynamic characteristics of vehicle improve with fins near the centre of mass? Also will the fins ...
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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 ...
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How large can heatshield holes be?

The tiles on the underside of the STS Orbiter had gaps between them to allow for the frame underneath to shift slightly. However, if the gaps were too large fillers were used. What controls the ...
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3 votes
1 answer
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How did the Space Shuttle prevent flying up when reentering the atmosphere?

Always when reentering the atmosphere, the shuttle was pitched up, right? When gliding through the mesosphere, how was it that it didn't fly up again then? Was it due to a certain distribution of ...
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How to make a model rocket that doesn't spin?

I'm attempting to build a rocket with 8 fins (four on bottom and four smaller ones towards the top). The four fins near to the top will be attached to servo motors and programmed to stabilize or guide ...
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2 votes
2 answers
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Can the Space Shuttle land on Mars assuming there is a paved surface for landing?

Can the Space Shuttle land on Mars if it had a paved runway? Can the Space Shuttle use aerobraking and will its control surfaces provide attitude control? Can the parachute and braking systems stop ...
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What benefit do the aerodynamic stabilization "pods" on the PSLV-CA provide?

Whilst writing this answer about the PSLV, on this informative page about its Secondary Injection Thrust Vector Control system, this image (cropped) is displayed, showing that for the Core Alone ...
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7 votes
1 answer
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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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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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Changes in Orbital Parameters Due to Drag

Other than STK, are there any commercially software packages available to model changes in orbital parameters due to increases/decreases in satellite drag. I am trying to figure out if aerodynamic ...
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3 votes
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Seeking Book about Aerodynamic Design of the Space Shuttle

a few years ago I found a book written by an engineer working on the aerodynamics of the shuttle during design, ALT, and early STS. I have since forgotten the title and author's name. Does that ...
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1 vote
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What was the leeward surface temperature of the Apollo Command Module during reentry?

From the Apollo Experience Report: Thermal Protection System, there is a diagram that shows the surface temperatures of the Command Module at various points (image was obtained from this answer). It ...
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4 votes
1 answer
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Which deorbit trajectory minimizes reentry heating?

Atmospheric reentry, as I understand it, is a balancing act between minimizing delta-v needed and not burning up or breaking up in the atmosphere. The higher the velocity on reentry, the greater the ...
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6 votes
3 answers
2k views

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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2 votes
2 answers
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Is aerodynamic control in an exosphere possible, in case velocity is high enough?

Exospheres are different than the lower parts of atmospheres (if there are any): the molecules don't collide anymore and it doesn't behave like a gas. However, it still causes some tiny little drag on ...
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How to fit, into a cubesat, 29 trackable high drag subsatellites with well-defined aerodynamic profiles

Johnathan McDowell's recent tweet says: The @AerospaceCorp Aerocube-10a cubesat carries 29 small passive high-drag subsatellites used to probe the density of the upper atmosphere. 3 have been ejected ...
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3 votes
2 answers
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Number of segment in Wing leading Edges

Can anyone highlight the basis of having 22 NO’s of segment in wing leading edges of space shuttle.
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2 votes
1 answer
171 views

During their climb, when did/do the SpaceShipOne and Two pilots lose all or most of aerodynamic control over the spaceplane?

When, at what altitude and speed, did the pilots of SpaceShipOne and SpaceShipTwo lose all or most of aerodynamic control over their spaceplane when rising into space? The SS1 and SS2 conducted five ...
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9 votes
2 answers
1k views

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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2 votes
1 answer
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How much heat is reabsorbed by a high-speed object?

I have been playing around with an app to demonstrate high speed objects entering earth's atmosphere. I am using the drag equation to approximate how much kinetic energy gets converted into heat at ...
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-4 votes
1 answer
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Using side thrusters on a missile to create an angular acceleration

Assume a rocket is standing on the ground with mass = 1000 kg, and near the top of rocket we apply a force of 100 N for say 1 sec, now assume that this is sufficient to tip the rocket over/start ...
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7 votes
1 answer
228 views

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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2 votes
1 answer
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Shape of satellite launch vehicle

I was watching videos on YouTube, and I came across a fact that satellite launch vehicle has shape like a nose or you can ogive shape and I search on Google related to that, and I found that it ...
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Have studies / worked examples, including mass figures, been published for these reentry methods for reusable upper stages?

(Related: is there a general rule of thumb for thermal protection systems?) For a fully-reusable launch vehicle to be developed, we need a lightweight thermal protection system and method for (...
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2 votes
1 answer
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Looking for dataset of trajectory data consisting of latitude, longitude, altitude and time

I am working on a project in which I need to cluster trajectories of different type of flying objects like rocket, plane, missile, etc. For that I am looking for a database or data-set which contains ...
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3 votes
0 answers
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Disadvantage of interstage trusses on Soyuz launch vehicle?

Brian Tompsett gave a detailed explanation of the advantages of the trussing in his answer to the question Why do the Russians use these fence-like interstage fairings? The gap between Stage II and ...
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7 votes
2 answers
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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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1 vote
1 answer
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Calorically perfect gas calculations of re-entry vehicles

We know that pressure is least sensitive to high temperature gas effects. Thus, how much of calorically perfect gas calculations (for pressure alone) are used in space vehicle design? Historically, ...
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Why was the nose cone on the Space Shuttle's external tank pointy?

Inspired by comments under this answer to this question Just how pointy does a rocket's nosecone need to be? (see also Why are the nose cones of current spacecraft less pointy?) Why was the ...
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24 votes
2 answers
4k views

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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Is it useful to exploit turbojets or turbofans for rockets like that (for mid & heavy-lift ones)? [duplicate]

In fact, Atmo is very hostile for classical rockets. It makes them too sizable, heavy & inefficient as well. To shift this situation needs to get another propellant, but we have fallen short here. ...
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5 votes
3 answers
711 views

Would a standard gravity turn still be the most optimal path to orbit if Earth did not have an atmosphere?

If Earth had no atmosphere, then would a standard gravity turn still be the most optimal path to orbit? Why or why not?
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5 votes
4 answers
2k views

Just how pointy does a rocket's nosecone need to be?

There are some beautiful images of the Qu8k rocket launch on this web page and I show a few below. There's a video (below) and the PDF Qu8k Final By Derek Deville, November 27, 2011 The stainless ...
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Required speed for interplanetary aerodynamic effects [duplicate]

In the atmosphere, craft may use aerodynamic effects to their benefit. As you start getting higher in the atmosphere, the atmosphere becomes rarified, requiring you to model the atmosphere not as a ...
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