# Questions tagged [rocket]

For questions about rockets as they pertain to aviation. Questions about rockets in the context of space are off topic here.

39 questions
Filter by
Sorted by
Tagged with
11 votes
2 answers
4k views

### Propulsion method for MANPADS missiles

What propulsion method is used for small short range handheld missile systems? Liquid fuel rocket engines are the gold standard but I suspect require too many components for the size requirements. Is ...
• 353
1 vote
2 answers
175 views

### What was the last rocket-plane?

Starting with the legendary Heinkel He 176, these unorthodox planes broke the sound barrier and other records. My question is: What was the last rocket plane to be produced?
• 421
0 votes
1 answer
139 views

### How to determine the length of the CD nozzle?

I am designing a convergent nozzle as well as a CD(Converging-Diverging) nozzle. How do I find out the length of those nozzles? If the throat of the CD nozzle has 0 length then what should be the the ...
1 vote
0 answers
68 views

### Why pressure and temperature decreases along the length of a convergent nozzle?

I know that the pressure and temperature follows stagnation relations of pressure and temperature as well as area mach relation inside a convergent nozzle along the length. And according to that ...
3 votes
3 answers
3k views

### Why does a rocket engine increase power with speed if the burn rate is constant?

A rocket produces constant thrust with speed, and that means increasing power with speed. Where does this increase in power come from if the fuel burn rate is constant? How can we explain this in the ...
• 1,150
2 votes
1 answer
200 views

### What is the maximum Mach number that can be achieved at the exit of CD nozzle?

I understand that you can get Mach 1 at the throat of a convergent-divergent (CD) nozzle and after that you can have two roots, one is for subsonic and other is for supersonic. Considering the ...
0 votes
0 answers
88 views

### What's the altitude and velocity record for a ground-launched rocket plane?

Most rocket planes are air-launched but there were/are a few ground-launched rocket planes as well, such as the Messerschmitt Komet. What's the altitude and airspeed record for a ground-launched ...
• 201
1 vote
1 answer
246 views

### Why aren't air turborockets used in military fighters?

Why aren't air turborocket engines used in jet fighters? Few Third World countries have the capability to manufacture high quality turbine blades. Thus, why not use air turborocket engines for the ...
14 votes
2 answers
3k views

### Why are the grid fins on Starship pointy and sharp?

The grid fins on Starship are serrated, why? Does it help in transonic maneuvers? Source: Starbase Factory Tour with Elon Musk [Part 1], YouTube, at 30:28
• 141
-4 votes
2 answers
133 views

### how missiles or rockets change direction if gyroscopes prevent any direction change? they would bring back the rocket to same path? [closed]

Gyroscopes are instrument which prevent any wobbling or direction change but then how rockets and missiles change their directions. To change direction we have to give signals to gyro or to the servo(...
3 votes
1 answer
225 views

### Does/did Russia or the Soviet Union ever fly rocket planes?

Did Russia or the Soviet Union ever have their own experimental or military rocket planes (other than the Buran), or did their military merely use jets and other non-rocket aircraft? America flew ...
• 175
0 votes
0 answers
76 views

### What should the inlet to throat area ratio be for a CD rocket nozzle on an aircraft flying at Mach 10?

I am analysing a rocket CD (convergent-divergent) nozzle at a altitude of 15,000m. I am stuck on how to calculate the areas so that at the throat of the nozzle Mach number equals to one. The ...
-3 votes
1 answer
80 views

### When was the first manned rocket-propelled plane launched? [closed]

I believe that it's an issue of some interest in the history of aviation.
• 10.4k
0 votes
0 answers
183 views

### What's the highest altitude ever achieved by a (rocket-?)plane for level flight?

As probably most of us know, the SR-71 Blackbird holds the altitude record for leveled flight for (manned) jet planes (and ground-launched planes) at 90,000 ft MSL. However, the very altitude record ...
• 17
2 votes
1 answer
253 views

### Did every X-15 pilot become weightless when flying into the upper strato- and mesosphere?

The North American X-15 was aimed at breaking airspeed and altitude records. The flights that sought to achieve new airspeed records (Mach 5+) were rather leveled but the flights into the upper ...
0 votes
1 answer
78 views

### What valve would be the best for a model rocket with a hybrid engine? [closed]

I am planning on building a model rocket with a hybrid engine. I am trying to find the best valve that could be used for the MOV, main oxygen valve. I plan to use gaseous oxygen and would like the ...
-1 votes
2 answers
357 views

### How calculate water rocket thrust? [closed]

both nozzle is 2cm diameter one "rocket" has air pump which hold constant 5 bar second "rocket" it has water inside and also air pump which hold cosntant 5 bar,(water column is ...
21 votes
1 answer
5k views

### What's wrong in this engine test cell picture from the book 'Ignition'?

This is picture taken from 'Ignition' book by John D Clarke. I am bewildered after seeing picture that I can't find wrong in this picture. I guess this is related to the structure of mach ...
• 1,475
1 vote
2 answers
585 views

### Does an engine that combines an air-breathing rocket and non-air-breathing rocket exist?

Does a rocket engine that combines air-breathing and non-air-breathing modes exist? The advantage would be it would have to carry a smaller tank and less oxygen, leaving more room for payload on a ...
• 8,379
3 votes
2 answers
353 views

### What is wrong with my understanding about total pressure for a rocket nozzle?

I’m using the ideal rocket equations and isentropic flow but cannot determine what is wrong in my understanding about total pressure. Can anyone explain where I am wrong using the following example? ...
4 votes
1 answer
366 views

### Would "Mad" Mike Hughes' steam-powered rocket have been certified airworthy by the FAA?

Daredevil 'Mad' Mike Hughes died after his homemade rocket crashed on 22 February 2020. The cause appears to be the premature deployment of the parachute used for a safe return. He was hoping to reach ...
• 9,451
5 votes
2 answers
533 views

### Credible Sport Project: Is it possible to revive the idea with modern avionics?

Synopsis: On a secret mission to rescue 52 hostages in Iran, Operation Credible Sport was created. The project consisted of a modified Lockheed C-130 Hercules and developed so that it would be able to ...
• 222
-2 votes
1 answer
268 views

### Rocket Thrust vs Air breathing jet engine why is a rocket better [duplicate]

What are design dynamics that give the rocket engine higher thrust than an air breathing jet engine of similar size in comparison to a turbo jet engine, turbo fan engine, high by pass turbo fan engine,...
• 8,379
0 votes
1 answer
65 views

### Are solid fuel rocket engines designed differently and how? [closed]

How do solid fuel (Hydrazine, UDMH) and oxidizer (N2O4) differ in design from cryogenic rocket engines such as LH2 and LOX? Are there differences related to temperature, material design, turbopumps, ...
2 votes
1 answer
174 views

### Why Apollo 11 was launched in summer? (Performance question) [closed]

The question could seems stupid, but i think that best moment to launch a rocket is when temperature is lowest in order to achieve the best performance in a reaction engine. I do not know if there is ...
5 votes
2 answers
641 views

### Could the Space Shuttle take off like an airplane?

This question got me thinking, would the Space Shuttle have been able to use its main engines to roll up to speed and take off horizontally like an airplane? (I'm not asking about getting to space, ...
• 357
2 votes
2 answers
451 views

### Why is the center of pressure of a rocket at its centroid?

From thin airfoil theory, at subsonic speeds, the center of pressure of any uncambered airfoil is at quarter chord. For sounding rockets, however, the center of pressure is generally assumed to be ...
• 10.8k
6 votes
2 answers
846 views

### At what altitude does a wing become useless? [duplicate]

At what speed or altitude does an aircraft become more efficient as a rocket then a plane using thrust vectoring instead of the wings to steer? At what altitude did the flight control surfaces of the ...
• 1
2 votes
1 answer
166 views

### Are the nearby airplanes cleared of the sky when launching Falcon Heavy? [duplicate]

I was checking Flightradar24 when launch occurred and didn't see any difference. Also, 3 boosters landed back successfully. I assume the sky has to be clear of airplanes to avoid any potential ...
2 votes
1 answer
522 views

### Why are hexa airfoils used on rockets despite having more drag that diamond airfoils? [closed]

I was doing a study on airfoils shape for a rocket. I tested the diamond and the hexagonal airfoil with Missile DatCom, RasAero and the Shock Expansion theory and from my results it seems like the ...
• 121
-5 votes
1 answer
263 views

### How can ballistic techniques be used for passenger transport? [closed]

Going anywhere on the globe in half an hour, instead of up to 29 hours, is of course very appealing. How can ballistic technology be used for the purpose? The acceleration is supposed to not exceed ...
0 votes
0 answers
53 views

### Are throttleable rocket engines the less efficient the lower the power setting?

Are throttleable rocket engines less efficient the lower the power setting? Logically that would lead to lower pressures in combustion chamber and so lower thermodynamic efficiency. Or is it remedied ...
• 2,292
4 votes
5 answers
386 views

### Can air to air refueling can be done in the rocket engines as done in the Aircraft jet engines?

Can air to air refuelling can be done with rocket engines as is done with conventional aircraft jet engines? If no then what are the possible hazards or conditions preventing this?
• 41
18 votes
5 answers
4k views

### Why was a Lockheed L-1011 chosen by Orbital ATK for its Pegasus launches?

Not sure whether this fits better here in Aviation, or would be better suited for Space, but since the question is about a terrestrial aircraft, I'll start it out here. The topic of my question is ...
• 1,555
3 votes
1 answer
213 views

### Are there any locations where I could launch a rockoon with minimal red tape?

I'm currently working on a research project on hypersonic control surfaces, and as part of it, I'd like to launch a rocket-assisted lifting body from a high-altitude balloon. Are there any locations ...
0 votes
3 answers
1k views

### What is the theoretical maximum speed of a rocket-powered aircraft in the atmosphere?

I read that the scram jet has a theoretical maximum speed of Mach 24. What is the theoretical maximum speed of a rocket-powered aircraft designed to operate in the atmosphere?
• 8,379
4 votes
1 answer
2k views

### Would it be possible to build a "rocket" using a series of ducted fans?

I'm wondering if it would be possible to build ducted fan "rocket". My idea is to construct the duct from 18650 batteries, and to have a series of contra rotating fans along its length. I can 3d ...
15 votes
2 answers
5k views

### What is this plane and what are the rockets on the back used for?

While reading this question I saw an image of a plane marked as a US Marines plane of some sort with thrusters or rockets of some sort attached to the sides just past the CG. What plane is this and ...
• 2,263
16 votes
7 answers
11k views

### How do rocket engines produce more thrust than aircraft jet engines?

I can't find the reason why rockets are able to produce so much thrust when compared to turbojets. I do know that the rockets carry their own own supply of oxygen since there is no oxygen in space or ...