Questions tagged [rockets]
Questions regarding the boosters or thrusters used to propel man-made objects. For rockets firing opposite the primaries, see [retrorockets]. See wiki for other related tags.
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Can liquid mercury be used as a reusable rocket fuel? [closed]
If liquid Mercury is changed into solid Mercury thus generating energy and specific impulse why can I not then re-use the solid Mercury as a fuel?
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Disposing of Obsolete Satellites by Propelling to the Sun
I'm not scientifically adept, so bear with me. Would it be feasible to retain enough fuel on new satellites/space stations, etc., that we could dispose of them when obsolete by sending them to the ...
Jim Elmore
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Nozzle contour estimation (Merlin 1D Vacuum)
I would like to run a fluid simulation of the diverging section of a Merlin 1D Vacuum engine. While most relevant parameters (such as expansion ratio, flow rate, and nozzle area) are readily available,...
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Are rockets deliberately throttled back towards the end of the burn to spare crew and airframe g-forces?
Throughout its burn, a rocket gets lighter as propellant is consumed. As a result, acceleration (and g-force) increase. In the shuttle, the SSMEs were throttled back towards the end of the burn ...
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Are smaller rockets easier to land? [closed]
Is it easier to land a smaller rocket compared to bigger rockets?? Since they are lighter
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Single shaft turbopump vs two turbopumps
What are the pros and cons of using same turbopump for fuel and oxidizer and using 2 different pumps for both?
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Does an overexpanded nozzle behave like a suction cup?
It is generally said that, to obtain optimal specific impulse, a nozzle should be just the right size that the exhaust pressure is equal to the ambient pressure. Quoting this answer, a relevant ...
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Methane vs propane as rocket fuel [duplicate]
How would propane compare with methane as rocket fuel?
Propane can also be stored as liquid under pressure.
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Gas generator exhaust for roll control
Can the exhaust from the turbopump of a rocket engine be used for roll control if a rocket only has 1 engine?
Did the falcon 1 rocket control roll this way?
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Dual expander bleed cycle
Would dual expander bleed cycle be a good idea?
The lox will pass through the nozzle and drive the lox pump
And the fuel will also pass through the nozzle to drive the fuel pump
Both will be expander ...
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What are the major tradeoffs for a launch vehicle having either one 400 kN engine or eight 50 kN engines?
Given the problem of choosing to build and launch a small rocket to put a smallsat into orbit with either of these two configurations, what are the major tradeoffs between them?
For specific issues ...
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What was the exhaust pressure of the Saturn V? [duplicate]
I am trying to write some code to simulate rocket launches, and I am doing a proof of concept using the Apollo 11 as a model, to fill my values. When calculating thrust I am using the equation:
F=m⋅Ve+...
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How to calculate the tank boost system for the displacement feed system?
There is a liquid rocket engine running on two components: highly concentrated hydrogen peroxide and kerosene, fuel vapor is ...
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How can I determine characteristic length (L*) of a rocket engine combustion chamber if there is little to no data collected on a similar engine? [closed]
I am designing a liquid bi-propellant rocket engine using Nitrous Oxide and Isopropyl Alcohol. I have all the necessary parameters for nozzle design and am at the stage of determining the combustion ...
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What is the significance of a heat flux value of 1135 W/m^2 when jettisoning the payload fairing? [duplicate]
I have seen that many rockets jettison their payload fairing at an altitude where the aerothermal heatflux is leass than or equal to 1135 W/m^2. What is the reason behind considering this particular ...
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How do you approximately calculate the center of pressure during flight? [duplicate]
I'm working on a simulator for landing the falcon 9 booster rocket. I'm aiming to incorporate aspects like the effects of restorative torque. However, I've been trying to figure out how to determine ...
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Rough values for the staytime or characteristic length of the combustion chamber of an oxygen/methanol rocket engine?
I'd like to have some idea of the staytime or characteristic length of the combustion chamber of an oxygen/methanol rocket engine.
Are there sources for this, or a way to estimate it?
I've tried, but ...
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Why was Booster 9's 29 engine static fire ended 2.36 seconds early? [duplicate]
Suggested by Darth Pseudonym in answer to my other similar question. Recently (August 7), Booster 9 conducted a static fire test where it shutdown after only 2.74 of the planned 5 seconds of burn ...
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Why were 4 engines shutdown prematurely during Booster 9's static fire?
Recently (August 7), Booster 9 conducted a static fire test where it only ignited 29 of 33 engines. This is the big static fire, there not another one. I have found that they were shutdown prematurely ...
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What is missing in the conversion of specific impulse from units of seconds to thrust/mass flow rate? [duplicate]
I was trying to get the Specific Impulse of the Saturn V engines, hoping for a value in N/kg/s, as I need to know the mass consumption rate per thrust value. Any and all sources give me the value in ...
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Horizontal transportation of space rockets
Inspired by this picture from Does this Soyuz vehicle burn coal or oil? What is its official name?
and related to
What are the advantages and disadvantages of assembling a launch vehicle ...
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What is the cheapest/simplest way to deliver a camera to the moon? [closed]
The primary objective is this: to deliver a camera to the moon that live streams to Earth throughout the journey AND once it arrives on the moon.
A bonus is if it can then move around on the Moon.
An ...
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Is there a rocket that is publicly in the process of being certified to carry nuclear payloads to space?
As it currently stands in the US, only 1 rocket has the proper certification to carry a nuclear payload to space, and that is Atlas 5. (At least, this was my last knowledge). Atlas is nearing end of ...
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Contraction Ratio Impact on Performance for Liquid Rocket Engine
How does one go about calculating the necessary contraction ratio (combustion chamber/nozzle throat cross sectional areas) of an engine with these parameters known...
thrust
nozzle throat area
mass ...
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How to find the correct size and angle for a conical nozzle on a rocket engine? [closed]
So I need to know the equations for finding the size and angle for a conical nozzle. I am making a rocket engine and I decided the conical nozzle would be the easiest to build. The rocket is going to ...
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Rocket Engine Failure Rate
I am a reciprocating engine machinist and understand that rocket engines are much much more complex. But I am curious why they have such a high failure rate. Even modern rockets are designed to ...
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Is StarShip/Booster stack inherently unstable after Booster burns most of its fuel?
Few will ever forget the flight of Starship 24/Booster 7.
Perhaps the first moon rocket to perform aerobatics and hold itself together before finally self destructing. But would it be aerodynamicly ...
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Why wasn't SpaceX heavy rocket tested thoroughly on ground before being sent to space?
I do not know how much testing SpaceX did before launching their heavy rocket but it to blow up 3 mins later and call is a success seems a bit misleading. I understand they gathered data but to what ...
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Is the failure to separate Starship from the Super Heavy booster a "dumb failure" and does it tell something about the project reliability? [duplicate]
Sorry for the possibly dumb question, but I don't know much about rocket technology.
As I gather, the main problem in the recently failed Elon Musk's Starship launch was that the Starship "...
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Rocket Turbopump Energy Balance
The exhaust velocity of a rocket is given by:
$v_e = \sqrt{\frac{2k}{k-1} \cdot R \cdot T_c \cdot (1-(P_e/P_c))^{\frac{k-1}{k}}}$
The velocity tends to a finite asymptote as $P_c$ increases. Therefore,...
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Do rocket exhausts produce an electromagnetic signature to allow remote sensing of said rocket?
Rocket exhaust contains ions, the composition of which varies depending on temperature and fuel. https://arc.aiaa.org/doi/10.2514/3.27825 and https://www.eucass.eu/doi/EUCASS2017-434.pdf
Figure 12 : ...
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Why Aren't they Building Cosmodromes on Mountains? [duplicate]
Why Aren't they Building Cosmodromes on Mountains? Constructing a road leading 10000 feet or more up-hill should potentially save a lot of fuel.
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Where and how many RCS thrusters are installed on Starship?
Starship from SpaceX will soon launch. During the 10 km test it used RCS thrusters to flip itself in the right position. On the website it mentions how important it is to use air friction to slow down ...
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How close was the ISS to running out of supplies after the failure of CRS-7?
2014-2015 probably was a scary time to be aboard the ISS, though not for the usual reasons. They were worried about supplies running low, at least somewhat. There was quite the string of bad luck.
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Are Falcon Heavy fairings reused?
I heard a lot about SpaceX reusing the fairings from the Falcon 9. Do they/ are they planning to do the same for Falcon Heavy?
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Why did the maiden flight of H3 fail?
Recently, JAXA (Japan Aerospace Exploration Agency) finally launched the ALOS-3 (Advanced Land Observing Satellite-3) after more than 2 years of delay. On then all seemed to be going well on the first ...
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Could a “solar gravitational synchrotron ” use solar thermal rockets to "powerslide" spacecraft out of the solar system?
Could a “solar gravitational synchrotron ” use solar thermal steam rockets to launch spacecraft out of the solar system?
Solar thermal steam rockets https://en.wikipedia.org/wiki/Steam_rocket have ...
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What happens if the range control fails?
Your rocket was launching. Something went wrong. It is outside of the safety corridor. The range control attempts to terminate the flight, but the Flight Termination System (FTS) fails. Now what ...
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Do full flow rocket engines still use injectors? If so, how? How exactly are the oxidizer and fuel sent into the combustion chamber?
I'm learning about rocket engines and full flow engines, and I'm a little confused about what goes on in the combustion chamber. It was my understanding that injectors were pretty much necessary to ...
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How can you make a rocket quieter?
Usually during a rocket launch on Earth, lots of water is poured to decrease the sound (deluge discussed in Wikipedia's Sound suppression system) and some other methods are used.
What I am looking for ...
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After SLS, what is the next rocket building project for NASA?
I know that ESA is working on a new reusable first stage booster.
Does NASA have similar plans?
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What caused the H3 rocket to squeal so loudly after its launch abort?
Immediately after the H3 rocket's first launch attempt was aborted, a loud squealing noise could be heard on the live stream. What was this?
The only thing I could find about it when searching the ...
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Why did only 31 engines ignite during Starship's static fire?
What could be the reasons behind only 31 engines of the planned 33 engines igniting during Starship's recent static fire, given that the spacecraft is designed to have 33 engines and how could this ...
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What's inside the white round elevated container next to the Falcon 9 starting base? [duplicate]
On images of the Falcon 9 start you see a kind of round elevated container (on the left hand side of the picture).
What does it contain and why is it elevated?
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Air-Augmentation on a VTO&L super heavy lift
I'm working on a basic design for an Air-Augmented first stage, which boosts the second, expendable, stage from a near-orbit, to allow for deorbit of the second stage.
Essentially it's an SSTO that ...
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Does the payload capacity of an interplanetary launch rocket increase with decreasing fuel mass or with increasing escape velocity?
Does the payload capacity of an interplanetary launch rocket increase with decreasing fuel mass or with increasing escape velocity? I was thinking that the escape velocity has nothing to do with it ...
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Do launching states need to seek permission for jettisoning rocket stages over waters not counted as international waters?
Rocket debris such as boosters and payload fairings are often discarded over bodies of water. If the debris is set to be discarded over waters outside the launching state's territory, do they need to ...
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What space applications could benefit from batteries with much higher power densities than the common Li-ion type?
This Australian company claims the development of the Graphene Aluminium-Ion Battery that is up to 70 times faster in charging and has up to 3 times more battery life than current Lithium-Ion ...
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How were inflatable fuel tanks for NASA supposed to work?
When the Washington State University researchers looked through the literature, they came across research that described the development of a bellows that took advantage of origami, the Japanese art ...
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What is a bimodal or multimodal space rocket engine? Especially a nuclear-powered one?
I can't seem to find a specific answer anywhere....
I wonder if it means using the radioactive fuel to power the electronic equipment, purely via natural decay, but also using the same fuel to power a ...
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