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Questions tagged [thrust]

Force produced by pushing against a reaction mass in space à la Newton's third law: "For every action there is an equal and opposite reaction." The thrust of a rocket engine is the forward force produced by expelling the exhaust mass (reaction mass) in the backwards direction.

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What are the various ways that rockets measure the instantaneous thrust of each engine?

@DavidHammen's answer to Engine failure: how to detect? mentions thruster sensors. This intrigued me and so I thought I'd ask about how this is done. Thrust is a critical parameter to know in real ...
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Relationship between part dimensions and performance of ion electrospray thruster

I got the relationship between power, thrust and specific impulse for an ion electrospray thruster as follows: $$P/T= 1/2 \times g_o \times I_{\mathrm{sp}}$$ Where: $P$ = power required (in Watts), $...
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Why is a 1.5:1 TWR desirable for a reusable launcher?

According to a Teslerati article linked from another QA: The most critical component for the booster, according to Musk, is that there is “a lot of force pushing up.” He states that to launch ...
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Mathematical reasoning behind pe=pa leading to maximum thrust

I've been looking at both the thrust and thrust coefficient equations (below) and I understand that they will be optimum in a vacuum when $P_a=0$. But, I see in textbooks that $p_e=p_a$ corresponds to ...
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Deriving the thrust of a rocket

I understand the the thrust of a rocket is given by $$F_x = M_e V_e - M_i V_i + (P_e - P_i) A_e$$ However when I try to derive it myself using Reynold's transport theorem I get the following: ...
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What does a high Hall Effect Parameter mean in MPD thrusters?

MagnetoPlasmaDynamic Thrusters are plasma thrusters in which the acceleration of the fluid (plasma) is carried in a electromagnetic way. The electric field and the lorentz force are the primary causes ...
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Computing Flight Characteristics for Different Propellant Grain Geometries?

Consider the following image: I am interested in mathematically accounting for some of these different geometries but have had little success so far in finding how this can be done. The first thought ...
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How fast can a rocket with constant thrust but changing mass travel a linear distance with limited delta V?

Background I am developing a game / simulation that has spacecraft with advanced albeit at least not physically impossible drives travelling in the solar system. As operation time should be far more ...
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What is the maximum thrust of the Starlink satellites?

As in the title, what is the maximum thrust (in N) that the satellites of the Starlink constellation can achieve? I read that they use Hall-effect thrusters, but I couldn't find a specification of the ...
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Thruster firing time for station keeping

I am simulating the example of LEO station keeping in GMAT with a delta-v thrusters of 2.5m / s, my question is how can I determine the time in which the thrusters act to raise the height of the orbit ...
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How strong is the Starship bottom bulkhead?

I am wondering how much of a role does the pressurization of the propelant tanks play in making them withstand the engine thrust. What I am getting at is how much would the pressure offset or balance ...
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Propulsion thrust vs high winds?

While I do understand that high wind speed is a risk for space launches (and all air flights), still, is it a physical constraint or a computational problem given we are not dealing with a hurricane/...
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Matching reference thrust to engine given certain parameters

I am running a simulation where a reference thrust value is meant to be matched by a liquid engine which I know the following information about: $"F_{vac}=100000"$ N, $I_{sp}=364$ sec, $D_e=1.01$ m, $...
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How to propagate the trajectory in GMAT with a custom thrust profile

So basically I was trying to design a low thrust maneuver to increase the apogee of the spacecraft. I solved it separately and got some thrust profile (thrust and it's direction as a function of time)....
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Sources for values for realistic thrust calculation exercise?

I want to use this simplified equation to calculate the thrust of multiple different real engines: $$F = \dot{m} V_e + (p_e - p_0) A_e$$ Source: https://www.grc.nasa.gov/www/k-12/airplane/rockth....
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Are there any other examples of right-angle exhaust diverters in spacecraft?

The Scott Manley video The Only Pilot to Shoot Down A Spacecraft - A Space Ace talks about the ASM-135 ASAT and its successful test launched from an F-15. He shows images from the page The F-15 ASAT ...
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Can effective thrust in the more dense layers of the atmosphere be considered constant (as approximation)?

I am reading some course material about the 'Thrust load ratio'. It states the following: The thrust load ratio is: $Psi = {T \over Mg}$ $T$ being the effective thrust, equal to the actual (constant) ...
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What was the maximum thrust the RS-25 was capable of producing?

The Rocketdyne RS-25, a large hydrolox engine best-known in its role as the main engines (SSMEs) of the space shuttle orbiter, was originally certified to a thrust level of 1.67 meganewtons (mN) at ...
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How do you calculate total Thrust and Specific Impulse for a rocket stage?

Given the stage has the following configuration: Thrust 741.4 kN (Main) 47.1 kN (Vernier) Specific impulse 297.999 s (Main) 288.999 s (Vernier) How ...
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Is this equation for NEP thrust correct?

I have bolded the part that I am most interested in checking, because I am not sure if the formula is valid. I have been using Excel to find the thrust, power, etc for a NEP mission. I have been ...
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Linear Control Lock?

Assume a spacecraft with a less-than-perfect maneuvering thruster configuration such that in a particular attitude while attempting to dock, the thrusters will not allow translation along a particular ...
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How should mass specific impulse calculated for relativistic exhaust?

This answer says: Optimising for Isp only is problematic, as it's simply: $$I_{sp} = \frac{v_e}{g}$$ Which is the same as optimising for exhaust velocity. With no constraints on thrust, particle ...
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Ion Lifter Thrust Calculation Problem

I've recently started building an ion lifter. I tried calculating the thrust the lifter produces but I came to a value that is way to high for such a small lifter. I'm using a 40kV at 1800mA AC ...
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VASIMR thruster at scale

I am working on making one, the truth is that the principles are not so difficult, but does anyone have any plans? or reference "with numbers"? because the truth is that it is quite difficult to scale ...
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