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.

113 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
10
votes
0answers
245 views

Were there any launch vehicles with so heavily pronounced Plume Induced Flow Separation (PIFS), other than Saturn V?

This answer describes a very interesting phenomenon of Plume Induced Flow Separation on Saturn V vehicle. (Apollo-6 S68-29737 photo, courtesy NASA) This is, basically, when "fire" from ...
7
votes
0answers
136 views

Silane as a rocket fuel

At about 6:55 into the video Why Moon Mining Will DEFINITELY Be A Thing it is stated that lunar silica (SiO2) could be turned into silane (SiH4), which is the silicon analogue of methane. It also ...
7
votes
0answers
164 views

What performance can be expected from chemical rockets under Venusian atmospheric conditions?

Is it feasible to use either solid or bipropellant liquid rocket engines to lift off from the surface of Venus? "Reference datum" air pressure on Venus is around 9.3 MPa; even on the top of, say, ...
7
votes
0answers
180 views

Why aren't injector pumps used in rockets?

Is there something that makes injectors unsuitable as oxidizer pumps? Seems to me that rockets would benefit significantly from a pump with no moving parts that runs off its own exhaust.
7
votes
0answers
506 views

What would be the range safety for vertically landing over land rockets?

sideFrom the Wikipedia article on range safety: Rockets are usually launched into a space above the launch range called the launch corridor. If rocket engines fail while the rocket flies inside ...
6
votes
0answers
177 views

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 ...
6
votes
0answers
83 views

SpaceX Dragon Shape: Power Series, Ellipsoid, or Haack/Von Karman?

The SpaceX Dragon module has a round apex typical of power series, ellipsoid, and Haack/Von Karman shapes. I'm wondering which of these SpaceX actually used. References would be appreciated. My guess ...
6
votes
0answers
157 views

What are these wires on the side of the SLS core stage?

I was reading about the SLS core being moved for testing and I noticed something odd on the core stage. There's several lines on the stage, which in closer inspection are wires. It's not obvious what ...
6
votes
0answers
203 views

Are DUMBO, TIMBERWIND, and other high-thrust NTRs realistically going to deliver on promises of very high thrust/weight?

Nuclear thermal rockets (NTRs) are notable as the most mature technology (the second-most-mature is Project Orion) to provide both high thrust and higher specific impulse than chemical rockets. But "...
6
votes
0answers
1k views

Potential improvement to BFR or New Glenn if equipped with aerospike exhaust on their engines?

Aerospikes basically tackle the issue of the variability in required expansion ratio for a rocket engine to be efficient at a given altitude. A recent example though mired in legal issues is a small ...
6
votes
0answers
3k views

Propellant mass calculation

I have been given the following problem: To solve it I used the formulas: $v_e = I_{sp}.g_0$ $M_{propellant} = (e^{\Delta_v/v_e} - 1).M_{final}$ And I assumed that the apogee kick manoeuvre was ...
6
votes
1answer
424 views

How does the flight trajectory of a GEO vs LEO mission vary for a Falcon 9 first stage?

How does the trajectory vary between the two types of missions? Specifically, how does the speed and velocity vary for the booster for a Falcon 9 mission?
5
votes
0answers
106 views

What is the benefit of an inverted rocket stage?

For example the Chinese rocket Jielong 1 has an inverted 4th (final) stage. So the payload sits between 3rd and 4th stage. When 3rd stage separates it has to do a 180 degree turn before igniting the ...
5
votes
0answers
160 views

Trussed strongback or hollow shell strongback?

I noticed that rocket Lab has a hollow rectangular section strongback made of steel, while few strongbacks like that of Astra [similar size] has a trussed structure for a strongback. is there any ...
5
votes
0answers
99 views

Have any stages of rocket killed aquatic animals?

This question may seem off-topic but I am curious.Those rockets that aren't reusable let their stages fall and splash down on the ocean. Is there any news reported that they have killed some aquatic ...
5
votes
0answers
93 views

Low-pressure pump-fed rocket engine?

I saw the above suggested in LEO on the Cheap. In P.130 it says: A compromise between high-performance/lightweight pump-fed vehicle designs and cost-optimized pressure-fed vehicles with heavier ...
5
votes
0answers
114 views

Why does kerosene need inducer?

We see inducers before the main kerosene turbopump in engines such as F1 and RD180. Given the property of kerosene having extremely low vapor pressure (~0.007 bar around room temperature), is this ...
5
votes
0answers
94 views

How much would mass-production impact the cost of solid-fuel rockets?

Let's imagine that, for some arbitrary reason, solid-fuel rocket stages were needed and built en masse in factories, like planes or even like cars. How much would it drive down the cost of an ...
5
votes
0answers
83 views

Russian Soyuz MS-09 Launch - back and forth rotation of the second stage (along the length axis). Precession?

In the ISS Expedition 56-57 Launch of Russian Soyuz MS-09, in the first view from the external camera at around 3:30, an obvious back and forth rotation (along the length axis) of the rocket can be ...
5
votes
0answers
337 views

Are there any benefits on Venus compared to Earth with respect to reusing launch vehicles?

My assumptions around building up infrastructure for dealing with space launches from Venus assumes colonization based on the principles outlined by Geoffrey A. Landis of NASA in paper Colonization of ...
4
votes
0answers
41 views

What is the highest RPM achieved through a spin-stabilized rocket/spacecraft?

The title explains it all. I know that the Star 48 kick motor rotated at 60 rpm through its burn. I'd like to know the fastest a rocket/stage has spun during a launch, as well as the highest ...
4
votes
0answers
170 views

How many turbine blades, engine seals and bearings do reusable rocket engines have and how are they inspected?

From previous year statements of SpaceX representatives, the most difficult and longest part of used F9 booster refurbishment are inspections of the most volatile parts of the booster's nine Merlin ...
4
votes
0answers
153 views

Most open source spaceflight missions revealed unintentionally

As of 2021 there are few fully open source satellites (OSSI-1, UPSat, FossaSat-1, Oresat, some more?) and numerous student groups building and documenting rockets. These projects are intended to be ...
4
votes
0answers
93 views

What are the implications of North Korean black and white patterns on missiles?

Black and white patterns on rockets were originally intended as roll patterns. They helped as a visual back-up for acceleration sensors measuring the roll, as discussed in this previous question What ...
4
votes
0answers
60 views

Is there any work in English that gives a systematic treatment of Soviet/Russian rocket engines?

There seems to be some piecemeal information online such as RussianSpaceWeb.com, and of course, Sutton's History of LPRE gives an anthropological treatment of Soviet/Russian rocket engine lineup ...
4
votes
0answers
161 views

Why is the relative axial position of oxidizer vs fuel tank inverted in the upper stages of most rockets?

In the first stages of most rockets, e.g. Atlas V, Delta IV and Falcon 9, the oxidizer tank is stacked on top of the fuel tank, with the usual explanation that such an arrangement gives the rocket a ...
4
votes
0answers
247 views

Books on Vertical-Landing Vertical-Takeoff (VTVL) of Rockets? or Rocket Design in General?

I am working on a rocket control system design and I am trying to understand the the fundamental principles and concepts to design an efficient controller for recovering and landing the rocket, ...
4
votes
0answers
153 views

Why are hexa airfoils used on rockets despite having more drag that diamond airfoils?

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 ...
4
votes
0answers
531 views

Falcon 9 Landing Speed

I wanted to know what the fastest speed is that a Falcon 9 can land at and thus the max force the landing legs can withstand. I assumed the mass when landed is 26,000 kg (I once heard that somewhere). ...
4
votes
0answers
55 views

How do international students attend the SA Cup sounding rocket competition?

How do the international students carry the rocket along with propellants to this competition, if Airport Authority does not allow flammable substances?
4
votes
0answers
79 views

Why doesn't a regeneratively cooled engine crack due to differential expansion induced by thermal gradients?

A liquid rocket engine with regeneratively cooled chamber walls and nozzles would definitely be one among those components experiencing the steepest thermal gradients (Chamber wall inner - $3000 K$ ...
4
votes
0answers
142 views

Marman vs collet seperation mechanism

The Marman and the Collet mechanisms are used for stage separation in rockets and launch vehicles. Which of these is most efficient, cost wise, weight wise and ease of usability wise? Which of the ...
4
votes
0answers
320 views

From a strictly engineering standpoint, would Venturestar have worked as an SSTO?

In looking at the questions here and here, I'm wondering - was the VentureStar platform doomed from the start (in ways nobody could foresee), or was it only the cooling problems with aerospike engines ...
4
votes
0answers
230 views

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 ...
4
votes
0answers
283 views

What is the minimum melting point a material need to have in order for it to be used for the rocket chamber and nozzle?

I know the rocket temperature can go up to 3500 degree Celsius especially at the combustion chamber where it is the hottest. However I know there are cooling measures to cool the surface of the ...
4
votes
0answers
161 views

Is the variety in the Delta rocket family the result of an artisanal rocket industry?

Between the years of 1980 and 1990 the McDonnell Douglas company supplied at least 10 different variants of the Delta rocket family. Some of these were considered to be Delta rockets while some were ...
4
votes
0answers
633 views

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: ...
4
votes
0answers
1k views

How is the process of launching a rocket mathematically modeled up front?

What I am looking for is an example where real persons in the real world really need to mathematically model a situation before they need to calculate the average and instantaneous rate of change. I ...
4
votes
1answer
92 views

How to experimentally determine the degree of atomization of the propellants mixing in a fuel injector?

When validating a fuel injector design on a test stand using liquid water to simulate a liquid-liquid fuel injector(the one i'm working with currently is a pintle design but I suppose one could ...
3
votes
0answers
61 views

How to estimate total CO2 emission per year due to rocket manufacture?

I'm working on a study on greenhouse gas emissions related to rockets. While I have the post-launch (atmospheric) emissions, I need data for emissions related to production. For example, according to ...
3
votes
0answers
59 views

Rocket equation with Drag factor

For the avg Thrust of 2 kN, burn time = 3.5 s, burn rate= 1.4, over the time diff of dt = 0.1 sec Isp = 140 sec Cd for the Ogive nose cone C-section = 0.75 Cross-sec Area of the ogive nose cone = 0....
3
votes
0answers
121 views

SpaceX estimates for Starship and Super-heavy heat shields maximum heating during their orbital and suborbital reentry

Did SpaceX made public their estimates for Starship orbital vehicle heat shield maximum heating (and overall reentry heating profile) during orbital reentry on Earth and same for Super-heavy booster ...
3
votes
0answers
92 views

Rocket Engine - Actuator in Loop Simulations

For Actuator-In-Loop simulations, why are the rocket engine nozzles along with the thrust vector control assembly (including the actuators) kept inverted on a platform like in the attached image or as ...
3
votes
0answers
91 views

Can we re-fuel solid-core nuclear thermal rockets?

Most solid-core nuclear rocket designs seem to have a rather short fuel lifetime (and one that wastes most of the uranium or plutonium) due to the buildup of fission products (combined with the very ...
3
votes
0answers
318 views

Cost of launch unrelated to cost of building rocket

ULA CEO Tory Bruno said long time ago that only 1/2 cost of orbital launch is cost of building of rocket. SpaceX never denied this. F9R block 5 total cost of launch can be about 60-80 million per ...
3
votes
0answers
34 views

What's the most optimal method of motor attachment for Horizontal Static Fire Tests?

I'm a college student new to rocketry, and am working on the horizontal test structure for a static fire test of our motors. The max thrust for the booster motor is about 6000 pounds, and the ...
3
votes
0answers
696 views

PID Controller for Thrust Vector Controlling of High Power Rocket

We are trying to design a Thrust Vector Control system for a High Power Rocket using PID Controller. Can anyone guide us what approach should we use to create this Controller? Rocket Details: Mass: ...
3
votes
0answers
96 views

What is the physics behind a rocket landing on a celestial body with an atmosphere?

I would like to know the different physics concept I would need to land a rocket being in orbit. I know the timing is important to leave it, how can one find this out ? Then how to compute the ...
3
votes
0answers
166 views

What is holding SLS back from launching?

I'm kind of confused on this point SLS has engines, a tank, side rocket boosters, a capsule, and seemingly all of the pieces. What is the major technical issue right now that is keeping SLS from ...
3
votes
0answers
54 views

What is the minimal distance of clearance in the direction of flight path for a rocket?

Usually the rocket launch sites are placed on a coast or a place where there's basically no civilian buildings in the direction of flight path. Is there a standard/regulation on the minimal ...