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Questions tagged [rockets]

Questions regarding the boosters or thrusters used to propel man-made objects.

6
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0answers
136 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.
1
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1answer
183 views

Satellite Launch Direction

Most rockets hoping to achieve earth orbit are launched West -> East and from near the equator to gain maximum advantage from the spin of the Earth. I know the launches often also are deliberately ...
6
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1answer
536 views

Does the entirety of the efficiency of an aerospike engine occur in the lower atmosphere, or are the advantages in a vacuum as well?

I mean, it's called an aerospike engine for a reason, I guess, but are there any other advantages to the engine that accrue in space? Is the bell configuration better in a vacuum?
4
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1answer
215 views

Falcon-centaur or Falcon-ACES?

For very high delta-V missions (eg outer solar system) the Falcon family really starts to suffer from that fact that its second stage is still using RP-1/LO2 rather than LH2/LO2 with a consequently ...
2
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1answer
537 views

How does the Thrust-to-weight ratio of a rocket affect its efficiency and performance in atmosphere and vacuum?

Is there an optimal thrust to weight ratio or does it not matter at all?
4
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0answers
162 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 ...
3
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1answer
366 views

Why do astronauts spend a night at a hotel one day before the launch? How did they board the Shuttle

I heard somewhere that it was some sort of a tradition for astronauts to spend one night at some kind of hotel. As far as I know, astronauts and cosmonauts ride in a bus down to the launch site, where ...
4
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0answers
123 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 ...
13
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1answer
818 views

What was the purpose of the small red tank attached to the Titan-Centaur launcher?

Watching a documentary on the Viking missions, I noticed the launcher had a small red tank/rocket attached to one of the solid boosters. It struck me as an odd feature/placement, as I thought you'd ...
11
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3answers
4k views

Is it true that nuclear rockets cut the journey to Mars in half?

The biggest challenge of our Mars journey is the journey time (9 months). Now I have seen news coming stating that atomic or nuclear rockets would cut the journey time in half. Is that right? When I ...
3
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1answer
101 views

What is the correct term for the exterior of a rocket or space launch system?

Would you call it the casing, cladding, exterior structure, hull, shell...?
36
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2answers
6k views

Did the Saturn V rocket have any purely aesthetic features that didn't serve an actual function?

The rocket itself is magnificent, yes, but with so many ins and outs to it, curious if the entire design was solely purpose built, or if there were features specifically for aesthetic purposes.
3
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1answer
145 views

Why haven’t upper stages used the RL-60 engine?

The Space Launch system is being designed to use initially a modified Delta IV upper stage, but then the Exploration upper stage with 4 RL-10 engines. Why wouldn’t they just use a RL-60 engine which ...
21
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4answers
5k views

Why 31 engines for the BFR?

I understand the philosophy of using relatively many smaller engines so that a single engine failure has minimal impact on the mission (provided you can keep the shrapnel from shredding the others) ...
4
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1answer
146 views

Is Engine thrust noticeably increased near the ground

I know next to nothing about Rocketry and Space Flight. I assume that the majority of the force generated by a rocket's engine is simply the result of throwing gasses out of the bottom very fast, and ...
3
votes
1answer
140 views

Would a lunar or interstellar rocket use a gravity turn on take-off, today?

Is a gravity turn only used for rockets interested in orbit or a gravitational slingshot? From this answer it sounds like Apollo 11 only used a gravity turn for the crew to maneuver. Are there ...
43
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6answers
5k views

What technological breakthroughs were required to land booster stages?

It is only recently that SpaceX developed first stages that can land again, and be reused. The (until recent) non-existent landing of re-useable rockets is presumably, partially, due to a lack of ...
6
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1answer
4k views

How deep into space will the live feed from Starman remain active?

Assuming they keep it streaming for us to watch, at what distance will it no longer broadcast?
2
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1answer
384 views

Why spray LOx into combustion chamber, if GOx is more effective?

Are there any issues in transforming the liquid oxygen into gaseous oxygen before injecting into the combustion chamber? Gaseous Oxygen will be readily available for combustion and will mix well with ...
12
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2answers
2k views

How do rockets keep their fuel in a liquid state?

What are some of the measures engineers would take to ensure that the LOX and other similar fuels are kept below their boiling point during flight?
16
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2answers
756 views

Where does the thrust act in a rocket engine and how is it transferred to rocket structure?

A rocket engine is basically a device that generates a high pressure inside the chamber and the pressure difference creates a force. A nozzle helps in effectively accelerating the flow and increases ...
1
vote
1answer
387 views

Chamber pressure for Merlin vs Raptor

So, I've been doing some digging, and I found that the chamber pressure for the raptor engine is more than 4 times that of Merlin (~4,000 psi to ~980 psi). How would SpaceX manage to pressurize the ...
3
votes
4answers
593 views

Has anyone considered using multiple rockets to lift a single payload?

I mean something like Kerbal Space Program style - payload between 2 parallel rockets e.g. Also, space shuttle configuration comes to mind where we have the large fuel tank between 2 solid boosters: ...
7
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1answer
443 views

RS-25 Hot Fire Test

Yesterday, NASA Stennis successfully completed a hot fire test of Aerojet Rocketdyne RS-25 a.k.a SSME. It was noted in the webcast before the test started that they were testing the 'engine controller'...
0
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2answers
94 views

What affects the flight of rockets? [closed]

I need some help on my science experiment. I have tried researching it on the internet but nothing seemed to have answered my question. I am currently doing a science fair project on "How does Rocket ...
26
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2answers
5k views

Why did SpaceX retire Falcon 1?

Why did SpaceX retire Falcon 1? Wouldn't it have been more cost effective then Falcon 9 for lighter missions?
4
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0answers
145 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 ...
13
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2answers
2k views

What are these yellow devices attached to the Falcon Heavy?

I was looking at the pictures of the newly rolled out Falcon Heavy and I noticed these odd yellow extensions on the payload faring. What are they?
9
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2answers
2k views

What do rockets eject?

So for instance, for the space shuttle,liquid hydrogen will react with liquid oxygen to produce water vapour. Is only water vapour ejected from the rocket? Or will the ejected mass be a mix of water ...
3
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2answers
254 views

Does “What happens beyond Kármán, stay beyond Kármán”?

The title refers to the promotional slogan "What happens in Vegas, stays in Vegas." The question How much CO2 would city-to-city rocket flight produce compared to airliners? seems to be focused on ...
4
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0answers
121 views

Challenges in Development of small scale liquid propellant engines [closed]

Being aeronautical engineering graduate, I have gone through huge literature regarding design of Liquid propellant engines(LPRs). But as I am planning to develop small LPR based on gasoline and oxygen....
20
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3answers
6k views

Why are the Falcon Heavy boosters stacked in a row instead of a triangle?

I wonder if triangle stack would be a better design to handle thrust and stability of the flight. Photo source (public domain).
4
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1answer
136 views

Does regenerative cooling reduce specific impulse?

Specific impulse of exhaust velocity depends on the temperature in the combustion chamber. Won't regenerative cooling lower the chamber temperature, causing the exhaust velocity to decrease?
-2
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1answer
4k views

How far is zero-gravity from ground? [closed]

If I make a rocket and want to reach a point in space above sea level where I don't need to burn fuel to rise, how far is that point? space or zero gravity area? I am just trying to figure out ...
9
votes
2answers
914 views

Range of BFR as single stage

The depictions of the BFR for earth to earth travel include the 1st stage booster. I would think if you are just going ballistic, the upper stage would have enough delta V to go it alone, for closer ...
2
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0answers
44 views

Where can i book a flight for scientific experiment to 100 km high? [closed]

I have just been wondering if is there any company in Europe which launch scientific experiments into an altitude of about 100 km?
0
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3answers
215 views

What fuel is used in the second stage of orbital launch vehicles?

What types of propellant are used in the second stage of multi-stage rockets? For example, the Falcon 9. Is it the same combination as the first stage? I've found plenty of information about the first ...
2
votes
0answers
230 views

What ratio of fuel is needed for launching a mass up to low earth orbit compared to the Lagrange point? [closed]

I've heard an argument that moon landing was at best improbable as it would have required too much more fuel than simply achieving LEO. It seems to me that it would be relatively little more. I'm just ...
3
votes
1answer
384 views

What are the thrusters present on the side of the Mercury-Atlas launch vehicle?

I just watched a documentary about the Mercury program and was wondering what those "side rockets" (don't know how to call them properly) are for? Further stability or generating some extra thrust? ...
3
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0answers
224 views

How long can it be reasonably expected to wait for the first flight of SpaceX's BFR? [closed]

Elon Musk has said that he's planning to launch two uncrewed BFR rockets to Mars by 2022. And of course there would be some test launches even before that. For such an enormous project, I don't see ...
35
votes
1answer
5k views

Why does this rocket have a nose cone “cozy”?

A tea cozy keeps the tea in a teapot warmer longer by insulating it. Why does the nose of the rocket shown in Apollo-era file footage used in this video (lower your volume before watching) have a ...
9
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0answers
233 views

What were some of the first two stage rockets flown?

The first US two stage rocket was bumper, a combination of a german V2 liquid fuel rocket with an US second stage. The Soviet Union had the R-1 and R-2 based on the V-2. In this list, the R-7 is the ...
-1
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2answers
141 views

Rockets with n-engines, for n = 1, 2, 3… [closed]

The question Astronomical ABCD…! suggests a corollary for SXSE. I'm looking for one example of a rocket with $n$ first-stage engines, for each $n$ for which you can think of an example for. It should ...
0
votes
0answers
86 views

What is the largest number of engines ever used on an orbital class rocket? [duplicate]

Specifically the number of engines simultaneously ignited. So not summing up over different stages. I am interested in the max for both number of engines and number of combustion chambers. What I ...
0
votes
1answer
159 views

Is it necessary for a vertical landing rocket to have the upper fuel tank empty?

You may imagine that having an upper fuel tank still having heavy liquid inside while landing, as today some reusable rockets do in a vertical attitude, may ease the machine falling on its side. Is ...
1
vote
2answers
262 views

Zenit Launch Costs

I am compiling a table of data on price-mass ratios of various modern rockets, and I have been unable to find any information on how much it costs to launch a Zenit rocket. Does anybody know how much ...
16
votes
1answer
454 views

What will J002E3 be like on its return?

J002E3 is believed to be the S-IVB third stage of the Apollo 12 rocket. It is expected to return to temporary Earth orbit in the 2040's. If some enterprising soul decided to build a rocket capable ...
5
votes
2answers
349 views

Estimate of effectiveness of gravity turn compared to vertical flight

How much higher is a rocket following a gravity turn going to be able to reach compared to a rocket following a vertical flight ? I understand that it depends on which type of rocket and which type ...
8
votes
1answer
444 views

How much CO2 would city-to-city rocket flight produce compared to airliners?

After seeing Elon Musk's proposal of using rockets to travel from city to city I was wondering how much fuel such a rocket would use, and how would that compare to traditional flights in terms of ...
4
votes
2answers
604 views

Longest continuous burning chemical rocket engine?

I'm curious as to what rocket engine in a launched rocket burned the longest in a continuous fashion. I'm not interested in testing burns or inter-planetary engines which are designed for low-thrust ...