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Questions tagged [raptor]

Questions about an engine SpaceX has been developing using Methane/LOX as fuel, which has a 2,200 kN (500,000 lbf) thrust range.

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Does Raptor rocket engine of SpaceX include a cracker or fuel conversion system to crack the hydrocarbon fuel into its constituents?

In the Raptor rocket engine, where is the hot turbine exhaust gas transferred, when gaseous fuel arrives from the heat exchanger? Does the Raptor rocket engine include a cracker or fuel conversion ...
Lakshay's user avatar
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4 votes
1 answer
118 views

What (if any) modifications would SpaceX raptor engines need to run on liquified natural gas LNG?

Natural gas is 97% methane. Most of the rest is low molecular weight alkanes (hydrocarbons which would be at home in RP-1), along with a little CO2, H2S, N2 and He . Could Raptors run on straight ...
Woody's user avatar
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7 votes
5 answers
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Why doesn’t SpaceX sell Raptor engines commercially?

I have never studied rocket science and am just curious about this. I would assume one Raptor 2 engine could launch a small rocket to space. I heard they are able to make them for less than a million ...
user51440's user avatar
3 votes
1 answer
343 views

Why will the Raptor not face the same turnaround issues as Space Shuttle engines?

The RS-25's notoriously slow, expensive turnaround was blamed on its complexity. The Raptor appears about as complex. Both use regenerative cooling. Both use preburners to drive turbopumps. While the ...
Abdullah is not an Amalekite's user avatar
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1 answer
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How does SpaceX Raptor deliver a more benign turbine environment?

Raptor has been claimed to be able to deliver "long life ... and more benign turbine environments". https://en.wikipedia.org/wiki/SpaceX_Raptor The Raptor has hot oxygen flowing out of the ...
Abdullah is not an Amalekite's user avatar
7 votes
2 answers
708 views

Does methalox fuel have a coking problem at all?

Methane was chosen for SpaceX Raptor because it has less coking problem that kerosene. But does it completely eliminate it? If not, how much less severe is it? I googled 'thermal decomposition of ...
Abdullah is not an Amalekite's user avatar
0 votes
1 answer
149 views

SpaceX Raptor Vs Raptor Boost

I'm asking all these questions as one because I don't think they're worth cluttering the site separately for. How much does Raptor Boost weigh compared to normal Raptor? How much more thrust does ...
Abdullah is not an Amalekite's user avatar
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1 answer
141 views

Where are the Raptor Boost engines on Super Heavy?

SpaceX Super Heavy has two types of Raptor, one of them being Raptor Boost, which has no gimbals and limited throttling but increased thrust. But I can't find information on Wikipedia on how many ...
Abdullah is not an Amalekite's user avatar
3 votes
0 answers
205 views

What is the cause of soot in the plume of the Raptor engine?

Though the Raptor engine burns quite clean, it was clear from some early test flights that it did produce some visible soot: There have been differing explanations for the exact cause of/source of ...
quinnkenri's user avatar
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5 votes
0 answers
168 views

How Spacex's Raptor Rocket Engine starts?

How does the Spacex Raptor rocket engine start? What are the different stages of startup? Is the propellant pressure in the tanks sufficient to drive the turbopumps and ignite the preburners and then ...
Sebastyen Laroche's user avatar
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2 answers
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What is the maximum weight a raptor 2 engine can lift up at sea level on earth?

Regardless of target orbit, how can I calculate the maximum weight one engine can lift? If the raptor's TWR is 140 and its Thrust is 1.81 MN then: W = F / TWR = 12,900 N ==> m = W / g = 1.3 tons ...
Alice Miller's user avatar
11 votes
5 answers
4k views

Is a Raptor 2's thermal output really comparable to that of a nuclear power plant?

After about 01:10:10 in the 2022-02-10 SpaceX Starship Update part of Musks answer to Tim Dodd's question about Raptor 2 development: The only remaining issue that ...
uhoh's user avatar
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Looking for a more specific Raptor engine model, that follows fuel and oxidiser flow. Anyone know where to find good Raptor resources?

Here is our raptor inspired model in SATSIM, our virtual aerospace lab. Want to be able to model the fuel and oxidiser flow at some stage both in Blender, then WebGLbut it's trickier than it looks. ...
Satsimmer's user avatar
9 votes
4 answers
2k views

How are vacuum optimized engines tested without disintegrating them?

SpaceX recently test fired vacuum optimized raptor engines of starship. Doesn't vacuum optimized engines disintegrate when operated in atmosphere? If yes, what additional modifications are made to the ...
Ashvin's user avatar
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2 votes
2 answers
1k views

Technical feasibility of using Raptor engines for Vulcan rocket

According to a recent GAO report (p. 116), ULA's Vulcan rocket's BE-4 engines are "experiencing technical challenges" and there is some concern whether they will be ready / certified in time ...
Charles Staats's user avatar
1 vote
3 answers
149 views

Starship and Raptor

All these SN-flights...seems that Raptor and the surrounding system is still in development and is pretty unreliable. So why go through all the trouble of flying until the Raptors are more mature?
Lars Olsson's user avatar
3 votes
1 answer
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Could another fuel be used in the SpaceX Starship header tank?

A memory of hexane and water in a separatory funnel brought to mind the issue of helium and LNG in the header tank while the Starship flips and does its powered landing. There was discussion of the ...
Robert DiGiovanni's user avatar
6 votes
1 answer
468 views

SpaceX Starship: Could they use the Vacuum engines during landing in case of other engine failure?

With the recent test (and RUD due to single engine relight failure) of SN-9, Musk has stated that what they should've done was light all three raptor engines simultaneously then turn one off so as to ...
Ingolifs's user avatar
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Any large scale rocket static fires, like SpaceX's 3 in one day?

SpaceX on Jan 13, 2021 did three static fires in one day. Elon Musk tweeted: All three static fires completed & no RUDs! And that was in response to this tweet of his own: Today at SpaceX is ...
geoffc's user avatar
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27 votes
2 answers
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For the Starship SN8 flight, did they lose engines in flight?

Watching the first (only?) test flight of SN8 we saw them start flying with three Raptor engines firing and then one looked like it flamed out, with lots of fire inside the engine bay. Then later a ...
geoffc's user avatar
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8 votes
1 answer
422 views

Why do some rockets have closed boattails around the engines and others do not?

During launch and landing, dust, dirt and debris may be stirred up. For non-gimbaling engines like the vac Raptors on Starship, can't the engine fairing/boattail be closed? I imagine titanium sheet ...
seccpur's user avatar
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5 votes
1 answer
278 views

Issues with multiple raptor engines working in tandem in starship

To get the super heavy starship structure airborne and accelerate vertically, SpaceX is considering using multiple raptor engines. Clustering together huge powerful engines such as Raptor in a ...
seccpur's user avatar
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4 votes
2 answers
239 views

Were there any experiments that produced rocket fuel grade methane on mars?

One of the main reasons that SpaceX's Starship engine raptor uses methane is because it can theoretically be produced there from atmospheric CO2 and subsurface H2O. Where there any experiments that ...
moshevi's user avatar
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6 votes
0 answers
146 views

How much pressure would the raptor engines experience when Starship does an atmosphere entry burn at Mars?

The Starship second stage has 3 sea level engines and 3 vacuum engines. When doing the atmosphere entry burn to mars, how many Bars will the raptor engines experience? I'm thinking that because of the ...
moshevi's user avatar
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23 votes
2 answers
9k views

If rocket engines only need fuel and oxidizer, then why there are so many pipe lines on the engines?

If fuel and oxidizer are pumped by turbines to the combustion chamber, then why there are so many pipes around? It should only have a two-cylinder shaped turbine assembly. I doubt there are other ...
Aarav Prasad's user avatar
7 votes
1 answer
310 views

Which are good resources to learn more about the components of a rocket engine?

A detailed and annotated image of a SpaceX raptor engine (found on a SpaceX website) illustrates that in addition to the major components (e.g. pumps, inlets, combustion chamber, nozzle), there are ...
Aarav Prasad's user avatar
2 votes
0 answers
80 views

Full Flow Staged Combustion Benefits vs Closed Staged Combustion [duplicate]

I am aware that the RS-25 space shuttle engine was a closed staged combustion engine, and used two preburners (both fuel rich) to drive the turbines and pumps to pump the LOX and fuel into the ...
Patrick's user avatar
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9 votes
2 answers
689 views

As of January 2020, what is the single longest duration firing executed with a Raptor engine?

Can someone cut through the woo for me? As of January 2020, what is the single longest duration firing executed with a Raptor engine? Have any successfully run for full mission duration? Sourced ...
Organic Marble's user avatar
4 votes
1 answer
281 views

Falcon 9 Type Rocket with Raptors

I've seen the question "Why don't SpaceX just use Raptors in the F9 now since their better" asked here and there, and I understand why it isn't possible to do that- they're not a drop-in replacement ...
Eoin O'Kelly's user avatar
2 votes
1 answer
409 views

What materials can withstand corrosive oxygen-rich hot-gas environments inside rocket engines?

Russians figured out the metallurgy behind those super alloys since the N1 moon rocket era. Blue Origin is running its BE-4 engines on oxidizer-rich preburners and SpaceX’s full-flow Raptor engines ...
Aungmyintmyat Hane's user avatar
37 votes
4 answers
7k views

Why did Starhopper's exhaust plume become brighter just before landing?

In 2019 Aug 27's test flight, during the final 8 seconds before landing (T+00:45), Starhopper's plume was suddenly much brighter. Why? The Raptor's thrust can't ...
Camille Goudeseune's user avatar
3 votes
1 answer
432 views

What causes this diamond to appear from a single Raptor engine firing?

As seen on this video posted by Elon Musk https://twitter.com/elonmusk/status/1154629726914220032?s=19
Stickyz's user avatar
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11 votes
3 answers
5k views

Why is SpaceX's Raptor's design so simple in comparison to SSME?

What is especially striking to me is how simple Raptor is in configuration compared to SSME. The Raptor doesn't have an LP fuel or oxygen pump. What's even more surprising, if we are to compare the ...
Meatball Princess's user avatar
3 votes
1 answer
282 views

For the Starhopper testing, how will SpaceX hold down the vehicle?

SpaceX is testing the Raptor engine on the Starhopper they built in Boca Chica. For static fires of a Falcon 9/Heavy they use the pad itself, the holddowns to the pad, to keep it from taking off. ...
geoffc's user avatar
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1 vote
1 answer
707 views

What is a raptor engine manifold and what's happening in these tweeted pics?

When I think of the words "engine manifold" I think of these. I saw this tweet by Elon Musk which shows the image below, and then there is a reply image with a checkerboard pattern behind part of the ...
uhoh's user avatar
  • 149k
6 votes
3 answers
2k views

New BFR Engine arrangement

Watching the announcement at SpaceX I was confused about the new engine arrangement. All the nozzles look the same size. Is there still a mixture of vacuum engines and sea level engines? Or did they ...
Johnny Robinson's user avatar
15 votes
2 answers
4k views

Benefit of Raptor Engines

I know that the Raptor engines are significantly different from the Merlin 1-D's since they use liquid methane and are cryogenic. However, what exactly enables the Raptor engines to produce a lot more ...
Vivek's user avatar
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1 vote
2 answers
440 views

SpaceX Raptor engined first stage landing

Reusability is a key strategy for SpaceX to lower the cost of orbital and interplanetary launches. With the Falcon 9 they are using the powered landing approach to recover the first stage for reuse. ...
Shane Taylor's user avatar
8 votes
2 answers
693 views

Progress of the raptor engine

I have seen that SpaceX has tested a scaled down version of the raptor, but that was about a year ago. Does anyone know the current progress? Do they have a full scale model? Have they hot fired a ...
Johnny Robinson's user avatar
4 votes
1 answer
609 views

Don't Preburner exhaust fumes disturb the combustion in a Full-flow Staged Engine?

Since Full-Flow Staged Engine uses preburned fuel/OX-rich gases in combustion chamber, don't those exhaust fumes produced by the preburner somehow unbalance or 'pollute' the pure combustion of fuel ...
Spacha's user avatar
  • 168
8 votes
1 answer
955 views

How does turbine power output of a full-flow staged combustion engine compare to Oxygen-rich staged combustion?

One of the benefits of the SpaceX Raptor full-flow staged combustion engine is the extra power generated by having all of the fuel and all of the oxidizer flow through the turbines to produce power to ...
nyDavid21's user avatar
1 vote
2 answers
292 views

How much methane to push Titan into Saturn?

How much methane would have to be expended (think Raptor engine) to propel Titan into Saturn? It's clearly a humongous amount.
ikaruss's user avatar
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25 votes
3 answers
23k views

What's so special about SpaceX's Raptor rocket engine with 300 Bar chamber pressure?

What allows the Raptor engine to have a high chamber pressure of 300 Bar? Compared to other rocket engines which have been or that are now operational, it has the highest chamber pressure. What does ...
John Howell's user avatar
12 votes
1 answer
11k views

Rocket Engine Plumbing: Still don't understand the Full Flow Staged Combustion Cycle

I just found this incredible video KSP Doesn't Teach: Rocket Engine Plumbing and ran through it a few times. It's very helpful in the way it outlines the various issues first, and then designs the ...
uhoh's user avatar
  • 149k
38 votes
6 answers
9k views

Why did it take so long for methane to be used as a rocket propellant?

SpaceX have put methane on the map as a rocket fuel, but they weren't the first to consider its use. The first experiments in building a rocket engine that uses methane date back to 2007. Now methane ...
Hobbes's user avatar
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3 votes
0 answers
2k views

What will the SpaceX BFR booster look like? [closed]

SpaceX's next big booster is notionally known as BFR - Big F-ing Rocket [or Big Falcon Rocket]. (Like the B-52 is the BUFF - Big Ugly Fat F-er, it is a term of enderarment). We know that it will use ...
geoffc's user avatar
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71 votes
10 answers
55k views

Why is SpaceX considering Methane as fuel for their next engine, the Raptor?

Currently, SpaceX has developed the Merlin 1 family (1B (Falcon 1), 1C (Falcon 9 v1.0), 1D (Falcon 9 v1.1/F9-R/Falcon Heavy), vacuum versions and sealevel versions) which are LOX/RP1 based. (75-...
geoffc's user avatar
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