Questions tagged [stage-separation]

Questions covering how different parts of a rocket with propulsion (stages) of a rocket disconnect from each other.

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3
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1answer
119 views

Rocketlabs: springs for stage separation?

Video of stage separation from Rocketlab's latest launch shows clearly what seem to be springs to push off stage 2. Are those actual springs? I've read about linear charges and pneumatic pushers, but ...
3
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1answer
87 views

What is the sun-lit aura/haze seen above the Space Shuttle post-ET separation?

Source: NASA, via YouTube Watching that video for the nth time since 2011, I realized I never really asked what that sun-lit haze seen post-external tank separation is. This is what I would expect a ...
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0answers
28 views

Blue Origin New Glenn/Shepard Stage Separation: Linear Charges or Pneumatic Pushers?

Falcon 9 uses pneumatic pushers for stage 1 separation presumably because it helps with reusability---even though linear charges are far more extensively space-proven. So I'm wondering, since New ...
2
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1answer
178 views

Multistaging and its issues [duplicate]

Multistage rockets have the benefits of trimming dead weight and using different engines for different heights. But do they have some momentum gain benefits too? For instance, during their detachment, ...
6
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0answers
86 views

How common is the ejection of small objects during final stage separation?

Source: Crew-2 launch; YouTube (timestamp link) That object seen moving right to left is the reason I ask. By playing the video frame-by-frame, it seems like it's a small object close to the camera ...
7
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2answers
285 views

Which explode in spaceflight more often, nuts or bolts?

The history of spaceflight is littered with exists because of exploded nuts and bolts (and upon further reflection, a whole lot of other items!) "Exploding bolts" is really a generic term. ...
3
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1answer
108 views

Rocket dashboard: separation/pyro indicators

I'm curious about rocket dashboards. Separation events are big things and they depend on pyro bolts detonating and linear charges or pneumatic pushers firing immediately afterward. There must be ...
4
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0answers
92 views

Does Falcon-9's second stage “blow” into the first stage's top intentionally? [duplicate]

Every time I watch Falcon-9 moments like that at , I wonder: Is it really intentional that the main engine of stage 2 after startup blows directly into stage 1´s top, ...
1
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2answers
78 views

During an Apollo mission, were separations after dropping the S-II considered as staging events?

I would like to clarify what is a staging event. Maybe there is no definite definition. First I though it was easy as the Nasa definition is clear. Then I though of the stage-and-a-half Atlas SLV-3, ...
5
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0answers
134 views

Why did Tianwen-1 payload separate upside down?

China recently launched its Mars exploration mission Tianwen-1. Separation of the payload from the second (or third?) stage can be seen in a post-launch news clip. In this clip, the computer animation ...
9
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3answers
3k views

Why are stages not connected by the engine nozzle? Why are interstages used?

First, a clarification: I understand the aerodynamic reasons that interstages are used, and I understand that the shockwaves that would be generated without an interstage would wreck the rocket. My ...
7
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1answer
272 views

How does the Dragon trunk separate from the Falcon second stage?

I've pored over the pictures and still I can't figure it out. I know the second stage separates from the first stage using positive force from pneumatic pushers. I also know that the payload ...
6
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1answer
392 views

What were the space shuttle’s emergency procedures for an SRB or ET separation failure?

The space shuttle, like most launch vehicles, was a multistage vehicle (albeit one where the various stages were mostly stuck to the sides of each other rather than being stacked vertically), reducing ...
20
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1answer
754 views

Why was the Polyus mounted backward?

This blog post (and other resources) states the Polyus was mounted engines facing the front and this stage must turn 180° before firing its engine. I easily imagine that staging outside the ...
7
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1answer
269 views

Why isn't the Falcon 9 first stage severely damaged by the blast of the second stage following separation?

When the Falcon 9 experiences stage separation, why isn't the first stage severely damaged by the blast of the second stage? When separation occurs, there seems to be some mechanical force to push ...
2
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1answer
250 views

Model vehicle separation on STK Astrogator?

I am trying to model a multi-stage lunar mission with STK Astrogator. The vehicle separation happens after the first Trans Lunar Injection Burn. I've been trying to figure out how to arrange the ...
8
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1answer
358 views

Why do Soviet and Soviet-derived rockets hot-stage instead of using ullage motors?

I am only aware of one US rocket that used hot-staging for maintaining proper ullage during stage seperation--the Titan family. Otherwise, US rockets tend to use reaction control systems or small ...
1
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0answers
96 views

When were “2nd stage pushers” first used?

The question Falcon 9 2nd stage pusher; how far does it continue to extend as it accelerates separation? includes (and further explains) the GIF below. Question: What was the first use of a "2nd ...
3
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1answer
273 views

Are “2nd stage pushers” limited to the Falcon-9, fairly standard, or somewhere in-between?

Falcon 9 2nd stage pusher; how far does it continue to extend as it accelerates separation? (currently unanswered) includes (and further explains) the GIF below. Question(s): Is there a better term ...
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0answers
47 views

Mass/weight information about stage separation mechanism

How can I get mass/weight information about rocket stage separation mechanisms that are used in multi-stage rockets? I plan to create an excel table to compare stage separation mechanisms by weight ...
3
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0answers
172 views

What is the largest energy stored in a spring or other stress-based energy storage device that's ever been put in space?

The question What is the largest delta-v ever produced in space from mechanically stored energy? asks of course about the delta-v produced, but here I'm asking about the largest amount of stored ...
5
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1answer
449 views

Falcon 9 2nd stage pusher; how far does it continue to extend as it accelerates separation?

I've just watched Scott Manley's video SpaceX's Water Landing Reveals Rocket "Secrets" (or, What We Learned from CRS-16) (again) and he mentions the second stage "pusher" in the center of the view (...
6
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0answers
177 views

What's the sudden pitching of Rocket Lab's 'It's Business Time" launch at separation?

In today's Rocket Lab launch of the "It's Business Time" mission, there was a substantial and swift change in attitude upon stage separation. It looks scary. I understand that The first ...
15
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3answers
7k views

Why not keep the engine for multi-stage rockets?

Rocket engines are a huge weight in a multi-stage rocket. and they are stacked like so: Fairing/Payload Fuel Engine -- Seperator -- Fuel Engine and so on, which means multiple engines. Is there ...
6
votes
1answer
625 views

Which rockets have their upper stages separating at(around) 100 km?

Are there any current rocket systems that go to the Karman line with just 1 stage without boosters? Recent Rockets like the Falcon 9 separate at 80 km. New Shepard launches recently touched 100 km ...
3
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0answers
70 views

Why GSLV uses different stage seperation mechanism for their different varients

Why GSLV mk II is using Marman mechanism for stage separation but GSLV mk III is using Collet mechanism for stage separation?
4
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0answers
134 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
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1answer
2k views

Apollo 11 mission report shows velocity well below escape velocity thousands of km on the way to the Moon

This is from the Apollo 11 mission report. It says the vehicle was going at 7.6 km/s when the CSM separated from the third stage. It was not in orbit at this point, it was thousands of KM from earth. ...
34
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4answers
6k views

When did the concept of “stages” enter rocketry?

The staged rocket design is common now, but at some point in the history of rocket design it must have been revolutionary. When was the staged design introduced? Was it quickly accepted or did it ...
5
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1answer
131 views

1/st Stage slow down after MECO and separation for F9's

Once the Falcon 9 Full Thrust 1st Stage reaches "MECO" - main engine cut off - and separates from the 2nd Stage how much velocity does it lose? Specifically at "MECO" its velocity is approx. 5,900 km/...
6
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1answer
968 views

Did the Saturn V interstage ring burn up in the atmosphere?

In Saturn V launch footage, the interstage ring falls away shortly after stage I separation, briefly catching fire from the stage II exhaust. Does this ring continue to drop uncontrolled and impact ...
10
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1answer
889 views

Why did Amazonas5 2nd stage ignite before 1st stage separation? [duplicate]

Watching the Amazonas5 launch, and at 1st stage separation, the commentator noted that the 2nd stage would ignite before the separation in order to "maintain constant acceleration." I'm wondering how ...
7
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3answers
1k views

Reliability of explosive bolts and redundant initiators

Explosive bolts are often used for stage and payload separation. If only one of the many explosive bolts used fails to break into two pieces, the payload of the rocket may be lost. Are there more than ...
3
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2answers
451 views

Why is the Falcon 9 upper stage tumbling so much after separation? (SES-10)

Immediately after separation, the upper stage of Falcon 9 seems to head 30 or so degrees sideways. What causes that? Is it a problem or a feature? Separation occurs at 4:40 in this video of the ...
39
votes
1answer
5k views

Why do the Russians use these fence-like interstage fairings?

When we look at various Russian rockets we often see a metal structure looking like a kind of garden fence separating some stages. To my knowledge, only the R7 family (Vostok, Voshkod, Soyuz) and N1 ...
13
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2answers
1k views

Why does Blue Origin land the crew capsule separate from the booster?

New Shepard of Blue Origin separates the crew capsule from the booster. The crew capsule is in free fall for a while, then the parachutes open and finally the landing rockets give a brief impulse to ...
23
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2answers
3k views

Why does the Soyuz Rocket system fire the third stage while stage two is still attached?

Also, I believe that the second stage continues to burn for quite some time even after seperation of stage 3.
33
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6answers
8k views

Why is there a “coasting” phase in some space launches?

During the PSLV (India's Polar Satellite Launch Vehicle) C24 launch on 4 April 2014, once stage 3 (PS3) had burned out, it wasn't immediately jettisoned, but instead there was a coasting phase for ...
16
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1answer
587 views

Is there an explanation for repeating Soyuz accidents involving misfiring of explosive bolts?

In the Soyuz program, quite a few accidents have been caused by malfunctions of the explosive bolts: Soyuz 11: Explosive bolts designed to fire sequentially fired simultaneously instead, causing a ...