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Questions tagged [first-stage]

The bottom section of a rocket with multiple sections, that lifts the mass of the entire loaded rocket off the ground and accelerates it through the lower atmosphere. Once its fuel is spent, it separates from the rocket and falls, and the next section - the second or upper stage - ignites to complete the journey to orbit.

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How was the thrust for the STS-94 launch and other space shuttle launches balanced? [duplicate]

I've been looking at of the STS-94 skylab launch and other launching involving asymmetrical rocket launch vehicles, mostly because I've never been able to design something similar in KSP with ...
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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 ...
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Floating Launch

Can a space rocket launch if it had no platform underneath it? If a blimp could lift a rocket into the stratosphere to launch, What problems would arise and how big would it be? What prevents a blimp/...
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Why GSLV is so strange rocket? [duplicate]

GSLV looks strange: 1. It has liquid fuel boosters and solid fuel core, while all other launchers with boosters have solid fuel boosters 2. Its boosters finish to work after core, so actually they are ...
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What was the point of the re-entry and landing burn of the first stage of the GovSat-1 launch?

Supposedly SpaceX did not intend to recover the first stage of the GovSat-1 launch. If so, what was the point of doing a re-entry burn and a landing burn, if they were just planning on dumping the ...
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Why do we only add boosters to increase payload launch by a rocket?

I may be mistaken but it seems to me that to increase the payload a rocket can put into orbit, manufacturer add booster but do not modify upper stage(s). falcon heavy is a falcon 9 with additional ...
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Is it possible to use RCS instead of gimbal to control first stage attitude?

Questions like this one emphazise the role of gimbal to control the attitude of the first stage. But once in orbit, satellites usually uses reaction control systems. Is it possible to use RCS to ...
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I don't understand the speed readings for stage 1 on CRS-12

I don't understand the speed reading for the CRS-12 misson's stage 1. While being around an altitude of ~100km the minimum speed that is shown in the webcast for stage 1 is ~1600km/h. If the speed ...
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How many kilo's of nitrogen does Falcon 9 load for its first stage cold gas thrusters?

Watching the video of the 1 May NROL launch, I was surprised at the frequency and apparent size of the cold gas thruster firings. Does anyone know approximately how many kilograms of N2 are required ...
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Why do some rockets not ignite all their engines during liftoff? (GSLV MK3 LV)

As I understand it, a rocket should produce its maximum thrust on liftoff. As time progresses, the mass of the rocket will decrease, but since the engines produce the same thrust, the rocket will ...
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Why is it such a big thing to recover the first stage in a reusable way? [duplicate]

When I got it right, the big problem to overcome for SpaceX was, to get the right technique to land the first stage properly. This requires the first stage also to have enough fuel, so it can burn ...
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How long does it take SpaceX to mount a stage on the McGrgeor test stand, run the test, and dismount it?

Gwynne Shotwell at SmallSat 2016 in Utah mentioned that SpaceX would be using the JCSAT-14 recovered first stage as a fleet leader in wear and tear. That they would be mounting it on the McGregor, TX ...
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How does a simple construction keep a firing rocket on the ground?

Today I have seen this report of a SpaceX Falcon 9 rocket test firing. The force of a burning rocket is tremendous, and in the video we see an apparently simple construction keeping the rocket (or ...
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How does the SpaceX Falcon 9 first-stage straighten for landing?

I just saw this video of supposed "SpaceX Rocket Camera Landing Footage Fakery" with over a million views. The narrator repeatedly says it's complete garbage because he doesn't understand and would ...
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How does the Falcon 9 first stage land on the moving surface of the barge?

From this question we know the barge can be held at a set position with an accuracy of one meter or so. So the barge doesn't really move in the X and Y direction. This takes care of yaw as well. But ...
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SpaceX first stage landing: Why not use an elevated net above the landing platform to catch the rocket?

The rocket would keep same descent system as now (no parachute). But instead of landing on feet, it would have long grid fins on its top that would be catched by an elevated cable net. The previous ...
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Falcon 9 - fuel needed to hop back from a barge

There were multiple mentions of the future ideal first stage ASDS landings - if the mission won't have enough deltaV to do a RTLS, then just land on the barge, refuel and "hop" back to the launch site....
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How does static test firing before launch affect design of rocket mass and structure?

Some launchers, like Falcon 9 recently as in a video clip linked to below, and I think some other launchers since long ago in the space race history, test their engines before launch by firing them ...
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Move landed rocket stage back to launch pad

How are SpaceX supposed to return the rocket's first stage to the launch pad/hangar for re-fitting after it has landed on a landing zone on land, or on a barge? Since they aren't landing on a launch ...
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How rough was the redirecting, re-entry and landing of the first stage of the Falcon 9?

How big was the acceleration during the different phases after the stage separation? Would it be safe to land a human being that way? (at least taking only the g-forces into account, as I suppose ...
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How did the Falcon 9's 1st stage return back to Cape Canaveral?

SpaceX's original plan was landing the 1st stage to a landing ship, that waits far away from the launch site, and it was like this: But tonight, the rocket's first stage landed at Cape Canaveral. ...
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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 ...
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Could SpaceX start testing to return the Falcon 9 first stage to land instead of water?

My thinking is that: The primary reason to try to land on a barge instead of land appears to be safety (Answers to this question). Ultimately, it looks like they want to return it to land. SpaceX ...
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How stable would a Falcon 9 first stage be after it has landed on a drone ship?

Presumably, the booster would be a very light, very tall tube (Most of the fuel spent) standing on 4 fairly small legs on a ship in the middle of the ocean. It would also still contain some LOX and ...
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Why does the Falcon 9 have 9 engines?

What are the reasons for using 9 engines in the first stage of the Falcon 9? Why not 8 or 10? Looking at the Raptor engine, they seem to be looking at 9 engines again. Is there some specific advantage ...
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Would it not be easier for SpaceX to make their first stage only partly reusable?

Very excited about the upcoming test to land the first stage of the next Falcon 9 on an ocean platform. Elon Musk & Co. make it sound incredibly difficult though. I'm assuming that the first ...
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Why would SpaceX not use parachutes for the final descent of the first stage?

According to what I've read, SpaceX tried to use parachutes to recover the first stage of the Falcon 9, but it did not survive reentry. Now they plan to use 2 separate rocket burns to land: Reentry ...
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How far would the STS get without the SRBs

This is a very stupid hypothetical - sorry! Would the Space Shuttle Orbiter plus external tank have been able to leave the pad just using the SSMEs (i.e. without the solid rocket boosters ~80% of its ...
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Can a solid first stage compete with a liquid fueled first stage?

The thing about solids is that they can have awe inspiring amounts of thrust compared to liquid engines, as you can see in this collection of boosters and thrust levels: Shuttle SRB - 2.8 Mlbs Ariane ...