Questions tagged [launch]

Questions regarding the takeoff or the liftoff phase of the flight of a rocket and the set of activities required for preparation of the launch vehicle leading to it.

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How did "the kid" (John Meisenheimer) calculate that there was a wave in the jet stream and Explorer 1 would be okay to launch?

The tough but timely question NASA at sIxty years, will there be a new moonshot mandate? links to the NASA YouTube video NASA 60th: How It All Began which shows a lot of really nice, historical file ...
uhoh's user avatar
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9 votes
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242 views

What rocket uses the largest percentage of Fuel/Oxidizer before liftoff?

inspired by this question: How much propellant is used up until liftoff? which asks how much propellant (fuel/oxidizer) a typical rocket uses before liftoff. What has been or is the most non-typical ...
Sdarb's user avatar
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7 votes
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192 views

Does the low gravity on Moon eliminate the need for a launch pad/flame trench for a reusable rocket launch?

I'm new to rocket science and I learned how the rockets do not reach full thrust immediately and isn't really stable for the initial couple of seconds - hence the need for "launch clamps" and a ...
Atakan Okan's user avatar
7 votes
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101 views

Are "launch-on-minute" or other discrete launch times protocols currently the norm for wide launch windows?

This excellent answer to a question about collision avoidance practices for launches begins with: While the length of a launch window varies, launches within the window typically occur at discrete ...
uhoh's user avatar
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How far does the sound of a rocket launch carry?

Having never been to a rocket launch, can you tell me how far the sound carries? I can hear the rumble of F-15 Eagles take off from inside my office building five miles from the airport. An F-15C is ...
Dan Sorensen's user avatar
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7 votes
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579 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 ...
Val's user avatar
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6 votes
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159 views

How much did it cost to refurbish the Launch Complex 39 hardware after an Apollo Saturn V launch?

A launch pad used for a rocket of some 30-35 MNewtons of thrust does not come out of it unscathed. It must be refurbished before it can be used again. How much does that cost? As an indication of such ...
Tom Spilker's user avatar
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6 votes
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How long does it take to chill the LOX and RP1 for Falcon 9 V1.1 Full Thrust?

The new version of the Falcon 9 v1.1 Full Thrust, or as SpaceX would like everyone to start calling it "Falcon 9", uses super cooled LOX and RP1 to improve the density of the fuel for better ...
geoffc's user avatar
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6 votes
1 answer
465 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?
PearsonArtPhoto's user avatar
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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 ...
user16734390's user avatar
5 votes
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288 views

Did the EU successfully ban hydrazine? What about French Guiana?

Hobbes' answer to Is the EU really banning “toxic propellants” in 2020? How is that going to work? includes Yes, the EU is aiming to end the use of hydrazine by ~2020. This has been in motion since ...
uhoh's user avatar
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527 views

Falcon 9 plot of pitch angle vs time during launch?

I found this super helpful plot of the Saturn V pitch angle vs time during launch: Is there an equivalent plot for a typical (or atypical if must be) Falcon 9 launch?
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5 votes
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138 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 ...
nialv7's user avatar
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Which nations own tracking ships for support of rocket launches?

This wikipedia list of tracking ships contains ships of the following nations: China, France, Russia and USA. Are there no other missile range instrumentation ships for support of space operations of ...
Uwe's user avatar
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What were Hubble's jerk and jounce limits? Did JWST have the same?

From Wikipedia: In physics, jerk is the rate of change of acceleration; that is, the derivative of acceleration with respect to time, and as such the second derivative of velocity, or the third ...
uhoh's user avatar
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Commentary-free launch video?

Does NASA broadcast live video of their launches (specifically from Kennedy) that does not feature commentary? I appreciate Mike Curie's comments but... sometimes I just want to hear the controllers ...
blamblambunny's user avatar
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217 views

Were composite materials used on Soyuz and on Atlas launchers?

I would like to know if composite materials were used on Soyuz and Atlas launchers but I can't find a lot on the web. I also would like to know which components of other launchers are made of ...
Mirko88's user avatar
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426 views

Shortest and longest times a real rocket got into LEO from liftoff?

I'm looking for the record shortest and longest times a real rocket took to get its payload into LEO, such that it didn't need any additional delta-v to stay in orbit, starting from launch at the ...
Thomas's user avatar
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5 votes
1 answer
769 views

How much noise would the BFR make at launch?

In addition to multi-planetary travel, SpaceX has plans to use the BFR for intercontinental travel. However, would the sound generated by the BFR's launch disrupt local communities and therefore make ...
Vivek's user avatar
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4 votes
1 answer
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How do space launch providers calculate how many millipeople a rocket launch could kill?

I was intrigued by this post which states... To get a license you have to show that your launch will kill no more than ~1 milliperson, which usually means not flying close to population centers. I ...
phil1008's user avatar
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4 votes
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What caused the H3 rocket to squeal so loudly after its launch abort?

Immediately after the H3 rocket's first launch attempt was aborted, a loud squealing noise could be heard on the live stream. What was this? The only thing I could find about it when searching the ...
Infinite_Maelstrom's user avatar
4 votes
0 answers
94 views

Why are the four launch opportunities within each Inspiration4 launch window "about an hour apart"?

In the SpaceX Inspiration4 Launch broadcast at about T-01:31:05 (91 minutes before launch) the process for selection of launch windows for the mission is roughly ...
uhoh's user avatar
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4 votes
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96 views

How old is the use of "L minus" to denote the number of days before launch?

In the SpaceX Inspiration4 Launch broadcast at about T-01:31:05 (91 minutes before launch) the term "L minus five" is used. While "T-minus" is a ...
uhoh's user avatar
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4 votes
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159 views

Do space transportation firms such as SpaceX receive a financial compensation if a launch is cancelled because of an airplane entering the launch zone

I read on https://arstechnica.com/science/2021/06/spacex-to-launch-second-rideshare-pressuring-small-launch-industry/ (mirror 1, mirror 2): The countdown clock got to T-11 seconds on Tuesday ...
Franck Dernoncourt's user avatar
4 votes
0 answers
111 views

Which crewed spacecraft provides the gentlest ascent?

The Space Shuttle is considered to be the spacecraft with the gentlest decent and landing. I was surprised to learn that its ascent was quite a rough experience. So I was wondering: Which orbital ...
DarkDust's user avatar
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4 votes
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230 views

Fastest Manmade Object

I remember reading somewhere that during the cold war, a nuclear weapon was placed underground with a manhole cover on-top and then detonated. I'm pretty sure the manhole cover then went orbital ...
und3niable's user avatar
4 votes
0 answers
258 views

SN11 was launched in fog. Why not wait for better conditions?

The fog certainly frustrated the external observers, but it doesn't seem ideal from SpaceX perspective either. All the external observers were very distant from the launch/landing site and would be ...
Roger Wood's user avatar
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4 votes
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48 views

How much of NASA's annual budget goes to launch

I've been trying to figure out how much of NASA's budget goes to launch costs. I would also be interested in the same question for the global space market. What I've tried I started with a simple ...
DiceMaster1018's user avatar
4 votes
0 answers
135 views

If I were to launch an rocket from the top of the troposphere, how much fuel would it save compared to launching it from sea level?

Let's say we have some kind of rockoon design where our rocket gets carried 20 kilometers up before it finally launches from its balloon/blimp platform. Would that maneuver save a significant amount ...
stoby's user avatar
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4 votes
0 answers
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How soon after launch is pitchover done?

I'm reading conflicting things on the timing of the pitchover. When exactly does it start? Many people write that it's almost immediately after launch, as soon as it's practical. Once the rocket ...
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4 votes
0 answers
149 views

During ascent, can SPACE-X ever be seen from Long Island, NY?

At night I have seen Space Shuttles' engine exhaust from Long Island NY, in the southeast sky 7 minutes after liftoff from the Cape. Does Space-X ever launch in a direction that it can be seen from ...
WarrenBackyardAstronomer's user avatar
4 votes
0 answers
92 views

Does the FAA have anything to do with landing on the Moon specifically?

The Motley Fool's Space Investors, Rejoice! There May Be Something Worth Mining on the Moon begins with: It's been four years now since Bigelow Aerospace filed its application with the Federal ...
uhoh's user avatar
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4 votes
0 answers
2k views

Differential Equations for Rocket Launch in Polar Coordinates

I'm trying to understand the equations of motion for a rocket launched from earth, through the atmosphere, and into LEO. I found a set of ordinary differential equations which describe the motion of ...
Paul's user avatar
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4 votes
0 answers
340 views

Was it another Fishing Tournament?

@KimHolder's thorough answer to What are the consequences for a person who violates a launch exclusion zone? mentioned a fishing tournament. @PearsonArtPhoto's comment about scheduling launches during ...
uhoh's user avatar
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4 votes
0 answers
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 ...
Markus Dittrich's user avatar
3 votes
0 answers
108 views

Does Starship perform a launch tower avoidance maneuver?

Does Starship perform a launch tower avoidance maneuver? If yes, is this accomplished using gimbaled raptor engines or RCS rockets? How far laterally is the Starship axis shifted by this maneuver and ...
Woody's user avatar
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3 votes
0 answers
145 views

Energy Needed for Lunar Lander to Ascend?

Is it possible to calculate how much energy was expended when the Apollo 11 lunar lander ascended from the Moon's surface to join the Command Module in lunar orbit? Many relevant parameters for the ...
David_B's user avatar
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3 votes
0 answers
224 views

How much of a rocket energy is needed to overcome aerodynamic drag?

this question How much of a rocket's energy is used to achieve altitude vs horizontal velocity? addresses the energy split of kinetic vs. potential energy to get to space - and to stay there. We ...
henfri's user avatar
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3 votes
0 answers
136 views

What is this thing that goes zipping past the Electron launch?

Watching the Electron launch 07 October 2022 on https://www.rocketlabusa.com/live-stream, what do I see in the video at T + 9:12, just after they confirm secondary engine cut off? I thought it was a ...
kmort's user avatar
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3 votes
0 answers
120 views

Reaction control system testing

How are RCS (reaction control systems) for Launch vehicles usually tested? After going through some literatures, I came across two different testing schemes, Leans more towards testing the Cold gas ...
nik's user avatar
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3 votes
0 answers
151 views

How does US crewed launch abort coverage "jump" the ocean in an instant?

As I understand things, the Commercial Crew Program stipulates full abort coverage from pad to orbit. An abort to the middle of the Atlantic ocean is understandably not acceptable. Watching the OFT-2 ...
BrendanLuke15's user avatar
3 votes
0 answers
77 views

Info needed on PSLV launch adaptors and configurations

I want to understand how satellites are accommodated in PSLV. I know about few configurations and adaptors that've been used in the past. Is there any document which gives detailed info on Multiple ...
Suyash's user avatar
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3 votes
0 answers
214 views

Most dog-legged launch?

There are enough questions about dogleg maneuvers that there is now a dogleg tag, but the definitive dogleg answer is @JakeBlockers (linked below) which includes images of a dogleg from Florida that ...
uhoh's user avatar
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3 votes
0 answers
327 views

How much would it cost to launch a 0.5U Satellite?

I have seen the figures for 1U, 3U and 12U Satellites such as those provided here, but I have been unable to find pricing for the launch of a single 0.5U or 0.25U satellite. I have seen many academic ...
codeosaur's user avatar
3 votes
0 answers
71 views

Falcon 9 Flipover Direction?

Consider a Falcon 9 at MECO. The rocket's close to 30 deg relative to the local horizon, down from the 90 deg it had at launch. Stage 1 separates and flips more or less 180 degrees for the return ...
user avatar
3 votes
0 answers
67 views

Detailed description of space shuttle major and minor GNC loops

Warning: repetitive question ahead. Please skip if you're tired of splitting hairs on these things. Is there a detailed description of the major and minor GNC loops of the space shuttle? I've learned ...
user avatar
3 votes
0 answers
225 views

Likely explanation for the bottom of the SLS rocket being covered with reflective silver "muffler" tape?

NASA.gov's First Artemis Rocket Stage Moved onto NASA Barge Ahead of Green Run contains a high resolution image of the rocket. The bottom end of the rocket's cylindrical shape is closed flat and ...
uhoh's user avatar
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3 votes
0 answers
153 views

Saturn V launch footage from in/on first S-IC stages

There first launches of each Saturn-class rocket were instrumented with, among other sensors, video cameras to learn about the vehicles’ behavior. The cameras were jettisoned at some point and then ...
Ludo's user avatar
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3 votes
0 answers
380 views

Cubesat/Nanosat dispensers/deployers costs

I’ m looking for informations about dispensers/deployers equipement costs and associated launch costs, espacially for 12U configurations and over. I’ve got price information on Tyvak 12U Deployer in a ...
Jean-Pierre Madier's user avatar
3 votes
0 answers
392 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 ...
bigbang's user avatar
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