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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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Details about traveling from EM-L2 to SE-L1

Would the optimal time to launch be when the Moon was on the opposite side of the Earth from the Sun. What direction would be optimal leaving EM-L2, radially away from the moon? Is the last line of ...
2
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1answer
82 views

How would 2 spacecraft be launched to be in sync in opposite directions?

How would 1 spacecraft be launched to have a prograde orbit and the another be launched retrograde to have a mirrored orbital path around the sun or otherwise? Would the 2 spacecraft launch together ...
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2answers
594 views

What regulations, agreements, or other forces can help mitigate “PrankSats”? [closed]

comment: I've used a somewhat innocuous abstraction of 'pranks in space' below, but there's no end to the trouble that could be caused and the increasing ease with which a state (nation or otherwise) ...
2
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0answers
63 views

Space-X Canaveral launch question

In the past, I could see space shuttle launches from my front door on the gulf coast of Pinellas County by looking due east on a clear day or night. I have tried to catch Space-X launches a couple ...
3
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3answers
233 views

Why SpaceX have the T+0 second in the countdown while the Space Shuttle 'skip' the T+0 second?

Does the space shuttle countdown skip the first second after launch (T+0) and if yes why? You can see this effect in videos like this one: In comparison with an ...
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1answer
205 views

What is meant by “a high-energy geostationary orbit”? (SpaceX Arabsat 6A)

The Teslarati article SpaceX’s April 7th Falcon Heavy launch a step toward new commercial markets says: While there is some inherent uncertainty surrounding the (once again) fairly new rocket, ...
97
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4answers
15k views
14
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5answers
3k views

Why does Arabsat 6A need a Falcon Heavy to launch

Is it just me or does a falcon heavy seem like a bit of an overkill to launch Arabsat 6A? Falcon Heavy - GEO payload: 26,700 kilograms Arabsat 6A - weight: ~6000 kilograms Wouldn't some other ...
6
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1answer
204 views

Optimal thrust vs isp for variable isp rockets (VASIMR) when taking off/orbiting

This question was initially inspired through playing Kerbal Space Program, however I am seeking a more general answer. I've been playing the excellent Near Future Propulsion mod for KSP, using ...
14
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4answers
7k views

What is the base of a launchpad made of?

I'm curious as to what launchpad bases are made of - it seems to always be made of concrete, but wouldn't the concrete disintegrate rather quickly with jets of fire pounding on it?
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1answer
100 views

Can an Ion engine in tow assist in launch? [closed]

This question asks: How large a body could a probe with ion engines land on and launch from? and made me think could an ion engine that is the payload be mounted in a way to assist in the launch?
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7answers
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How far south can one see a rocket launch from Cape Canaveral, Florida?

I'll be in Miami this Thursday 30th of March and there is a SpaceX Falcon 9 rocket launch from LC-39A, Kennedy Space Center, Florida (if it's not delayed). I won't be able to drive north to be on ...
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1answer
35 views

Resources for planning and schedule a launch-watching day-trip in Florida?

I know some busy people in Florida who I'd like to encourage to take a break and go watch a launch. They aren't "space people" and won't be keeping up on technical blogs or NASA or industry websites. ...
12
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2answers
3k views

Can a rocket refuel on Mars from water?

Can a rocket run only on hydrogen and oxygen? Could a rocket, rover, and electrolysis machine be sent to either of Mars' poles to excavate ice to make hydrogen and oxygen to refuel an unmanned rocket? ...
6
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1answer
302 views

What is the source of the 'whoop' sound made before the liftoff (T-3s) of Atlas-V rocket?

For reference, you can hear the distinct 'whoop' sound at T minus 3 seconds mark of the recent TDRS-M launch. This sound has been distinctive for most previous Atlas-V launches as far as I can ...
2
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1answer
88 views

What is the point in which metal turns white hot during launch or reentry called?

This is a slow motion film of the Sprint missle. There is a point where to skin goes white hot like a light switch. What is that called? What metal gets white hot while keeping its shape?
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1answer
125 views

Could a rocket launch off water horizontally in stages us using water and air for lift to save fuel? [duplicate]

A term I have heard is the "water was like class". Meaning that the water had 0 waves. Could a rocket be modified to take off a horizontal surface starting slowly increasing throttle on each stage? ...
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0answers
111 views

Are there “Space Jellyfish” in Florida? Would they be possible?

The Wikipedia article Space Jellyfish shows the image below with the caption: A California space jellyfish from 22 December 2017 I think that when other Q&A here have shown similar space ...
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3answers
255 views

Can more thrust come from launching parallel to water?

Would having the exhaust of a rocket or air breathing engine in an early stage in close proximity to water on a horizontal launch provide more thrust? Could a rocket launch off water horizontally in ...
4
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1answer
142 views

What kind of “jet engine-like propulsion” does HyperSciences use to accelerate projectiles to sub-orbital altitudes?

The Teslarati article For HyperSciences, geothermal energy builds a path to space describes the use of technology which has been applied to drilling to launching projectiles to sub-orbital altitudes ...
6
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3answers
207 views

Can a flock of birds crash a rocket?

Has there ever been a situation when birds caused damage to a rocket? At what speed would birds be a problem? Could a rocket launch off water horizontally in stages?
3
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2answers
244 views

Could a fat rocket be used on Mars?

Since Mars' atmosphere is around 2% the density of Earth's then could a much wider rocket achieve orbit? Could the rocket be in the shape of a capsule or an optimal shape for reentry on Earth?
4
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1answer
162 views

Could escape velocity be achieved in the atmosphere?

When rockets launch for orbit they travel up and the air thins respectively to the speed increasing. How fast can a rocket for travel at sea level before it would fail or the elevation would have to ...
10
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1answer
527 views

How should one analyze the video of the Antares CRS-3 explosion to find the clues to the cause?

From the raw video of the event (which just happened), a trained eye can narrow the possibilities, given good general knowledge of the rocket. What in the video indicates which systems were involved, ...
2
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2answers
126 views

Break Away Valves for Launch [duplicate]

I forgot to hang up the fuel pump and broke it off and costed around 80 dollars to replace. While there I wandered could this be adapted to a rocket in some way? How much fuel capacity would be saved ...
4
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1answer
74 views

What rocket system launch contained the highest amount of propellent potential energy?

In regards to rocket launches, what rocket launch contained the most potential energy (joules/btu/etc.) in its thrust propellant to achieve is basic mission? I'm not as much concerned with ...
14
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0answers
246 views

Has SpaceX ever done a hot restart of a 2nd stage?

Another question highlighted this Space X commentary for the GRACE-FO launch: Now in order to fly an efficient trajectory for both of the payloads, we’re actually now running the second stage ...
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0answers
68 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 ...
16
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1answer
170 views

When have secondary payloads damaged the primary payload of a launcher?

Primary payload customers have traditionally been cautious when allowing secondary payloads on the same launcher. For example, a secondary payload is not trusted to have its own chemical propulsion ...
2
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0answers
42 views

What is the minimal distance of clearance in the direction of flight path for a rocket?

Usually the rocket launch sites are placed on a coast or a place where there's basically no civilian buildings in the direction of flight path. Is there a standard/regulation on the minimal ...
67
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10answers
41k 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-...
8
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4answers
279 views

What prompted all of those private launch companies to get into the business?

It seems that, somewhere around the turn of the century, a bunch of private companies started gearing up for launching things into space when nobody (at least not private entrepreneurs) seemed very ...
4
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1answer
173 views

Most recent launch of a nuclear reactor, and current barriers to launching the next one?

This question about Kilopower nuclear reactors got me thinking. Answer(s) to How many nuclear fission reactors have been launched into space? How many are still there? suggest that most nuclear ...
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2answers
601 views

What is the most number of stages, including fractional stages?

Falcon 9 clearly has two stages, but the smaller two-stage Electron has a "kick-stage" so some might call that 2.5. The question Quantitative benefits of Atlas II's engine-dropping or 1.5 staging? and ...
2
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1answer
273 views

Help me understand what Farside, a ten “stage” rockoon looked like? How was it configured?

@OrganicMarble's answer links to NASA Sounding Rockets, 1958-1968, A Historical Summary and in Appendix A starting on page 79 it lists: Farside: A type of rockoon developed by Aeronutronics ...
3
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3answers
1k views

When was the first strap-on booster used in spaceflight?

The first use of the term "strap-on" in Google Ngram viewer is in 1930 and presumably that wasn't about a booster being attached to a rocket for additional thrust at lift-off. When was a strap-on ...
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1answer
1k views

How much propellant is used up until liftoff?

How much of the total propellant mass (fuel+oxidizer) of the first stage/boosters is usually burnt between ignition and liftoff?
4
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2answers
841 views

Which are the main obstacles of launching my own home-made space object?

What's missing for everyday people to be able to launch his own satellite (or any other space objects) into space? I mean, I know that mostly money and technology, but what does it actually mean? ...
4
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3answers
274 views

Has SpaceX applied for license to broadcast video from space?

SpaceX stopped broadcasting live video out the rear of the Falcon 9 2nd stage while the engine was firing after they were informed they needed a license to do so. This is further discussed in the ...
6
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3answers
548 views

Soyuz has a Space Periscope?

The image Photo ID: ISS049-E-003166 can be found in Flikr and Wikimedia Commons as well as in Spaceflight Now. There is a long (perhaps 1 meter?) green structure that is sticking out from the side of ...
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0answers
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What happened to International Microspace's $100 million contract?

This might be an obscure one. As I understand it: Diamandis co-founded Microsat Launch Systems, which was renamed International MicroSpace, in 1989. (This is apparently not the Micro-Space of 1977 to ...
8
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1answer
159 views

Launching east from a mountain on the equator at midnight during a new moon; ranking of each contribution?

This answer is intriguing and I'm curious if it's correct, and especially which effects are most important. If you want to avoid gravity assists, the most fuel-efficient way out of the Solar System ...
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2answers
7k views

What is the ideal shape for a rocket?

Obviously there are many factors that go into the design of a rocket. However, to me, many rockets seem very tall and skinny. What I mean is that an ideal rocket would have as little mass used for ...
6
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2answers
380 views

Why is NASA buying expensive rockets from ULA when SpaceX is offering the same thing for almost half the price?

Source: https://www.teslarati.com/spacex-ula-nasa-launch-contract-win-vastly-overpriced-official-protest/ SpaceX has filed an official protest with the US Government Accountability Office (GAO) ...
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1answer
165 views

Are we changing Earth's rotation?

Can rockets launching change Earth's rotation, and can going into orbit do the same?
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4answers
819 views

Do the propellant tanks of actual (not planned) expendable vehicles' upper stages have relief valves?

This question was inspired by the answer to this question. The answer, in part, states that overpressurization of propellant tanks is a cause of upper stage explosions, leading to orbital debris. ...
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3answers
13k views

Effect of atmospheric drag on rocket launches and benefits of high altitude launch sites

What is the approximate influence of atmospheric drag on the cost of rocket launches? Is it beneficial to have launch sites located at higher altitudes? Cape Canaveral is at sea level, but I've ...
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0answers
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What light was the Falcon 9 grid fin occulting in todays SpaceX Nusantara Satu Mission live broadcast?

What light was the Falcon 9 grid fin occulting in todays SpaceX Nusantara Satu Mission live broadcast? I backed up the time slider on the YouTube live broadcast and snapped some screen captures, ...
55
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5answers
6k views

How much bigger could Earth be, before rockets would't work?

hint: Apparently the Tsiolkovsky rocket equation does not actually say that you can launch a conventional rocket into orbit around an arbitrarily large and massive body. Question: "How much bigger ...
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2answers
2k views

In the Saturn V launch sequence, what defined COMMIT, and what happened between COMMIT and LIFTOFF?

With the Saturn V, there were two critical moments during launch that I am curious about: The vehicle COMMITs to liftoff The vehicle LIFTS OFF LIFTOFF is fairly obvious: the booster has risen some ...