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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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Satellite retrieval, fix and deploy possible remotely?

Is there any satellites that are designed to come back to Earth for repairs or upgrades and then be deployed again? Would there be any benefits to creating a capsule or inflatable heat shield to go on ...
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2answers
137 views

Can a rocket be intercepted in mid air?

Suppose that: 1-an interplanetary crewed rocket such as SpaceX BFR is built in secret. 2-the launch station can be arbitrary located. 3-the rocket is launched without any warning. 4-the rocket is ...
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0answers
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How to make a orbital launch tube work?

Normal rockets would not work in a pressurized tube, but could a stage be made for the diagonal launch tube to save fuel and weight? Can the bottom stage be nuclear powered? Unlike the piston launch ...
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1answer
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Does a retrograde launch impact the return booster propellant requirements, as compared to prograde?

Space-X's latest launch, of SAOCOM-1A, was a retrograde launch from Vandenberg, with a landing back at Landing Zone 4 - at Vandenberg. A retrograde launch requires more energy (to counteract the ...
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1answer
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Would a Martian landing and take off require a flame trench/deflector?

Flame trenches/deflectors are essential for avoiding reflections of acoustic waves from damaging the rocket system while taking off. This is discussed in this YouTube video - Why doesn't the sound of ...
3
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1answer
70 views

Should all the Air-Launch systems be deployed at sub-sonic speeds?

There have been several proposals to develop Air-Launched rockets, like what Virgin Orbit or Pegasus rocket doing. All of the concepts are released from aircrafts in a Sub-Sonic velocity (0.7 to 0.8 ...
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8answers
5k views

How would a long pole be transported to space?

Can a long pole or a set of poles be strapped to the out side of a rocket (like a bottle rocket)or on the nose as an external payload without interfering with the aerodynamics of the rocket? How would ...
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2answers
201 views

What happens to rocket stages that land in the oceans, and how many are still there?

When a rocket stage is jettisoned into the ocean, does it typically sink? Assuming yes, how many rocket stages are now lying on the ocean floor? Are there, on the ocean floor, areas where there ...
5
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1answer
294 views

What do you need to do legally to have an object in orbit?

Hello fellow explorers, I've been looking into amateur satellite and rocket launches. Now, I'm by no means saying I'm an expert and have all my plans ready for launch. However, hypothetically if I ...
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1answer
227 views

Could electric fans lift a rocket? [closed]

An electric turbine engine used in planes have nowhere near the thrust needed to lift a rocket anywhere. What if the amount of electricity needed to lift a interplanetary rocket delivery system and ...
7
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1answer
292 views

Are there any dog-leg hot-spots? Where are dog-leg maneuvers used most frequently?

Dog-leg maneuvers are nicely explained in @JakeBlocker's excellent answer. If you go there now (and hopefully come back here) you can see a diagram of a dog-leg maneuver along with a comparison to an ...
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1answer
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Does the ISS still “need” to be at around 400 km?

The video Why is the International Space Station 400 km above the Earth? first mentions that there are fairly hard limits at 300 km (due to imminence of reentry) and 700 km (loss of protection from ...
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1answer
89 views

Deciding factors for launch site

While deciding the launch site layout, what parameters are considered? I understand that the various components like monitoring station, propellant storage tanks are kept at some safe distance. How ...
2
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1answer
239 views

Beyond the Apollo 12 incident, have there been any instances of triggered lightning?

As explained in this answer, the ionised plumes of engine exhausts can provide a low-resistance route for lightning strikes during a launch, potentially endangering the vehicle. This is thought to ...
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2answers
269 views

Aerodynamically - can a rocket be over 30 meters in diameter?

The past and current designs of rocket launchers have diameters up to 8-10 meters (Saturn-5, N-1, SLS, BFR), up to 13-14 meters for max cross-section dimension for Space Shuttle and Energia-Buran (...
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1answer
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What is 'triggered lightning'?

In NASA's pre-launch briefing for Parker Solar Probe, the Weather Officer Kathy Rice discusses briefly the possibility of 'triggered lightning'. See around 40:55 in this video1. She explains: We ...
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1answer
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Launch cost of a small satellite

The satellite mass is 100 kg. The volume is 150 $dm^3$. The orbit is sun-synchronous (700km altitude) I'm doing a research to find the actual launch price of this satellite by ISRO, Arianespace, ...
5
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1answer
103 views

Is the atmosphere a positive or a negative for reusability?

Does the atmosphere provide a benefit or detriment in terms of fuel economy for rockets that take off and land back on Earth? We know that the atmosphere plays a large role in helping slow down ...
2
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1answer
53 views

What is intermediate thrust and brief pause for checkout on launching Soyuz spacecraft?

In a book I'm reading, the author mentioned the launch of Soyuz spacecraft as follows: What made it more spectacular was how close we were when it lifted off the launch pad. Yuri, Tim and I were ...
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2answers
119 views

Does (or has) the US military launch anything besides weapons and weapons tests into space themselves?

Discussion below this question has lead to this question. I'd like to know if the US military has in the past, or still does, launch non-weapon payloads into orbit themselves. (Orbit, as opposed to ...
15
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2answers
3k views

What are “Ohms burns” in the context of Scott Kelly, KSP, and the Space Shuttle?

The Ars Technica video Astronaut Scott Kelly teaches orbital mechanics with Kerbal Space Program (also in YouTube) is a little bit humorous. When Scott Kelley is talking about orbit circularization ...
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0answers
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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?

This tough question links to the NASA YouTube video NASA 60th: How It All Began which shows a lot of really nice, historical file footage and stills. After about ...
3
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1answer
150 views

Temperature and pressure of rocket exhaust

What is the temperature and pressure of the exhaust that comes out of the rocket during the last three seconds of countdown (smoke that stays near ground)? How much carbon dioxide is there in that ...
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0answers
120 views

What would be the implications of high-altitude or catapult launch for orbital rocket?

There are lots of questions on here which ask "Why aren't rockets launched from railguns/mountains/balloons/etc." and lots of nice answers mainly dealing with the practical difficulties of doing so, ...
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1answer
61 views

Heavier Rockets Launched By Planes [duplicate]

Would it be physically possible to use a plane to assist heavier rockets with their launches (I know orbital ATK launches their pegasus rockets from planes but would it be possible to launch something ...
4
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1answer
154 views

For an Apollo Lunar Module Ascent Stage launch, what is the optimal profile of $\beta$ (or $\gamma$) vs time?

When Apollo astronauts departed the lunar surface in the Lunar Module's Ascent Stage, it appeared to rise vertically ($\beta$ = 0) for ~10 seconds and then begin the "tipover" (videos of Apollo 15, 16 ...
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2answers
173 views

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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1answer
77 views

What is the maximum speed can a space rocket can travel with an air pressure of 14psi? [closed]

What is the highest threshold speed of a space rocket traveling in an air pressure of 14psi with all of its stages if they where able to leave a solo at Mach 1 or more? Related: What benefits can be ...
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2answers
154 views

What sensors or combination of sensors do rockets use during takeoff for their orientation?

I know that after using up rockets and before reaching final orbit, satellites use Earth, Sun, Star trackers to find the absolute position depending on the application and orbit. After that, they use ...
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6answers
2k views

What benefits can be gained from launching below ground?

ICBMs are commonly launched from below ground. How much fuel could be saved if a missile is launched below ground instead of above? If the tube was deeper with modified launch by a separate chemical ...
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2answers
156 views

What prevents the use of electric engines to assist with spacecraft launches? (Launch Booster Supplement)

Much fuel is used to get rocket off the platform on the initial launch. Could electric turbine engines be used like booster rockets? Could an electric engine like a rail gun work similar in the way ...
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3answers
2k views

What is the largest and/or heaviest object that could be sent to space?

What is the largest and/or heaviest object that could be sent to space? I know the space station is sent in pieces but I am looking with one launch.
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3answers
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Is there anything like a standard for maximum temperature for mission-critical electronics in spacecraft?

In addition to radiation, acceleration, and vibration, a launch vehicle can encounter excursions in temperature, and critical electronics for guidance and control should probably be resistant to ...
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1answer
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Is there an optimal accelaration for first stage going in LEO?

I know every engineering works is based on compromises, and rocket design is no exception. A rocket should go as quickly as possible to high altitude to avoid flying for a long time and at high speed ...
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3answers
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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 ...
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1answer
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How do I prepare a preflight excel sheet template for satellite launch?

I would like to know if anybody has any advice regarding a preflight check that I am doing for a satellite. I would like to know if anybody has any experience regarding a standard excel sheet for all ...
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0answers
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During the launch of a rocket, how close are the nearest humans?

I've been wondering how close other people are to large rockets when they launch. launch complexes looks huge; are there people near the launch pad during a launch? If yes, how do they handle the ...
31
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2answers
4k views

What holds SpaceX’s rocket in place in this launch?

On a recent launch video, the gantry is at an angle and only loose tethers are attached as the rocket is prepared for launch. What is keeping it upright and in place at this point? The engines haven'...
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4answers
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Why aren't payloads their own fairings?

...or if they can, why so rarely? I mean: instead of placing a satellite of nondescript shape inside a fairing which is discarded somewhere above the atmosphere, build it in such a way that its ...
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2answers
218 views

When does $I_{sp}$ become more of a concern than thrust?

In an orbital launch from Earth, the priority in the initial phase of the launch is high thrust, so as to actually get off the ground, and minimise losses due to "gravity drag" and air resistance. ...
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0answers
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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 ...
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0answers
54 views

Launch corridors

I was wondering where I could find a list of the launch azimuth ranges - i.e. the corridors - for the main launchpads worldwide (Baikonur, Kourou, KSC, ... as many as possible). Thank you in advance!
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1answer
258 views

Why has the number of European space launches dropped in 2018?

There is a table of space launches from wikipedia in 2018 (Images have been updated on July 11, 2018): For now about half of year has been passed, but share of ESA launches is comparable with share of ...
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0answers
242 views

Which launch was the first to use a dogleg maneuver?

Jake Blocker's excellent answer explains what a dogleg maneuver is, what it's for, what it looks like, and even what a real dog's leg looks like for comparison! A dogleg maneuver is done to change ...
4
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1answer
157 views

SpaceX nose fairing heating during launch?

In watching the Space-X SES-12 launch last night, I noticed what looked like the nose fairing of the rocket glowing a bit a while after launch. This was most obvious in the video about T+1:30 to T+1:...
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1answer
168 views

Ground personnel proximity to space shuttle at launch?

In watching some YouTube videos of US Space Shuttle launches, I was wondering how close personnel were to the actual launch pad during a launch that weren't actually on the Shuttle itself? Obviously ...
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3answers
355 views

What are these circular structures around the rocket?

Youtube video of the Iridium-6/GRACE-FO NASA Launch (Falcon 9 SES-12). Edit 31 May: Too bad they have changed the content of the video (and still call it 'live'), so that you can no longer see the ...
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1answer
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How to identify loads for a Payload Adapter System during Rocket Launch?

Good afternoon, A classmate and me are doing a project for university in which I have to perform several structural analysis of the Payload Adaptar System 937C from Ariane V (picture shown). The ...
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1answer
210 views

Why would a significant non-zero angle of attack be an advantage during 1st stage burn?

From videos of both the SES-10 launch shown in @RusselBorogrove's question, Cause of apparent plume deflection on SES-10?" and the Block 5 launch Bangabandhu Satellite-1 Mission at ...
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0answers
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Non-axial thrust during Falcon 9 Block 5 launch? [duplicate]

Looking at video of the Block 5 launch today (2018 May 11) I noticed that from the ground tracking views, the vehicle roll axis and the exhaust plume appeared not to be collinear. When they cut to the ...