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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.

2
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1answer
58 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 ...
5
votes
2answers
241 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 (...
6
votes
1answer
86 views

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 ...
2
votes
1answer
53 views

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
votes
1answer
96 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
votes
1answer
47 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 ...
1
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2answers
99 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
28 views

Low space elevator / high space launch [duplicate]

Launching from the ground is expensive, building space elevator is too complicated for now and expensive as well. Would it bring any benefits to try to build elevated space launch platform? Lets say ...
6
votes
0answers
109 views

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
votes
1answer
81 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 ...
3
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0answers
111 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, ...
1
vote
1answer
59 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
votes
1answer
112 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 ...
0
votes
2answers
167 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/...
1
vote
1answer
71 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 ...
8
votes
2answers
118 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 ...
6
votes
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 ...
1
vote
2answers
149 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 ...
8
votes
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.
2
votes
3answers
133 views

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 ...
2
votes
1answer
145 views

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 ...
3
votes
3answers
154 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 ...
0
votes
1answer
66 views

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 ...
4
votes
0answers
113 views

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 ...
30
votes
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'...
26
votes
4answers
4k views

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 ...
10
votes
2answers
173 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. ...
3
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0answers
63 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 ...
0
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0answers
49 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!
3
votes
1answer
252 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 ...
4
votes
0answers
125 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
votes
1answer
152 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:...
4
votes
1answer
157 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 ...
7
votes
3answers
328 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 ...
4
votes
1answer
51 views

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 ...
8
votes
1answer
191 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 ...
1
vote
0answers
26 views

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 ...
5
votes
1answer
305 views

What caused launch abort on SpaceX's Bangabandhu-1 launch

On Thursday, May 10th, 2018, SpaceX attempted a launch of the first Falcon 9 block V rocket carrying Bangabandhu-1 however the countdown was stopped at t-58 seconds and the launch was scrubbed for 24 ...
1
vote
2answers
126 views

Help understanding negative apogee coinciding with exact center of Earth (Mars InSight launch)

Watching the NASA JPL video NASA Launches InSight to Mars (Part 2) after MECO-2, the orbital parameters shown in the video don't make sense to me; specifically the apogee altitude. At this point in ...
4
votes
1answer
148 views

Did InSight take a “mean left” turn on its way to Mars? Is it an out-of-plane maneuver?

In the NASA JPL video NASA Launches InSight to Mars (part 1) after about 14:30 (currently) NASA's new Chief Scientist Jim Green (better photo here) explains: ...
6
votes
1answer
516 views

Did the medium range KTM tracking cameras for the Shuttle really have a “150 inch lens”?

The Curious Droid YouTube video How did NASA get those great film shots of Apollo and the Shuttle? found here and linked-to in this comment contains the following passage starting at ...
3
votes
1answer
109 views

Visibility requirement for launch; when can it be ignored (or “mitigated”), and why?

The Space.com article NASA Gives 'Go' for InSight Mars Lander Launch, Visible or Not includes the passage: As of Thursday morning, there was an 80 percent chance of the marine fog layer exceeding ...
3
votes
0answers
80 views

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 ...
7
votes
1answer
152 views

How much jerk do astronauts experience? Is there a safety limit?

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 ...
23
votes
5answers
8k views

What is the feasibility of a rocket hobbyist achieving a LEO orbit with a microsat?

Along with being a rocket hobbyist, I'm also an Amateur Radio Operator. I would like to determine the possibility of placing a "microsat" a miniature packet radio satellite, into a low earth orbit.
0
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1answer
72 views

Is NASA's Performance Vehicle Calculator website open for public use?

This answer links to "NASA's Performance Vehicle Calculator" with the link https://elvperf.ksc.nasa.gov/Pages/Query.aspx I've also found the same link in https://forum.nasaspaceflight.com/index....
5
votes
1answer
166 views

What stole the INSPIRE cubesat launch opportunity, and will there be another?

Doing research for this answer about interplanetary cubesats, I watched the NASA Jet Propulsion Laboratory YouTube channel video CubeSats (live public talk) of a talk by Dr. Andrew Klesh, Chief ...
1
vote
1answer
111 views

First interplanetary launch from California! How far from Earth will InSight be when it separates from the Centaur 2nd stage?

The Phys.org article Bound for Mars—countdown to first interplanetary launch from California says: In the early morning hours of May 5, millions of Californians will have an opportunity to witness ...
3
votes
1answer
137 views

First interplanetary launch from California, why the initial polar orbit? [duplicate]

The Phys.org article Bound for Mars—countdown to first interplanetary launch from California says: In the early morning hours of May 5, millions of Californians will have an opportunity to witness ...