52

Those are jets of water released by the sound suppression systems installed on the pads and the mobile launcher platforms to protect orbiters and their payloads from being damaged by acoustical energy, reflected from the platform during the liftoff stage of a rocket launch. For example, this is the sound suppression system at the NASA Kennedy Space Center's ...


45

Not even close. In fact, at 12 seconds in, you're looking at maximum damage to not just the pad itself, but the surrounding area as well. You're going to have tons of debris (most of it burning and possibly carrying even more unburnt fuel) fall from 1500-2000ft range in a giant umbrella of destruction. In 1997, a Delta II carrying the GPS IIR-1 satellite ...


32

Because it is. It is a very tall structure, first stage alone is 140 feet, plus second stage, plus fairing. It is considered at the limit of how tall and thin they can make it. Wikipedia says the total height is 230 ft (70m). That is very tall, and 12 feet wide is quite thin. The only connection holding it down, is via the Octoweb clamped to the launch ...


26

The American Petroleum Institute, in its standard 521, outlines limits for exposure of personnel to heat radiation from flares. As hydrocarbons and hydrogen are commonly flared, and also commonly used as rocket fuel, the data is relevant. This publication is used throughout the oil industry worldwide (and therefore is in far wider use than anything produced ...


22

The platform holding launch vehicle is called "launch pedestal" or "пусковой стол" or "стартовый стол" (in russian). Usually there are special "Hold-Down Arms" or "support arms" ("опоры пускового стола") to hold rocket. Examples: 1.. Proton is supported at bottom. There is launch pedestal model: http://www.cardmodels-r.narod.ru/html/Proton-LP1.htm In the ...


17

Rockets can use different systems for attitude control (control thrusters, fins, gyroscopes, TVC, ...). Since you ask for the seconds after liftoff, the relevant system is TVC (Thrust Vector Control). TVC basically means that the engines themselves can gimbal to change the direction of the thrust. This can influence the attitude of the rocket by inducing ...


16

Most US Launchers use a similar water suppression system for the same reasons as the Space shuttle. At some level, if you intend to launch often you do not wish your launcher to destroy the launch pad. A rocket launching usually has between 600,000 lbs thrust (Delta 4's single RS-68) to 7 million lbs thrust (Space Shuttle, or Saturn V range) and that is an ...


16

1) Startup cost. Buying and converting a boat is much more complicated and time consuming than pouring some concrete and welding some steel. 2) Logistics. You will need at least 2 boats. One as the launcher and one as the command centre. You also need to have a reliable comms link to the rocket. You also need to house the personnel and maintain both boats. ...


14

It typically takes a total expenditure of 9400-10000 meters per second of delta-v to reach LEO. Per the rocket equation, delta-v is proportional to the log of the propellant mass ratio, but also proportional to the exhaust velocity of the rocket engines or their specific impulse. Solid rocket boosters have relatively low specific impulse: 275 sec for ...


13

On e.g. the Saturn and Shuttle launches, vulnerable items like umbilicals are retracted into closed spaces, with a door closing over them in time to protect them. This very detailed video of a Shuttle launch shows some of those (at 9:40, for example). The audio commentary mentions (around 9:00) that the cameras on the platform and tower are inside ...


12

Based on this article, 39A is just concrete on top of sand. That does seem a little ridiculous though. The pumps piled up another portion of the dredged sand on the launch pad, creating a flat-topped pyramid of sand and shell 80 feet (24.4 meters) high. During the process, draglines, bulldozers and other earth-moving equipment molded the mound into the ...


11

The closest launch to the public for an orbital launch is almost certainly the one you listed, Baikonur. I'm quite confident that for people outside, that is probably about the closest you can get as well. Quite frankly, a mile away isn't very safe to watch a launch... As for just how close can you get in a protected environment, outside of the spacecraft? ...


11

Weight distribution would be be the main reason. The Shuttle stack (or Saturn V stack) empty, weighed an immense amount. Shuttle more so, since the SRB's were full during movement. (Can't fuel a solid rocket on the pad). The SRB's weighed 1.3 million pounds each ready for flight. That is really an immense amount, over a small area. The tracks of the ...


11

The Flame Trench is the big hole used to manage the flame from the rocket initially. Here's a shot of the Space Shuttle's Flame Trench: A closer look at the flame trench at LC-39A from the Space KSC blog: Note that essentially it deflects the flame so that it won't damage the rocket. All flame trenches have similar objectives. My favorite example comes ...


11

To avoid damage to the pad, the rocket must have traveled down range far enough that if it exploded, the debris would not land back on the pad. The issue isn't height, it's horizontal distance. 12 seconds, as mentioned above, wouldn't get you downrange much. 30 seconds definitely would.


10

The majority of the heat of the exhaust plume can be redirected away from the actual launchpad where the rocket is sat, be it by building exhaust plume tunnels or trenches beneath the launchpad, using jets of water that also double as acoustic shock suppressors and flame deflectors, by using concrete flame deflectors, or as is the case with some launches (e....


10

The major reasons for Sea Launch's approach is to be able to launch on the equator, and not to have to worry about overflying any territory, where stages might drop. The cooling aspect is probably the least interesting part. But the main argument against it is the infrastructure costs, and salt water corrodes everything, it would seem. No matter how well ...


10

On the prelaunch press conference about LC-39A Gwynne Shotwell (SpaceX COO) said that they plan on repairing the SLC-40 pad now, hoping to finish it in summer. Youtube: NASA Holds Pre-launch Briefing at Historic Pad 39A at Kennedy Space Center Preparations for that [Falcon Heavy debut] launch will begin once repairs to SLC-40 are completed, which ...


9

Keep in mind that a rocket engine is simply a controlled explosion. The explosion is directed at the ground, so most of the heat/flames/exhaust won't reach you unless you were very close. It would be simple to just stand on the side opposite to where it was being directed on launch. However, other than a suppression system consisting of trenches and/or ...


9

Those are remnants of the Apollo program era when the Launch Complex 39 was built. They were used to transport large removable blast deflectors to the pad when the Saturn V and Saturn 1B launch vehicles were already transported there on the crawler-transporters.    Blast deflectors at the Complex 34 launch pad. Prior to a launch, one of the ...


9

Thrust to weight ration of boosters at takeoff needs to be greater than 1, else they do not go up. However, it is usually not greatly higher than 1. Usually 1.2-1.8 perhaps. This is obvious in boosters that seem slow or fast off the pad. Thus the boost is gravity plus a bit but not that much. So the stage is able to handle gravity just to stand up. This ...


9

Yes, the water heats up. Lots of it evaporates. There is a system to catch and filter the remainder, which is polluted with combustion products of the SRBs. Those massive clouds in the foreground are water vapor mixed with combustion products of the SRBs. For the Shuttle, this report states that 166 tonnes of water is evaporated, out of 1135 tonnes ...


9

Newton's Third Law states that if object A pushes on object B with a certain amount and direction of force then object B pushes on object A with same amount and opposite direction of force. Notice how the two bulleted clauses are nearly the same, except A and B have swapped roles, and the direction is reversed? In a rocket, object A is the rocket and ...


8

Space port usually means cosmodrome: that is a framework of buildings and technical infrastructure dedicated to launching rockets into the space. A launch pad is part of the technical infrastructure. So launch pad and space port are not 2 things of the same category, but rather a launch pad is part of a space port. See here and here.


8

It's just easier access and more convenient to work on a tall thing that's on its side, rather than having to pick stuff up with cranes to put on top of the tall thing, and require lots of gantries for access. However for the most efficient structure, i.e. the lightest, you would like to not add load cases for ground handling that are substantially ...


8

This depends on the rocket you're launching. The first stage usually lands a few hundred km away from the launch point. Here is an example of the exclusion zones for a SpaceX Falcon 9 launch. The red zone is the first stage landing zone, and stretches from 300 to 600 km outward from Cape Canaveral. The Saturn V second stages ended up halfway across the ...


8

This is a frame from a video I shot in the Shuttle Mission Simulator back in the 90s. I was sitting in the commander's seat. The shoebox with the red stripes is supposed to be the launch tower, you can see the ground at the bottom. The simulator window field of view was supposed to be accurate. But although I didn't have a helmet on, I would say yes.


8

At least in the shuttle days: To access a NASA site you must either have a NASA badge (the issuance of which required you to pass a Homeland Security Presidental Directive - 12 or equivalent background check) or be escorted by a properly badged individual. In addition to general site access, you must also be badged for the specific work areas. To access ...


7

I may have my own answer. It looks like this test vehicle uses a single BE-3 engine, which only has about 110,000 lbs of thrust. We have seen the SpaceX Grasshopper and F9R Dev1 vehicles take off from flat surfaces on a single engine as well, and the Merlin 1D engine produces 145,000 lbs of thrust (in 85% performance mode that apparently it has been ...


7

There are different concrete formulations that allow for better heat resistance and whatnot. Same as there are better steel alloys to resist heat as well. However, modern launchpads, in the US at least, have a water deluge system that dumps amazingly large amounts of water onto the pad, starting a few seconds before launch and through the launch. This ...


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