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 ...
Newton's Third Law states that if
object A pushes on object B with a certain amount and direction of force
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 ...
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 ...
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.
This paper surveys a large number of umbilical designs.
For the mechanical connections to the vehicle, it lists two types of detachable locking devices.
The type of locking mechanism used in this application
is shown in Figure 16. This system is a simple ball and
socket type of locking device where a sleeve captures ...
The Kennedy Space Center Story, written by NASA in June 1970, NTRS document 19710024295, p. 29 describes the options that were considered, and the reason for the final choice:
The scheme by which to transport launchers and assembled Saturn V vehicles was carefully explored by NASA engineers. A barge canal system was investigated. Models were tested in the ...
This answer is largely speculative but based upon knowledge of similar systems.
The Safir space launch vehicle may use hypergolic propellants.
The launch site shown in the photograph has minimal permanent
Hypergolic propellant storage facilities at Johnson Space Center and
White Sands Test Facility have burner stacks to safely dispose of ...
The landing legs are made to support a 30-ton empty stage, not a 600-ton full rocket.
The thermal loads on launch are much higher and would likely lead to damage on the legs.
The strongback is needed to fill the second stage tanks and to provide connections to the payload.
The launchpad is carefully designed to lead the flames away from the rocket. ...
How soon will LC-39A be at significant risk to storm-surge damage?
It is currently at risk to storm surge damage, and measures have been and will continue to be taken to mitigate risk.
This answer is about engineering of beaches and seawalls, but it's likely that waterproofing of the launch structures themselves has been attended to as well. Hopefully a ...
Another thing to consider is that (most of) Kennedy Space Center launch pads are significantly elevated above average ground level, whereas Baikonur Cosmodrome is flat, instead having large trenches dug underneath the pad.
Where the Russians ride over smooth, level terrain, the Americans have to overcome this elevation as the ...
The first place to look for that kind of information is NASA's Technical Reports Server.
I did some searching there, but I found no high-level overview. There's lots of detailed information, e.g. this report on acoustic models.
So your starting point may have to be something like the Wikipedia article on launch pads, and look up the more detailed info in ...
I think the principle you are thinking of is "ground effect".
When plane wings are very close to the ground, the deflected air is compressed slightly between the wing and the runway, thereby generating extra lift. For other reasons, it also reduces drag.
Planes fly parallel and close to the runway for several seconds and the ground effect can be ...
Rocket engines don't "push back" on anything. Rocket engines are basically controlled explosions. To find the answer of your question, we first need to know how a rocket engine works.
Rocket engines rely on Newton's third law of motion. "Every action has an equal and opposite reaction".
In the image above, liquid fuel and oxidiser come into contact with ...
Welcome to the site. Flame deflections are not always used on small rockets
But as rockets become larger they are increasingly necessary at least on Earth, Flame deflectors such as flame trenches serve a number of purposes. Firstly they prevent damage to the rocket caused by the rebounding of foreign objects such as concrete ...
The blanket was a temporary solution. Later Agena launches have an AC supply to the fairing itself. This was Thor-Agena 11, a reconnaissance satellite launch:
I haven't found a source that gives a rationale for this choice. But keep in mind this was the start of the age of spaceflight, and many things were tried out - and replaced if/when a better solution ...
What does a rocket engine push on?
Here's a cross-section of a rocket engine:
A combustion process expands gases in the combustion chamber. This exerts a pressure on the walls. This pressure is equal in all directions except at the bottom of the combustion chamber, where the gases can escape through the nozzle.
In the nozzle, again the gases push on all ...
The Payload Changeout Room (PCR) ...
...is an environmentally controlled clean-room-type enclosure. It has
a set of outer airlock doors with inflatable environmental seals so
that the payload may be transferred from the payload canister into the
PCR without exposure to the external environment.