27

Payloads are attached to (expendable or vertical landing) vertical take off vehicles at the ends where they touch. Given satellites weigh several tonnes, and are several meters in length horizontal integration puts a lot of torque on that connection, and to lesser degrees on other parts of the spacecraft structure. Reinforcing the spacecraft to withstand ...


12

I didn't dig too hard for sources because this is probably a very minor expansion on top of the other answers, but WHICH payloads might require vertical integration? Ones with big stinking mirrors inside like spy satellites and space telescopes. This reddit post lays out some rationale: This is mostly telescopes like Hubble. They have a very delicate ...


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 ...


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

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 ...


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.


7

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 ...


7

Read the whole article: Most importantly, the tower would allow SpaceX technicians to crane certain US military payloads – encapsulated inside a Falcon payload fairing – onto the top of the rocket. At the end of the day, that’s really the only reason SpaceX needs such a tower – certain customers (the US military and, to a lesser extent, NASA) have ...


7

Something of a guess but it sounds plausible: Satellite propulsion systems that use surface tension devices to separate the pressurant gas from the propellant may have some orientation constraints to prevent gas bubbles being trapped in the surface tension device (aka propellant management device, PMD). There are several types of PMD, some are rather ...


7

For the shuttle program, the water was not recovered. The water that was not vaporized ran through concrete channels and was collected in two holding ponds. (NASA photo, annotations mine). The water was later pumped out and allowed to soak into the sandy soil. The discharge of deluge and firex water (during the launch of each Space Shuttle) resulted ...


6

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 ...


5

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 infrastructure. Hypergolic propellant storage facilities at Johnson Space Center and White Sands Test Facility have burner stacks to safely dispose of ...


5

No. 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. ...


3

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. Compare KSC: with Baikonur: Where the Russians ride over smooth, level terrain, the Americans have to overcome this elevation as the ...


3

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 ...


2

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 ...


2

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 ...


2

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 ...


1

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. From https://commons.erau.edu/cgi/viewcontent.cgi?...


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