The most commonly accepted explanation of this is that the space agencies of the world are involved in a conspiracy faking space travel and exploration. This likely began during the Cold War's 'Space Race', in which the USSR and USA were obsessed with beating each other into space to the point that each faked their accomplishments in an attempt to keep pace with the other's supposed achievements. Since the end of the Cold War, however, the conspiracy is most likely motivated by greed rather than political gains, and using only some of their funding to continue to fake space travel saves a lot of money to embezzle for themselves.

121) When you observe the Sun and Moon you see two equally-sized equidistant circles tracing similar paths at similar speeds around a flat, stationary Earth. The “experts” at NASA, however, claim your common sense every day experience is false on all counts! To begin with, they say the Earth is not flat but a big ball; not stationary but spinning around 19 miles per second; they say the Sun does not revolve around the Earth as it appears, but Earth revolves around the Sun; the Moon, on the other hand, does revolve around the Earth, though not East to West as it appears, rather West to East; and the Sun is actually 400 times larger than the Moon and 400 times farther away! You can clearly see they are the same size and distance, you can see the Earth is flat, you can feel the Earth is stationary, but according to the gospel of modern astronomy, you are wrong and a simpleton worthy of endless ridicule if you dare to trust your own eyes and experience.
If the Earth were a globe, rolling and dashing through "space" at the rate of "a hundred miles in five seconds of time," the waters of seas and oceans could not, by any known law, be kept on its surface - the assertion that they could be retained under these circumstances being an outrage upon human understanding and credulity! But as the Earth - that is, the habitable world of dry land - is found to be "standing out of the wafer and in the water" of the "mighty deep," whose circumferential boundary is ice, we may throw the statement back into the teeth of those who make it and flaunt before their faces the flag of reason and common sense, inscribed with a proof that the Earth is not a globe.
1.) The aeronaut can see for himself that Earth is a Plane. The appearance presented to him, even at the highest elevation he has ever attained, is that of a concave surface – this being exactly what is to be expected of a surface that is truly level, since it is the nature of level surfaces to appear to rise to a level with the eye of the observer. This is ocular demonstration and proof that Earth is not a globe.
178) People claim Google Earth somehow proves the ball model without realizing that Google Earth is simply a composite program of images taken from high-altitude planes and street-level car-cameras superimposed onto a CGI model of a ball Earth. The same could be just as easily modeled onto a square Earth or any other shape and therefore cannot be used as proof of Earth’s rotundity.
196) Quoting Marshall Hall, “In short, the sun, moon, and stars are actually doing precisely what everyone throughout all history has seen them do. We do not believe what our eyes tell us because we have been taught a counterfeit system which demands that we believe what has never been confirmed by observation or experiment. That counterfeit system demands that the Earth rotate on an 'axis' every 24 hours at a speed of over 1000 MPH at the equator. No one has ever, ever, ever seen or felt such movement (nor seen or felt the 67,000MPH speed of the Earth's alleged orbit around the sun or its 500,000 MPH alleged speed around a galaxy or its retreat from an alleged 'Big Bang' at over 670,000,000 MPH!). Remember, no experiment has ever shown the earth to be moving. Add to that the fact that the alleged rotational speed we've all been taught as scientific fact MUST decrease every inch or mile one goes north or south of the equator, and it becomes readily apparent that such things as accurate aerial bombing in WWII (down a chimney from 25,000 feet with a plane going any direction at high speed) would have been impossible if calculated on an earth moving below at several hundred MPH and changing constantly with the latitude."

Mr. J. R. Young, in his work on Navigation, says. "Although the path of the ship is on a spherical surface, yet we may represent the length of the path by, a straight line on a plane surface." (And plane sailing is the rule.) Now, since it is altogether impossible to "represent" a curved line by a straight one, and absurd to make the attempt, it follows that a straight line represents a straight line and not a curved one. And, Since it is the surface of the waters of the ocean that is being considered by Mr. Young, it follows that this surface is a straight surface, and we are indebted to Mr. Young, a professor of navigation, for a proof that the Earth is not a globe.

In Figure 12, the ship now appears beyond the pier. Notice that the inferior mirage of the lettering on the hull is much more obvious now. In Figure 13, the lettering and its inferior mirage have not merged. In Figure 14, the lettering is difficult to see. This probably is because most of the lettering is below the horizon, and what appears to be the bottom of the hull is an inferior mirage of the top of the hull. This is clearly seen by the inferior mirage of the first layer of red containers below the turquoise. In Figure 15, the inferior mirage of the bottom layer of containers is more obvious, and the inferior mirage of the bottom of the bridge castle is beginning to show up. Clearly, at least half of the turquoise visible here is an inferior mirage. Most of the hull is below the curvature of the earth. Unfortunately, at this point the sun was about to set, so light levels were dropping quickly, forcing me to use longer exposures. At that point, I stopped taking photographs.
3. The moon is self luminous, creating its own light and is not a reflector of the sun. A reflector can only reflect the same light that it is given. If the light is yellow and hot then the reflector can online reflect yellow hot light. The moon’s light has been proven to be a cool light with a cooler temperature in direct moonlight than in the shade. How can a reflector create cool light when it is reflecting heat? This proves that the moon is self luminous and therefore is shining it’s own light during an eclipse.
118) Furthermore, the velocity and path of the Moon are uniform and should therefore exert a uniform influence on the Earth’s tides, when in actuality the Earth’s tides vary greatly and do not follow the Moon. Earth’s lakes, ponds, marshes and other inland bodies of water also inexplicably remain forever outside the Moon’s gravitational grasp! If “gravity” was truly drawing Earth’s oceans up to it, all lakes, ponds and other bodies of standing water should certainly have tides as well.
44) If Earth was a ball, and Antarctica was too cold to fly over, the only logical way to fly from Sydney to Santiago would be a straight shot over the Pacific staying in the Southern hemisphere the entire way. Re-fueling could be done in New Zealand or other Southern hemisphere destinations along the way if absolutely necessary. In actual fact, however, Santiago-Sydney flights go into the Northern hemisphere making stop-overs at LAX and other North American airports before continuing back down to the Southern hemisphere. Such ridiculously wayward detours make no sense on the globe but make perfect sense and form nearly straight lines when shown on a flat Earth map.
It is often said that the predictions of eclipses prove astronomers to be right in their theories. But it is not seen that this proves too much. It is well known that Ptolemy predicted eclipses for six-hundred years, on the basis of a plane Earth, with as much accuracy as they are predicted by modern observers. If, then, the predictions prove the truth of the particular theories current at the time, they just as well prove one side of the question as the other, and enable us to lay claim to a proof that the Earth is not a globe.

93) The St. George’s Channel between Holyhead and Kingstown Harbor near Dublin is 60 miles across. When half-way across a ferry passenger will notice behind them the light on Holyhead pier as well as in front of them the Poolbeg light in Dublin Bay. The Holyhead Pier light is 44 feet high, while the Poolbeg lighthouse 68 feet, therefore a vessel in the middle of the channel, 30 miles from either side standing on a deck 24 feet above the water, can clearly see both lights. On a ball Earth 25,000 miles in circumference, however, both lights should be hidden well below both horizons by over 300 feet!
70.) Mr. Lockyer, in describing his picture of the supposed proof of the Earth's rotundity by means of ships rounding a "hill of water," uses these words: – "Diagram showing how, when we suppose the earth is round, we explain how it is that ships at sea appear as they do." This is utterly unworthy of the name of Science! A science that begins by supposing, and ends by explaining the supposition, is, from beginning to end, a mere farce. The men who can do nothing better than amuse themselves in this way must be denounced as dreamers only, and their leading dogma a delusion. This is a proof that Earth, not a globe.
If the Earth were a globe, there certainly would be - if we could imagine the thing to be peopled all round - "antipodes:" "people who," says the dictionary, "living exactly on the opposite side of the globe to ourselves, have their feet opposite to ours: - people who are hanging heads downwards whilst we are standing heads up! But, since the theory allows us to travel to those parts of the Earth where the people are said to be heads downwards, and still to fancy ourselves to be heads upwards and our friends whom we have left behind - us to be heads downwards, it follows that the whole thing is a myth - a dream - a delusion - and a snare; and, instead of there being any evidence at all in this direction to substantiate the popular theory, it is a plain proof that the Earth is not a globe.
One of the most common objects reflected in this way is blue sky, which our brains interpret as light reflecting off a body of water. The reflected image appears below the object, which is why we call this an inferior mirage. The layer of warm air near the surface acts much like an ordinary mirror. As a mirror reverses direction left to right, an inferior mirage reverses direction from top to bottom (you see the same thing with a mirror if you tilt your head 90 degrees and look at reflections in the mirror.) The reversal happens because light from the top of a distant object will reflect closer to the observer than light from the bottom of the object. Therefore, inferior mirages usually appear inverted. Early in the morning or late in the afternoon, solar heating of the ground is not nearly as great, so inferior mirages are less likely to happen then. The same is true during autumn and winter when the sun is much lower in the sky.
46.) It has been shown that an easterly or a westerly motion is necessarily a circular course round the central North, The only north point or centre of motion of the heavenly bodies known to man is that formed by the North Star, which is over the central portion of the outstretched Earth. When, therefore, astronomers tell us of a planet taking a westerly course round the Sun, the thing is as meaningless to them as it is to us, unless they make the Sun the northern centre of the motion, which they cannot do! Since, then, the motion which they tell us the planets have is, on the face of it, absurd; and since, as a matter of fact, the Earth can have no absurd motion at all, it is clear that it cannot be what astronomers say it is – a planet; and, if not a planet, it is a proof that Earth is not a globe.
138) Another favorite “proof” of ball-Earthers is the appearance from an observer on shore of ships’ hulls being obfuscated by the water and disappearing from view when sailing away towards the horizon. Their claim is that ships’ hulls disappear before their mast-heads because the ship is beginning its declination around the convex curvature of the ball-Earth. Once again, however, their hasty conclusion is drawn from a faulty premise, namely that only on a ball-Earth could this phenomenon occur. The fact of the matter is that the Law of Perspective on plane surfaces dictates and necessitates the exact same occurrence. For example a girl wearing a dress walking away towards the horizon will appear to sink into the Earth the farther away she walks. Her feet will disappear from view first and the distance between the ground and the bottom of her dress will gradually diminish until after about half a mile it seems like her dress is touching the ground as she walks on invisible legs. Such is the case on plane surfaces, the lowest parts of objects receding from a given point of observation necessarily disappear before the highest.

Astronomers tell us. that the Moon, goes round the Earth in about 28 days. Well, we may see her making her journey round every. day, if we make use of our eyes and these are about the best things we have to use. The Moon falls behind in her daily motion as compared with that of the Sun to the extent of one revolution in the time specified; but that is not making a revolution. Failing to go as fast as other bodies go in one direction does not constitute a going round in the opposite one - as the astronomers would have us believe! And, since all this absurdity has been rendered necessary for no other purpose than to help other absurdities along, it is clear that the astronomers are on the wrong track; and it needs no long train of reasoning to show that we have found a proof that the Earth is not a globe.

The Rev. D. Olmsted, in describing a diagram whish is supposed to represent the Earth as a globe, with a figure of a man sticking out at each side and one hanging head downwards, says "We should dwell on this point until it appears to us as truly up," In the direction given to these figures as it does with regard to a figure which he has placed on the top! Now, a system of philosophy which requires us to do something which is, really, the going out of our minds, by dwelling on an absurdity until we think it is a fact, Cannot be a system based on God's truth, which never requires anything of the kind. Since, then, the popular theoretical astronomy of the day requires this, it is evident that it is the wrong thing, and that this conclusion furnishes us with a proof that the Earth is not a globe.