Was the Apollo 11 Saturn V Seriously Underpowered?
Paolo Attivissimo, in his book Moon Hoax Debunked (2013) states in section 7.10 that:
"Apart from the inaccurate data, Pokrovsky's analysis is invalidated by the fact that the Saturn V's first stage, together with the second stage, only had the task of placing the third stage and the Apollo spacecraft into Earth orbit (with some help from the third stage. The first two stages did not contribute to the actual trip from Earth orbit to the Moon, which was instead powered by the third stage.
"Since Pokrovsky acknowledges that Earth orbit was achieved by the Apollo vehicles, all his remarks and calculations regarding the actual speed of the first stage are simply irrelevant in terms of how many tons of payload could be sent to the Moon. Moreover, in the laws of physics that govern orbital flight what matters is the final speed of a spacecraft, which must be sufficient to stay in orbit without falling back to Earth. The speed during the climb to altitude is only relevant in terms of fuel consumption and crew comfort: a faster climb uses less fuel, but subjects the astronauts to higher acceleration stresses (up to 4.7 g for the Saturn V; Gemini's Titan launchers reached 7 g). In principle, a slow climb to orbital altitude followed by acceleration to orbital speed would still achieve orbit. Therefore Pokrovsky's issue of first stage speed is irrelevant.
"Moreover, Pokrovsky assumes that the retrorocket plume somehow stopped in mid-air, instantaneously losing the tremendous speed of the spacecraft that generated it, and therefore can be used as a fixed reference point to calculate the speed of the Saturn V rocket."
Rebuttal
Claiming that Pokrovsky "assumes that the retrorocket plume somehow stopped in mid-air, instantaneously losing the tremendous speed of the spacecraft that generated it, and therefore can be used as a fixed reference point to calculate the speed of the Saturn V rocket" is a total misrepresentation of Stanislav’s calculations. He never assumed in his study that "the plume stopped in mid-air, instantaneously".
Figure 1 in the first paper shows asymptote V=1300 m/s. "The speed of the cloud lag asymptotically increases to 1300 m/s, which is 1100 m/s below NASA’s specified rocket velocity at SP." So, in twelve frames the lag speed stopped increasing which means that it came to stop not instantaneously, but in 0.5 sec.
Stanislav Pokrovsky’s reasoning is that: “It is quite clear that there are no physical reasons for the aerosol cloud to asymptotically brake until reaching the essentially supersonic speed of 1100 m/s relative to undisturbed air.”
In other words, thinking that the aerosol cloud would be slowing down to 1100 m/s and then stopped slowing but stayed with this speed for the rest of the video has no physical backing.
Conclusion: the cloud came to virtual stop, not instantaneously, but in 0.5 sec.
The rest of Paolo Attivissimo's comments are more bad science, claiming that it doesn’t’ matter how a rocket gets up into LEO, what is important is that it gets there. Any rocket scientist will say that this is simply not true. Gravity drag! – (a measure of the loss in the net performance of a rocket while thrusting in a gravitational field). The rate of climb does matter because fuel consumption depends upon it. The lower the rate of climb the more fuel will be expended and therefore less payload will get into low-Earth orbit (LEO). Pokrovsky explains this fact at the end of his study.
“In the flight plan 1m/s delta-v corresponds to the payload increment of 15 kg [2]. Even taking into account nonlinearity of a payload from delta-v, with a large difference from that projected, it appears that the Saturn V booster was only capable of launching at least 10 tons of payload less into translunar trajectory than oficially stated in the Apollo record.”
Does Paolo Attivissimo really intend to say that NASA’s data on the Saturn V speed is inaccurate and that it was picked up in Stanisalv’s study – but that nevertheless the Saturn V did reach LEO with the same payload? Because the other two stages made up the deficit of delta-V? That would have been impossible.
Stanislav Pokrovsky PhD concludes that if low-Earth orbit was achieved by the Apollo vehicles it could only have arrived there with a lesser payload. Period. Pokrovsky has concluded that no more than 28 tons, including the Apollo 11 craft, could have been placed into lunar orbit. (Significantly less than the 46 tons claimed by NASA.)
NOTE: Further research by Gennady Ivchenkov, PhD indicates that the F-1 engines could only lift off the pad a modified version of the Saturn V – just 2000 tons instead of the stated 2,800 tons.
Alexander Popov PhD and Andrei Bulatov have concluded that 'such a slow rocket as the Saturn V' most likely ended up in the waters of the Atlantic. Moreover, it carried no space craft, and had no astronauts aboard. The true F-1 design and its characteristics were significantly different from those stated.
Extensive analysis of the available data on the Saturn V, and its engines in particular, has revealed that with high probability, NASA’s published characteristics were substantially overstated.
"With such a start to the flight, the Apollo 11 craft had no chance of catching up with the required ascent schedule.”
N V. Lebedev, Veteran of Baikonur Cosmodrome
Aulis Online, 2015
