SpaceX's first launch site was at Omelek Island. It appears that the challenging environment may have contributed to one of the failures.
"Why the nut cracked is still a bit of a mystery. Musk said the "prevailing thought" among investigators, which included a mix of government and SpaceX personnel, is that the heat and humidity on Omelek Island was a factor. Though the nut was anodized to guard against corrosion, Musk said, it may have been scratched at some point, compromising its protection against the elements. "We had a series of countdowns [during which] the rocket was exposed for quite a bit of time," Musk said. "And the vehicle hangar for about three months was not climate controlled."
Another possible contributing factor, Musk said, is that there was an adverse reaction--so-called galvanic corrosion--between the aluminum nut and the pipe fitting itself, which was made of stainless steel.
Musk said SpaceX will replace the $5-a-piece aluminum nuts with less-expensive stainless steel nuts to avoid that problem in the future."
