Board Thread:Help/@comment-58.104.224.11-20170805151828/@comment-27794543-20170805225438

Based on clues given in the show, when Becca landed, she was met by the Second Dawn cult. It's unclear how people were chosen to receive the Nightblood serum. Perhaps the cult's leaders made the decision or perhaps Becca did. For all we know, the cult's leaders killed Becca but told the populous that she was a deity that brought them the cure. The real history seems to have been lost.

Becca was never on the Ark, she was on Polaris. At the time of the nuclear apocalypse, there were thirteen space stations in space. After the apocalypse, they agreed to join to become the Ark. However, when Polaris hesitated (because Cole McAdams wanted Becca to get rid of A.L.I.E. 2.0 before it infects the Ark), Alpha Station destroyed Polaris. The twelve remaining stations formed the Ark.

As for why Becca was in space, we've been given two explanations. According to A.L.I.E., Becca feared the AI and decided to take her further reasearch to space where A.L.I.E. couldn't reach it. However, in season 4, it's revealed that Nightblood can only be made in space, so Becca may have gone to space to develop the serum. (While the bone marrow transfusion can be made on Earth, the original Nightblood serum, back when there were zero Nightbloods, had to be made in space.)