SpaceX has purchased two deep-water oil rigs off the Texas Gulf Coast to someday use as sea-going spaceports for their Starship spacecraft. The commercial space firm, through an entity called Lonestar Mineral Development, bought the platforms from offshore drilling company Valaris in July, according to public filings. Several media reports say Lonestar Mineral Development bought the rigs that were headed to the scrapyard for $3.5 million each, a...