BOSTON (AP) — NASA wants its moon dust and cockroaches back. The space agency has asked Boston-based RR Auction to halt the sale of moon dust collected during the 1969 Apollo 11 mission that had subsequently been fed to cockroaches during an experiment to determine if the lunar material contained any sort of pathogen that posed a threat to terrestrial life. NASA said in a letter to the auctioneer that it still belongs to the federal government. RR said Thursday that the material from the experiment was expected to sell for at least $400,000, but has been pulled from the auction block.