Idk if this is another spaceship in fallout 3 or not?

i was doing the reillys rangers quest in fallout 3 and i had just come out from the metro near the hopsital and was finishing off some super mutants. after i was done with them i looted the area as always and i came across a huge hole in the ground with like a big rocket ship in it. it had high levels of radiation and a sewer right next to it in the hole. also, ther were steps leading down to the sewer hole. second spaceship? anybody living in the sewer? anything else i should know?