Pretty sure this is a Tardis bigger-on-the-inside situation

Then where is the 15k lightyears figure supposed to come from?

I took those distance estimates to mean "as measured by the instruments".

The longer they're in it, the larger the estimate, and they've hypothesized that it will approach the size of the universe itself.

	▲	swiftcoder 3 days ago \| parent [-]
		Also worth noting that they’ve already crossed their own tracks at least once - thus their estimate is probably extremely suspect