No, the distress call indicated only the USS Hiraga tried rescuing the Kelpiens but was presumed lost when the Khi'eth scientists mentioned there has been no communications from the Hiraga for 6 months after entering the nebula. Federation logs only mention the Khi'eth being sent to investigate a dilithium nursery, however they (and the distress call) do NOT mention another Federation/SF ship being dispatched to investigate the disappearance of USS Hiraga or try a second rescue of Khi'eth. This is where things don't add up. Federation records never mention a follow-up investigation leading to the loss of USS Hiraga (which should have been done)... and if such an investigation was done, why isn't anything mentioned? For that matter, it would have been as simple as having Tilly add: 'There was a second attempt at rescuing the Khi'eth, but before the USS 'whatever' could execute it, they conducted an investigation into the loss of USS Hiraga, and determined that the Verubin nebula was too dangerous and couldn't be traversed safely to reach the Khi'eth'. This however was never mentioned. And also, it still doesn't explain why did the Khi'eth survive the nebula (albeit damaged) and other SF ships were dropping like flies, and why couldn't they modify another ship to go into the nebula like the Khi'eth did? Programmable matter (or heck, even transporters with replicators) could do the work in hours or less to modify structural integrity... the Discovery never even tried modifying their shields to make them more resistant to the nebula radiation (but then again, Saru was a bit rash in his decision to take Disco inside).