There's not going to be any research lost in the long-term here. The to-do list is always much longer than time available.

It's to be prudent, that is the only explanation. When this mission was launched, it had a price tag in the millions of dollars. Now that Stardust is safely back, the cargo in many scientific corners is described as priceless in terms of the data it can provide.

That does not mean that these were the highest priority experiments. These are hands-on activities, so they require a lot of crew time.

All the systems on the space station are operating fine. This is a fairly simple emergency plan.