by DiscoReilly
Two other suggestions:1) If you use the card and fail, you would keep it (as unused) or pay a resource (one that you would have had to trade) as a penalty to the bank to discard and/or flip it; or, my personal favorite
2) A failed "attempt" at using the card i.e. two people are asked for a resource to no avail should result in the player having to flip the card to side B forcing them to use it again on their following turn once more. This is the happy medium between punishing the player for failure...but not punishing other players a) by allowing the player to keep naming resources until s/he succeeds or b) by allowing them to discard the card after one attempt. The 'flip' allows one attempt and if failed forces the player to retain the card at least one more round so failure is thus discouraged...in addition if the player loves the card failure is also discouraged because this attempt burns up one of their possible two uses of Uhura. Now if the person succeeds in making one trade out of the two people asked..THEN...they can discard the card even on the first attempt as they have satisfied the conditions of use...this motivates the player to succeed if their preference is to discard for another helper card. On the second round or attempt...the player discards regardless of success or failure.
I absolutely understand the inclination to play it like a failed Monopoly but: if you play a Monopoly and fail, there is a punishment - you get no cards; no benefit. If you play Uhura and fail, the potential benefit is you could swap for a Spock or McCoy, etc. which you shouldn't be able to do unless you "use" the advantage. Example: if i know one player has no wood, I could ask that player for wood, stop there, discard Uhura, and take Spock, or another available card. In my opinion, without a trade, that shouldn't be allowed.