I'm sorry dzima, but I am at a loss as to what the Russian name might be. I was able to contact my Russian speaking niece, but she wasn't able to offer many suggestions, for she says the possibilities are nearly endless, especially without knowing the total number of letters in the name, even though the first five are known.
I will make another try, but it is really just a guess, based on a potential suggestion that my niece made. I will try: Ulyanin or Ulyanina (Ульянин) as I understand, although it is not a direct translation, can be related to "test". My thought is that this vehicle was a prototype, and might thus be called a test.