Translation:The travelers arrived at the space station yesterday.
"The travelers arrived ON the space station yesterday" was marked incorrect in favor of "the travelers arrived AT the space station yesterday". If I'm not mistaken, either should be acceptable (along with "arrived to", if it isn't already - although now that I'm thinking about it too much I'm beginning to doubt my own English).
"The travelers arrived ON the space station yesterday" should be accepted -- it's listed as one of the possible alternatives in the backend.
"arrive to" sounds wrong to me, though non-native speakers sometimes suggest that, perhaps thinking that "arrive" is a motion verb like "go".
Teach me to comment before my first qa'vIn of the day. your question was about "arrive to". Hmm, you are right it does sound a little off, but I don't see any obvious reason it would be incorrect.
Native speaker of English here, if something has a surface you can be on, you can arrive on it. But it might also get confused with the concept of "arriving on the space station on a ship."