I personally believe that objects of mass will never be able to travel back in time. However I do think that electronic data will. for example, the recipies for cures of diseases.
Now here is my idea, instead of building a machine that can send information back surely experts should be trying to build a machine that can recieve it, because then in the future a machine capable of sending will be built.
In theory, as soon as the reciever is built and turned on it should start recieving data!
Im not very good at wording my thoughts but i hope you get the gist!