A couple of things about Carl Sagan's novel "The Contact".

Black holes are the loops of time. When information falls in the singularity. It comes out from the point where the black hole formed. This is the thing called the time paradox. The time moves backward in the black hole. 

And if people would go to space travel by using black holes they would come out from the place in time and space where that black hole formed. So the hypothetical astronaut cannot ever prove to be on that journey.

There is a theoretical possibility that engineers can create the hollow singularity around the spacecraft. The system requires the impacting gravitational waves. If the system wants that time moves forward in the craft. It makes the singularity around the craft. And when that thing wants that time moves backward the singularity forms inside the craft. 

And why does the hollow black hole rip astronaut into pieces? The answer is that their system requires two black holes. The symmetry of the gravitation of those two singularities or gravitational cores denies that astronauts ripped into pieces. When the outer gravitational core will pull an astronaut to it. Other black holes in the middle of the capsule pull our hypothetical astronaut back to the capsule's center. 

In the novel and movie "The Contact" the alien civilization tells humans how to create an artificial black hole. And humans send the astronaut journey by using that capsule. Then the astronaut returns and all collected data from that journey is lost. Jodie Foster plays the main character in that film. 

So what if we will make that thing in real life? Or what is the context of reality in that novel? The fact is this. If we would create singularity around the astronaut.  That singularity does not probably rip that person into pieces. In that case, the singularity forms around the traveler.

There are two ways to make that kind of craft. In the first case, the craft will stress by using radiowaves until it turns into a black hole. In another version, the electromagnetic radiation that reflects from the craft pushes atoms and electromagnetic radiation away from its core. 

And that thing makes the WARP bubble around the craft. Then that craft will put spin with extremely high speed. That kinetic energy will turn that object's mass so high that it slips from the universe. 

The thing is that inside a black hole time moves backward. And that's why everything that is stored in tapas is gone. So when black holes form and information fall in a black hole it comes out at the point in space and time where the black hole is formed. 

So this is Einstein's time paradox as I wrote at the beginning of this text. That means even if an astronaut will travel to stars inside a black hole that person will come out from that thing at the point in space and time, where the black hole formed. And that means nobody can even see that our astronauts were on that journey.