This is John Batchel, conversation with colleague Anatoly Zach of Russian Space Web.com.

About 50 years ago, the Russian mission called Soyuz 16, two cosmonauts doing a dry run on what was

expected in six months' time to be an offer of detain in space.

An Apollo spacecraft launched from the United States and a Soviet spacecraft launched from Kazakhstan, Bikin, or Cosmatorium, would rendezvous in orbit,

and the astronauts would then put in an airlock and go back and forth.

There were challenges.

One of them was the Apollo spacecraft was pure oxygen interior.

The Soyuz spacecraft was air.

In other words, that oxygen and nitrogen mix, what we breathe on Earth?

So what is to be done?

How do you put these two together?

Anatoli describes in detail here.

Fifty years ago, the practice run for what becomes the successful offer of Dayton in space

in the middle of 1975.

Couldn't we get back there?

No.

Rendezvous in space.

Anatoli, Zach.

So they found the kind of technical way to, first of all, they added Apollo carried

additional airlock, this kind of additional docking module, which kind of served as an airlock.

The second, they also, the second step which they made to facilitate the, to kind of, because

the atmosphere on Apollo was pure oxygen, and on Soyuz, it was a mixture of air, it was

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