when the launching of planet mars trip of no return.?

I take it you mean by Humans

They could go any time

But getting there would be the easy part

They would need to stay there at least till earth has come back around again

Plus they need to match Earth's orbital Velocity which requires more power as earth has an inferior orbit

This is why Missions to Venus have been so rare and the outer planets so popular

Only those prepared not to come back should go

Already done. Lots of trips by probes for orbiting and landing on Mars during the last 55 years. But no returns of any of them with Mars surface samples. Just too hard to bring anything back (right now).

Now try actually asking a question in English.

I don't believe any date's been set yet...

Your question is unclear, but first you need to think of the finances. Such a huge project is likely to run into financial trouble long before any rocket carrying humans towards Mars is launched.

If you mean the MarsOne's idea of establishing a colony on Mars, it is not going to happen.