10 minutes of...
...breathable air; about 5 grams of oxygen. It doesn't sound much and the limitless supply of breathable air we have on earth means it doesn't sound an impressive quantity. Yet the location and production of these 5 grams of oxygen make it important.
In between the first two flights of the martian helicopter, Nasa announced the Perseverance rover's MOXIE instrument made a less visually dramatic but potentially more useful contribution to manned space exploration; producing breathable air from the thin, carbon dioxide-heavy, martian atmosphere.
The nickel alloy MOXIE instrument achieved this by taking in samples of Martian air, heating it to 800 degrees celsius and thermochemically splitting the CO2 into oxygen and carbon monoxide. The latter gas was vented and the oxygen stored.
Moxie can produce twenty minutes of breathable air per hour, per person. So three modules could sustain an astronaut indefinitely. Assuming continuous supply of power and reliability.
There will be at least nine further tests carried out over the next two years, or one sol, to further establish the reliability and production rates in different conditions.