What happened to the other 9 astronauts?

In the beginning of the mission, it's mentioned that 12 pioneers went out to try to find a new world for humanity. During the duration of the film, they only visit 3 of those 12 planets and respective astronauts. What happened to the other 9? Did they communicate back to NASA that their planet was inhospitable?

Since only one system with 3 worlds show promise, we can infer that the other 9 astronauts are dead. Either they didn't make it to their worlds or they landed on uninhabitable worlds.

PROFESSOR BRAND

Twelve possible worlds. Twelve Ranger launches carrying the bravest humans ever to live, led by the remarkable Dr Mann.

DOYLE

Each person’s landing pod had life support for two years - but they could use hibernation to stretch that, making observations on organics over a decade or more. Their mission was to assess their world, and if it showed promise, send a signal, bed down for the long nap, and wait to be rescued.

COOPER

And if their world didn’t show promise?

DOYLE

Hence the bravery.

COOPER

Because you don’t have resources to visit all twelve.

DOYLE

No. Data transmission back through the wormhole is rudimentary, simple binary ’pings’ on an annual basis to give some clue as to which worlds have potential. One system shows promise.

COOPER

One? Kind of a long shot.

BRAND

One system with three potential worlds ... no long shot.

Full script here

• Well at the very least this system showed the most promise with 3 potential colony worlds. With only one Endurance ship they have to choose the most likely destination. Commented May 24, 2017 at 13:24
• That is a good point. It is possible one of the other 9 did manage to land on a habitable planet, but since they where never 'rescued' by the Endurance crew, they would have eventually run out of supplies and died. Commented May 24, 2017 at 13:29
• Wow, I must have missed that third line of Doyle's the two times I watched this film. I guess that papers over some of the plot holes, though maybe not really. Did that line actually make it into the film? Commented May 24, 2017 at 16:25
• @Muzer: Yes, I watched it a week ago and it was there. Commented May 25, 2017 at 11:57