Nell Greenfield Boyce

Now, though, in a social media post, President Trump has announced Isaacman is his choice to be the head of NASA, making no reference to the first nomination.

The Senate must confirm Isaacman, whose nomination comes as NASA and its contractor SpaceX, are facing delays in their efforts to return humans to the moon.

Nell Greenfield Boyce, NPR News.

Jared Isaacman is a wealthy entrepreneur who's been to space twice in capsules operated by SpaceX, the company run by Elon Musk.

Isaacman is the first private citizen to ever go on a spacewalk.

When President Trump previously withdrew Isaacman's nomination, he said at the time he had concerns about Isaacman's political leanings.

Now, though, in a social media post, President Trump has announced Isaacman is his choice to be the head of NASA, making no reference to the first nomination.

The Senate must confirm Isaac Min, whose nomination comes as NASA and its contractor SpaceX, are facing delays in their efforts to return humans to the moon.

Nell Greenfield-Boyce, NPR News.

Jared Isaacman is a wealthy entrepreneur who's been to space twice in capsules operated by SpaceX, the company run by Elon Musk.

Isaacman is the first private citizen to ever go on a spacewalk.

When President Trump previously withdrew Isaacman's nomination, he said at the time he had concerns about Isaacman's political leanings.

Now, though, in a social media post, President Trump has announced Isaacman is his choice to be the head of NASA, making no reference to the first nomination.

The Senate must confirm Isaacman, whose nomination comes as NASA and its contractor SpaceX, are facing delays in their efforts to return humans to the moon.

Nell Greenfield Boyce, NPR News.

This is NPR.

In the fall, to recover nitrogen, trees take apart green chlorophyll.

This reveals yellow pigments that were there all along.

But the red pigments are different.

Trees make brand new red chemicals just days before a leaf is about to fall.