Building the rocket engine that will take us back to the moon, this week on planetary radio. Hi everyone, welcome to Public Radio's travel show that takes you to the final frontier.

I'm Ad Kaplan.

And are we jam-packed this week? We'll hear from

John Vilia, the man from Pratt and Whitney Rocketdyne who is in charge of

getting the J2X rocket engine built.

Emily Lachtowala will tell us what we know about asteroids that can and do smack down on

Mars, not much really.

And then Bruce Betts will join me for a look at the night sky and news about our expanding fifth anniversary prize package.

Now you can win more than a Mars meteorite fragment.

Just time enough to mention this week's top story kudos to

spacewaker Scott E. Parazinsky who completed one of the most challenging and

dangerous repair jobs ever. Scott successfully mended a torn solar array on the International Space Station.

He also managed to avoid going down in history as the first electrocuted astronaut.

We'll put a link to the story atrocuted astronaut.

We'll put a link to the story at planetary.org slash radio.

Back in a minute with John Vilia.

Here's Emily. Hi, I'm Emily Loch Duwala with questions and answers.

A listener asked, we hear a lot about the hazard from near-Earth objects.

Is there such a thing as near-Mars objects?

Although there probably are asteroids whose orbits will eventually intersect with Mars,

there is no one in the astronomical community

who is specifically looking for potential Mars impactors.

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