"Hello Tom and Ray, this is John from Houston. I occasionally drive this government vehicle..."

So began one of the more interesting calls we've ever had on Car Talk--a call from Mission Specialist John Grunsfeld, a real-life, genuine space shuttle astronaut bumping around the insides of the Shuttle Atlantis.

The call was a complete surprise. When we finally got it through our thick noggins who was on the other end of the line, we were completely dumbfounded.

Of course, this is hardly the first time we've been surprised by a call. There was the call from Jay Leno, while he was tooling around Hollywood Boulevard; Iowa's Senator Tom Harkin called in during recess; even that little twerp from Seattle, Melissa, has caught us off-guard.

More recently, we were somewhat surprised to hear FCC Chairman Reed Hundt on the line when we answered the phone. Oh and Dougie, thanks for the careful call screening. You might as well just put the cuffs on us and pull the plug on the transmitter.

Anyway, the call from Atlantis is this week's Car Talk moment. We hope you enjoy it. We sure did--once we figured out what was going on.

Who knows what is in store for us next? This will be a tough one to top.

P.S. We generally don't like to take calls from people who are driving--it's not safe. But, we figured we'd make an exception in this case. I mean, what are they going to hit? Mir? Big deal.

Space Shuttle Tech Specs

Data based on cartalk.com staff estimates