Being a NASA lover I just had to order it. An MTH 20-98483 NASA #2006 75' AutoTrain AutoCarrier.
When I opened the packing box I thought there had been a mistake and I was sent a G scale version. Nope. The behemoth is MTH O scale. Just a little bit of a difference from, say, a Lionel 6-16750 City Aquarium Boxcar (which seems to be the default size for Lionel's boxcars. 6464 cars?)
The NASA car is nearly 19" long and 3.5" high. The Lionel aquarium cars are about 9.5" long and about 2.25" high (measuring just the box, not the trucks.)
The NASA car says it needs O54 curves, of which I have none yet. But I had to see it on a track, of course, so I put it on the O36 FasTrack from a Lionel set (arranged in a squared-off circle.) It works fine. The trucks are articulated very well, so it makes it around an O36 curve without a problem. Of course it looks silly. When the car is centered on the curve, you can see all three rails exposed because the box is hanging well off the inside of the track.
I feel sorry for the little O scale person who stands on the curve to watch the train go by when this car comes along. Does K-Line make an operating ambulance van?
It looks especially funny being pulled by a little C&O Dockside Switcher. But that switcher is a powerful little beast. I can fill the track with cars, even the heavy ones such as the K-Line US Steel Die Cast Hopper and other die cast cars, and it pulls it all along without hesitation.
Now I have to work on a likely story for why the NASA car is on the track... Budget cuts. Yeah, that's the ticket.