"That thing was moving on a straight-line course when I picked it up on the radar."

That's certainly right for a straight-line course from Endicott.

"How do you plan to keep to a straight-line course from here?"

"Commander, just so you know, a straight-line course from here to the starbase is going to run right through the Mewesian asteroid belt."

Ironically, just as the road is beginning to straighten and level out, it becomes impossible to follow anything like a straight-line course along it.

I could not stay on a straight-line course.

The fighter continued off on a straight-line course toward the stars.

We're running a straight-line course between them, so their proper motion should be zero.

Both men and computers tried to maintain a straight-line course for the aircraft, but it didn't work.

"And the time it would take along a straight-line course from our present position to Epsilon Delta 4 at that speed?"