Depends where in space, and on your definition of a 'straight line'.

If you're in intergalactic space, yeah basically - although it would slowly get broken up by cosmic rays of various sorts.

If you're in LEO, it would end up in a very slightly different orbit to you - although in some ways an orbit is a type of straight line.

It probably wouldn't stay up there for too long, atmospheric drag would pull it down a lot faster than a human or a space station due to its higher surface area vs mass ratio - also it might get melted by sunlight.

In other areas in space, you'll have some blend of those effects (plus other smaller ones like solar wind) depending on local conditions.