Show which direction the Rigidbody is accelerating in?

Hello. I have a rigidbody that I can AddForce to and change its speed, etc. I have not been able to figure out how you can make a little line or arrow that shows what direction you are travelling in. For example I can be going 5m/s straight up, and still rotate the player. It's all done in zero gravity so the only way to slow down is to accelerate in the opposite direction you are moving. However I want a little arrow or something that shows the direction you are moving, that way people can turn 180 degrees and use that arrow as a reference to slowing down. The arrow will need to update in real time so if you suddenly change directions, you know which direction you need to be facing so you can slow down. I hope this makes sense. Let me know if you need me to clarify. I appreciate your help! Thanks