Vegeta and Nappa also share a scene where they are seemingly in space, yet right next to a planet. They are both standing outside their pods, then obliterate the planet and leave. Similar events occur with Bardock attacking Frieza near planet Vegeta and Goku fighting Beerus near Earth.
While I am not 100% sure if the creators meant to do this (having the above mentioned characters near the planets) they actually make it scientifically accurate. The same can even be said when Pan is flying in "space" with Hercule and co. during a Dragon Ball Super episode.
They are always in the upper atmosphere of the planet that they are near. While the air is much colder, and thinner then ground level conditions, it would still be breathable. For sayians since they are a hell of a lot more durable then the average human, they can easily survive in the upper atmosphere.