"Ring Around the Sun" is a science fiction short story by American writer Isaac Asimov.

When Asimov wrote the story, he intended it to be the first of a series featuring the two protagonists, Jimmy Turner and Roy Snead.

The Helios has been fitted with a new force field that allows it to deflect solar radiation around itself, so it can safely pass within twenty million miles of the Sun, cutting the length of the trip from the usual six months to two.

The Deflection Field remains on until they leave the Sun's vicinity; by then, the temperature has fallen to minus forty degrees Fahrenheit.

The latter explains that if they had read the written instructions he gave them, they would have known that they could adjust the intensity of the Deflection Field, thus allowing some solar radiation through and keeping the ship's internal temperature at near-normal.