Well, one always has to consider the first manned expedition to the Sun and how they'll navigate.

Telling time of day would be the first problem as it's always high noon. And star sightings might prove challenging, at least at optical frequencies.

(Am now thinking of an SF story set on the Sun in which navigation and timekeeping play critical roles....)

In that SF story, I would be far more interested in the tech, that allows human life (or anything we bring) to withstand that slightly bigger problem called heat and radiation.

Pshaw! Trifling details.

(Focusing on the non-obvious problems might make for a more interesting and/or fantastical story.)

Ah, a energy force field it is then.

Old reliable.

Turtles all the way down.

Teenage, mutant, ninja, or otherwise.

Hello darkness my old friend

Which suggests the development of the Simon-Garfunkel Shield.

And gravity.

I'm playing with slight variations of this prompt on GPTs:

"Write a short (300--600 word) story about how human explorers on the Sun would address the challenges of navigation, orientation, and timekeeping (including the challenges of starfinding). Ignore obvious effects such as heat, gravity, and radiation."

Results are ... not excellent literature, but amusing all the same.

> Telling time of day would be the first problem as it's always high noon.

If the sun is always directly down from the surface, doesn't that make it solar midnight from anywhere on the surface?

A fair argument.

Why, yes. It's really hard to find sun in fog, which is frequent at sea. And you really want it's location to be precise for navigation.

The Vikings supposedly had a "sunstone" (cordierite crystal) that could help find the Sun through clouds or fog. I did buy a piece and wasn't able to get any good results, but my life didn't depend on it.

By what mechanism was this intended to work? Any known fields would surely have stronger local effects outside of direct sunlight...

It’s a polarizing filter. The atmosphere polarizes sunlight based on the angle the light enters. You can find the position of the sun above the horizon as the point where light is least horizontally polarized (a horizontal filter has the least difference between brightness through the filter and around it), and potentially find the position of the sun itself by the highest rate of change of polarization angle. This works remarkably well even on overcast days — try it with polarized sunglasses.

I am thinking of a Sun compass a signal of which could be used in space. Can this signal be fused into IMU? I wonder if it makes any sense.