* A manned mission to *orbit* the Sun? This would be incredibly difficult and dangerous due to the intense heat and radiation. No such mission has been attempted.
* A robotic probe to *fly by* the Sun? This is possible and has been done! The Parker Solar Probe, for example, has been making close approaches to the Sun since 2018. It took about 7 years to reach its first close encounter, but its mission involves a series of gravity assists and orbital maneuvers to get closer and closer to the Sun.
* A hypothetical, direct, straight-line journey to the Sun? This is the most simple to calculate, but also the least realistic. It would take approximately 170 days (around 5.5 months) to reach the Sun's surface if you could travel at a constant speed of 35,000 km/h (around 21,750 mph), which is the average speed of a typical spacecraft on a long journey.
Important to note:
* Reaching the Sun's surface is impossible: You'd be incinerated long before you got there!
* The Sun doesn't have a solid surface: The Sun is a ball of plasma, so we talk about the "photosphere," its visible surface.
* Spacecraft are slowed down by gravity: This would make any straight-line journey to the Sun take longer than the 170-day estimate.
So, there's no single answer. It depends on the mission and the spacecraft.
