Section 1.1: Properties of Tungsten

Tungsten, often overlooked, has a striking silvery hue and is relatively rare on our planet. Despite its scarcity, it is widely utilized in everyday items such as light bulbs and electronic components. What sets tungsten apart is its exceptional melting point; it remains solid until it reaches 6192°F (3422°C).

Subsection 1.1.1: Creating a Tungsten Spacecraft

Imagine constructing a spacecraft entirely from tungsten. For this theoretical mission, we would design a solid spherical probe measuring about two meters in diameter. Multiple probes could launch together, each entering distinct orbits around the Sun.

Section 1.2: Proximity to the Sun

Our first probe would orbit approximately twenty-five million miles from the Sun. Here, near Mercury, the tungsten begins to absorb heat. Fortunately, metals like tungsten are reflective, which helps to deflect about two-thirds of incoming heat. As the temperature rises, the probe emits heat, reaching a balance where it radiates as much energy as it absorbs. We’ll refer to this balance point as the equilibrium temperature. For our first probe, this temperature would be around 310°F (155°C)—warm, but not enough to melt tungsten.

Section 2.1: The Parker Solar Probe

NASA's Parker Solar Probe aims to approach the Sun closer than any previous mission, scheduled for its closest pass on December 24, 2024, at just four million miles. However, our hypothetical third probe would surpass this, orbiting at 3.9 million miles. At this proximity, the probe would experience scorching temperatures of around 1500°F (815°C), far too high for any standard sensors or electronics to survive.

What Do You Learn When You Touch the Sun? - This video delves into the scientific insights gained from studying the Sun and its impact on space exploration.

Section 2.2: Understanding the Solar Corona

At four million miles, we still remain distant from the Sun's surface. However, we must consider the solar corona, a region of plasma that extends far into space, known for its extreme temperatures. The exact cause of the corona's heat is still under investigation, but it's believed that the Sun's intense magnetic fields play a significant role.

The Sun operates on an eleven-year cycle, during which the corona's intensity fluctuates. During quieter phases, the corona is less expansive, but it can unleash bursts of superhot plasma, which would be lethal to any spacecraft. To mitigate risks, we would choose a quieter year for our mission.

Section 2.3: Approaching the Photosphere

To maximize our proximity, we would guide our probe to skim just above the Sun's photosphere. This journey would confront numerous challenges, including extreme heat and radiation levels that could obliterate any onboard electronics. The anticipated temperature near the surface could reach around 10,000°F (5,000°C), far exceeding tungsten's melting point.

Ultimately, it appears that the closest we can realistically approach the Sun with current technology is around one million miles. Future advancements may allow for more daring explorations, perhaps even reaching the Sun's surface or its core. For now, while we may not achieve a direct touch, we can certainly get remarkably close.