Buzz
While private space companies often steal the spotlight, NASA sometimes goes unnoticed. Although the agency hasn't returned to the Moon since the 1970s, it remains relevant with groundbreaking missions like the new probe to the Sun, which is once again making headlines in the space world.
The Parker Solar Probe is designed to travel millions of miles and venture closer to the Sun than any spacecraft before. Along its journey, it will perform gravity assists with Venus, set speed records, and become the fastest and most autonomous human-made object, all while carrying data from over a million passengers.
Here are 10 incredible facts about NASA’s mission to the Sun.
10. The Ultimate Goal: ‘Touch the Sun’
The Parker Solar Probe has set out on a mission to do what no other human-made object has achieved before: to explore the Sun’s outer atmosphere. As NASA aptly states, 'This summer, humanity embarks on its first mission to touch the Sun.'
The probe's objective is not only to unlock the Sun's hidden secrets but also to enhance our understanding of how solar activity affects Earth's magnetic field. As solar-driven technologies continue to shape modern life, this mission’s importance cannot be overstated. It will also improve our ability to explore the rest of the solar system.
This groundbreaking mission to a star will resolve many long-standing questions while undoubtedly raising new ones.
9. A 50-Year Journey
The August 2018 launch represents the culmination of over five decades of theories and meticulous planning.
The scientific community first discovered the corona’s extreme million-degree temperature in the 1940s and confirmed the solar wind’s existence in the 1960s. Yet, the reasons behind the corona’s intense heat and the forces accelerating solar wind remained elusive. These mysteries can only be solved by directly interacting with the corona.
The concept of making direct measurements was first proposed in 1958. Since then, several spacecraft have approached the Sun, but none have ventured as close to the target destination of the Parker Solar Probe. Numerous planned missions were shelved over the years due to funding limitations, and the current project has faced several delays.
The Parker Solar Probe will bring over fifty years of dedicated work to fruition.
8. The First Spacecraft Named After a Living Person
NASA has named spacecraft after planets, Greek gods, and even a demon from Lord of the Rings, but it had never honored a living person—until now.
Born in 1927, Dr. Eugene Parker dedicated his life to physics, earning numerous accolades, including the National Medal of Science, the Gold Medal of the Royal Astronomical Society, and the Kyoto Prize. Beyond his achievements, Parker was a key figure in shaping critical theories about the Sun.
In the 1950s, Parker formulated a groundbreaking theory about how stars release solar energy. He coined the term 'solar wind' to describe the energy emitted by the Sun and proposed a theory to explain why the Sun's corona is hotter than its surface. His research has been crucial in advancing our understanding of the complex relationship between Earth and the Sun.
NASA typically renames missions after successful launches, but in the case of the Parker Solar Probe, the organization chose to honor Dr. Eugene Parker before the spacecraft even left Earth's orbit. It will be the first spacecraft named after a living person to journey beyond Earth's orbit.
7. Solar Wind
Solar wind is central to the mission's objectives. This wind, originating from the Sun's corona, travels through space at speeds that can reach up to 1.6 million kilometers per hour (1 million mph).
Unlike Earth’s wind, the extreme temperatures of the Sun’s corona affect gravity in such a way that the wind escapes the star and travels outward into space. By the time it reaches Earth, it can cause considerable damage.
The mission’s primary scientific goals focus almost entirely on solar wind-related phenomena. Specifically, researchers aim to uncover how the Sun’s corona is heated and the factors that accelerate solar wind.
Just as we can’t fully understand tornadoes without getting close to them, the Sun hides crucial answers about solar wind that can only be unlocked at its source. NASA scientists expect that by 2025, solar wind’s mysteries will be far clearer after the probe’s mission.
6. The Sun Is Incredibly Challenging to Reach
Despite the remarkable science behind the Parker Solar Probe, getting to the Sun presents immense challenges. While a mission to Mars is daunting, the energy needed to reach the Sun is 55 times greater than the much simpler journey to another planet.
The Sun lies an average of 150 million kilometers (93 million miles) away from Earth, but distance alone is not the main challenge. Surprisingly, speed is not the primary issue either—not in the way you might expect.
Earth travels at about 108,000 kilometers per hour (67,000 mph) and is nearly always aligned sideways with the Sun. A probe launched from Earth towards the Sun would continue on a sideways trajectory, completely missing the mark. To fix this, the solution is to cancel out the sideways motion by launching the probe backward at the same speed as Earth's forward motion.
The challenge doesn’t end with navigation, as entering the Sun's outer corona demands an extraordinary heat shield. The Parker Solar Probe is designed to solve both of these challenges.
5. Gravity Assists From Venus
NASA scientists will tackle the challenge of the probe's sideways motion relative to the Sun step by step. The team has come up with a plan that's literally out of this world.
Alongside powerful rockets, the Parker Solar Probe will rely on gravity assists from Venus. As the probe approaches Venus, it will harness the planet's gravity to slow down and get closer to the Sun. This maneuver will be repeated seven times over seven years, gradually reducing its sideways speed until it reaches the Sun.
The need for gravity assists from Venus even dictates the launch timing—a brief two-hour window each day for about two weeks during the summer when the planets align closely.
4. Fastest Man-Made Object In History
The gravity assists from Venus will slow the probe's sideways motion but boost its overall speed. By the end of its journey, the probe will reach an astonishing 692,000 kilometers per hour (430,000 mph), making it the fastest man-made object ever.
For perspective, the fastest human-made object so far is the Juno spacecraft, which reaches a maximum speed of 266,000 kilometers per hour (165,000 mph). Meanwhile, Voyager 1, which has left the solar system after 35 years of travel, moves at about 61,000 kilometers per hour (38,000 mph). The Parker Solar Probe will exceed Juno's speed by more than double and travel 11 times faster than Voyager 1.
To put that into a more familiar context, the Parker Solar Probe’s top speed is fast enough to cover the distance from Philadelphia to Washington, DC, in just one second.
3. Unique Cargo
This mission, requiring minimal weight, will still carry a very special cargo—human cargo, in a virtual sense.
In March 2018, NASA opened up a unique opportunity for the public to submit their names for inclusion on a memory card aboard the Parker Solar Probe. William Shatner, the actor famously known for portraying Captain Kirk in Star Trek, took part as a spokesperson, even creating a video encouraging people to send in their names. In the end, over 1.1 million individuals, Shatner included, received their virtual boarding passes to be part of the mission.
Nicola Fox, the project scientist, expressed, 'It’s fitting that as the mission undertakes one of the most extreme journeys of exploration ever tackled by a human-made object, the spacecraft will also carry along the names of so many people who are cheering it on its way.'
2. The Most Autonomous Spacecraft Ever
The probe’s ability to withstand the intense heat of the Sun’s corona is aided by highly advanced automation. With a communication delay of about eight minutes between Earth and the Sun, the spacecraft has only seconds to make real-time corrections. Its automated systems ensure it can safely adjust during those critical moments.
Equipped with programming for every potential scenario that scientists have envisioned, the Parker Solar Probe’s heat shield can rotate when needed, and the spacecraft can even adjust its direction autonomously.
Nicola Fox, a project scientist at the Applied Physics Laboratory of Johns Hopkins University, refers to the Parker Solar Probe as 'the most autonomous spacecraft that has ever flown.'
1. Heat Shield
The probe’s heat shield is as remarkable as its impressive speed. The shield, which has a diameter of 2.4 meters (8 feet), sits at the front of the spacecraft to protect its delicate instruments while deflecting heat away. It’s made of a 11.4-centimeter-thick (4.5 inches) layer of carbon foam, encased by specialized panels composed of superheated carbon–carbon composite. Despite its size, the entire shield weighs only 73 kilograms (160 pounds).
Understanding the difference between temperature and heat is crucial to how the heat shield functions. Temperature is a measure of thermal energy, while heat refers to the transfer of energy. Though the Sun’s corona has temperatures reaching between 1.1 and 1.7 million degrees Celsius (2 to 3 million °F), the heat is manageable due to the sparse arrangement of plasma particles.
Lead engineer Betsy Congdon explained, 'The temperatures are extremely high, but we’re not coming into direct contact with most of them. It’s similar to when you place your hand in an oven set to 204 or 260 degrees Celsius (400 or 500 °F) — the oven may be hot, but your hand isn't.'
The heat shield will protect the probe, allowing it to venture into the Sun's outer corona without risk of melting.
