In a Few Days, We’ll Launch to a Star
NASA is sending a probe that will pass right through the sun’s atmosphere
During the early morning of August 11, just days away, NASA will launch the Parker Solar Probe on a mission to touch our sun. It won’t get there right away; over the course of seven years the probe will circle Venus seven times in what’s known as a gravity assist — a path to slow down the probe so it can more carefully make its way to the sun. After all, when you’re approaching a star whose surface can reach 10,000 degrees Fahrenheit, you want to do so gradually. The gravity assist will happen by October 2nd, allowing the probe to start getting close to the sun by November 5th.
The goal is to get the probe as close as 3.8 million miles to the surface by 2025. For comparison, the closest we’ve ever come before is in 1976 when the Helios 2 came within 27 million miles. The Parker Solar Probe will get over 7 times closer, well within the orbit of Mercury. At this distance the probe will be flying in the outermost part of the sun’s atmosphere — a place known as the corona. It’s a very dangerous and intense place to be, full of heat and radiation. While the coronal plasma can get up to a million degrees Fahrenheit, the probe only has to withstand 2,500 degrees since the plasma’s low density means the heat transferred to the probe is primarily sunlight.
The spacecraft was engineered for this mission with a 4.5 inch thick carbon-composite shield that can not only withstand the immense heat but also the immense radiation which will be more than 500 times what we experience here on Earth. Instruments in shadow will be operating in 85 degree heat, not much warmer than room temperature. At its closest point of contact, the probe will be moving at 430,000 miles per hour. That’s fast enough to get from New York to Tokyo in a minute.
Onboard the craft will be four instrument suites capable of studying magnetic fields, plasma and energy particles, and taking images of solar winds. The measurements and pictures will help us better understand the corona and, in turn, the birth and development of solar wind. Researchers are hoping to answer questions like why the corona is hotter than the solar surface and how the solar wind accelerates. Where do high energy solar particles originate? These are all mysteries science has been trying to answer for over 60 years.
The data will also help us forecast the space environment around our planet — space weather that affects satellites’ orbits, lifetimes, and onboard electronics. These same satellites are crucial for the life and technology on Earth.
The probe is named after Eugene Parker who in the mid-1950’s wrote a paper on solar wind and the system of plasma, magnetic fields, and energetic particles around the sun. He theorized that nanoflares are what made the corona hotter than the surface. These ideas were so controversial that they were rejected at the time and yet his predictions for solar wind speed and temperature were almost exactly right. This mission will help find proof for his theories and ideas. At almost 90 years old, he’s still alive to see the probe go into space.
You can watch the launch live on August 11th at this website:
