The sun is a giant nuclear fireball that, as a rule, melts anything that comes close. Yet, there’s aplan to send a spacecraft into the sun’s upper atmosphere to get a closer look at it and gather data on coronal mass ejections (CME). The spacecraft is called Solar Probe Plus (SPP), and it’s by the Johns Hopkins University Applied Physics Laboratory. If all goes as planned, it’ll launch in 2018.
A coronal mass ejection is often associated with solar flares, but the two phenomena are distinct. A solar flare is simply an increase in brightness on the sun that is often accompanied by a prominence — a giant loop of plasma that leaps off the surface, but eventually settles back down. If there is a large release of plasma from the sun into space, we call that a coronal mass ejection.
CME’s have scientists worried because the charged particles can be extremely dangerous for Earth. A coronal mass ejection pointed at us can knock out satellites and cause damage to electrical systems on the ground. Astronauts on the ISS could be seriously affected by a CME without the protection of Earth’s magnetic field as well.
After its launch in 2018, SPP will make its way to the sun and complete 24 orbits as it studies the star. It will conduct seven flybys of Venus as it orbits the sun over the course of seven years. Each Venus pass will lower its orbit over the sun, eventually bringing it within 4 million miles (6.4 million kilometers) of the surface. That puts it inside the sun’s corona, where no other man made object has ventured.
Scientists working on the probe estimate it will need to withstand temperatures in excess of 2500 degrees Fahrenheit (1371 celsius). The probe will be equipped with a 4.5-inch-thick carbon composite shield to keep itself cool. While it’s inside the corona, SPP will attempt to accomplish three main objectives. It will attempt to trace the flow of energy that leads areas of the corona to heat up. It will also observe the structure of magnetic fields and plasma currents as the source of the solar wind. Lastly, SPP will gather data on the movement of energetic particles in the solar wind like electrons, protons, and helium nuclei.
The hope is a better understanding of mechanisms in the corona will allow scientists to predict the occurrence of dangerous solar phenomena like coronal mass ejections.
Source : https://www.extremetech.com/extreme/246881-upcoming-nasa-probe-will-fly-suns-corona