NASA's Parker Solar Probe targets the sun

NASA's Parker Solar Probe is about to embark on a cascade of space missions.

The spacecraft will be the first spacecraft to traverse the outside atmosphere of the sun, or crown, a devastating hell. Over the next seven years, Parker will bad the sun twice to several tens of millions of degrees, skirting the star's surface for a distance of about 6 million kilometers, more than seven times more than any previous spaceship. At his closest approach, Parker will travel the crown about 700,000 kilometers at the time, making the machine the fastest human object in the solar system. The probe would need only one second to pbad from Philadelphia to Washington, DC

Parker's close sightings on the crown and the solar wind, the torrent of charged particles that the sun spews into the air Space, could help solve mysteries the inner workings of the sun's atmosphere. And the new data could improve space weather forecasts that endanger space ships, astronauts and ground-based technology.

The mine of new data collected by this probe "will answer many questions that we could not answer in any," says Craig DeForest, a heliophysicist from the Southwest Research Institute in Boulder, Colorado, who is not involved in the mission. "There was a lot of anticipation."

Scientists have had a probe like Parker on their mission wish lists for nearly 60 years. In 1958, the year NASA was established, the National Academy's Space Studies Council recommended that the new agency send a spaceship inside Mercury's orbit to study the environment. of the sun

. Solar probe mission ideas, but none could be as close to the sun as astronomers wanted. "It's only recently that heat shield technology and everything else has converged so well that we can make it a reality," says DeForest.

About the size of a small car, the Parker Solar Probe 3D Images, measure electric and magnetic fields and catalog high energy particles. Although the crown is boiling at millions of degrees, the atmosphere is so diffuse that most of the heat that will endanger Parker's instruments comes from radiation emanating directly from the sun's surface. This intensely intense sunlight can heat the surface of the spacecraft to around 1370 °.

To protect Parker's instruments from this radiation, the probe is armed with a heat shield consisting of a layer of carbon foam sandwiched between the panes of another carbon. material similar to epoxy graphite used to make golf clubs and tennis rackets. As Parker turns around the sun, this heat shield will continually face the star to keep the instruments hidden away from radiation up to 475 times more intense than the space ships undergo. orbiting the Earth

Parker will dive into the sun's crown. for the first time just three months after launch, sending its first batch of data to Earth in early December. For scientists, it is a fairly fast satisfaction: for spacecraft such as New Horizons ( SN Online: 15/06/15 ) who have appointments with objects from the solar system more Remote, intermission can last for years.

The probe will surround the sun 24 times, using the gravitational pull of Venus to gradually shrink the orbit of the craft. In his first turn, Parker will fly about 24 million kilometers from the sun's surface; on its last loops in 2024 and 2025, the probe will reach about 6 million kilometers

The probe could have some fuel to continue sailing around the sun after 24 mission orbits, says Nicola Fox, project scientist for the mission. But eventually, Parker will not be able to shoot the thrusters he needs to keep his heat shield facing the sun. The probe "will begin to turn, and spaceship pieces that are not fully designed to see the sun will be in full illumination," says Fox, a heliophysicist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. At first, they will break into big pieces, then they will become smaller and smaller. Finally, Parker will only be a handful of dust scattered on the crown.

The legacy of the spacecraft will continue to live. Parker's observations should help answer questions about the solar corona and solar wind that researchers have embarked on for decades

For example, Parker's data could explain the odd temperature difference between the surface of the sun and the 5500 ° and the crown of several million degrees. This point may be due to vibrating magnetic field lines that warm the material in the crown, or to jets of material from the sun's surface that inject energy into its atmosphere ( SN Online: 8/20/17 ). Parker could also help explain where solar wind particles get energy to accelerate while they escape the immense gravitational pull of the sun ( SN Online: 8/18/17 )

The enigmatic coronal heat and acceleration of David McComas, physicist of space plasmas at Princeton University, explains that the solar wind probably has a common cause. McComas is the principal investigator of one of the instruments of the probe, the Integrated Science Investigation of the Sun. There are many competing theories to explain these two problems, but Parker's views on the sun should help clarify the list of possible explanations.

Parker's observations should also give a new insight into the origins of these highly energetic particles that escape from the sun. the solar wind, says McComas. The solar wind blows on Earth hundreds of kilometers per second, and the disturbances of this cosmic breeze can disrupt satellites, spacecraft and electrical networks ( SN: 8/19/06, p.120 ). A better understanding of the stormy atmosphere of the sun and the solar wind could lead to better forecasts for potentially dangerous weather events.

To top it off, Parker's expanded view of the sun will undoubtedly raise new mysteries about our star. McComas says. The data from "a mission [often] only arouses our curiosity for even more observations," he says

Fortunately, another spacecraft headed for the sun sets off just after the Parker probe. Solar Orbiter of the European Space Agency, which will take off in 2020, will provide the first direct images of the sun's poles. Coupled with the observations of Parker closer to the diaphragm of the sun, the Solar Orbiter data can reveal how the solar wind varies at different latitudes

These missions are not just about knowing our own solar system." Once you know how our star works, you will know much more about … other stars, "says Fox.

Whatever the scientific discoveries of the mission, it is difficult not to be excited by the "wow" factor of the imminent probe expedition. says: "We are launching a probe and we fly it through a million-degree plasma on the periphery of a star, I mean, it's cool, is that it?"