TOUCHING THE SUN

launching

Launch: August 12, 2018, at 3:38 a.m. EDT (7:31 UTC)

Max. Launch C3: 154 km2/s2

Launch Site: Space Launch Complex 37, Cape Canaveral Air Force Station

Launch Vehicle: Delta IV-Heavy with Upper Stage

Mission Duration: Baseline seven-year science mission

Ground Data Passes: Parker Solar Probe will transmit data via NASA’s Deep Space Network

The objectives

Trace the flow of energy that heats the solar corona and accelerates the solar wind.

1. How is energy from the lower solar atmosphere transferred to, and dissipated in, the corona and solar wind?

2. What processes shape the non-equilibrium velocity distributions observed throughout the heliosphere?

3. How do the processes in the corona affect the properties of the solar wind in the heliosphere?

Determine the structure and dynamics of the plasma and magnetic field at the sources of the solar wind.

1. How does the magnetic field in the solar wind source regions connect to the photosphere and the heliosphere?

2. Are the sources of the solar wind steady or intermittent?

3. How do the observed structures in the corona evolve into the solar wind?

Explore mechanisms that accelerate and transport energetic particles.

1. What are the roles of shocks, reconnection, waves, and turbulence in the acceleration of energetic particles?

2. What are the source populations and physical conditions necessary for energetic particle acceleration?

3. How are energetic particles transported in the corona and heliosphere?

The mission

Parker Solar Probe will swoop to within 4 million miles of the Sun's surface, facing heat and radiation like no spacecraft before it. Launched on Aug. 12, 2018, Parker Solar Probe will provide new data on solar activity and make critical contributions to our ability to forecast major space-weather events that impact life on Earth.

To unlock the mysteries of the corona, but also to protect a society that is increasingly dependent on technology from the threats of space weather, we will send Parker Solar Probe to touch the Sun.

In 2017, the mission was renamed for Eugene Parker, the S. Chandrasekhar Distinguished Service Professor Emeritus, Department of Astronomy and Astrophysics at the University of Chicago. In the 1950s, Parker proposed several concepts about how stars-including our Sun-give off energy. He called this cascade of energy the solar wind, and he described an entire complex system of plasmas, magnetic fields, and energetic particles that make up this phenomenon. Parker also theorized an explanation for the superheated solar atmosphere, the corona, which is -contrary to what was expected by physics laws - hotter than the surface of the Sun itself. This is the first NASA mission that has been named for a living individual.

Some Data about the parker solar probe

Mass

The mass of the spacecraft after fueling is about 1,400 pounds (635 kilograms). The heat shield, called the Thermal Protection System (TPS), weighs 160 pounds (73 kilograms).

Spacecraft Dimensions

The spacecraft is about 9.8 feet (3 meters) tall and about 3.3 feet (1 meter) in diameter below the cooling system. The Thermal Protection System is a little over 4.5 inches (11.43 centimeters) thick and has a diameter of about 7.5 feet (2.3 meters).

Power

Parker Solar Probe’s solar arrays can produce 388 watts of power, depending on configuration-about enough to run a kitchen blender.

Maximum Downlink Rate

The maximum downlink rate is 555 kilobits per second (kbps). The downlink time varies by orbit phase.

Antenna

The spacecraft has three types of antennas:

• One High-Gain Antenna (HGA) for downlinking high-rate science data.

• Two Fan-beam Antenna to support command uplink and real-time health and status telemetry downlink during nominal operations.

• Two Low-Gain Antenna (LGA) to support command uplink and real-time health and status telemetry downlink during contingency operations.

Solar Arrays

The two solar arrays are each about 3.7 feet (1.12 meters) long by 2.26 feet (0.69 meters) wide, for a total area of 17.2 square feet (1.6 square meters).

Why won’t it melt?

Parker Solar Probe has been designed to withstand the extreme conditions and temperature fluctuations for the mission. The key lies in its custom heat shield and an autonomous system that helps protect the mission from the Sun’s intense light emission but does allow the coronal material to “touch” the spacecraft.

What is the concept behind that?

the concept of heat versus temperature, in space, the temperature can be thousands of degrees without providing significant heat to a given object or feeling hot. Temperature measures how fast particles are moving, whereas heat measures the total amount of energy that they transfer. Particles may be moving fast (high temperature), but if there are very few of them, they won’t transfer much energy (low heat). Since space is mostly empty, there are very few particles that can transfer energy to the spacecraft. The corona through which Parker Solar Probe flies, for example, has an extremely high temperature but very low density. Think of the difference between putting your hand in a hot oven versus putting it in a pot of boiling water (don’t try this at home!) -in the oven, your hand can withstand significantly hotter temperatures for longer than in the water where it must interact with many more particles. Similarly, compared to the visible surface of the Sun, the corona is less dense, so the spacecraft interacts with fewer hot particles and doesn’t receive as much heat.

The surface of the heat shield that faces the Sun will only get heated to about 2,500 degrees Fahrenheit (about 1,400 degrees Celsius).