- NASA will launch Parker Solar Probe in July 2018 to study Sun more closely.
- It will orbit as close as 6.2 million km to the Sun, reaching a maximum speed of nearly 724,000 km/h.
- This mission will answer questions like how solar wind is accelerated, why corona is hotter than the photosphere, etc.
NASA is all set to launch a probe, named Parker Solar Probe, in July 2018. This will be the first mission to visit our nearest star, Sun. It will approach to within 6.2 million km to the photosphere (surface) of the Sun, facing extreme radiation and heat like no space probe before it.
The probe is named after solar astrophysicist Eugene Parker, who developed the supersonic solar wind theory and proposed the Parker spiral shape of solar magnetic field in the outer solar system. This is the first time, NASA has named their probe after a living astronaut.
As you might have guessed, the aim of the mission is to better understand our star, where gradually altering conditions could propagate out into the solar system, making a massive impact on our planet and other worlds.
Why This Mission?
Life on Earth is possible because of the Sun’s atmosphere. With this solar mission, NASA is trying to find some crucial links between the Earth and the Sun. The spacecraft is going so close to study the corona, intensive solar winds, flares and coronal solar mass ejections.
It’s quite surprising that the concept of the mission is more than 5 decades old. It was originally set to launch in 2015, and later, it rescheduled to summer of 2018.
The probe will answer some of the most fundamental questions like how solar wind is accelerated, why corona is hotter than the photosphere, and much more. Like other successful missions, the probe is likely to generate more questions than it answers.
Specifically, the probe will trace the energy flow that heats and accelerates the solar wind. It will analyze the plasma and magnetic field dynamics at solar wind sources, and explore the concept behind transporting energetic particles.
The probe will orbit as close as 6.2 million km to the Sun, which is 7 times closer than any other spacecraft ever before. To make it survive the extreme environment and Sun’s heat (the temperature of the spacecraft will reach 1,377 °C), the probe is packed with 11.4-cm-thick carbon-composite shield.
The Parker Solar Probe will have a maximum weight of 685 Kg and it will be launched on Delta IV Heavy vehicle. The scientific instruments and spacecraft system are placed in the middle of the shadow of the shield, where direct radiation from the Sun is entirely blocked.
The spacecraft is mainly equipped with solar array cooling system to maintain the operating temperature, blowdown monoprop hydrazine propulsion for giving speed and directions and high gain antenna providing science downlink rate of 167 kb/s at 1 AU (distance from Earth to Sun).
As the spacecraft passes around the Sun, it will reach a speed of nearly 724,000 km/h (77 km/s). This will be the fastest man-made object to reach such high speed, about 3 times as fast as Helios-B (the current record holder).
The Parker Solar Probe will accelerate as it comes close to perihelion (closest point to Sun) to higher velocity, and it will slow down again afterward at its aphelion (farthest point from the Sun).
The space probe will have a total of 24 perihelion, and 7 Venus gravity assist flybys. It will reach the first perihelion in November 2018. By 2024, probe’s orbital period will be reduced to 88 days (initially 150 days), allowing it to make the first closest approach to Sun (Perihelion #22).
This spacecraft is a part of NASA’s Living With a Star program to study different aspects of Sun and Earth connection that directly affect life on Earth. The program is managed by Goddard Space Flight Center in Maryland. The Johns Hopkins University Applied Physics Laboratory is developing the space probe and will operate it.