We discussed the Parker Solar Probe in our previous article. In today’s article, we will cover its journey and the important experiments to be conducted.
Parker Solar Probe’s Trajectory
The mission design uses repeated gravity assists at Venus to incrementally decrease its orbital perihelion to achieve a final altitude (above the surface) of approximately 8.5 solar radii, or about 6×10^6 km (3.7×10^6 mi; 0.040 au). The spacecraft trajectory will include seven Venus flybys over nearly seven years to gradually shrink its elliptical orbit around the Sun, for a total of 24 orbits. The near Sun radiation environment is predicted to cause spacecraft charging effects, radiation damage in materials and electronics, and communication interruptions, so the orbit will be highly elliptical with short times spent near the Sun.


The mission design uses repeated gravity assists at Venus to incrementally decrease its orbital perihelion to achieve a final altitude (above the surface) of approximately 8.5 solar radii, or about 6×10^6 km (3.7×10^6 mi; 0.040 au). The spacecraft trajectory will include seven Venus flybys over nearly seven years to gradually shrink its elliptical orbit around the Sun, for a total of 24 orbits. The near Sun radiation environment is predicted to cause spacecraft charging effects, radiation damage in materials and electronics, and communication interruptions, so the orbit will be highly elliptical with short times spent near the Sun.

The trajectory requires high launch energy, so the probe was launched on a Delta IV Heavy class launch vehicle and an upper stage based on the STAR 48BV solid rocket motor. Interplanetary gravity assists will provide further deceleration relative to its heliocentric orbit, which will result in a heliocentric speed record at perihelion.
As the probe passes around the Sun, it will achieve a velocity of up to 200 km/s (120 mi/s), which will temporarily make it the fastest human-made object, almost three times as fast as the previous record-holder, Helios-2. Like every object in an orbit, due to gravity, the spacecraft will accelerate as it nears perihelion, then slow down again afterward until it reaches its aphelion.
Science Goals and Mission Details
The goals of the mission are:
- Trace the flow of energy that heats the corona and accelerates the solar wind
- Determine the structure and dynamics of the magnetic fields at the sources of solar wind
- Determine what mechanisms accelerate and transport energetic particles
Within each orbit of the Parker Solar Probe around the Sun, the portion within 0.25 AU will be the Science Phase, in which the probe will be actively and autonomously making observations. Communication with the probe will be largely cut off in that phase.
Science phases will run for a few days both before and after each perihelion. They will last 11.6 days for the earliest perihelion, and drop to 9.6 days for the final, closest perihelion. Much of the rest of each orbit will be devoted to transmitting data from the science phase.
In our next article, we will explore more details about the Parker Solar Probe such as important experiments and the instruments onboard.
References:
- https://www.space.com/40437-parker-solar-probe.html
- https://www.nasa.gov/content/goddard/parker-solar-probe
- http://parkersolarprobe.jhuapl.edu/
- http://parkersolarprobe.jhuapl.edu/The-Mission/index.php
- https://en.wikipedia.org/wiki/Parker_Solar_Probe
- https://www.space.com/parker-solar-probe-spotted-stealth-sun-eruption.html
- https://www.nasa.gov/content/goddard/parker-solar-probe-humanity-s-first-visit-to-a-star
- https://en.wikipedia.org/wiki/Parker_Solar_Probe#/media/File:Magnificent_CME_Erupts_on_the_Sun_-_August_31.jpg