Designed, built, and operated by the Johns Hopkins Applied Physics Lab, NASA’s Parker
Solar Probe, is flying closer to the sun than any other spacecraft before.
It will pass by the sun 24 times, solving age-old mysteries surrounding the origins
of the solar wind and other activity that affects life on Earth.
What makes this mission possible is a unique trajectory with flights past Venus, which
shape the probe’s orbit and set its course toward the Sun.
Without them, there is no mission, and no great discoveries.
So why is Venus so important to a mission to the Sun?
It all comes down to power.
The truth is, no rocket could supply the amount of power required to get Parker Solar Probe
as close to the Sun as it needs to be.
So, we need to borrow force from Venus.
It sounds like science fiction, but in reality, spacecraft can leverage the gravity of other
planets to speed up, like a slingshot, or to slow down, like tapping the brakes.
This is called a gravity assist maneuver, or a gravity assist.
A planetary gravity assist changes a spacecraft’s heliocentric speed by rotating the direction
of the spacecraft’s flyby velocity.
Parker Solar Probe will use seven Venus gravity assist maneuvers over its mission to dive
closer and closer to the Sun.
As Parker Solar Probe speeds towards Venus, it flies in front of the planet to slow down
- kind of like swimming against a current.
This actually allows the spacecraft to leave a little of its momentum with Venus as it
zips by.
The flyby alters Parker Solar Probe’s orbit – sometimes by millions of miles, sending
it closer to the Sun.
This technique is actually nothing new.
In fact, several spacecraft have used gravity assists over the years: including Voyage,
Messenger, and New Horizons.
At its closest point, within four million miles of the Sun’s surface, the probe will
be moving 430 thousand miles per hour – fast enough to get from Philadelphia to Washington
D.C. in one second!
It’s all thanks to the Parker Solar Probe mission team, who makes sure everything stays
on track during this historic exploration.
Gravity assists are part of the unprecedented, record-breaking mission to uncover the secrets
of our star.
For Parker Solar Probe, it’s the fastest, most accurate, and most efficient, way to
fly.