NASA readies to launch the Parker Solar Probe and ‘touch’ the sun

An illustration of NASA’s
Parker Solar Probe (previously called Solar Probe Plus) as it
flies toward the sun.

NASA/JHU/APL

• NASA plans to launch a robot on Saturday that will fly
  closer to the sun than any mission in
  history.
• The Parker Solar Probe will use a high-tech heat
  shield
  to avoid being destroyed.
• The probe is designed in part to study the sun’s
  ultra-hot outer atmosphere, called the corona,
  among other mysteries.
• The mission may help scientists predict space weather events that
  can wreak havoc on Earth.

NASA is about to launch a $1.5 billion space mission to “touch”
the sun and study its
atmosphere, solar wind, and other mysteries.

The Parker Solar Probe (PSP) is scheduled to launch on
Saturday, August 11, though it may launch as late as August 23.
When it blasts off into space from Cape Canaveral, Florida, it
will ride atop a powerful Delta 4 Heavy rocket built by
United Launch Alliance.

The
Parker Solar Probe in the nosecone or fairing of a Delta IV Heavy
rocket.

NASA/Johns
Hopkins APL/Ed Whitman

PSP is designed to survive sunlight 3,000 times more intense than
occurs at Earth and plow through a “solar wind” of high-energy
particles that can get as hot as several thousand degrees.

Its mission is to crack two 60-year-old mysteries: why the sun
has a solar wind at all, and how the corona — the star’s outer
atmosphere — can heat up to millions of degrees.

“That defies the laws of nature. It’s like water rolling uphill,”
Nicola Fox, a solar physicist at the Johns Hopkins University
Applied Physics Laboratory, said during a NASA briefing in 2017.

“Until you actually go there and touch the sun, you can’t answer
these questions,” said Fox, who’s a project scientist for the new
mission.

If the robot pulls off all the science that NASA and its partners
hope, it might also help researchers learn critical information
about solar outbursts that can
overload power grids, cripple satellites,
disrupt electronics, and inflict
trillions of dollars‘ worth of damage in a matter of hours.

How to ‘touch’ the sun 24 times — and survive

An illustration of the
Parker Solar Probe flying through the sun’s searing-hot corona
and withstanding blasts of solar wind
particles.

NASA’s Goddard Space Flight
Center

Scientists plan to fly the Parker Solar Probe by our sun about 24
times. During the PSP’s closest approach, it will come within 3.9
million miles of the star.

That distance is about four times the width of the sun itself, 24
times closer than Earth is to the star, and seven times nearer
than any spacecraft has ever dared travel to the sun. This
dangerous proximity will enable PSP to record unprecedented
measurements of the sun’s corona, solar wind, magnetism, and
other properties.

Pulling these flybys off isn’t straightforward. To put PSP on the
correct path, NASA will zoom its probe past Venus seven times,
which will help it reach speeds of more than 425,000 mph when it
moves through the sun’s corona. At that speed, you could travel
from New York City to Tokyo in a minute.

The
orbital path that NASA’s Parker Solar Probe will have to fly to
“touch” the sun.

Johns
Hopkins University Applied Physics
Laboratory

The idea to do a mission like PSP started nearly 60 years ago.
But temperatures reach about 2,500 degrees at the proximity
scientists wanted to send a probe, so “the materials didn’t
exist” to make it happen, Fox said.

That changed recently with the development of a state-of-the-art,
lightweight carbon composite. Engineers have crafted that
material into a 4.5-inch-thick “ram” for the probe that will face
the sun,
absorb and deflect solar radiation, and protect a suite of
gadgets behind it.

“Solar probe is going to be the hottest, fastest, and — as I like
to call it — the coolest mission under the sun,” Fox said.

Unraveling the mysteries of solar wind

Shutterstock

Orbiting a star as close as Earth does means we live inside its
atmosphere: a sea of moving particles, or solar wind, spews
outward at about 1 million mph and bombards planets like ours.

Eugene Parker, an 89-year-old scientist after whom the probe was
named, first discovered this solar wind in the mid-1950s. An
editor of a science journal famously rejected his seminal paper
in 1958 and scolded Parker — who was later found to be correct —
for submitting it.

During the NASA briefing last year, Parker said he jokingly
thought in 1958 that the editor “didn’t have any real critique,
so it must have been a really good paper.” 

Since then, physicists have wondered what, exactly, accelerates
this stream of particles to breakneck speeds. They also question
how the sun’s atmosphere can jump from thousands of degrees
Fahrenheit to millions of degrees in a tight region just above
the star’s surface.

“We want to go down there, take the challenge of going into the
worst environment in the solar system and … really prove what the
processes are that, in fact, make and accelerate the solar wind,”
Thomas Zurbuchen, the associate administrator of NASA’s Science
Mission Directorate, said last year.

Protecting Earth from violent solar outbursts

A
solar flare erupting from the sun. Such blasts produce copious
X-ray radiation.

NASA
Goddard Space Flight Center

Earth’s magnetic field and atmosphere typically protect us from
the solar wind.

However, the surface of the sun occasionally flings giant blobs
of solar particles at us in events called solar storms or coronal
mass ejections. This triggers the beautiful auroras at our
planet’s poles, but can also temporarily disturb Earth’s magnetic
field, which can in turn disturb electrical systems of all kinds.

While figuring out how to protect Earth isn’t the main goal of
PSP, researchers hope the mission equips heliophysicists
(scientists who study the sun) with new information that can help
them predict, characterize, and prepare the world for a
potentially crushing solar blow.

“Until we can explain what is going on up close to the sun, we
will not be able to accurately predict space weather effects that
can cause havoc at Earth,” states the mission’s website.

Last year, NASA finished assembling the probe and put it through
a brutal testing program (including sizzling-hot thermal
exposure). It’s now inside the Delta 4 Heavy rocket’s fairing, or
nosecone, and awaiting launch.

If all goes well after its launch, PSP should make its first pass
of the sun in late 2018 and its final one in mid-2025.

This story was updated with new information. It was
originally published on June 1, 2017.