NASA’s Parker Solar Probe, shown in this animation, became the closest-ever spacecraft to the Sun on Nov. 5, 2018, when it passed within 15 million miles (24 million kilometers) of the Sun’s surface. Credit: NASA/JHUAPL

The probe was operating autonomously and out of contact with
mission controllers at
the Johns Hopkins University Applied Physics Lab since
it was so close to the sun.  


The moment of closest approach was 10:28 p.m. EST Monday Nov.
5 (0328 GMT Tuesday Nov. 6).   The encounter period
began on Oct. 31.


“Mission controllers at the Johns Hopkins University Applied Physics Lab received
the status beacon from the spacecraft at 4:46 p.m. EST (2146 GMT) on Nov. 7,
2018,” said NASA. 


“The beacon indicates
status “A” — the best of all four possible status signals, meaning
that Parker Solar Probe is operating well with all instruments running and
collecting science data and, if there were any minor issues, they were resolved
autonomously by the spacecraft.”


It currently takes
about 18 minutes for a round trip signal from the spacecraft to reach Earth and
return to the probe – which is approximately 1.2 AU (110 million miles, 180
million km) distant from Earth. 

Parker Solar Probe Mission Trajectory and Current Position after 1st solar perihelion in Nov 2018.  Credit: NASA/APL/Parker Solar Probe

On Oct. 29 Parker already smashed through the
existing 42 years old record set by the German-American Helios 2
spacecraft back in April 1976 – and will continue setting astounding
new records over the course of its seven year mission as it dives ever closer during
some two dozen solar perihelion encounters.


Parker became the closest human-made object to
the Sun in history when it plunged past the then current record of 26.55
million miles from the Sun’s surface on Oct. 29, 2018, at about 1:04 p.m. EDT.


“Parker Solar Probe was designed to take care of
itself and its precious payload during this close approach, with no control
from us on Earth — and now we know it succeeded,” said Thomas Zurbuchen, associate
administrator of NASA’s Science Mission Directorate at the agency headquarters
in Washington, in a statement. 


“Parker is the culmination of six decades
of scientific progress. Now, we have realized humanity’s first close visit to
our star, which will have implications not just here on Earth, but for a deeper
understanding of our universe.”


Eventually she will swing by the sun within a
final close approach of 3.83 million miles in 2024 while soaring by at a
record-breaking speed of nearly 500,000 MPH.


During this
1st solar perihelion at 15 million miles distance the Sun-facing
side of Parker Solar Probe’s heat shield, called the Thermal Protection System,
experienced temperatures up to about 820 degrees Fahrenheit. 


This
temperature will climb up to 2,500 F as the spacecraft makes closer approaches
to the Sun coming within 4 million miles.


But the TPS
is so effective that on the spacecraft facing side instruments and systems that
are protected by the heat shield are generally kept in the mid-80s F.


The 1st solar encounter period began
on Oct. 31 and lasts through Nov. 11.


Parker is equipped with four on-board science
instruments suites. Because of the probes proximity to the sun it will take several
weeks before the science data begins
downlinking to scientists on Earth.


The key goals are to try and
answer fundamental questions about the nature of the sun and develop an
understanding of how the sun works – such as why is the solar corona so hot.
Its much hotter than the suns surface.


Scientists also want to know why
the solar wind is accelerated to supersonic speeds. 


The mission will conduct 7 Venus flyby’s to
set up 24 perihelion close encounters with the sun through 2024. The Venus
flyby’s will precisely
set its trajectory toward the Sun and slow the probe down instead of speeding
it up. 


The $1.5 Billion mission began with a dazzling
middle-of-the-night blastoff of the mighty Delta IV Heavy rocket in the wee
hours of the morning, Aug. 12 – and delivered the car sized spacecraft to its
intended trajectory towards Venus and the Sun.