You're going into environment that's completely unforgiving. The temperatures
that we're seeing on the spacecraft or have not been seen by any other
spacecraft ever before. The scariest thing about the Sun is the unknown. We
see it every day but we see it from 93 million miles away.
This first perihelion were going into we have very minimal contact - all we can
get is a tone. I'm going to be waiting on the edge of my seat for those beacon
tones. The Sun facing side will be exposed to in excess of 2,500 degrees Fahrenheit
We're gonna go closer to the Sun than any other spacecraft has gone before. We're
not going to do that once we're not gonna do it twice - we're gonna do that 24
times - and that is terrifying. We really don't know what we're gonna find until we get
there. In 1958 Gene Parker had an idea that the
area around the Sun would behave in a certain way. There are two really
overarching mysteries that we have always wanted to study: why is the corona
hotter than the surface of the Sun? Why is the solar wind continuously
accelerated? We are now in what we call our encounter attitude the TPS is pointed
at the Sun and we will not leave that attitude until we get back around the
backside of the Sun. So we keep the thermal shield between the spacecraft
body and the Sun. We have designed the spacecraft to be able to do the right
thing no matter what it sees. You can't do Parker Solar Probe unless you're
willing to build a spacecraft that could take care of
itself; you can't build Parker Solar Probe
unless you can build a shield that could withstand the thermal environment; you
can't do Parker Solar Probe unless you can keep the power generation cool - and
all these things contain some level of risk.
The Sun is a wideband radio source so any spacecraft is either in front of the
Sun behind the Sun or near the Sun you can't talk to it. Parker Solar Probe is
designed to transmit four different kinds of beacon tones A is a good beacon,
the fault management system is reporting that all systems are nominal.
The other three tones mean that some type of fault has occurred on board. We
will be mostly out of contact with the spacecraft through encounter so the only
thing we will have is those beacon tones. We will be all waiting for the call: "APL,
APL - I am Parker Solar Probe. I'm doing well, and I have surprises for you. The fear
and tension and stress is all going to be focused on those last few minutes.
This truly is a mission of discovery.