SXSW 2018 Day 1 Session 1: Touch the Sun: NASA's first mission to our star

Session page, including audo: https://schedule.sxsw.com/2018/events/PP76167

Elizabeth Congdon, lead engineer at John Hopkins University Applied Physics Lab
Nicola Fox, NASA Parker Solar Probe project scientist


Around July 2018, NASA will launch its first ever probe to the Sun's corona.  The probe, called the Parker Solar Probe, is named after Gene Parker, a scientist who developed the theory of supersonic solar wind.  It's the first time NASA names a spacecraft after a living person.

The main purpose of the Parker Solar Probe is to gather information on the corona.  A major mysteries of the sun is how the Corona, which is outside of the Sun, can be hotter than the surface of the Sun itself.  The Sun's surface has a temperature of ~6000 degrees, while the corona is about 1.8 million degrees hot.  Plus, the plasma which makes up the Corona is so energetic that it can break out of the Sun's immensely powerful gravity and move away from it (generating Solar Wind).

The Parker Solar Probe will be launched sometime in the 20 day window that starts on July 20th 2018.  It will first spend six weeks travelling to Venus, where it will slingshot around it to give it speed as it heads towards the Sun, which it will reach in an additional six weeks.  At its peak it will reach speeds of 200 km per second, making it the fastest man-made object.

The mission faces some very difficult requirements.  First, temperature. Although the temperature of the corona overall is several million degrees, the Corona itself is not very dense, so the probe itself will not be subjected to that temperature. It's like putting a hand in a hot oven - as long as you don't touch the surface of the oven, the interior of the oven is bearable.  Still, the side of the satellite that faces the sun will be subjected to temperatures of about 1400 degrees.  Protecting the satellite will be a special heat shield designed to withstand this temperature.  The heat shield has to also withstand extreme colds, as the probe's orbit around the Sun will be elliptical, so it'll alternate between being very hot and very cold.  This is a special challenge as material tends to become brittle when alternatively exposed to hot and cold.
Another challenge was keeping the solar panels cool, as they do not operate efficiently in heat.  A special radiator system was designed for this problem.
A major challenge is the distance, where communication to the satellite will take 8 minutes to reach it.  As such, the satellite has to be highly autonomous - it will need to know to correct itself to ensure correct positioning with the Sun.
Additional design considerations had to be taken to protect the craft from the solar winds, which destroy electronics.
The team built a VR model of the probe to let their engineers practice on; not just for building or repairing pieces, but also to get used to the feel of the probe and learn how to operate around it.

The project has been running for a few decades.  Just the heat shield has been in work for the last 10 years, and integration and first tests started July 2016.  It will be flown to the Kennedy space center by the end of the month in prep for launch and for final testing.  Once launched, the probe will reach the Sun in about 12 weeks, but then will make several elliptical orbits around it, each time coming closer to the Corona.  It will reach closest to the Corona in about seven years after launch.

Some questions that were asked:
Q: What are we trying to answer?
A: The primary question we want to answer is why the Corona is so much hotter than the surface, but also what causes the Corona's plasma to become so energized.
Q: When were the designs locked down?
A: somewhere between 2013-2014
Q: What technology advances can we expect from the mission?
A: Other than the immediate advances that were achieved by the mare design of the probe (such as advances in solar panels and heat shield technology, Autonomous control of the vehicle and so on), we want to be better prepared for the next massive solar wind.  The damage from a serious solar wind could be in the trillions and cause outages of infrastructure for months or even years.
Q: How long is the delay of the data?
A: The distance delays data by eight minutes; however when the probe is behind the Sun it cannot communicate with us, so the average delay is expected to be about four months (which is why autonomous AI is imperative.