Science & Tech

Parker Solar Probe Launches August 6: Here’s How It Will ‘Touch’ The Sun And Not Melt

Published on: July 20, 2018 at 2:00 PM
By Alexandra Lozovschi

Less than three weeks from now, NASA will be launching its most daring mission so far. The Parker Solar Probe, sent to “touch” the sun and give us unprecedented data on the star at the heart of our solar system, will be taking off on its historic voyage on August 6, NASA announced yesterday.

Initially scheduled for August 4, the launch of the pioneering spacecraft has been pushed back two days, to give engineers sufficient time to deal with a few last-minute repairs, the space agency explained.

Among these final modifications, NASA listed the reconfiguration of a cable clamp on the payload fairing (the nose cone used to protect a spacecraft) and a fixed leak in the third stage motor of the rocket that’s going to fly the probe into space — a United Launch Alliance Delta IV Heavy.

The spacecraft is set to launch from Space Launch Complex 37 on Cape Canaveral Air Force Station in Florida and will begin a three-month journey to the sun, where it will study the solar corona.

The mission will last for seven years and is designed to help us understand “what drives the wide range of particles, energy, and heat that course through the region — flinging particles outward into the solar system and far past Neptune,” NASA stated in a separate news release.

Into The Solar Corona

The Parker Solar Probe has great things lying ahead. Its mission is to “revolutionize our understanding of the sun” and, in order to do that, the spacecraft will be flying closer to the sun than any other man-made vehicle before it.

Throughout its mission, NASA’s first solar probe will perform 24 orbits of the sun — three of which will take it within 3.8 million miles (6.1 million kilometers) of the solar surface, the Inquisitr previously reported.

Known as the first spacecraft to “touch” the sun, the Parker Solar Probe will boldly pierce through the star’ outer atmosphere, called the solar corona, and capture particles of solar wind — the outflow of highly charged particles coming from the sun.

To survive this extreme environment, where temperatures exceed a million degrees Fahrenheit and where intense sunlight pummels everything in sight, the Parker Solar Probe has a cool trick up its sleeve.

As the Inquisitr previously reported, the spacecraft has been fitted with a cutting-edge heat shield called the Thermal Protection System, or TPS.

Why The Parker Solar Probe Won’t Melt

The TPS is designed to withstand temperatures of up to 3,000 Fahrenheit (1,650 Celsius) and is made out of a carbon composite foam sandwiched between two carbon plates.

This makes the highly advanced heat shield extremely light (it weighs just 160 pounds, or about 72.5 kilograms), which allows the car-sized spacecraft to maintain its maneuverability. To make sure it reflects as much heat as possible, the TPS’ exterior has also been garnished with a coating of white ceramic paint.

But heat may not be as much of an issue as we imagine. As NASA explains, heat measures how much energy particles can transfer, whereas temperature is a measurement of how fast they’re moving.

“Since space is mostly empty, there are very few particles that can transfer energy to the spacecraft.”

The solar corona “has an extremely high temperature but very low density,” NASA points out, adding that “compared to the visible surface of the sun, the corona is less dense, so the spacecraft interacts with fewer hot particles and doesn’t receive as much heat.”

This means that, although traveling through an inferno of unbelievably high temperatures, the TPS (or, to be more exact, the side of the heat shield facing the sun) “will only get heated to about 2,500 degrees Fahrenheit (about 1,400 degrees Celsius),” notes the space agency.

This is well within the range of what the spacecraft’s fancy shield can take. At eight feet (2.4 meters) wide and 4.5 inches (about 115 mm) thick, the TPS will be casting an umbra over the solar probe, keeping everything behind it at a balmy 85 Fahrenheit (30 Celsius).

In the video below, Betsy Congdon of Johns Hopkins Applied Physics Lab, which designed the TPS, performs a neat experiment that shows the spacecraft’s heat shield is so robust you can take a blowtorch to it and it still remains cool enough to touch on the other side.

What Else Is On Board NASA’s First Solar Probe?

Well, we’re glad you asked. Aside from the memory card inscribed with 1.1 million names, including that of William Shatner, which will also make the journey to the sun, as reported by the Inquisitr in May, the spacecraft will be carrying a Faraday cup with which to catch solar wind particles.

The cup is made of titanium-zirconium-molybdenum, which has a melting point of about 4,260 Fahrenheit (2,349 Celsius). Meanwhile, the chips that produce the electric field for the instrument are forged from tungsten — “the metal with the highest known melting point 6,192 F (3,422 C),” NASA points out.

The cup’s electronic wiring is made out of niobium — which has a melting point of 4,491 Fahrenheit (2,477 Celsius), notes Science Alert — and is suspended inside sapphire crystal tubes, lab-grown especially for this mission.

The Parker Solar probe is also equipped with sensors that help it figure out whether the heat shield is in the right position and correct its orientation if needed, to avoid getting exposed to the sun’s rays.

Lastly, the spacecraft has a very ingenious cooling system, based on a gallon (3.7 liters) of deionized water — a liquid with fantastic properties that help it handle intense heat.

“While plenty of chemical coolants exist, the range of temperatures the spacecraft will be exposed to varies between 50 F (10 C) and 257 F (125 C), NASA officials stated.

And there you have it: this is how NASA’s Parker Solar Probe plans to venture into the sun’s corona and walk away with an amazing tale to tell.

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