Solar Orbiter on Its Way to Sun's Blazing Poles

Joint NASA and ESA mission to the tip of the Sun 

Solar Orbiter is a joint-mission between NASA and the European Space Agency (ESA), to send back unprecedented images and data, along with our first glimpse of the Sun's polar regions. Needless to say, the Solar Orbiter team is ecstatic.

"Whenever you launch something, it's incredibly exciting," said ESA's Director of Science Günther Hasinger, to Space.com. "The biggest relief comes when you see the light from the rocket and then when the sound waves hit you."

Those who have been can surely attest to the visceral, sonic thrill of a live rocket launch at Cape Canaveral.

The mission was first proposed more than two decades ago, in 1999. Officials at ESA initially planned for the mission to launch sometime between 2008 and 2013. But a few snags and scheduling issues delayed previous launch windows to 2020.

"The thermal protection system for the spacecraft has been one [of a few] challenges," said César Garcia, Solar Orbiter project manager at ESA.

Solar Orbiter's technical delays and equipment safety

Technology developments have advanced to help the team adapt in better ways to protect the spacecraft and its suite of extremely-sensitive instruments. To keep cool, Solar Orbiter has a 150-kg (324-lb) heat shield, capable of withstanding temperatures approaching 520 degrees Celsius (970 degrees Fahrenheit), said Hasing.

The Solar Orbiter will enter a region near the Sun's poles so hot that it's comparable to a pizza oven, according to Hasing. "It has a very intricate heat shield that is keeping it safe from the [S]un, with these little peep holes that open when we want to look at the [S]un, but then close because the instruments are so sensitive."

Shaped like a sandwich, the heat shield is composed of several layers of titanium foil, which (just like other parts of the craft) are coated with a special material called SolarBlack, created specifically for Solar Orbiter. Made of calcium phosphate (just like our bones), the cutting-edge coating has also seen application to adhere prosthetics to human bones, reducing the chance of biological rejection.

Interference between onboard instruments and solar magnetic fields (that the spacecraft is designed to measure) was another worry. Cleanliness too, according to Garcia.

Cosmic ledger for NASA and ESA

While the ESA is leading the Solar Orbiter mission, NASA paid for the Atlas V, and one of every 10 instruments aboard, reaching a total monetary contribution of about $386 million. The ESA invested $877 million in the mission, accruing a total cost of roughly $1.5 million, said Garcia, to Space.com.

With so many new active space missions, flagship and otherwise, the space organizations of the world are in for the most exciting decade in space flight. And, of course by proxy, so are we.