A newly launched spacecraft promises to broaden our understanding of the sun. Called the "Solar Orbiter" — or the "SolO" for short — it left the Cape Canaveral Air Force Station in central Florida Sunday, Feb. 9, at 11:03 p.m.
The new probe is part of an international collaboration between NASA and the European Space Agency (ESA). Both parties contributed to its arsenal of scientific instruments. Some of these gadgets will remotely image the sun, its atmosphere and the materials it spews forth. Others are built to keep tabs on the spacecraft's immediate surroundings.
During the wee hours of Feb. 10, 2020, the European Space Operations Centre in Darmstadt, Germany got a signal confirming that orbiter's onboard solar panels were functioning correctly. So begins a seven-year planned mission. To paraphrase Robert Frost, the orbiter is supposed to take the route less traveled.
All the planets in our solar system revolve around the sun on the same general plane (give or take a few degrees). Called the "ecliptic plane," it's like a giant invisible disc — one that very nearly lines up with the sun's equator.
Most of our spacefaring devices are gravitationally confined to this plane. But the SolO is meant to escape it.
A Pictorial Journey
By exploiting the gravity of Earth and Venus, the probe will orbit the sun on a unique and tilted pathway. This unique trajectory will give the SolO 22 close approaches to the sun (as close as 26 million miles or 35.4 million kilometers to the sun), as well as bring it within the orbit of Mercury to study the sun's influence on space. It will also give SolO the chance to do something no craft has ever done before: Take pictures of the solar poles.
Just like Earth, the sun has a north and south pole. In 2018, the ESA used data from the Proba-2 satellite to try and determine what the northern pole looks like. But Proba-2 couldn't photograph this region directly. If all goes according to plan, SolO will do just that. Its first close pass by the sun will be in 2022 at about a third the distance from the sun to Earth.
"Up until Solar Orbiter, all solar imaging instruments have been within the ecliptic plane or very close to it," NASA scientist Russell Howard noted in a press statement. "Now, we'll be able to look down on the sun from above."
And that's just the beginning.
Partners and Challenges
Another mission objective involves SolO partnering up with the Parker Solar Probe. Launched in 2018, this spacecraft is able to fly much closer to the sun than the new Solar Orbiter ever will.
Comparing the feedback from both probes ought to tell us a great deal about the mysterious phenomenon called solar wind. Any polar pictures the SolO gives us should provide relevant insights, too. The sun's polar regions probably have a big effect on its atmosphere as a whole — along with the charged particle streams (i.e., "winds") it unleashes.
SolO's unique travel plans will put it in contact with intense heat and extreme coldness. The new probe is going to revolve around the sun in a very long, very narrow oval-shaped orbit. As it nears the star, things will get rather toasty.
That's why designers fitted the Solar Orbiter with a reflective heat shield coated in titanium foil. According to NASA, this shield can withstand temperatures as high as 970 degrees Fahrenheit (521 degrees Celsius). It's also got radiators designed to ventilate excess heat produced within the craft itself.
Engineers can't be too careful about these things, you know. Certainly not when space travel is involved.