NASA and the ESA are hoping that a pair of satellites currently in development will solve some of the longstanding mysteries of the sun by getting up close and personal with our solar system’s host star, provided they can survive the extreme heat and harsh conditions.
One of the satellites, the ESA’s Solar Orbiter, is designed to perform close-up, high-resolution studies of our Sun and inner heliosphere. It will be the first probe to provide up-close views of the sun’s polar regions, and will travel to a distance just one-fifth that separating Earth and the sun, bringing it closer to our closest star and any other spacecraft in history.
NASA’s Solar Probe Plus, on the other hand, will be the first satellite to fly into the sun’s corona (or atmosphere). Using a combination of in situ measurements and imaging, the mission’s goal is to understand how the corona is heated and how the solar wind is accelerated. On its final three orbits, it will slow to within about 3.7 million miles of the sun, the US space agency said.
Givin’ em hell
BBC News science correspondent Jonathan Amos called Solar Orbiter and Solar Probe Plus “the two most audacious space missions currently in development,” noting that the spacecraft will be exposed to temperatures “into the high hundreds of degrees Celsius, and beyond.”
“You could say they are the missions to Hell,” he said, noting that engineers have been working hard to make sure that the instruments used by the two probes will be well-protected. The Solar Orbiter (SolO) will have a titanium-based heat shield, while NASA’s Solar Probe Plus (SP+) will be outfitted be using a carbon-composite material to protect it from the temperatures.
Both mission are progressing well, according to the latest reports. American officials recently selected a Delta-IV Heavy rocket to carry SP+ into space and towards the sun in 2018, while a European company, Airbus Defense and Space, has announced that it has produced a structural and thermal model of SolO for testing and to validate the design of the satellite.
The SolO model will be exposed to extreme heat and sound waves, and will be shaken to show that it can handle the rigors of the voyage. If it is able to survive the simulation, engineers will known that the actual flight model should be able to handle its mission as well, Amos said.
Tim Horbury, a SolO principal investigator from Imperial College London, explained that the two missions will combine to perform a series of three measurements. He told BBC News that Solar Orbiter will use its telescopes to conduct a remote measurement of the sun and a second once something emerges from the star’s atmosphere. The third comes from SP+, “which whams through the field of view very quickly, every so often, to sense what’s going on as well.”
By keeping some distance between itself and the sun, SolO will be able to deploy telescopes and capture images that should depict solar features and higher-than-ever resolutions, while SP+ will travel far closer to the surface of the sun to collect data on the processes that heat the corona and cause the solar winds to accelerate, providing new insight into the sun and stars like it.
The two missions are costing taxpayers more than $2.5 billion, according to BBC News, but as Horbury pointed out, the investment is a clear indicator of how important it is to scientists to study the sun. The research conducted by these two probes will benefit day-to-day life as well, as they shed new light on solar storms that can disrupt satellites and communications on Earth.
“The fact that we’re getting both Solar Orbiter and Solar Probe tells you that this community of solar and heliospheric scientists have made a compelling case,” he said, “and we’ve persuaded both space agencies – ESA and NASA – that going close to the Sun to see what the Sun does is very important. And it’s much better to run those two missions at the same time so they can complement each other.”