NASA has said it has plans in place to monitor the Sun during the Artemis II mission to keep its astronauts safe.
The space agency is preparing to launch four astronauts on board an Orion spacecraft, on a journey that will take the crew around the Moon and back.
When travelling beyond the protective shield of Earth's atmosphere, activity on the Sun in the form of coronal mass ejections and solar storms can cause very real problems for astronauts.
That's why, NASA says, it will monitor the Sun in real time throughout the 10-day mission, using a mixture of solar-observing spacecraft and rovers on Mars.
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The threats of space weather
Space weather is the term given to the effects of solar activity across the Solar System.
Solar storms and coronal mass ejections are types of space weather, and events like these generate incredible eruptions from the Sun that, on the one hand, produce beautiful aurora displays on Earth and its neighbouring planets.
But they can also cause damage to satellites and spacecraft, as well as risks to human life.
One famous case in point is a series of strong solar storms that occurred in August 1972, between the Apollo 16 and Apollo 17 crewed missions to the Moon.
Scientists say that, had the storms occurred during either of those missions, they could have been fatal to the astronauts working on the lunar surface.
That's why NASA and other space agencies are taking the potential risks from the Sun to future crewed missions very seriously.
Protecting Artemis
With Artemis II, NASA is preparing to send four astronauts around the Moon and back for the first time since the Apollo programme.
The crew’s spacecraft, the Orion capsule, will be launched towards the Moon on the Space Launch System, and Orion will then carry and protect the astronauts as they travel further beyond the Moon than any human before them.
They'll swing around the Moon and then return to Earth. During the 10-day flight, NASA says it and the National Oceanic and Atmospheric Administration will monitor the Sun and track space weather events to keep the astronauts safe.
NASA says solar flares unleash more energy than a billion hydrogen bombs, while coronal mass ejections can burst from the Sun in eruptions hundreds of times bigger than Earth itself.
Flares and coronal mass ejections can affect technology, but can also be a danger to astronauts.
For example, if a huge eruption occurs while the Artemis II crew are travelling through space, it could raise radiation levels inside the spacecraft.
Exposure to radiation over long periods can increase the risk of developing cancer, or affect the astronauts' ability to perform the rest of the mission.
NASA's solar-observing plan
"Our focus will be real-time space weather analysis, prioritizing solar energetic particles and events that could produce them,” says Mary Aronne, operations lead for the space weather analysis office at NASA’s Goddard Space Flight Center.
"We’re looking for the trigger, which would typically be a flare or a coronal mass ejection."
Luckily, NASA and other space agencies have a fleet of spacecraft that can help track space weather during Artemis II.
These include NASA’s Interstellar Mapping and Acceleration Probe and Solar Dynamics Observatory, the European Space Agency/NASA Solar and Heliospheric Observatory and NOAA’s Geostationary Operational Environmental Satellites-19 satellite.
And NASA says even its Perseverance rover on Mars will be able to help, by observing the far side of the Sun, which isn't visible from earth.
This could give scientists an early warning that a possible solar flare is about to occur, and make arrangements to help protect the Artemis II crew.
Orion's protective shield
Naturally, Artemis engineers built the Orion spacecraft with its own protections against space weather.
The capsule has six radiation sensors to measure radiation dose rates in different sections of the ship, and the Artemis II astronauts will wear radiation trackers.
Orion also has onboard warning systems that will trigger an alarm if radiation levels increase.
NASA says the Artemis II crew can even reconfigure their cabin during a strong solar event.
This involves moving equipment around within the capsule to effectively thicken its walls in the direction from which the solar storm is coming, to help mitigate the amount of radiation that reaches the interior.
"Once crews add mass to the places that tend to be hotter in terms of radiation exposure, they can then continue to go about their duties," says Stuart George, a space radiation analyst at NASA.
Artemis II and the Van Allen Belts
A favourite claim in conspiracy theories around human spaceflight and the Apollo missions is that it's impossible for humans to travel beyond the Van Allen Belts.
These are radiation belts that surround our planet, and despite some claims, they can be passed safely by crewed spacecraft, as a result of careful mission planning, the spacecraft's protective shield and the speed with which they're passed through.
NASA says the radiation exposure from the belts during Artemis II is about the same as that experienced by an astronaut during a 1-month stay on the International Space Station.
NASA astronaut and Artemis II crewmember Christina Koch, for example, has already more than exceeded that, during her 11-month stay on the Space Station in 2019/2020.
There are many risks involved with sending humans around the Moon and back, and space weather can be at the more extreme end of potential risks.
But, it seems that lessons learned from the Apollo missions, plus advances in solar science and space-weather monitoring, are giving NASA the tools to keep its next generation of lunar explorers safe.
