NASA, ESA’s Lunar Gateway Instruments to Improve Weather Forecasting for Artemis Astronauts
By NASA // November 21, 2020
NASA & SPACE NEWS
ABOVE VIDEO: Reinforcing decades of agency collaboration in space, NASA and the European Space Agency (ESA) are each building one of the instruments suites to monitor deep space weather and report data back to Earth.
(NASA) – Reinforcing decades of agency collaboration in space, NASA and the European Space Agency (ESA) are each building one of the instruments suites to monitor deep space weather and report data back to Earth.
Each agency was able to take advantage of this early opportunity to conduct science from Gateway – first realized in late 2019 – by capitalizing on technologies that were mature enough to be delivered by mid-2022.
The two complimentary mini weather stations will split up the work, with ERSA monitoring space radiation at higher energies with a focus on astronaut protection, while HERMES monitors lower energies critical to scientific investigations.
Earth’s magnetic field, which extends approximately 60,000 miles into space, protects us and our astronaut crew closer to home aboard the International Space Station.

As the Moon orbits Earth, it passes in and out of Earth’s long magnetotail, the part of Earth’s magnetic field blown back by the solar wind like a windsock.
Gateway, however, will spend only a quarter of its time within this magnetic field, so it provides a research opportunity to directly measure the solar wind and radiation from the Sun.
HERMES will measure lower energy radiation that will be considered for astronaut safety where applicable, but its primary goal is scientific.
“The deep space environment is harsh, but by understanding space weather and solar activity we can properly mitigate risks to our astronauts and hardware,” said Jacob Bleacher, chief exploration scientist in the Human Exploration and Operations Mission Directorate at NASA headquarters in Washington.
“HERMES and ERSA are a perfect example of the synergy between science and exploration.”
HERMES is led by NASA’s Goddard Space Flight Center, in Greenbelt, Maryland.
It consists of four instruments mounted together on a platform: A magnetometer, which measures the magnetic fields around Gateway, the Miniaturized Electron pRoton Telescope, or MERiT, which measures ions and electrons; the Electron Electrostatic Analyzer, or EEA, which measures the lower-energy electrons that make up most of the solar wind, and the Solar Probe Analyzer for Ions, or SPAN-I, which measures protons and ions including oxygen.
The magnetometer, MERiT and EEA are provided by Goddard; SPAN-I is built at the University of California, Berkeley.

ERSA
ERSA, or European Radiation Sensors Array, will study the solar wind’s effects on astronauts and their equipment.
Equipped with five instruments, ERSA measures energetic particles from the Sun, galactic cosmic rays, neutrons, ions, and magnetic fields around the Gateway.
Measuring these particles can tell us about the physics of radiation in the solar system, and understand the risks posed by radiation to human spacefarers and their hardware.
“Understanding the changing radiation environment around the Moon and at the Gateway is important if we are to understand the potential dangers astronauts will face and how to address them. It also helps us to understand and predict space weather across the Earth-Moon system,” said James Carpenter, ESA’s Exploration Science Coordinator.
The measurements from both HERMES and ERSA are made at the time of impact, once the radiation has already arrived.
But in the long term, the measurements will help NASA and ESA improve their models of space weather to better predict when such radiation could be on its way from the Sun, enabling better-advanced warnings in the future.
Gateway is a vital part of the Artemis program. Through Artemis, NASA and its partners will learn to live, work, and conduct science on and around the Moon, creating a sustained human-robotic presence at Earth’s nearest neighbor.
At the Moon, we will learn how to thrive on other worlds, preparing humanity for the next great voyage to Mars.