NASA to launch mission to study cosmic rays in the heliosphere

You could say the Heliosphere is the sun’s way of protecting the planets within our solar system from radiation – blocking some of the highly energetic cosmic rays that originated in interstellar space. When the solar winds collide with material from the rest of the galaxy, this limits how much harmful cosmic radiation gets through.

The IMAP mission

“IMAP is critical to broadening our understanding of how this ‘cosmic filter’ works,” said Dennis Andrucyk, deputy associate administrator for NASA’s Science Mission Directorate in Washington. “The implications of this research could reach well beyond the consideration of Earthly impacts as we look to send humans into deep space.”

Basically, IMAP will collect and analyze the particles that make it through the “cosmic filter.”

The heliospheric current sheet results from the influence of the Sun’s rotating magnetic field on the plasma in the interplanetary medium (solar wind). The wavy spiral shape has been likened to a ballerina’s skirt.

NASA – Werner Heil

Another objective of the mission is to learn more about the generation of cosmic rays in the heliosphere. Cosmic rays created locally and from the galaxy and beyond affect human explorers in space and can harm technological systems.

IMAP was chosen following an extensive and competitive peer review of proposals submitted in late 2017. It has a cost-cap of $492 million, excluding the cost for the launch vehicle. The principal investigator for the mission is David McComas of Princeton University. The Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland, will provide project management.

Position is important to the success of the mission

The mission will carry 10 science instruments provided by international and domestic research organizations and universities. The probe will be positioned about 930,000 miles (1.5 million kilometers) away from Earth towards the Sun at what is called the first Lagrange point or L1.

If the distance is just right – about a hundredth of the distance to the Sun – the spacecraft will travel slowly enough to keep its position between the Sun and the Earth. This is L1, and is a good position from which to monitor the Sun since the constant stream of particles from the Sun, the solar wind, reaches L1 about an hour before reaching Earth.

European Space Agency

The five LaGrange points or ‘L’ points are named for the 18th-century Italian astronomer and mathematician Joseph-Louis Lagrange. The points are basically locations around a planet’s orbit where the gravitational forces and the orbital motion of the spacecraft, Sun and planet interact to create a stable location from which to make observations.

IMAP will be the fifth mission in NASA’s Solar Terrestrial Probes (STP) program. The other missions include the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics mission (TIMED), which launched in December 2001; Hinode, a collaboration with the Japan Aerospace Exploration Agency that lifted off in September 2006; the Solar Terrestrial Relations Observatory (STEREO), a joint mission with the European Space Agency that launched in October 2006; and the Magnetospheric Multiscale mission, which launched in March 2015.