Researchers from NASA and the European Space Agency (ESA) wanted to find out. Using the Laser Interferometer Space Antenna (LISA) Pathfinder or LPF, operated in orbit between January 2016 and July 2017, the team conducted a kind of survey and examined how many times their spacecraft was hit by space debris.
The study published in the Astrophysical Journal in September describes 54 collisions with the LPF spaceship. Essentially, the mission was a tech demo – LPF-based devices will be deployed at the fully operational LISA observatory. The core task of LPF was to show that the technology on board can be used in the future for a full-fledged mission. Before the start, however, the researchers realized that very small impacts could be detected with the spaceship's uniquely sensitive instruments.
Every time LPF is hit, small engines help to correct the course. Examining these tiny course corrections revealed what it was and how much power. The researchers had access to 4,348 hours of LPF data to create a comprehensive record of micrometric collisions with the spacecraft.
The researchers then used the modeling of LPF effects to determine where the micrometeroids might have originated. Previous studies of space dust in this region of the solar system have shown that much of it originates from short-period comets such as 67P / Churyumov-Gerasimenko whose orbits are controlled by the gas giant Jupiter (Jupiter family comets). The "comet crumbs" that clashed with the LPF were consistent with these studies, with most of the effects coming from comets of the Jupiter family and a lesser contribution from longer-lived comets.
ESA will initiate further development of the LPF in 2034. – A series of three spacecraft arranged in a triangle, allowing astronomers to hunt gravitational waves of unprecedented precision. This will be a great blessing for astronomers investigating extreme cosmological events such as the merging of black holes on the other side of the universe. However, LPF has shown that next-generation instruments are also helpful in conducting experiments much closer to home.