New research from NASA’s Ames Research Center reveals that 73.3% of images captured by the SPHEREx space telescope between May and September 2025 were marred by artificial satellite trails. As the number of satellites in Low Earth Orbit (LEO) grows, these streaks are increasingly obstructing the scientific data collected by orbital observatories, creating a significant challenge for future deep-space exploration.
Why Is SPHEREx Struggling with Satellite Interference?
The SPHEREx mission, led by Principal Investigator Dr. Jamie Bock, was designed to map the entire sky in near-infrared light. According to the arXiv pre-print report by Alejandro S. Borlaff and colleagues, the telescope’s design—which requires long exposure times and a wide field of view—makes it highly susceptible to light pollution from orbiting satellites. Despite operating 700km above the Earth’s surface, the observatory recorded an average of 2.18 satellite trails per exposure. These trails often appear in an “X” pattern, mirroring the orbital paths of existing megaconstellations.
SPHEREx is tasked with surveying more than 450 million galaxies and over 100 million stars in the Milky Way. Its ability to capture 102 different color bands is intended to help astronomers answer fundamental questions about the origins of the universe.
How Does Satellite Contamination Impact Science?
The interference goes beyond mere aesthetic damage to space imagery. The SPHEREx telescope utilizes an automated “sample up-the-ramp” algorithm to prevent pixel saturation from cosmic rays. However, the study notes that modern commercial satellites are now bright enough to trigger this safety mechanism prematurely. This creates “railroad” tracks in the data, where the bright center of a satellite trail is scrubbed, but parallel lines remain permanently etched into the imagery. This process results in the loss of photometric data, effectively hiding the light from distant galaxies and stars that the mission aims to study.
Is This Problem Getting Worse?
The situation appears to be worsening as the density of objects in LEO increases. A study led by Sandor Kruk previously tracked the impact of satellites on the Hubble Space Telescope, finding that the fraction of images crossed by satellite trails rose from 2.8% in the early 2000s to 5.9% by 2021. The latest simulations for SPHEREx paint a more dire picture: if current launch manifests, which include proposals for up to 2 million satellites, are fully realized, researchers forecast that 100% of SPHEREx images could be polluted, with an average of 189 trails per exposure.
| Observatory | Historical/Current Impact | Future Forecast |
|---|---|---|
| Hubble | 5.9% (as of 2021) | N/A |
| SPHEREx | 73.3% (May–Sept 2025) | 100% (with 2 million satellites) |
Frequently Asked Questions
Can dark coatings on satellites solve the issue?
While satellite designers have experimented with dark coatings and visors to reduce optical brightness, the researchers note that newer, larger systems—such as direct-to-cell towers—are up to four times larger than existing satellites, which may negate the benefits of these mitigation efforts.
What is the current status of the SPHEREx mission?
SPHEREx is a current, two-year planned mission that launched on March 11, 2025. It is a joint effort involving the California Institute of Technology, the Jet Propulsion Laboratory, and Ball Aerospace.
Are there international agreements to limit this interference?
According to the research team at NASA Ames, there has been little progress on international agreements to address the growing presence of satellite megaconstellations, leaving the scientific community to advocate for new regulatory frameworks.
Pro Tip: To stay updated on the latest findings regarding space debris and orbital interference, keep an eye on the latest pre-print publications from NASA researchers.
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