ARCSTONE Hyperspectral Instrument Launch

Advancing Satellite Calibration Standards

The ARCSTONE hyperspectral instrument was successfully launched from Vandenberg Space Force Base aboard the SpaceX Transporter 14 mission on June 23, 2025, at 2:25pm PDT. First contact with the satellite was made approximately 2.5 hours later.

This research mission aims to improve data accuracy recorded from many satellites, including data already recorded, while also reducing costs for future satellite-based instruments.

Figure 1: The ARCSTONE instrument integrated with the CubeSat. Image courtesy of Blue Canyon Technologies.

ARCSTONE Mission Objectives

The ARCSTONE instrument addresses two primary objectives in satellite-based Earth observation:

Improved Data Accuracy: The mission will enhance the accuracy of measurements from Earth-viewing satellites by establishing a lunar reflectance calibration ~10x better than exists today. Increased data accuracy enables better weather/storm forecasting and more accurate climate models. Some previously collected satellite datasets will be recalibrated using ARCSTONE measurements, potentially improving the accuracy of long-term environmental and climate models.

Figure 2: Hurricane Florence as seen from the International Space Station. Image courtesy of NASA.

Simplified Future Satellite Missions: Lunar reflectance data from the ARCSTONE mission may eliminate the need for onboard calibration systems in some future satellite instruments, providing a long-term cost benefit.

Lunar Reflectance Calibration Methodology

Figure 3: Animation of the ARCSTONE instrument measuring solar and lunar signals. Courtesy of NASA/Tim Marvel/Blue Canyon Technologies.

ARCSTONE creates a lunar reflectance calibration with near simultaneous measurements of the signal from both the sun and the moon. This approach builds upon previous ground-based lunar reflectance measurements, which had higher uncertainties due to atmospheric interference.

Operating above Earth's atmosphere, ARCSTONE can measure lunar reflectance with significantly reduced uncertainty. The resulting lunar reflectance dataset will enable the moon to be used as an accurate “standard candle” calibration source, eliminating the need for expensive, complex, and heavy onboard calibration systems in future satellite-based instruments.

ARCSTONE Project Technical Challenges

The ARCSTONE project presented some significant technical challenges, including:

Dynamic Range Requirements: The instrument must accurately measure the brightness of the moon and the brightness of the sun. The sun is ~1,000,000 times brighter than the moon.
Orbital Environment Effects: Optical systems in low Earth orbit experience degradation from radiation exposure, highly reactive atomic oxygen, thermal cycling, and particle bombardment.
Platform Constraints: The instrument had to meet research-grade measurement requirements and still integrate into a 6U CubeSat satellite bus. The space for the instrument, the control computer, and the calibration system is about 9” x 9” x 3.5”—roughly the size of a shoebox!

Addressing the ARCSTONE Technical Challenges

Resonon addressed these technical challenges through several means:

Novel Optical Design: The system uses different integration times and measurement redundancy to achieve the Signal-to-Noise Ratios (SNR) required for 0.5% accuracy.
Common Optical Path: Both solar and lunar measurements use the same optical components. This approach ensures that any optical degradation impacts both solar and lunar measurement sets equivalently, allowing degradation effects to cancel out when ratioing lunar-to-solar measurements.
Compact Design: After many iterations, a simple but elegant design was created that fit into the 6U CubeSat volume.

Figure 4: The ARCSTONE instrument built by Resonon, prior to being integrated into the CubeSat bus. Image courtesy of Resonon.

A Collaborative Effort

The ARCSTONE project was made possible via the collaboration of multiple partners across different sectors:

Industry: Resonon, Quartus Engineering, and Blue Canyon Technologies (a subsidiary of Raytheon)
Academic: Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder
Government: National Institute of Standards and Technology (NIST), United States Geological Survey (USGS), and, of course, NASA

Acknowledgments

Resonon is honored to have been part of this project and would like to thank all project participants for collaborating with us. We would especially like to thank the NASA Earth Science Technology Office (ESTO) for funding this mission.

More Information

Our previous ARCSTONE blog post provides additional technical information and a list of publications pertaining to the ARCSTONE project.

This NASA.gov article provides additional detail on the mission objectives, and how an internationally accepted standard calibration for lunar reflectance could benefit many different fields.

Contact us

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Dr. Rand Swanson

CEO

Rand Swanson is the Chief Executive Officer and co-founder of Resonon. Along with overseeing company management, he applies his decades of expertise to optical design and radiometric modeling for commercial and R&D projects.

Working alongside the talented and dynamic Resonon team, he feels fortunate to focus his efforts on hyperspectral imaging—a technology that is simple in concept, complex in execution, and capable of solving many challenging problems.

More articles by Rand:

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