Watch the DAILI CubeSat Launch from the ISS Deployer
This new CubeSat could provide information about the high-altitude molecular oxygen density of the Earth’s atmosphere for more precise tracking of satellites on orbit.
Reliance on space-based capabilities to enable essential services including navigation, weather monitoring and communications, are fundamental to modern technology. With the number of signals and radio waves beaming back and forth from ground systems to satellites in space, it is essential to understand the influence of the Earth’s atmosphere to avoid potential disturbances that could disrupt critical operations.
The Daily Atmospheric Ionospheric Limb Imager (DAILI) is an instrumented six-unit (10x10x60 cm) CubeSat that images the limb of the Earth at approximately 3 km vertical resolution in two colors, to study molecular oxygen density of Earth’s upper atmosphere. These two colors allow information to be obtained about the neutral atmosphere during the day and the ionosphere at night.
The data gathered will primarily be used to study the neutral atmosphere at an altitude range of about 140 to 200 km—a region where measurements are scarce, and density and composition are highly variable and particularly difficult to measure.
“The ultimate goal is to really understand the processes that affect the upper atmosphere and ionosphere,” said Dr. James Hecht, Senior Scientist of Ionospheric & Atmospheric Sciences, “We should be able to see how the dynamics change in this portion of the atmosphere, which is something not very well known.”
There are several aspects of DAILI that contribute to its ability to study neutral atmosphere variability. DAILI’s forward three-unit long sunshade reduces intense scattered light from the Sun, the Earth’s surface, and low-altitude clouds by a factor of almost a trillion. DAILI’s sunshield is perhaps the most sophisticated ever flown on a CubeSat, according to Hecht, and is key to DAILI’s ability to examine the upper atmosphere’s dynamic variations during daytime. This gives DAILI the ability to track these variations continuously unlike other techniques currently being used.
The results of the DAILI mission should provide much needed data to inform atmospheric models, which currently demonstrate a limited understanding in this area. These improved models can help scientists to more precisely understand the propagation of radio signals and calculate precise orbits of satellites.
DAILI’s sensing technique was validated aboard the ISS by previous measurements made by Aerospace’s photometer portion of the Remote Atmosphere/Ionosphere Detection Sensor (RAIDS), a large suite of instruments developed jointly by Aerospace and the Naval Research Laboratory. RAIDS was responsible for collecting data on the composition, temperature and structure of the upper atmosphere and ionosphere between 85 and 200 kilometers and provided foundational knowledge for the DAILI CubeSat mission.
DAILI launched on December 21, 2021 aboard a Space X Falcon 9 rocket headed for the International Space Station. The CubeSat spent a month on the ISS and was released by the Nanoracks CubeSat Deployer on January 26. It will now be operated by Aerospace during its one-year mission. Data from DAILI will be analyzed in a collaborative effort by Aerospace, ASTRA LLC, Dixie State University, Johns Hopkins Applied Physics Laboratory, and the National Center for Atmospheric Research.
In addition, the DAILI mission complements two other NASA satellite missions, GOLD and ICON, launched in 2018 and 2019 respectively, that aim to help expand knowledge about Earth’s upper atmosphere and ionosphere.
Precise data about atmospheric conditions is critical for satellites to operate effectively. Expanding the available data and understanding how the Earth’s atmosphere could impact space-based capabilities is a significant component of advancing resiliency and adaptability for space missions.
