When the Landsat 9 satellite launched to space earlier this week on Sept. 27, it wasn’t the only spacecraft on the flight.
NASA partnered with the U.S. Space Force to launch four CubeSats — miniature satellites — on the same Atlas V rocket.

Some of the CubeSat missions sport adorable names — they’re dubbed CUTE (Colorado Ultraviolet Transit Experiment), CuPID (Cusp Plasma Imaging Detector), and Cesium Satellites 1 and 2 — these little satellites are pioneering some serious science and technology.

The four CubeSats were mounted on a ring-shaped frame, called the ESPA, or the “Evolved Expendable Launch Vehicle Secondary Payload Adapter.” (The program’s name, EFS, stands for ESPA Flight Systems.) The ESPA rode with Landsat 9 inside the top section of the rocket, the payload fairing. After the rocket’s second stage, called the Centaur, safely boosted Landsat 9 to its orbit, it dropped to a lower orbit and sent the CubeSats on their way.

“This is a pathfinder mission for NASA, so the process for doing it was undefined,” said Theo Muench, a NASA engineer and the partnership’s program manager. “NASA has never flown an ESPA ring with secondary payloads inside the fairing before, so we had to work with all our stakeholders to invent a plan to fly.”

NASA’s Wallops Flight Facility was responsible for the integration and testing of the CubeSats and their associated mounting and handling hardware with the ESPA ring at Wallops and supported integrating the ring with the rocket at the Vandenberg Space Force Base in California.

“Working with this mission required the Wallops team to develop new integration and testing plans, as well as design and build new ground support equipment. We were able to take advantage of investments we’ve made in unique small spacecraft I&T facilities,” said Dave Wilcox, chief of the Wallops Small Satellite and Special Projects Office. “The Wallops team maintained the schedule despite the challenges of COVID-19 and was able to conduct some unexpected testing for one of the CubeSats so that the mission could be certified for flight.”

Rideshare programs aren’t new — programs like NASA’s CubeSat Launch Initiative (CSLI) regularly coordinate rides for small satellites with larger missions. The Air Force, U.S. Space Force and commercial launch providers like SpaceX have let satellites tag along on their missions too. But the new EFS partnership provides access to more missions between NASA and the Space Force, increasing the number of options available to mission designers.

“This program is a big cost-saver, because a lot of times you can buy an ESPA ring for a fraction of what it would take to buy a small launch vehicle,” said Maj. Julius Williams, chief of the U.S. Space Force’s Mission Manifest Office, or MMO. The MMO’s goal is to seek out launch partnerships with other agencies. “If someone were to procure a satellite launch vehicle on their own, they wouldn’t use as much of the vehicle capability, on top of the fact that they’re using those funds themselves. This partnership saves taxpayer dollars for other programs.”

Two of the hitchhikers, CUTE and CuPID, are science satellites. CUTE is funded by NASA and managed by the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP) in Boulder, Colorado. The little satellite will carry a space telescope and a spectroscope, measuring near-ultraviolet light to learn about the atmospheres of planets outside our solar system. Specifically, they’ll be looking at escaping gases from “hot Jupiters” – large planets that orbit close to their parent stars. The team will study how these planets lose atmosphere in their suns’ heat, to better understand how likely atmospheres are to survive on all types of planets.

CUTE is smaller than the average space telescope, and the team is excited to push the envelope technologically as well as scientifically. “The cool story of CUTE is how all the ambitions we packed in at the beginning came together in the end,” said project scientist Brian Fleming, a researcher at the University of Colorado-Boulder. “In the early days, it was a big challenge to get the science performance we needed from this little ‘cereal box.’ We approached it with a little bit of fun–every time we came up with a new crazy idea, we said ‘okay, let’s try that too.’ That approach really paid off, and CUTE can do some amazing things for its size.”

The second science CubeSat, CuPID, will take measurements closer to home — this mission will study the interactions between the Sun’s plasma and Earth’s magnetosphere, or the protective “bubble” formed by Earth’s magnetic field that keeps harmful solar radiation away from the surface.

Cesium Satellites 1 and 2 are experimental satellites owned by CesiumAstro, an aerospace company that specializes in space communications. These CubeSats will test an antenna technology called an active phased array, which uses electromagnetic interference to move a signal beam without moving the physical antenna. This technology could make future satellites easier to use and repair, with fewer moving parts to break down. “Riding along with Landsat 9 provides Cesium Mission 1 with the opportunity to test their products in space before selling them to consumers,” said Scott Carnahan, Cesium Mission 1 manager.

Landsat 9 is a partnership between NASA and the U.S. Geological Survey.