"Each CubeSat was activated for about an hour in turn, in live sessions with the ground to perform commissioning - what we call 'are you alive?' and 'stowed checkout' tests," said Franco Perez Lissi, Hera's CubeSat Engineer at ESA.
Currently secured in their Deep Space Deployers, the CubeSats have passed tests on critical onboard systems, including avionics, instruments, and inter-satellite links. The tests also verified their reaction wheels, essential for attitude control during flight.
Launched on October 7, Hera is ESA's inaugural planetary defense mission and is en route to Dimorphos, the asteroid whose orbit was altered by NASA's DART mission in 2022. The CubeSats, each a shoebox-sized 10-cm unit, will venture closer to Dimorphos than the main Hera spacecraft, taking added risks to collect supplementary data.
Juventas, constructed by GOMspace in Luxembourg, will be the first radar to probe an asteroid's interior, while Milani, produced by Tyvak International in Italy, will conduct multispectral mineral analysis.
ESA's ESOC mission control in Darmstadt, Germany, carried out the CubeSat commissioning, in coordination with the European Space Security and Education Centre (ESEC) in Redu, Belgium. Juventas was activated on October 17 from a distance of 4 million km from Earth, followed by Milani on October 24 at 7.9 million km. The team managed delays in communication, with round-trip signal times of 32.6 seconds for Juventas and 52 seconds for Milani.
"During this CubeSat commissioning, we have not only confirmed the CubeSat instruments and systems work as planned but also validated the entire ground command infrastructure," noted Sylvain Lodiot, Hera Operations Manager. The process involved coordinated data transfer from ESOC to the CMOC at Redu, then to each CubeSat's mission control center for real-time monitoring, preparing all systems for the free-flight phase near Dimorphos.
Milani's Lead Software Engineer, Andrea Zanotti of Tyvak, reported that Milani's systems operated without any resets or unexpected power issues, even under the intense conditions of deep space. Similarly, Camiel Plevier, Lead Software Engineer for Juventas at GomSpace, noted that both CubeSats sustained optimal battery levels and consistent temperatures within their deployers, maintaining a stable environment.
The CubeSats are scheduled to remain in their deployers until Hera arrives at Dimorphos in late 2026, when they will be released at a slow speed to prevent them from drifting away in the asteroid's minimal gravitational field.
"This commissioning is a significant achievement for ESA and our industrial partners, involving many different interfaces that all had to work as planned," added Franco Perez Lissi. He noted that the success of integrating companion CubeSats aboard the main spacecraft provides a model for future missions, including ESA's upcoming Ramses planetary defense mission and the Comet Interceptor.
Throughout Hera's journey to Dimorphos, the CubeSats will be reactivated every two months for routine checkouts, battery maintenance, and software updates.
Related Links
Hera at ESA
Asteroid and Comet Mission News, Science and Technology
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
