7 October 2024: ESA’s Hera Launches Carrying the 6U XL CubeSats Milani and Juventas Toward Didymos–Dimorphos
Following MarCO-A/B at Mars and ASI’s 6U LICIACube at DART, ESA’s Hera mission launched on 7 October 2024 carrying the 6U XL CubeSats Milani and Juventas.
Deep-space 6U CubeSats have transitioned from experimental technology demonstrators to baseline planetary science assets. After NASA JPL’s MarCO-A/B (2018) relayed InSight’s Mars landing and ASI’s LICIACube (2022) autonomously tracked and imaged the DART impact plume at Dimorphos from 55 km range, ESA launched the Hera spacecraft on 7 October 2024.
Stowed inside Hera’s Asteroid Deck are two 6U XL CubeSats: Milani (developed by Tyvak International), carrying the ASPECT visible/near-IR hyperspectral imager and VISTA thermogravimetric dust analyser; and Juventas (developed by GomSpace), carrying the JuRa 60 MHz monostatic radar to probe the internal rubble-pile structure of Dimorphos.
Unlike LEO CubeSats that dump reaction wheel momentum against Earth’s magnetosphere via magnetorquers, deep-space 6U buses rely on cold-gas micro-thrusters, inter-satellite S-band links, and radiation-tolerant avionics.
In early November 2026, Hera arrived at the (65803) Didymos–Dimorphos binary system—returning its first 60 km close-up Asteroid Framing Camera imagery on 5 November 2026—entering the proximity characterization phase ahead of releasing Milani and Juventas from their Deep Space Deployers.
CELESTRAK SATCAT & TELEMETRY RECORD
Verified Spacecraft Key Facts & Orbital Dossier
| Spacecraft | Class | Operator / Country | Launch & Vehicle | NORAD / COSPAR | Orbit & RF Downlink | Catalog Status |
|---|---|---|---|---|---|---|
Milani | 6U | European Space Agency (ESA) & Tyvak International EU | Falcon 9 (Hera) · Hera Deep Space Deployer | Unassigned | Heliocentric rendezvous with binary asteroid (65803) Didymos–Dimorphos S | Active |
Juventas | 6U | European Space Agency (ESA) & GomSpace EU | Falcon 9 (Hera) · Hera Deep Space Deployer | Unassigned | Heliocentric rendezvous with binary asteroid (65803) Didymos–Dimorphos S | Active |
LICIACube | 6U | ASI (Italian Space Agency) & Argotec IT | Falcon 9 (DART) · Spring Dispenser on DART | Unassigned | X | Completed |
MarCO-A / MarCO-B | 6U | NASA JPL US | Atlas V 401 (InSight) | Unassigned | Heliocentric (Mars flyby) X | Completed |
Catalogued Mission Summaries & Flight Notes
- Milani (6U, 2024):
- ESA 6U XL deep-space CubeSat (~12 kg) carried aboard the Hera planetary-defense mothership, arriving at the Didymos–Dimorphos binary system in November 2026 with the ASPECT visible/near-IR hyperspectral imager and VISTA thermogravimetric dust detector.
- Juventas (6U, 2024):
- ESA 6U XL deep-space CubeSat (~12 kg) delivered to Didymos–Dimorphos aboard Hera in November 2026 to perform the first low-frequency radar tomography of an asteroid interior (JuRa 60 MHz radar) alongside the GRASS surface gravimeter.
- LICIACube (6U, 2021):
- Italian 6U deep-space CubeSat (14 kg) deployed from NASA’s DART spacecraft 15 days before impact; autonomously tracked and imaged the kinetic impact plume on asteroid Dimorphos from 55 km distance.
- MarCO-A / MarCO-B (6U, 2018):
- The first interplanetary CubeSats. They relayed InSight’s landing data of 26 November 2018 in near real time. Last contact: WALL-E on 29 Dec 2018, EVE on 4 Jan 2019. The mission was ended in February 2019.