LICIACube: a small Italian probe that witnessed history!

LICIACube is an acronym standing for “Light Italian Cubesat for Imaging of Asteroids”. This mission is carried out by the Italian Space Agency (ASI) and it is an integral part of the NASA DART mission (Double Asteroid Redirection Test), whose goal was the first full-scale test of the kinetic impact technique, for planetary defense purposes.

Which is the target of the DART mission?

The primary purpose of DART was to measurably change the orbit of Dimorphos, a natural satellite of the asteroid Didymos, around its primary body. The variation of the period of revolution of Dimorphos will be measured in the days following the impact and then cumulatively for the following months and years.

Illustration of how DART's impact altered the orbit of Dimorphos about Didymos. Telescopes on Earth are used to measure the change in the orbit of Dimorphos to evaluate the effectiveness of the DART impact. — *Didymos asteroid together with Dimorphos which is the primary target of the DART Mission closely followed by LICIA. Credits: ASI*

Asteroid Didymos and its small moonlet Dimorphos make up what’s called a binary asteroid system: the primary asteroid (Didymos, the bigger one), is about 780 meters in diameter, and has been classified as a member of the S-type asteroid class, with an affinity for L / LL-type meteorites. The composition of Dimorphos, with a diameter of about 160 meters and a distance of about 1.2 km from its primary, is not yet known.

The objectives of LICIACube can be summarized as follows:

witness the impact of DART on the Dimorphos surface;
study the formation of the debris cloud raised by the impact, in particular, to characterize its structure and its evolution;
characterize – also as a function of the dissipation rate of the debris cloud – the site of the impact on the Dimorphos surface, to obtain measurements of the size and morphology of the crater;
observe the non-impacted hemisphere, and commit to measuring the size and volume of the target itself.

Now let’s dig a little bit into LICIA technical details

The project for the LICIACube probe is based on a 6U platform developed by the Italian aerospace company Argotec in the context of the ArgoMoon mission. Appropriately redesigned for the LICIACube mission, it has 2 main payloads onboard:

– LEIA (LICIACube Explorer Imaging for Asteroid), a narrow-field panchromatic camera that can acquire images from a great distance with a high level of spatial definition.

– LUKE (LICIACube Unit Key Explorer), a wide-field RGB camera, for a multicolored analysis of the asteroid environment.

The mission team behind LICIAcube

Argotec team with LiciaCube ready to be shipped to NASA for the launch. LICIACube acronym which stands for “Light Italian Cubesat for Imaging of Asteroids”, is a mission of the Italian Space Agency (ASI) and an integral part of the NASA DART mission (Double Asteroid Redirection Test - Redirection Test of a Double Asteroid), whose goal was the first full-scale test of the kinetic impact technique, for planetary defense purposes. — *Argotec team with LiciaCube ready to be shipped to NASA. Credits: Argotec*

The project, integration and test procedures have been entrusted by ASI to Argotec. At the same time, the management of in-flight operations is based on the joint activity of the Argotec Mission Control Center, the antennas of the NASA Deep Space Network, and the ASI Space Science Data Center regarding data processing and storage.

Quick fact: LICIACube is the first deep space mission developed and managed independently by an all-Italian team!

The scientific team is made up of a large Italian community that involves numerous members of research institutions and academies, is coordinated by INAF (National Institute of Astrophysics), and deals with the following activities:

design of the mission trajectory (Politecnico di Milano);
definition of the mission and determination of the orbit in real-time during operations (University of Bologna);
simulation of the impact, of the formation of the debris cloud, of the in-situ images, in preparation for the analysis and interpretation of the data obtained during the mission.

Do we already know the results of this mission?

Asteroid Didymos (bottom left) and its moonlet, Dimorphos, about 2.5 minutes before the impact of NASA’s DART spacecraft. The image was taken by the on board DRACO imager from a distance of 570 miles (920 kilometers). This image was the last to contain a complete view of both asteroids. Didymos is roughly 2,500 feet (780 meters) in diameter; Dimorphos is about 525 feet (160 meters) in length. Ecliptic north is toward the bottom of the image. This image is shown as it appears on the DRACO detector and is mirror flipped across the x-axis from reality. — *Asteroid Didymos (bottom left) and its moonlet, Dimorphos, about 2.5 minutes before the impact of NASA’s DART spacecraft. Credits: NASA*

Of course, we do! And they are astonishingly great! By how much? Before DART, Dimorphos’ orbit took 11 hours and 55 minutes, while in the post-impact period, it’s down to 11 hours and 23 minutes. For those averse to math, that’s 32 minutes shorter (about 4 percent). NASA estimates that the orbit is now “tens of meters” closer to Didymos. This orbital shift was confirmed by radar imaging, which can resolve the two asteroids (although barely, as Dimorphos occupies a single pixel in these images).

Data from ground-based telescopes show that Dimorphos isn't getting eclipsed when we'd expect it to if it were in its previous orbit. — *Data from ground-based telescopes show that Dimorphos isn’t getting eclipsed when we’d expect it to if it were in its previous orbit. Credits: NASA*

What’s next?

For planetary scientists, the next steps will involve carefully comparing impact images to pre-collision modeling to identify whether there are significant differences. For example, even if small, these discrepancies can be helpful if wrong assumptions in the composition of Dimorphos have been made. That will be a long process, and results may not be available for a year or more.

For NASA, the planetary defense was the mission’s focus, and it’s already clear this was a success. Everybody at the announcement, however, indicated that the slight difference produced in the asteroid’s orbit means that a similar mission will need to act well in advance of any potential collision with a similarly sized object. To get that level of warning means it is mandatory to start working on cataloging all the small asteroids with orbits that could overlap with Earth’s—a task it’s estimated that we’re only halfway done with.