European Space Agency Is Testing JuRa, A Mini Radar To Peer Into An Asteroid

Juventas CubeSat will carry a compact radar that is set to become the smallest radar system to be taken to space. ESA is now testing the operation of the radar using a structural model of the CubeSat.

The Juventas CubeSat will carry a compact radar, which is set to become the smallest radar system to be flown in space | Photo: ESA

New Delhi: European Space Agency's (ESA) Hera spacecraft, designed to undertake a detailed "crime scene investigation" of DART mission's targets, will deploy a pair of shoebox sized CubeSats, named Milani and Juventas. The Juventas CubeSat will carry a compact radar, which is set to become the smallest radar system to be flown in space. But before that, ESA is testing the operation of the radar using a structural model of the CubeSat, the space agency said on its website.

Juventas's low-frequency radar is called JuRa.

When ESA's Hera spacecraft will fly to the Didymos binary asteroid system, the radar aboard Juventas will perform the first ever radar soundings inside an asteroid. The technique will serve as a means of mapping the asteroid's topography and conditions at its base. The Juventus CubeSat will peer up to 100 metres deep within the 160-metre-diameter Dimorphos satellite of the 780-metre-diameter Didymos, according to ESA.

Testing The Mini-radar System

Juventas is a '6-unit' CubeSat or mini-satellite, measuring 10×20×30 cm. There are four radar antennas atop Juventas, each being 1.5 metres long. In order to evaluate how the body of the spacecraft may affect radar signals, a test campaign, that includes a structural model of the Juventas CubeSat, is being conducted inside the "Hybrid European Radio Frequency and Antenna Test Zone" or the "Hertz" chamber at ESA's European Space Research and Technology Centre (ESTEC) in the Netherlands, the space agency stated.

ESA antenna engineer Paul Moseley explained that the radio-absorbing foam spikes lining the inside walls are an essential element of anechoic test chambers (room designed to completely absorb reflections of either sound or electromagnetic waves) like Hertz, ESA mentioned on its website. This is because such spikes allow the test to mimic the infinite void of space.

He added that instead of a dark room, the Hertz chamber would be turned into a hall of mirrors, so that multiple radio reflections, that interfere with the accuracy of test measurements, can be thrown out.

Franco Perez Lissi of ESA's CubeSats Systems Unit said their team is measuring the radiation pattern in a full sphere surrounding the antennas, and the total radiated power. He said the results of the campaign will prove to be useful for Juventas's critical design review.

The Juventas radar system has a synthetic aperture radar design. This means the radar system will take advantage of the proximity of Juventas's orbit to the surface of Dimorphos. The radar system will integrate multiple reflections and resolve them into images, according to ESA.

The radar aboard Juventas is developed from the radar system of CONSERT, which had peered into the interior of the comet 67P/Churyumov-Gerasimenko, and was a part of ESA's Rosetta spacecraft, the first spacecraft to orbit a cometary nucleus.

Alain Henrique, Principal Investigator of JuRa, said ESA was proud to see Rosetta's legacy living on in the next generation of deep-space missions, mentions the statement.

The Planétologie et d'Astrophysique de Grenoble group at the University Grenoble and Technical University Dresden, is developing Juventas's radar technology. The antennas are being constructed by Astronika in Poland. EmTroniX in Luxembourg is contributing to the signal generation system.