Hera and its CubeSats speak with mission control

ESA’s Hera asteroid mission and its two CubeSats interacted as in the event that they have been in space, inside the foam pyramid-lined partitions of the Company’s Maxwell check chamber within the Netherlands. The trio communicated collectively, sharing knowledge and ranging info similtaneously their Hera mothership obtained instructions from its mission controllers on the European Area Operations Heart in Darmstadt, Germany.

Testing occurred contained in the Maxwell electromagnetic compatibility chamber, a part of ESA’s ESTEC Take a look at Heart, the most important spacecraft check facility in Europe. Maxwell’s 9-m excessive metallic partitions protect it from all exterior radio interference, whereas its inside foam pyramids take in all radio waves from the space techniques being examined. The result’s a location that mimics the infinite void of space.

“As soon as the door of Maxwell is closed, this turns into the one place the place we will function the antennas of Hera and its two CubeSats collectively freely and safely,” explains Hera CubeSats engineer Franco Perez Lissi.

“For the remainder of the mission’s check program telecommands have been being despatched to the spacecraft through cables as an alternative. We have already got detailed fashions of how the connection to Earth and the inter-satellite hyperlinks between the satellites will work, however this testing permits us to validate these fashions towards actuality.”

The testing prolonged to ESOC, permitting the Hera operations group primarily based there to function the spacecraft remotely, and downlink telemetry and knowledge through Hera’s 1.13-m diameter Excessive Achieve Antenna, precisely as they’ll as soon as Hera is in space. On the similar time Hera and its CubeSats have been additionally speaking through devoted inter-satellite hyperlinks.

Manufactured by HPS in Germany and Romania, Hera’s Excessive Achieve Antenna boosts its X-band sign greater than 4000-fold with the intention to attain distant Earth. The S-band inter-satellite hyperlinks connecting Hera and its CubeSats are a lot weaker, akin to home wifi.

Based mostly on software-defined radio, these inter-satellite hyperlinks—equipped by Tekever in Portugal with antennas from Anywaves in France—do double obligation: not solely exchanging knowledge with Hera, which serves as a relay again to Earth, but in addition supplying ranging info, letting the trio know the place they’re at anybody time relative to one another, minimizing any danger of collision.

The multi-point Doppler knowledge offered via these inter-satellite hyperlinks can even allow a extra correct measurement of the gravity fields of the Didymos and Dimorphos asteroids than Hera might obtain by itself.

“By having every little thing transmitting immediately via the air we have proved that every one the hyperlinks can run with out interfering with one another,” explains Hera communications techniques engineer Paolo Concari. “We really anticipated to see some minor degradation however did not actually discover any—one thing known as the ‘coupling issue’ the place adjoining antennas can decide each other up—so ended up with superb efficiency.”

The check marketing campaign additionally took within the preliminary part-deployment of the CubeSats from Hera’s topside Asteroid Deck: the pair will probably be prolonged out from their Deep Area Deployers one after the other, however will stay related to Hera till their operations and radio-links are with Hera are confirmed by testing.

About Hera

Hera is ESA’s first mission for planetary protection. Due for launch in October this yr, Hera will fly to the Didymos binary asteroid system in deep space to carry out a close-up survey of the Dimorphos moonlet in orbit across the major physique. The Nice-Pyramid-sized Dimorphos is already historic, as the primary solar system object to have its orbit modified by human exercise, by the 2022 influence of NASA’s DART mission.

Hera is meant to assemble essential lacking knowledge about Dimorphos for scientists, to show DART’s grand-scale experiment right into a well-understood and probably repeatable planetary protection approach. To extend its yield of knowledge, Hera carries with it ESA’s first deep space CubeSats, carrying further devices and deliberate to fly nearer to the asteroid’s floor than the primary spacecraft, earlier than finally touchdown.

The Juventas CubeSat carries a radar instrument, to carry out the primary radar probe of an asteroid’s inside construction, together with a gravity-detecting gravimeter. Its Milani counterpart hosts a multispectral imager to survey floor mineralogy in addition to a dust surveyor.