[not verified in body] Hera has a mass of 1,128 kg (2,487 lb) and carries a payload of cameras, an altimeter, and a spectrometer.

Hera is intended to fully characterize the composition and physical properties of the binary asteroid system including, for the first time, the sub-surface and internal structures.

It will also perform technological demonstrations linked to operations in the vicinity of a small Solar System body and the deployment of and communication with CubeSats in interplanetary space.

The DART project would evolve thereafter by incorporating the LICIACube nano-satellite, released before the impact and responsible for taking and retransmitting the first 100 seconds of it.

Hera was planned to be launched in October 2024 to catch a workable planetary/asteroid alignment and study the effects of the DART impact on Dimorphos, the satellite of Didymos, 4 years after it occurred.

In September 2020 the European Space Agency awarded the construction of the spacecraft to a consortium of companies led by OHB, under a contract of 129.4 million euros.

This deflection method consists of modifying the trajectory of the asteroid by launching a spacecraft at a speed of a few kilometers per second.

The most important thing is the production of a guidance software which, by using data from several sensors, will make it possible to reconstruct the surrounding space and thus to independently define a safe trajectory around the asteroid.

[7] In order to be successful, the impact needed to change the orbital period of Dimorphos around Didymos by a minimum of 73 seconds from its pre-impact value of 11.9 hours, which should be observable by terrestrial telescopes.

[9] Following a gravitational assist at Mars on March 12 2025 where Hera will spend some time observing the Martian Moon Deimos.

Once close to the double asteroid, five stages will follow: The main bus of Hera has a box-shape based on a central tube and adapter cone of 1.6 × 1.6 × 1.7 meters.

Two solar panel wings extend from opposite sides, and a high-gain dish antenna is mounted on one face.

Spacecraft orientation is maintained by 4 reaction wheels, gyroscopes, using star trackers and solar sensors, as well two Asteroid Framing Cameras (AFC).

These cameras are to provide physical characteristics of the surface of the asteroid Didymos and Dimorphos as well as the crater created by DART and the Juventas landing zone.

[citation needed] PALT is a micro-Lidar planetary altimeter using a laser emitting an infrared light beam at 1.5 microns.

[citation needed] TIRI is a thermal infrared imager provided by the JAXA, the Japanese space agency.

[citation needed] The mass of the two asteroids making up the binary system, the characteristics of their gravity field, their rotational speed, and their orbits will be measured using radio wave disturbances caused by the Doppler effect.

[citation needed] Two CubeSat type nanosatellites, named Milani and Juventas, are transported by Hera and released before arrival in the asteroidal system 65803 Didymos.