Hera will reach Dimorphos a month early, in November

The European Space Agency’s Hera mission will reach the Didymos-Dimorphos binary system in November 2026, a month ahead of the original schedule. The reason is technical and favorable: the probe’s good performance has allowed more aggressive maneuvers to be designed, as indicated in the agency’s communications reported by NASASpaceflight and consistent with the official ESA calendar of the year’s events.

What it will measure

In 2022 NASA’s DART probe deliberately struck Dimorphos, the smaller body of the binary system, in a test of asteroid deflection. The experiment produced a crater and a change in orbit, but from Earth one can observe the effect, not the scene itself.

Hera does the complementary work: it goes to look closely at the result. It will study the binary system and the crater produced by the impact, that is, it will provide the physical parameters — mass, internal structure, morphology of the point struck — without which a successful experiment remains a single case rather than a replicable method. It is the difference between knowing that a technique worked once and knowing why it worked.

The probe will release two miniature satellites. Milani was developed by an Italian-Czech-Finnish consortium; Juventas by the Danish company GomSpace with GMV in Romania. In March 2025 Hera had carried out a flyby of Mars, useful both for adjusting its trajectory and for testing onboard instruments before arrival at its destination.

Traffic to the Space Station

In low Earth orbit, the schedule change instead concerns crews. The 2026 flight program for the International Space Station, revised by NASA together with partner agencies, moves the NASA/SpaceX Crew-13 mission from the initially indicated November to mid-September 2026; the launch will take place from Space Launch Complex 40 at Cape Canaveral. The stated reason is to increase the frequency of US crew rotation missions to the Station.

The same document places in the autumn the SpaceX CRS-35 resupply flight: on board, more than 7,200 pounds of material, including the roll-out iROSA solar arrays — the progressive upgrade of the orbital outpost’s electrical power system. The launch opportunities for the uncrewed Boeing Starliner-1 cargo mission, however, remain under review, due to technical issues that emerged during the 2024 Crew Flight Test.

The news about the flight plan currently comes from a single source, the update published by NASA; no independent confirmation is available. It is, however, the institutional primary source of the decision.

What we don’t know

Regarding Hera, we do not know the precise arrival date in November nor the release schedule for the two CubeSats. We do not know how long the close-observation campaign will last nor which instruments will be activated first.

We do not know the dimensions of the crater produced by DART: that is exactly what the mission is going to measure, and any figure circulating before the arrival would be an estimate from Earth, not a survey.

On the Space Station front, the exact launch date of Crew-13 within mid-September is not specified, nor is the crew composition. We do not know which technical issues from the 2024 Crew Flight Test remain open for Starliner-1, nor whether a new window has been set.

The first verifiable milestone is therefore the launch of Crew-13 from Cape Canaveral, scheduled for mid-September 2026.