After a decade of development, ESA finally starts testing a part of its Callisto grasshopper

Callisto's basic design
Callisto’s basic design

My heart be still! First proposed in 2015 as Europe’s answer to SpaceX’s Falcon 9, the European Space Agency, in partnership with Japan, has finally begun acoustical testing of just one part of its Callisto grasshopper-type reusable test prototype, as shown on the right.

Callisto consists of five main sections: the Aft Bay, which includes the engine and landing legs, the LH2 Tank, the LOx Tank, the VEB, and the Fairing. The VEB houses much of the demonstrator’s electronics, including its onboard computer, avionics, and a reaction control system that uses H2O2 propellant. Its distinctive features include a pair of control fins.

In addition to confirming that the VEB had been transported to the CNES facilities in Toulouse, the 4 March Institute of Space Systems update also revealed that the acoustic test campaign for the key Callisto module had commenced last week. The acoustic test campaign simulates the intense sound vibrations the demonstrator will experience during flight to ensure structural integrity and component reliability.

The whole project has a budget of $100 million. The first test hop won’t occur until 2026, eleven years after the project began, and six years behind its original launch date. In that same time, SpaceX has completed several hundred commercial landings of its Falcon 9 first stage, reusing those stages up to two dozen times.

Nor is Callisto part of any program to develop a similar reusable rocket. It is a typical dead-end government project, with ESA having no clear goal to apply it commercially. The best Europe can hope for is that the engineering lessons from its tests will be given freely to the new European commercial rocket startups, so that they can use it someday.

First flight of government-built hopper to test vertical landings delayed two years

Callisto's basic design
Callisto’s basic design

This story about a first stage government-built Grasshopper-type rocket designed to demonstrate and test vertical landing has instead become a perfect demonstration of why governments should not design, build, and own anything.

It appears the first test flight of the Callisto test rocket, first proposed in 2015 and being built by a joint partnership of the German (DLR), French (CNES), and Japanese (JAXA) space agencies, has now slipped from 2024 to 2026.

Earlier this month, CNES deployed a refreshed website. Prior to that deployment, the agency’s Callisto project page had stated that the rocket’s first flight would occur in 2024. The new Callisto project page has a more detailed timeline, stating that the detailed design phase will be completed by the end of 2024. Vehicle integration in Japan is then expected in 2025, followed by a first launch from the Guiana Space Centre between 2025 and 2026. This revision outlines an approximate two-year slip in the project’s timeline. [emphasis mine]

These three agencies took almost a decade to simply conceive and design the project. Apparently they not yet even built anything. This despite a budget of slightly less than $100 million carved out of the entire budget for creating the Ariane-6 expendable. Compare that with SpaceX, which conceived its Grasshopper vertical test prototype in 2011, began flying that year, and resulted in an actual Falcon 9 first stage landing in 2015.

Will Callisto ever fly? Maybe, but don’t expect it to produce a rocket that is financially competitive with SpaceX. Instead, expect these three government agencies to subsidize its cost in order to make its price competitive on the open market. More likely Callisto will fly a few times, but will likely result in no new orbital rocket. Instead it will be superseded by the private rocket startups worldwide that are now building actual orbital rockets and will likely make them reuseable before Callisto even leaves the ground.

Europe has decided to build a probe, dubbed JUICE, to study Ganymede, Callisto and Europa, Jupiter’s big icy moons.

Europe has decided to build a probe to study Ganymede, Callisto and Europa, Jupiter’s big icy moons.

Known as JUICE, the Jupiter Icy Moons Explorer, the probe will enter orbit around the gas giant planet in 2030 for a series of flybys of Ganymede, Callisto and Europa. JUICE will brake into orbit around Ganymede, Jupiter’s largest moon, in 2032 for at least one year of close-up research.