I'm surprised this didn't show up in test firings to be honest...
Even the lunar ascent engine had test firings - not the actual ones used but ones produced the same way, they were strictly one time firings only.
In December of last year, two of Airbus’ Pléiades Neo Earth-imaging satellites intended for a polar Sun-synchronous orbit aboard an Arianespace Vega C rocket ended up in the Atlantic Ocean instead. The European Space Agency (ESA) announced the cause of the failure, as determined by an independent commission, last Friday: a …
This kind of failure illustrates the environment these days; back in the late 50's we had the same things happen because we were starting to learn how to build this type of rocket but nowadays we're being told that "It's easy to build and easy to use with this new efficient material" ... the evidence for this can be seen on a website, not anyone's actual series of launches working.
Test a launch engine on the ground, then if it works send a few up, and if there are no problems then including a satellite will almost certainly work.
I suppose a lot depends on relative costs. Especially since they have insurance. How much would a full test burn cost compared to the cost of a launch?
With an enterprise like this I suspect there's a lot of good old fashioned cost/benefit analysis going on. I can just hear a bean counter saying "it would cost how many million euros for a test burn?" But probably in French.
Clearly the "very deep investigation" was not deep enough. The failure of three out of the last eight flights of Vega and Vega-C must be both embarrassing and expensive.
You do have to wonder if the ESA project is trying to outcompete Space-X in order to get the paid-for launches for Europe.
With Virgin Galactic (ok one failure to-date) and Blue Origin playing in the same space then they need to get more successful launches under their belts soon else the business will go elsewhere. If they do fail then the whole project is doomed as the money will dry up.
ESA is not competing with SpaceX just like NASA isn't competing with SpaceX.
NASA and ESA do not build rockets. They hire private companies like Boeing, Lockheed-Martin, Arianespace, and SpaceX to build rockets and, often, space probes. Their job is to run space exploration missions as funded by associated governments, usually without a concern for profit.
SpaceX is a delivery company (with a side hustle in communications) that builds its own delivery vehicles. It doesn't build, design, or operate space exploration missions. It doesn't have the labs, networks of astronomers, and university researchers to conduct basic space exploration.
The French Space Agency (CNES) said it wasn't satisfied with having a technical analysis only. It asked on February 28 for ESA to make an internal investigation. "CNES considers that the investigation is not thorough enough to determine why and how such an accident took place and what made it possible, and what decisions taken by the industry and by the agency led to a such a risky and uncontrolled situation". It seems to be quite angry.