TURIN, Italy — Thales Alenia Space Italy officials reacted with stupefaction and incredulity that their miniature spaceplane experiment’s launch had been postponed indefinitely because of last-minute concerns over range safety.

These officials said their 40-strong engineering team preparing the Intermediate Experimental Vehicle (IXV) for a mid-November launch aboard a European Vega rocket — also Italian-led — had worked nights and weekends to make the November date.

The November launch, they said, would have shone a light on Italy’s space technology prowess on the eve of a conference of European space ministers that will decide Europe’s space station and launch vehicle future.

With Italy’s government still apparently undecided about how much to invest in Vega upgrades, a new Ariane 6 heavy-lift rocket and the European share of the international space station, they said, a successful IXV flight and Pacific Ocean splashdown might have provided an important preconference impetus for further investment.

Italy’s space minister attended the departure of the IXV recovery ship from Genoa. The ship is now in Panama awaiting word on whether it should turn around.

Officials attending a briefing at the company’s production plant here on Europe’s ExoMars two-launch mission to Mars in 2016 and 2018 — also Italian-led — declined to speculate on how much the launch delay would cost the IXV program.

The 20-nation European Space Agency, in concert with the French space agency, CNES, on Oct. 24 said the Nov. 18 launch would be delayed for an undetermined amount of time while CNES and ESA examine safety concerns about Vega’s equatorial flight path as it leaves Europe’s Guiana Space Center spaceport in French Guiana, which is French territory.

Vega is a four-stage vehicle whose three lower stages are solid-fueled, meaning two fully loaded solid-propellant tanks will be overflying French Guiana in the early minutes of the IXV flight.

ESA and CNES officials up to now have either declined to comment or, in the case of ESA, said they were at a loss to explain why a program whose mission profile has not changed in several years is now suddenly stalled for safety issues that in principle should have been aired and resolved long ago.

One official, saying he could not believe that the two agencies simply forgot to evaluate the safety issues, said he preferred to suspect political motives.

“Look, we are about to send a spacecraft and lander to Mars, in one year,” this official said. “Europe has rendezvoused with a comet a decade after the [Rosetta comet-chaser] satellite was launched. You want me to believe that somehow the agencies just forgot to evaluate safety? That is too far-fetched. I would rather believe there is some political motive.”

Europe’s lead launch-vehicle nation is France, which initially balked at participating in the Vega program. A French minister said that in Europe, launch vehicles are French. The French government declined to allow the export, to Italy, of the avionics suite that guides Vega, forcing Italy to develop its own. Italy has since done so and successfully flown it on Vega.

As it stands now, one official said, France must accept the idea that with Vega, Italy has led development of a vehicle that at least in principle resembles an intercontinental ballistic missile. “Some people don’t like that,” this official said.

In addition to providing a flashy, if brief — IXV’s mission lasts less than two hours from launch to Pacific Ocean splashdown — display of Italian space technology, a successful IXV launch was supposed to have given European governments an incentive to support a follow-on program, which up to now has received only enough funding for studies.

One industry official said ESA and CNES were aware, since June, that for some reason they had not fully vetted the Vega IXV flight plan from a range-safety point of view. Why the issue was not resolved since then remains unclear.

“It was as though the two agencies were saying, ‘We’ll get around to it,’ and yet they never did,” one official said.

Europe’s Arianespace launch consortium is managing a full manifest of launches of the Ariane 5 and the Europeanized Soyuz medium-lift rocket. If it misses its Nov. 18 Vega launch date, IXV is likely to be put into storage for several months to wait for the next opportunity.

Peter B. de Selding was the Paris bureau chief for SpaceNews.