COPENHAGEN, Denmark — Three European Earth observation missions that had been scheduled for launch this summer are now facing delays of undetermined length because of unrelated issues at three different launch sites, European government officials said.

The latest delay is to the European Space Agency (ESA) Swarm mission to study Earth’s magnetic field. The three Swarm satellites were scheduled for launch in June aboard a Russian Rockot vehicle from the Plesetsk Cosmodrome in northern Russia.

Rockot, a converted SS-19 ballistic missile, has been grounded since February 2011 when its Breeze upper stage failed to place the Russian government’s GEO-IK2 geodesy satellite into its intended orbit.

For reasons that have not been disclosed, the investigation into that failure took more than a year to complete. Officials said at the time that because the anomaly occurred while the Breeze upper stage was outside the range of Russian ground stations, almost no telemetry data was available.

Russia’s Khrunichev Space Center of Moscow announced June 1 that the Rockot would return to flight in early July with the launch of two Russian satellites, the Gonets-M and Mir.

A Rockot launch of another Russian government payload will follow that, and only then will Swarm be launched.

Attending a conference here on Europe’s GMES — Global Monitoring for Environment and Security — Earth observation program, ESA Earth observation Director Volker Liebig said the agency has been informed that Swarm likely will not launch before November.

Liebig said ESA is of two minds with respect to the delay. On the one hand, he said, it is more reassuring to be third on the manifest of a rocket returning to flight than to be first or second. On the other hand, there are costs the agency incurs in maintaining mission teams.

Europe’s Metop-B polar-orbiting meteorological satellite, meanwhile, is awaiting the resolution of a dispute between Russia and Kazakhstan over rocket-stage drop zones for launches from the Russian-run Baikonur Cosmodrome, which is in Kazakhstan.

The late-May launch aboard a Russian Soyuz rocket has been indefinitely postponed as Russia and Kazakhstan negotiate a settlement.

Another European weather satellite, the geostationary-orbiting MSG-3, is awaiting the next flight of Europe’s Ariane 5 heavy-lift rocket. The launch had been scheduled for late May, but was postponed to give manufacturers of MSG-3’s co-passenger on the launch — the EchoStar 17 Ka-band broadband satellite — time to verify a suspect component.

Metop-B and MSG-3 are both owned by Europe’s Eumetsat meteorological satellite organization of Darmstadt, Germany.

Eumetsat Director-General Alain Ratier, in a June 4 interview here, said that until June 2, the Ariane 5 flight was to occur June 29.

But the May 31 failure of the Intelsat 19 telecommunications satellite to deploy one of its two solar arrays is likely to delay the launch still further. Intelsat 19 uses the same Space Systems/Loral-built satellite platform as EchoStar 17.

New York-based Loral Space and Communications, which owns Space Systems/Loral, on June 4 said the company and its customers were still evaluating what, if any, effect the Intelsat 19 anomaly will have on other Loral satellites awaiting launch.

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