VENICE, Italy — Sea Launch Co., whose launch manifest is already suffering because of shortages of rocket components, is likely to further curtail its activity in 2009 because the limited hardware available will be used for one or more Russian government missions, Sea Launch President KjellKarlsen said.

In an April 3 interview here during the 15th Annual Space Insurance Conference, organized by Pagnanelli Risk Solutions, Karlsen said it now appears that the Long Beach, Calif.-based company will perform no more than two Sea Launch and two Land Launch missions in 2009. The Sirius XM Satellite Radio XM-5 satellite, which had been manifested on Sea Launch for late this year, will slip to 2010, Karlsen said.

Karlsen reiterated his confidence that Sea Launch, which must finance part of its debt this year, will receive full backing from Boeing Co., Sea Launch’s largest shareholder, in securing fresh bank commitments.

“Boeing has an existing guarantee where they must either back our refinancing or pay it off in cash,” Karlsen said. “I don’t think Boeing has an interest in paying off $250 million in cash. We have 14 banks in our bank group. If we don’t do a bank deal then we will do a private placement, which is what we did a couple of years ago. In either case I am not worried.”

After multiple delays related to the readiness of Italy’s Sicral 1B military telecommunications satellite, the Sea Launch floating launch platform and the command ship have set sail for the equatorial launch site in the Pacific Ocean in preparation for an April 19 launch.

Weighing just 3,038 kilograms, Sicral 1B is only half the weight of what Sea Launch can place into geostationary transfer orbit. But Italian authorities elected to use Sea Launch rather than book Sicral 1B on an Ariane 5 rocket as one of two passengers in hopes that, as the sole passenger aboard, Sicral 1B could be placed closer to its final orbit to maximize its service life.

The satellite is to be used by the Italian Ministry of Defense, the NATO alliance and by Telespazio of Rome, which has rights to commercialize part of Sicral 1B’s capacity.

Sea Launch had expected at least two more Sea Launch campaigns this year, but the strains on the supply chain, which Karlsen said will continue until 2011, will make it difficult to perform more than one more launch this year if the Russian government needs Zenit rocket hardware for a priority government mission.

Russian authorities have said three long-awaited missions may be ready for Zenit liftoffs in 2009: the Spektr-R astronomy satellite; the Elektro meteorological spacecraft, also known as GOMS or Geostationary Operational Meteorological Satellite; and the Phobos-Grunt mission to collect samples from Phobos, a moon of Mars.

These missions have suffered multiple delays and it remains doubtful that all three will be launched in 2009, according to European government officials tracking the programs.

But the possibility that one or more will be ready this year has exacerbated pressure on Sea Launch for both the ocean-launched Sea Launch operation and its Land Launch variant, which is basically the same Zenit 3SL vehicle but operated from Russia’s Baikonur Cosmodrome in Kazakhstan.

As a result, Karlsen said the company hopes to launch the Measat 3 satellite, owned by Measat Satellite Systems of Malaysia, aboard a Land Launch vehicle sometime in June. The launch was contracted by Intelsat of Washington and Bermuda as one of four Land Launch contracts signed by Intelsat several years ago, when Land Launch prices were, as Karlsen concedes, “ridiculously low.”

Measat 3 suffered damage as it was being prepared for launch at the Baikonur site in August 2008 and was returned to manufacturer Orbital Sciences Corp. of Dulles, Va., for repairs.

The oceangoing Sea Launch operation still expects to launch the Eutelsat W7 satellite by September, Karlsen said. Following that mission, the Intelsat IS-15 satellite is being readied for a Land Launch mission late this year.

Sirius XM Satellite Radio Inc. had planned on a late-2009 liftoff but “we are now working with Sea Launch for a 2010 launch,” Sirius XM Technical Executive Robert D. Briskman said here April 2.

The merger of the former Sirius and XM satellite radio companies, plus the collapse of the automobile market in the United States, has complicated the new company’s financial condition. Industry officials said that even without the Sea Launch supply chain pressures, Sirius XM likely would prefer to delay the launch and the capital expenses it will incur.

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