Russia's powerful First Deputy Prime Minister Sergei Ivanov Monday called on Roskosmos, the Russian Federal Space Agency, to take a hands-on role in helping solve the continuing design and production problems plaguing the Bulava submarine-launched ballistic missile.

"There are flaws in the testing of the (Bulava) components on the ground. Often, real tests are substituted by mathematical calculations to match technical requirements," Ivanov told a gathering of senior Russian space officials, RIA Novosti reported.

Ivanov, who also served for many years as Russia's defense minister, has been a strong supporter of the Bulava program. He pledged that despite another test launch failure of the missile from the nuclear submarine Dmitry Donskoi on Dec. 23 in the White Sea, the program would continue until the design and development problems had all been resolved.

The Bulava has now failed in five of its last 10 test launches, a failure rate of 50 percent. RIA Novosti said Russian military officials believed production flaws were probably responsible for the unsuccessful test launches.

The Kremlin has scheduled the Bulava SLBM to be operationally deployed on its nuclear submarines this year, but that timetable is now in doubt because of the recent test failure and continuing production problems. RIA Novosti cited what it described as a senior Russian navy official as acknowledging that further test firings will be required through 2009 before the Bulava can be approved for operational service.

RIA Novosti said each Bulava -- NATO designation SS-NX-30 -- had a payload of 10 multiple independently targeted nuclear warheads that could fly as far as 5,000 miles. The Bulava SLBM has been designed to be the strategic armament of Russia's new Borey-class Project 955 nuclear-powered submarines.