Russia's Proton-M heavy carrier rocket will remain a key space launch vehicle despite its rather poor safety record, a prominent Russian space scientist said Wednesday.

"I think the Proton will keep its clients and maintain its niche because the [commercial] space launch market has a shortage of launch vehicles of this class," Alexander Zheleznyakov, from the Russian Academy of Cosmonautics, said during a news conference at RIA Novosti.

Russia's Proton-M and Europe's Ariane 5 are currently the most widely used heavy-lift space launch vehicles. Zheleznyakov believes that after 2015 they may face strong competition from China, with its Long March 5 rockets, and India, with its GSLV MK-III.

The Proton-M experienced several failed or partially failed launches in the past three years, which prompted insurers to significantly raise premiums for insuring Russian rockets. The Proton that was lost on July 2 had been insured for 6 billion rubles ($182 million) with the Russian Insurance Center.

Zheleznyakov said it would not be surprising if insurance premiums for future Proton launches would go up even more, a cost that would be reflected in higher prices for Proton services.

Meanwhile, Russia has begun a criminal investigation into last week's failed launch of a Proton-M carrying three Glonass navigation satellites.

Russian officials have said the preliminary results of the probe could be available by the end of July, but some media outlets reported on Tuesday that the explosion of the rocket was caused by sloppy assembly work.

Source: RIA Novosti