With the return-to-flight of its Proton rocket scheduled for next week, International Launch Services (ILS) is planning to launch seven missions between now and the end of August, including one for the Russian government.

Reston, Va.-based ILS, which markets commercial launches of Proton for Moscow-based Khrunichev, will loft the Satmex 8 commercial communications satellite on March 26, the first Proton mission since a Dec. 8 mishap left the Gazprom Space Systems Yamal 402 Ku-band commercial telecom satellite in a low orbit after the rocket’s Breeze M upper stage shut down 4 min. early.

“Customer confidence is returning,” ILS President Phil Slack told reporters on the sidelines of the Satellite 2013 conference here March 18. “Obviously we need to have a good string of successes to really win back full customer confidence, but we’re certain we’ll be able to do that.”

Failure review

Slack said a failure review investigation found the shortfall was caused by a combination of worst-case factors, including temperature and pressure, that led to damage in a turbopump bearing in the upper stage.

“This last failure wasn’t where there was something manufactured wrong or a procedure wasn’t followed,” he said. “This was a buildup of tolerances where the combination of these ended up creating a condition that caused a failure.”

The December launch mishap followed a spate of failures that have plagued Proton over the past three years, including the December 2010 loss of three Russian Glonass navigation satellites due to over fueling of the rocket’s Breeze upper stage, followed by an August 2011 failure that cost Russia its Express-AM4 telecommunications spacecraft due to a programming error in the rocket’s guidance system. On Aug. 6, 2012, an out-of-specification component in a Breeze M fuel line led to loss of the Russian Express-MD2 and Indonesian Telkom-3 telecommunications satellites.

Slack says Proton manufacturer Khrunichev is in the process of implementing a quality management system audit and is planning to conduct a reliability improvement study of the rocket’s Breeze M upper stage over the next year. “Khrunichev will look at the whole system, on a subsystem-by-subsystem basis, to try to get the demonstrated reliability up to where the theoretical reliability is,” Slack said. “That study will take a year or so to complete, and from that there will be a number of recommendations that will be implemented going forward.”

In the meantime, Slack says the December launch failure has led to higher launch insurance premiums for customers, forcing ILS to lower prices in response. Still, he says ILS expects to receive orders for five or six launchers this year, and that the company has not lost any customers as a result of the December 2012 failure.

“You’re not going to win any business if you’re not going to respond to market pressures,” he says. “We think once we have a string of successes, that will create a separate set of pressures.”

New fairing

By 2016 he says ILS will begin offering commercial launches of Proton equipped with a new 5-meter-dia. fairing that Khrunichev is now developing.

“We think it will put us on par with our competitors,” notably the European Ariane 5 heavy-lift rocket and new Falcon 9 v1.1 launcher being developed by Space Exploration Technologies (SpaceX) of Hawthorne, Calif., Slack says. “I don’t think that today there are a lot of spacecraft that require it, but as spacecraft evolve we think it’s going to be important.”

In addition, the company is planning to increase the rocket’s carrying capability by 200 kg (440 lb.), bringing the Proton’s total lift capacity for geostationary missions to 6,350 kg starting in 2014