WASHINGTON — Challenged to compete with SpaceX on price, other commercial launch providers are emphasizing an alternative attribute they believe makes them more competitive: the ability to launch on time.

That focus on schedule reliability, a theme during a launch services panel at the Satellite 2015 conference here March 18, coincided with a delay by SpaceX in a commercial launch of the Thales-built TurkmenAlem52E/MonacoSAT satellite that was scheduled for March 21.

“We found an anomaly somewhere in another area of our factory, and we decided we were going to be careful,” said Barry Matsumori, senior vice president of sales and business development for SpaceX, during the panel. “The vehicle itself we have not found any problems with.”

Although Matsumori declined to estimate the length of the delay, SpaceX spokesman John Taylor said March 19 that the launch is now planned for no earlier than April 24. It will take place after the Falcon 9 launch of a Dragon cargo spacecraft to the International Space Station that remains scheduled for April 10.

Matsumori didn’t go into greater detail about the delay, but SpaceX President Gwynne Shotwell, speaking at a Washington Space Business Roundable luncheon March 17 during the conference, said the issue was with tanks on the vehicle that store pressurized helium.

“We were doing some component stress testing over the weekend and got a little uncomfortable with the helium pressure bottles on board,” she said. “They passed inspection, but now is not the time to have an issue in flight, and so we’re going to go in and do some work on those.”

At the conference panel, executives of other companies, while not directly mentioning the SpaceX launch delay, took pains to emphasize their ability to launch on schedule.

“We do not have unexpected events before the launch,” said Arianespace chairman and chief executive Stéphane Israël, emphasizing the maturity of the company’s Ariane 5 launch vehicle. That rocket’s next launch, of the Sicral 2 and Thor 7 satellites, is scheduled for April 15.

“I think it’s important that when we say we will launch on the 15th of April,” he said, “I do not expect that we will have some quality issues forcing us to postpone the launch.”

Steve Skladanek, president of Lockheed Martin Commercial Launch Services, emphasized the schedule performance of the Atlas 5 rocket, a vehicle that is a workhorse for the U.S. government but only a bit player on the commercial market.

“Atlas is one of the most reliable systems available to the commercial market space to deliver on time,” he said. He cited an internal study that indicated that the average delay for Atlas 5 launches caused by the vehicle over the last four years is less than ten days. “That’s a fairly admirable track record.”

Matsumori said he didn’t put much weight on such studies. “There’s not actually a good reference on true schedule performance for anybody,” he said, citing the difficulty in determining the length and cause of any schedule slips.

Instead, he emphasized SpaceX’s growing launch capacity, particularly for launches to geostationary orbit. Currently SpaceX uses only Launch Complex 40 at Cape Canaveral for GEO missions, a pad also used for ISS cargo and other missions.

Matsumori said that renovations to Launch Complex 39A at the Kennedy Space Center, previously used for shuttle launches, will be done by late summer. That pad will host launches of future ISS crew missions as well as the larger Falcon Heavy launch vehicle. SpaceX is also developing its own launch site near Brownsville, Texas, primarily for GEO missions, which Matsumori said should be ready by late 2016.

Those additional sites, the company argues, will allow it to avoid schedule bottlenecks in the future. “We have found that crowded launch sites are a single point of failure of any launch organization,” Shotwell said, saying the sites will allow the company to do as many as 36 GEO launches per year by 2016.

The ultimate metric in schedule performance, Matsumori argued, is what customers do. “Our business is about how will that customer will vote next,” he said, “and it’ll be based on what they experienced before.”