HOUSTON — NanoRacks LLC says difficulties discovered with the activation of recently returned experiments flown aboard the International Space Station will not affect upcoming company research endeavors planned for the orbiting science laboratory, including the ongoing operations of two NanoLab platforms and a soon-to-launch variable gravity centrifuge facility.

The company began an inquiry following the return of the 29 Soyuz mission on July 1 with three U.S., Russian and European station crewmembers and 15 student experiments housed in MixStix containers that were launched to the station aboard the successful SpaceX/Dragon commercial resupply mission in late May. A yet-to-be-determined number of investigations had not been activated. “We’re investigating what happened. It could be a hardware problem, but I kind of doubt it,” said Michael Johnson, NanoRacks chief technology officer, on July 10.

One avenue of inquiry is the video training provided to the astronauts while they are on the station and just prior to activation. The 7-in.-long, 0.5-in.-wide, Teflon-coated MixStix containers are activated like chemical glow sticks, by bending them until a crack is heard. Activation instructions to the station crews are provided by video uplink. The cracking sound of a successful activation can be drowned out by the station’s air circulation fans and electronic gear, Johnson said.

The MixStix contents are obscured by the Teflon exterior and double safety bagging.

NanoRacks disclosed the problem late July 9. The 15 competitively selected National Center for Earth and Space Science Education experiments were not designed to be powered or monitored during flight.

NanoRacks plans to refly them at no additional charge.

The three-year-old company has flown 48 previous MixStix experiments successfully, Johnson said.

NanoRacks developed the small containers for crystal growth experiments but markets them to academia and commercial customers for a range of investigations that do not require active monitoring at costs between $10,000 and $20,000 for 30 to 45 days of activation.

The company currently maintains two NanoRacks platforms, each capable of holding 16 of the 10-cm. NanoLab cubes that provide power and data collection for a range of compact research activities associated with the station’s U.S. National Lab designation. The platforms, which are currently half occupied, are housed in the Japanese Experiment Module, as were the MixStix tubes.