An artist's concept of a Spaceflight Sherpa tug capable of carrying 87 small satellites into low Earth orbit. Credit: Spaceflight Industries

WASHINGTON — Delays in SpaceX’s launch schedule have led an aggregator of secondary payloads to find alternative rides for dozens of satellites it planned to fly on a Falcon 9.

In a March 2 message, Curt Blake, president of Seattle-based Spaceflight, said that “significant” delays in the planned launch of the Formosat-5 mission on a Falcon 9 from Vandenberg Air Force Base in California forced the company to find alternative rides for nearly 90 satellites that were to launch as secondary payloads on a payload adapter called Sherpa.

“We learned our launch would occur potentially much later than expected,” Blake wrote, not giving a specific launch date. “While delays are inevitable in the launch business, we made the decision to rebook all our customers slated to launch on the FormoSat-5 mission.”

Formosat-5 and Sherpa were scheduled to launch on a Falcon 9 last year but were delayed, in part because of the Sept. 1 pad explosion of a Falcon 9 during preparations for a static-fire test at Cape Canaveral. That halted all Falcon 9 launches for four and a half months.

Blake, in an October 2016 interview, said Spaceflight was waiting on the Falcon 9 return to flight before getting a new launch date, and at the time didn’t expect a launch before early 2017. The company had told the owners of the satellites not to ship them to Spaceflight for integration onto the Sherpa adapter until it got a confirmed launch date from SpaceX.

SpaceX has not disclosed a launch date for Formosat-5, or many other upcoming launches from Vandenberg. SpaceX President Gwynne Shotwell, speaking at a Feb. 17 press conference at NASA’s Kennedy Space Center, said the company had delayed the next Falcon 9 launch of Iridium satellites, from Vandenberg, from mid-April to mid-June “to fill in the queue of folks that have been waiting for a flight since we were down last September.” The company hasn’t identified those customers.

Blake said that, given the extended delays, the company decided to find other rides for the satellites that were to fly on Sherpa. “It took a huge effort, but within two weeks, the team hustled to have all customers who wanted to be rebooked confirmed on other launches!” he wrote.

Spaceflight spokeswoman Jodi Sorensen said March 2 that most of the satellites that had been flying on Sherpa will be rebooked on one of two launches. One is on the company’s own dedicated Falcon 9 mission, dubbed SSO-A, scheduled to launch from Vandenberg later this year. The other is an unspecified “international launch” scheduled for this summer or fall.

Spaceflight has brokered launches of small satellites as secondary payloads on a number of different vehicles. That included nine cubesats that launched on an Indian Polar Satellite Launch Vehicle (PSLV) Feb. 14. Eight of the nine satellites were from Spire, a company deploying a constellation of cubesats for ship tracking and weather data. The ninth satellite was a cubesat from an Israeli university.

Blake, in a recent commentary, defended the use of PSLV, which developers of small satellite launchers in the U.S. have criticized for undercutting the market. “Contrary to popular belief, foreign launches are not less expensive than domestic ones” in part because of regulatory costs, he wrote in the SatMagazine op-ed.

In comments directed at President Trump, Blake called on the administration to avoid any making policy changes that would make it harder to launch on Indian or other non-U.S. rockets while the capacity in the domestic market grows. “We ask the current administration to allow these international launch options that are critical to the smallsat industry and to support the efforts and policies that expand — not restrict — access to space,” he wrote.

As for Sherpa itself, Sorensen said it could fly on the SSO-A mission or another launch with a different set of satellite payloads. “It’s completely flight ready, so if we can, we’ll definitely use it,” she said.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...