Spanish Science, Innovation and Universities Minister Pedro Duque, a former astronaut, inaugurates PLD Space test facilities at Teruel Airport in February 2019, with PLD Co-Founders Raul Verdu, left, and Raul Torres, right. Duque has publicly supported a large increase in Spain’s space budget, but Nov. 10 general elections make it unclear who will represent Spain at ESA’s Space 19+ ministerial conference, to be held Nov. 27-28 in Seville, Spain. Credit: PLD Space

PARIS — Startup smallsat launch-service provider PLD Space has suffered a series of engine test-firing anomalies in recent months, including one explosion, that will delay its first suborbital test flight for an undetermined amount of time, PLD Chief Executive Raul Torres said.

Torres said the Miura-1 LOX-kerosene engine’s basic design does not appear to be at issue in the problems, which have occurred during startup and shutdown and not during the engine’s nominal 3- to 4-minute burn.

He said the problem may be related to the test stand itself, at Spain’s Teruel Airport, which was built on a shoestring budget and is now being enhanced.

“We now have the budget to do engine qualifications and long-duration tests,” Torres said in an Oct. 11 interview. “I see this as part of the process that most launcher companies go through. It’s in qualification that you find out what’s wrong. But we have not solved the problem yet.”

PLD Space is one of several startups designing rockets to carry small satellites into orbit from European territory. In addition to sites in Spain, PLD is part of a consortium including veteran aerospace companies Deimos and GMV, and Britain’s launcher startup Orbex, that is bidding for a license to operate from Portugal’s Azores Islands.

PLD raised about 20 million euros ($22 million) private sources including GMV, Deimos and Aciturri and the European Commission and the 22-nation European Space Agency (ESA): http://bit.ly/2VwIyFP It has also secured backing from JME Venture Capital of Spain: http://bit.ly/2IGrk3k

Torres said these funds are sufficient to overcome the engine issues and complete testing of the Miura-1 pressure-fed engine.

A test firing of PLD Space’s Miura 1 engine. Credit: PLD Space

“This problem is not yet solved and we are modifying the test bench,” Torres said. “We have continued testing and hope by the end of the year to have made progress. We know the engine is well-designed; that is not the problem. It looks to be related to the interface between the engine and the bench.”

PLD reduced is headcount and is operating on a lower-cost basis.

In April, the company performed a helicopter drop test over the ocean of its reusable Miura-1 first stage, in part to determine how the stage reacts to salt water.

Torres said tests are still being run but that the status of the engine and the stage were good enough to give confidence that, if the recovery is done quickly enough, the hardware can be refurbished and reused in a way that makes business sense.

PLD had planned one suborbital flight this year. Those plans are now on hold, and Torres said he did not want to announce a target date before the engine issues are resolved.

“Too many people in this business give dates before they have solved problems,” he said. “I prefer to solve the problem and then propose a launch date.

Like other Spanish space companies, and like the 22-nation ESA, PLD is uncertain about Spain’s space budget in the run up to Nov. 10 general elections.

Spanish Science, Innovation and Universities Minister Pedro Duque, a former astronaut, has favored a substantial increase in Spain’s space budget. Much of which would go to ESA for programs to be approved at ESA’s ministerial conference, to be held Nov. 27-28 in Seville, Spain.

At this point it isn’t certain who the host nation’s minister responsible for space will be, or whether Spain will be able to make the multi-year commitments that ESA proposes at these ministerial conferences, held every three years.

Spain is ESA’s fifth-largest contributor among the 22 member nations, accounting for 4.6% of the agency’s budget.