WASHINGTON — Laser communications terminal provider Mynaric says it raised 11 million euros ($12.5 million) in post-IPO funding from a mystery constellation venture that plans to buy up to 1,000 terminals.

Gilching, Germany-based Mynaric, which recently hired a former SpaceX Starlink vice president as its co-CEO, said the funds came from the “lead investor of a satellite constellation it is working with,” specifying that it is the same unnamed customer Mynaric disclosed in October as having signed a memorandum of understanding for terminals.

Mynaric spokesperson Paul Cornwell said by email that the March 18 stock transaction provides a “cash injection” that will give the constellation venture a 6.9 percent ownership stake in Mynaric.

The constellation venture paid 55 euros per share, about three-and-a-half euros below the stock’s 52-week high, but about 10 euros higher than Mynaric shares closed March 18 on the Frankfurt Stock Exchange.

Mynaric, which went public in October 2017, has raised 50 million euros to date. The company started producing optical ground stations last year, and says an airborne version will enter production in the second half of this year.

Mynaric’s mystery customer is waiting for Mynaric to test its laser terminals in space, a milestone originally expected this year. Cornwell said the in-orbit test will now take place in 2020, citing a delay caused by the fundraising effort.

Optical satellite terminals can provide higher data transmission speeds than radio-frequency links. Three notable constellation ventures plan to use optical intersatellite links — SpaceX, Telesat and LeoSat — though none exactly fit the profile of Mynaric’s unnamed investor.

The only large, low Earth orbit constellation currently using intersatellite links is Iridium Next, which features four Ka-band links per satellite — one on each side. Four links per satellite is what Telesat and LeoSat have said they have planned for their respective LEO constellations. If Mynaric’s mystery investor takes a similar approach, then 1,000 terminals would equip a constellation of 250 satellites.

SpaceX is planning a constellation of up to 12,000 satellites, which would require a dramatically higher number of laser links than the 1,000 terminals Mynaric says its unnamed constellation customer is interested in buying.

Last week, Bulent Altan, Mynaric’s SpaceX hire, said he would try to sell SpaceX on using Mynaric terminals, but he also said there is no current business relationship between the two companies.

LeoSat’s constellation partner Thales Alenia Space in 2016 purchased Ruag’s opto-electronics business line, bringing expertise “specialized in scientific satellite instruments and in equipment for optical communications in space” in house that it could use for LeoSat’s 108 satellites.

Telesat, which declined to say whether it is Mynaric’s investor, is planning a constellation of 292 satellites, each equipped with four intersatellite links — meaning it would need closer to 1,200 terminals rather than the no more than 1,000 that Mynaric has said its unnamed constellation customer intends to buy.

OneWeb does not plan intersatellite links, citing concerns from national regulators about the flow of digital traffic beyond their borders (a concern Telesat said can be avoided by routing traffic within those countries without using intersatellite links). Mynaric’s in-orbit test timeline also doesn’t align with OneWeb’s manufacturing plans, which call for large-scale satellite production this spring.

Altan said the investment “underlines the traction we are now getting here at Mynaric as we move into the next key phase of our evolution.”