The private equity firm AE Industrial Partners (AEI) on Thursday said it has agreed to acquire a “significant stake” in Firefly Aerospace, a deal that would add to its portfolio in the space market.

Terms of the deal, which requires approval by U.S. regulators, were not disclosed. AEI is acquiring the stake from Noosphere Venture Partners, an investment firm with a portfolio of space-related companies. Noosephere acquired Firefly in 2017.

Firefly, which is based in Texas, is developing a space launch vehicle to flexibly deliver payloads weighing between 1,000 and 10,000 kilograms to low earth orbit for as little as $15 million. The Alpha launch vehicle completed its first test flight last September but failed to reach orbit. A second test vehicle is awaiting approvals for launch.

The company is also developing a lunar lander and has a contract to deliver payloads to the lunar surface in 2023.

Some of AEI’s other investments include the space company Redwire Corp. [RDW] and Sierra Space.

AEI said that as of May 2021 Firefly had raised financing at a $1.1 billion valuation.

AEI’s financial adviser on the deal is Ernst & Young. Noosephere is being advised by Jefferies.