Investors are focused on SpaceX's massive Starship rocket. Its Starlink satellite-internet service is its chief moneymaker. But on Thursday, one of its newest spacecraft signed up a customer.

Space-and-defense company Redwire said it had agreed to send its orbital pharma technology to low-Earth orbit on SpaceX's Starfall spacecraft, a vehicle that hasn't flown yet.

SpaceX hasn't said much about Starfall, but has submitted plans to federal regulators that describe it as a cylindrical capsule 2.5-feet high and more than 10 feet in diameter.

Redwire plans to fill a Starfall vehicle with its Pharmaceutical In-Space Laboratory devices, which allow researchers to experiment with drugs in microgravity environments, with the aim of producing new compounds. Starfall would reenter Earth from space as part of the mission, bringing the pharma cargo back for analysis.

Redwire said its Starfall flight is slated for 2028. Shares of Redwire jumped more than 13% on Thursday to $12.16.