Updated with quotes and details after NASA press conference.

An unpiloted space plane developed by Sierra Nevada Corp. will join cargo carriers built by SpaceX and Orbital ATK to resupply the International Space Station beginning in 2019, NASA announced Thursday.

The Dream Chaser spaceship, originally conceived to carry astronauts, can deliver up to 12,000 pounds — 5,500 kilograms — to the space station per trip, then detach and return to Earth for a runway landing like the space shuttle.

Sierra Nevada’s lifting body spacecraft has never flown in orbit, and the company aims to drop the craft from a helicopter for an approach and landing demonstration in the coming months.

NASA’s current cargo transportation providers, SpaceX and Orbital ATK, also received new contracts Thursday, giving the space station three U.S. resupply carriers operating alongside Russia’s Progress logistics freighter and Japan’s HTV cargo ship.

The cargo flights covered by the new agreements will begin in 2019, and the contracts have options for missions extending through 2024, the space station’s current projected retirement date.

NASA signed the agency’s previous commercial cargo contracts with SpaceX and Orbital ATK in December 2008, and those Commercial Resupply Services — or CRS-1 — agreements have been extended to meet the space station’s supply needs through 2018.

The space agency turned to commercial providers to haul supplies to the space station after the retirement of the space shuttle, and NASA plans to debut new commercially-owned crew capsules developed Boeing and SpaceX to transport astronauts to and from the orbiting research lab in 2017.

NASA officials said Thursday they chose three companies to expand their options when routing experiments, crew provisions and other hardware between Earth and the space station.

“One of the considerations from an operational standpoint with ISS is it’s really important to have more than one supply chain, and mulitple offerers means that at any given time, the sequence of flights could be one Sierra Nevada, Space, Orbital ATK, so if you lose one, you have the ability for another one being right after it from a dissimilar redundancy, or a different supplier, so that’s a big help to us,” said Kirk Shireman, NASA’s International Space Station program manager at the Johnson Space Center in Houston.

Orbital ATK and SpaceX had launch failures in October 2014 and June 2015, grounding their Cygnus and Dragon supply ships for months. Orbital ATK purchased two United Launch Alliance Atlas 5 rocket flights to keep flying the Cygnus spacecraft while the company’s Antares booster is grounded.

SpaceX has resumed flying its Falcon 9 rocket after its launch mishap, and the next Dragon cargo mission to the space station is scheduled for no sooner than March, nine months after last year’s failure.

Sam Scimemi, director of the space station’s division office at NASA Headquarters, said the agency learned lessons from the first round of cargo contracts cinched in 2008.

“It has not been easy by any measure,” Scimemi said. “Both our CRS-1 providers have experienced launch failures and are in the process of recovering. NASA and our industry partners have learned valuable lessons from these failures and the recovery to flight.”

SpaceX and Orbital ATK have carried a combined 35,000 pounds of gear to the space station since commercial flights to the outpost began in 2012, Scimemi said.

The fresh cargo contracts, which go into effect immediately, have an aggregate value of up to $14 billion. Tenets of the deals allow NASA to order additional missions beyond each company’s six guaranteed flights as needed until the total cost reaches $14 billion, and Shireman said the space station’s actual cargo requirements will almost certainly fall short of the cap.

NASA can procure the add-on cargo flights based on price, capability, past performance and other factors.