Today, NASA awarded a new round of contracts to supply the International Space Station with food, water, and scientific research from late 2019 through 2024.

The space agency both expanded the number of companies providing services from two to three and more than doubled the potential value of awards to as much as $14 billion over about five years. “This is the next chapter,” said Ellen Ochoa, director of Johnson Space Center, which manages the International Space Station program.

Both Orbital ATK, with its Cygnus vehicle, and SpaceX, with its Dragon, won new contracts. Sierra Nevada Corporation joined them with its Dream Chaser. Unlike the other two capsules, the Dream Chaser is a winged vehicle that resembles the space shuttle and lands on a runway. Each of the companies is guaranteed to fly at least six supply missions to the station.

Whereas NASA once provisioned the station mostly with the space shuttle, it sought to cut costs by opening its supply needs to private bidders. Instead of offering traditional cost-plus contracts that did not encourage private companies to work quickly and efficiently, it gave up some oversight and paid a fixed price for services provided directly by the private sector. The result was supply services that cost significantly less.

Since the first contracts were awarded seven years ago, at a value of $3.1 billion to each company, Orbital and SpaceX have delivered more than 16,000kg of supplies to the Space Station. Their initial contracts have been extended through most of 2019.

Each company has also suffered an accident. In October 2014, Orbital's Antares rocket carrying its Cygnus spacecraft exploded 15 seconds after launching. Then, in June 2015, SpaceX’s Falcon 9 rocket exploded during a supply flight to the station. Both companies have largely recovered from those accidents, and NASA believes they have learned valuable lessons about the challenge of spaceflight.

Those accidents led to intense speculations about the second round of cargo supply missions to the space station. Orbital and SpaceX were joined by more traditional aerospace contractors, Boeing and Lockheed Martin, in the bidding process. However, the newer space companies, joined by Sierra Nevada, emerged triumphant.

Although NASA would not discuss specifics of the bidding process, industry sources told Ars the winning companies simply offered lower prices. In her comments during a news conference on Thursday, Ochoa appeared to back that sentiment up. “We must be lean, agile, and adaptive to change,” she said of NASA in the 21st century.

By expanding to three suppliers, each of which offers slightly different services in terms of pressurized and unpressurized cargo upmass and downmass, NASA now has a smorgasbord of options to supply the station. For example, while all of the rockets can launch from Florida, Orbital ATK will also have the capability to launch Cygnus from Wallops Island in Virginia. NASA will be able to order specific missions as it needs them.

“I have to tell you I’m really excited about the suite of capabilities we have,” said Kirk Shireman, the program manager for the International Space Station, during a news conference at Johnson Space Center in Houston. “It’s really going to allow us to greatly increase our flexibility and capability of the station.”

The Dream Chaser offers the most new flexibility to NASA. Because it lands essentially like an airplane, the vehicle offers a less dynamic return to Earth than a capsule. Scientists said experiments such as protein crystals grown in space would likely survive such a return. While NASA said Dream Chaser would likely land in Florida, it has the capability to land on any runway that can accommodate a Boeing 737 jet. NASA would also be able to retrieve experiments from Dream Chaser within a few hours of landing.

Thursday’s decision marks a comeback for Sierra Nevada, which entered the Dream Chaser into NASA’s 2014 competition to win “commercial crew” contracts to carry astronauts to the station. It lost to Boeing and SpaceX, and the company filed a protest after NASA announced its decision. Instead of quitting, the company persisted with its goal of returning a winged vehicle to NASA’s fleet.

“Within a few short years, the world will once again see a United States winged vehicle launch and return from space to a runway landing,” said Mark N. Sirangelo, corporate vice president of Sierra Nevada Corporation’s Space Systems, after Thursday’s announcement.

The second round of awards for commercial cargo providers signals NASA’s continued faith in the private sector to develop low-Earth orbit missions. However, the space agency doesn’t want to be the sole customer—NASA would also like to see other businesses begin to use the transport services now being offered by Orbital, SpaceX, Sierra Nevada, and others.

That’s because in 2024, or 2028 at the latest, the space agency will stop supporting the space station. The most likely outcome is that the station will be safely deorbited, break apart in the atmosphere, and fall into the Pacific Ocean. After that, NASA hopes the private space industry will “take over” low-Earth orbit with a smaller, successor space station or orbiting module. In December, NASA’s chief of human spaceflight operations, Bill Gerstenmaier, essentially said that NASA is serious about the commercialization of low-Earth orbit, and the agency will help for about the next decade before moving on to deep space.

“NASA investing in three different ways of delivering experiments and supplies to the ISS is more evidence that the agency is committed to opening up the space station and low-Earth orbit to new commercial and scientific uses,” Jim Muncy, a space policy consultant who favors commercial development of space, told Ars.

Whether the private sector can thrive in Earth orbit without NASA as an anchor tenant is unclear. But what once seemed like science fiction—having private US companies take over the government’s role in spaceflight operations—is quickly coming true.