Dream Chaser concept drawing. Image: Sierra Nevada/NASA
NASA will soon be able to customize resupply missions to the International Space Station, ordering them a la carte or in bundles from three different providers. The agency announced the next round of commercial resupply contracts—dubbed CRS2—will go to: Sierra Nevada Corporation, SpaceX, and Orbital ATK.
The trio, serving as a space delivery service, will ferry more cargo to and from the ISS, which is good news for scientists. More cargo means more research opportunities. During a press conference on Thursday, Kirk Shireman, ISS program manager at NASA’s Johnson Space Center, explained that each company would be awarded a minimum of six flights, with the option for additional flights based on NASA’s need. The agency will begin working with its new partners immediately, though Shireman doesn’t expect to see the first mission under the new CRS2 contract launch until late 2019.
The first commercial resupply contracts were awarded seven years ago to SpaceX and Orbital Sciences (now Orbital ATK). NASA evaluated those contracts, and the performance of each carrier before taking new proposals. “To date, as part of the CRS1 contracts, over 35,000 pounds of cargo has been delivered to the ISS. It hasn’t been easy,” Sam Scimemi, ISS division director at NASA said during the briefing. “NASA and its commercial partners have learned valuable lessons along the way”.
Both CRS1 partners experienced major mishaps resulting in the loss of the payloads. So far, Orbital Science’s Cygnus spacecraft is the only one to resume flights to the space station albeit on an ULA Atlas V, with SpaceX expected to resume flights sometime in February or March. As a result of these two failures, and to safeguard against future mishaps, NASA now requires each of the carriers to carry insurance as part of the contract.
It’s no surprise that both incumbents, SpaceX and Orbital, made the cut for the second round of contracts, but space fans were pleasantly surprised to hear NASA granted a third contract to Sierra Nevada Corporation.
“SNC is honored to be selected by NASA for this critical US program,” Eren Ozmen, president of Sierra Nevada Corporation said in a statement. “In such a major competition, we are truly humbled by the show of confidence in SNC and look forward to successfully demonstrating the extensive capabilities of the Dream Chaser spacecraft to the world.”
SNC’s Dream Chaser spacecraft failed to grab a coveted spot in NASA’s new fleet of Commercial Crew vehicles. Determined to see their winged space plane fly, SNC changed their focus temporarily from crew to cargo. Their efforts paid off as the Dream Chaser’s design and unique specifications earned it a slice of the commercial cargo pie. Steve Lindsey, SNC's senior director of Space Exploration Systems and former NASA astronaut noted in a briefing today that the crewed version is still alive. "All the things we are doing for the cargo system will lead to the crewed system," he said.
These awards mean we can get the most out of the ISS, as each vehicle and provider brings its own unique capabilities. Efficiency and flexibility are important to NASA, and having a fleet of cargo ships to support a variety of payloads is vital to ensuring the ISS operates as efficiently as possible.
“Our goal with ISS is to have a robust fleet of vehicles to help foster an economy in low-Earth orbit,” explained Shireman. “We have that capability with these contracts. They will help develop the commercial market as we move toward cis-lunar space and onto Mars.”
Sierra Nevada’s Dream Chaser spacecraft offers some unique advantages over its competitors. For starters, its winged design allows for a gentle runway landing, just like the space shuttle, providing a smoother re-entry than the capsule designs of Dragon and Cygnus, which is designed to burn up in the atmosphere. Dream Chaser is also capable of returning to Earth within a few hours, a feature Julie Robinson, ISS chief scientist, said is important for certain kinds of biological and physical science experiments.
“Upcoming missions will feature live animal studies and plant studies that must be returned to Earth within a few hours as living organisms and even tissue samples and viruses adapt quickly to gravity,” Robinson explained. “Having the capability of returning the samples to the researchers within three to six hours is crucial to the data.”
The new CRS2 contracts will also increase the amount of science carried out on-station by maximizing crew time in many ways, and allowing for the addition of a seventh crew member. Coordinating the arrival and departure of vehicles visiting the station is complex, and takes a lot of planning. All three cargo ships will transport both pressurized and unpressurized cargo (2.5-5 metric tons per mission), ultimately decreasing the number of trips to the space station each year.
Vehicles connect to the space station in one of two ways: berthing or docking. When a vehicle docks, it’s an autonomous process that requires minimal crew assistance. Berthing, on the other hand, involves space station crew, and ground controllers working together to use the station’s robotic arm to grapple incoming vehicles and attach them to the station.
If berthing is such a labor-intensive process, why doesn’t every spacecraft just dock to the station? Berthing and docking ports are different sizes. Docking ports are barely larger than a human, while berthing ports are much larger and can support more massive payloads. Within the cargo fleet, NASA will have a variety of options and be able to select a vehicle based on mission requirements. Cygnus, for example, only has berthing capabilities, while both Dragon and Dream Chaser will be able to berth and dock.
Right now, the Russian Soyuz is the only “space taxi” capable of transporting humans to and from the space station. There’s a limited number of parking spots and each Soyuz (there’s normally two attached to the station) can only hold three people, so the crew aboard the space station is limited to six. However, the new contracts will overlap with NASA’s Commercial Crew Program, set to launch in 2017. With a new fleet of cargo vehicles and the availability of extra “lifeboats” we will see more crew members on board the ISS, which means more science. The extra crew member will basically be doing research the whole time, allowing the crew to conduct more labor-intensive experiments and essentially doubling the amount of research. A boon for scientists around the world.