Today Sierra Nevada Corporation (SNC) held a press conference announcing their selection of the United Launch Alliance (ULA) Vulcan rocket to launch their reusable Cargo Dream Chaser ‘spaceplane’ on its upcoming uncrewed resupply missions to and from the International Space Station (ISS) for NASA.
Leadership from both companies also shed some light on where development of the spacecraft and rocket is, and what’s ahead between now and launch.
Although SNC lost a bid for a contract to fly NASA astronauts to SpaceX and Boeing in 2014, they were later awarded a multi-billion dollar Commercial Resupply Services (CRS-2) contract to fly at least six missions to resupply the ISS through the first half of the 2020s, to deliver more than 12,000 pounds of pressurized and unpressurized cargo, and remain attached for up to 75 days as an orbiting laboratory.
Upon departure, Dream Chaser would dispose of about 7,000 pounds of trash and return large quantities of critical science and other items back to Earth, accessible within minutes after a gentle gliding landing on the Kennedy Space Center runway, where many of NASA’s Space Shuttles landed after their missions.
“Dream Chaser can launch from any conventional rocket so we had great options,” said SNC CEO Fatih Ozmen. “SNC selected ULA because of our strong collaboration on the Dream Chaser program, their proven safety record and on-time performance. This is bringing America’s spaceplane and America’s rocket together for best-of-breed innovation and exploration.”
Both companies have been working together on flying Dream Chaser for years, having made plans originally to launch atop the now soon to be retired Atlas V rocket, a veteran workhorse which has flown 80 successful missions and has proven itself dependable over and over again in delivering many of the nation’s most expensive, secretive and highest priority science and national security missions to space for NASA, the Dept of Defense and other government agencies.
And with Vulcan already basically a new and improved Atlas V as it is, employing heritage hardware and design, it is easy to see why SNC stayed with ULA, and comes as no surprise to anyone. Additionally, SNC’s first Dream Chaser will launch on only the second Vulcan, which itself will already be flight proven thanks to having various systems incorporated into Atlas V flights before Vulcan comes online.
“All of the major elements of Vulcan, its payload fairing, its solid rocket motors, its avionics, its software are all going to be feathered in on Atlas flights between now and then,” said ULA’s CEO Tory Bruno. “So that by the time we actually fly for you guys (SNC), or even our very first flight, everything but the first stage engine, the BE-4, will actually have been flown several times.”
However, Bruno noted that, if something should arise with Vulcan between now and then, the Atlas V would be ready to fly Dream Chaser as a backup, telling SNC “we’re going to make sure that you fly when you are ready.”
SNC looked at several other launch providers including ESA, JAXA, SpaceX and even Blue Origin, and while the spaceplane can launch on all, ultimately SNC says it came down to their already long-standing relationship with ULA on Dream Chaser, competitive costs (although they did not say how much), as well as ULA’s flawless track record with the Atlas V program, which SNC feels is a solid telling for the future.
The orbital Dream Chaser for that first mission is well into construction too, following two free flight Approach and Landing tests at Armstrong Flight Research Center, CA in 2013 and 2017. The second test also served as a bridge between previous work with NASA’s Commercial Crew Program and the latest cargo-only vehicle currently under development for CRS-2 missions.
The second free flight test flew with orbital avionics software too, the same which the autonomous Dream Chaser cargo variant will use on its ISS missions. In doing so, SNC earned direct certification credit from NASA, eliminating the need for an orbital flight test before operational CRS-2 missions; all the testing and certifications happen on the ground and within the atmosphere.
NASA gave SNC the ‘GO’ to begin full production of the first orbital vehicle in Dec 2018, after clearing a thorough Critical Design Review; the culmination of many years of design work, analysis and development testing. Dream Chaser also cleared a key NASA review towards flight earlier this year known as Integrated Review Milestone 5 (IR5), which analyzed SNC’s performance of a variety of ground and flight operations, including development of the vehicle’s flight computers and software, mission simulator and Mission Control Center.
SNC has also conducted cargo demonstrations using high fidelity mock-ups of the vehicle and its cargo module, showing loading and unloading time and efficiency, and when all was said and done NASA declared the SNC team is on track to operate Dream Chaser in advance of the first mission.
Many critical parts of the orbital vehicle are already complete, built and being tested, including major structural components, thermal protection system tiles and avionics hardware. The primary structure of the first orbital flight vehicle will be delivered to SNC from Lockheed Martin in Ft Worth, Texas in the next month or so, to begin assembly, integration and testing to support a 2021 launch. The cargo module, built by Applied Composites, is nearly complete as well, in final testing now and will be ready for SNC by the end of the year.
When that first Dream Chaser arrives in Florida, it will be processed at NASA’s Kennedy Space Center (KSC) Operations and Checkout Building (O&C), and will then be transported to nearby Launch Complex-41 on Cape Canaveral Air Force Station for integration atop its Vulcan rocket.
When launched, the rocket will send Dream Chaser into either a 160 or 180 nautical mile circular orbit, in order to catch up with the ISS within 72 hours. Once arrived and flying formation with the ISS at 5 miles per second, it will slowly approach to within 10 meters before being grappled by the station’s robotic Canadarm 2 for berthing to Node 2 NADIR.
Dream Chaser can dock as well, but NASA prefers the berthing option for the cargo vehicle, because it allows for a larger cargo delivery. And while the vehicle is cargo only, it could serve as a liferaft and accommodate crew if needed, although NASA has not asked for such a need, but has left the option open to contract with SNC to fly astronauts on Dream Chaser in the coming years.
The bridge between the cargo and crew vehicles is not a long one either. The testing SNC has done so far with the prototype has aided development of both versions, so both the cargo and crew Dream Chasers share an 85 percent commonality.
When NASA offers up another round of Commercial Crew contracts in the coming years, SNC will put in a bid for their crew-version Dream Chaser.
As for the initial cargo missions, Dream Chaser would take 4-6 hours from ISS departure to landing, however SNC has said that time could be narrowed to 2 hours, if needed in an emergency.
Once back on the ground the vehicle will go back to the O&C, get looked over, and be readied for its next flight. Turnaround time between landing and next launch would be around 60 days, however there are a lot of other factors that go into turnaround times, such as whether or not the rocket is even ready. The Dream Chaser itself, says SNC, could be turned around in much less than 60 days, implying a flight rate annually of 4-6 missions per vehicle.