Dream Chaser Team's 20 Most Memorable Accomplishments of 2020
December 17, 2020
While 2020 was certainly a year unlike any other, Sierra Nevada Corporation (SNC) remained innovative and tenacious in the face of new challenges. Our Dream Chaser® spaceplane team stayed busy on the production floor meeting milestones. It wasn’t easy to narrow it down, but as 2020 comes to a close we’re celebrating the Dream Chaser team’s 20 most memorable accomplishments!
- February 2020- Pressure Test Article (PTA) testing complete
Some consider failure a necessary step on the path to success, but in this instance, failure was the success! Our team completed testing of the PTA in February by pressurizing the structure to failure. The PTA is a full-scale model of Dream Chaser developed for SNC’s crewed mission proposal. This testing demonstrated the cabin’s safety level and the spaceplane’s high tolerance to withstand damage to NASA. It also increased our confidence in the vehicle’s structure and in SNC’s ability to simulate complex systems.
- March 2020- Shooting Star™ transport vehicle structural testing
In a year of the unknown, this flight worthiness testing is an example of how our colleagues learned to be flexible and innovate their way through the circumstances. Initially, SNC employees were supposed to fly to San Diego for testing at Applied Composites, where Shooting Star was built. However, because COVID-19 travel restrictions, the Dream Chaser team had to figure out how to do the test remotely from our Mission Control Center in Louisville, CO. The testing was a success and verified Shooting Star is able to carry 100% of its external cargo capability. Shooting Star is a 16-foot tall attachment to Dream Chaser that has capacity to carry more than 10,000 pounds of additional payloads to the International Space Station. It is also the first composite pressure vessel ever test-verified for visiting the International Space Station.
- April 2020- Dream Chaser wings arrive in Louisville, CO
The wings for Dream Chaser arrived on our Louisville, CO production floor in April, kicking off the integration of the Wing Deployment System (WDS) – part of the vehicle’s continued assembly and integration. The Dream Chaser wings presented an interesting design challenge; not only must they survive in low-Earth orbit like a satellite, but they need to be operational in Earth’s atmosphere, like an aircraft. The wings are single bonded composite structures. This state-of-the-art technology saves weight without compromising strength and stiffness.
- May 2020- SNC announces name for first Dream Chaser- Tenacity™ spaceplane
SNC marked National Space Day on May 1st by announcing the name of its first orbital vehicle set to launch under contract with NASA: Dream Chaser Tenacity.
- May 2020- Shooting Star arrives in Louisville, CO
Shooting Star arrived in Louisville, CO, marking the beginning of a key integration phase, including the installation of the SNC-built Passive Common Berthing Mechanism (PCBM). The PCBM will allow Dream Chaser to berth to the International Space Station. Shooting Star is now undergoing subsystems integration before it’s delivered to NASA’s Plum Brook Station in Cleveland, OH for testing to ensure it can withstand both launch and space environments.
- May 2020- First Thermal Protection System (TPS) tiles bonded to Dream Chaser
Right now, when you look at Dream Chaser, it’s a copper color. But, pretty soon it’ll get the full white and black color treatment most commonly seen in renderings. In May, engineers and technicians started bonding the TPS tiles to Dream Chaser. Around 2,000 of these tiles will protect Dream Chaser from re-entry temperatures that could reach upwards of 3,000°F on entry, while keeping the vehicle itself at only 350°F.
- June 2020- Shooting Star pull test and leak checks
In June, our engineers completed pull tests and leak checks on Shooting Star. A pull test verifies the structural integrity of Shooting Star’s potted inserts. Potted inserts are the mounts used to attach structures like the solar arrays to Shooting Star. Without them, it’s not possible to fasten structures to Shooting Star.
Shooting Star is designed to prevent air from escaping while operating in a vacuum of space, but nothing is perfectly leak tight, so the structure must be tested to see how much air is lost to space. Any leaks could have a dangerous impact on the space station. The testing is ongoing, but has so far been successful.
- June 2020- Shooting Star Solar Array Structural Assembly Complete
Our engineers and technicians completed assembly of the solar array components that will fly on the first cargo resupply mission for Shooting Star and Dream Chaser. The solar arrays will provide power to Dream Chaser once on-orbit to support small maneuvers. With the structure complete, the solar panels and electrical systems can be integrated with the structure ahead of installation on vehicle.
- June 2020- Cabin Structural Adapter Installed
The cabin structural adapter was the first major installation to take place on Dream Chaser. With this installation complete, we’re one step closer to attaching Dream Chaser to Shooting Star.
- June 2020- Main Landing Gear Trunnions installed
We kicked off main landing gear integration on Dream Chaser this summer with the trunnion installation. They attach to the primary structure to provide a mounting location for the landing gear axle. When we reach the runway on our return trip from the International Space Station, the trunnions will help transfer the weight of Dream Chaser from the wings to the wheels.
- July 2020- Shooting Star Modal Testing
Shortly after completing pull testing and leak checks, the next step for Shooting Star was modal testing. These tests required test engineers and technicians to suspend Shooting Star with accelerometers attached to measure vibrations in the structure. With the data, we were able to show that the forces and vibrations experienced during launch won't cause structural problems.
- August 2020- Dream Chaser team performs successful wind tunnel testing
Wind tunnel testing was completed at NASA’s Ames Research Center. This test isn’t a common one for our industry because it requires specialized instrumentation, but it’s crucial to prepare for Dream Chaser missions. Unsteady forces, like vibrations, could produce a critical amount of force on the Dream Chaser airframe. That excessive force could cause the spaceplane to break. It’s important engineers know all the forces acting on the airframe with as much accuracy as possible to design the structures with enough strength for safe flight operations.
- September 2020- Dream Chaser mockup delivered to JSC for astronaut training
NASA’s Johnson Space Center (JSC) received a brand new addition to its Space Vehicle Mockup Facility in September, a mockup of Dream Chaser. One of the sides is noticeably missing, and for good reason. The mockup will be used for astronaut training! Astronauts will receive their initial training on Dream Chaser using SNC’s full-scale mockup at our production facility in Louisville, CO, where they’ll learn how to unpack cargo once Dream Chaser reaches the space station. The mockup at JSC will provide crew members with a refresher, since their initial training in Louisville is often years before they actually fly.
- October 2020- Wing Tooling Arrives
With the wing tooling’s arrival on our production floor in Louisville, CO, engineers and technicians started the assembly, integration and testing process for the wings. More than 65 individual pieces need to be installed on the wings to make them fully functional. That doesn’t even include the Thermal Protection System tiles, which give the wings their black and white color. The first installation will be the hard points. Those are pieces of hardware that give the engineers and technicians handling points to allow for installation on Dream Chaser.
- October 2020- Wing Co-machine Installation Starts
The co-machines are complex components that interface between Dream Chaser and the wings. The installs present challenges with maintaining precise installation tolerances to ensure the wings are oriented correctly on the vehicle. As work progresses on this installation we are closing in on attaching wings to Dream Chaser.
- October 2020- All forward aeroshells test fit on vehicle
This test fit was the first time all of the forward aeroshells for the Dream Chaser “nose” were installed together after rough trimming and drilling was completed. Aeroshells provide Dream Chaser with the necessary aerodynamic shape. Now, final trimming and drilling is underway. Bonding TPS tiles to give the vehicle its black and white color is the next step.
- October 2020- Dream Chaser Structural Test Fixture Proof Load
The test fixture designed to put the Dream Chaser through its paces for structural testing was loaded using hydraulics to certify the fixture’s strength and stability. Test hardware is used to pull on the wings and verify they don't break under loads similar to what they'll see in flight. Now that we’re confident in the test hardware, we can use it to certify Dream Chaser’s critical structural installations like the wings.
- November 2020- Rudder Installation Starts
With the wing installations under way, the rudder is the last big piece of the structural integration puzzle. Ground support equipment was installed to align the axis of the rudder installation since supporting brackets are installed ahead of the rudder itself. The rudder is what helps us control our glide during descent to make sure we run into enough air to slow down before it's time to land.
- November 2020- Cabin leak checks started
After a large testing campaign to determine sealing methods, our hardware and processes were put to the test of practical application. The electrical pass through panels on Dream Chaser allow data and power through its cabin skin while preventing airflow in or out. This design intent held up successfully to vacuum checks spaceplane showing that Dream Chaser is a safe pressure vessel fit for astronaut occupation.
- November 2020- Flight Releasable Grapple Fixture Installed
The grapple fixture is the first part of the Dream Chaser payload to make contact with the International Space Station. The installation was completed on our Shooting Star transport vehicle after dimensional checks confirmed its location. It’s important to know the location so we’re confident the space station will grab Shooting Star in the right orientation.