Dream Chaser Tenacity Is Preparing To Launch

For decades now a new more modern spaceplane has been undergoing near-constant development, manufacturing, and testing. All of this has led up to its maiden flight, which is expected to happen just later this year. Only days ago Tenacity, the first flight-capable Dream Chaser, arrived at NASA Kennedy in Florida. This will be the location of its final tests and eventually its launch site.

Tenacity was completed months ago however NASA and the company responsible, Sierra Space, are doing everything in their power to ensure the vehicle is ready and can withstand the forces of launch, reentry, etc. The recent move to NASA’s facility marks the final journey and practically the end of testing. Here I will go more in-depth into the final tests, arrival at the facility, expected launch date, and more.

Arrival In Flordia

Over the past several months, Dream Chaser has undergone intense shock, vibration, and thermal vacuum testing at the Armstrong Test Facility in Ohio. These tests not only were meant to check Tenacity’s capabilities in space, but also the initial journey. For example, in December, the test teams conducted shock tests with Sierra Space’s launch partner United Launch Alliance (ULA), using the flight separation system that will deploy the spacecraft from the upper stage of ULA’s second Vulcan Centaur rocket. Officially, earlier this month on the 9th, they announced the successful completion of Dream Chaser’s Neil Armstrong Test Facility environmental test suite. With that done, the vehicle along with Shooting Star, the spacecraft attached to the back, were packaged up and sent to Florida.

A few days ago on the 20th Sierra Space tweeted saying, “Dream Chaser has arrived at NASA Kennedy in Florida ahead of its first flight to the Space Station. This included an image of Tenacity with its wings folded getting ready to be unloaded. Specifically, it arrived on the 18th with plans to complete its final tests before being integrated into the launch vehicle and sent to space.

Yesterday they tweeted again pointing out, “Upon arrival at NASA Kennedy, teams moved Tenacity to the high bay inside the Space Systems Processing Facility. The remaining pre-flight activities include acoustic and electromagnetic interference and compatibility testing, TPS completion, and final payload integration.” Provided footage shows crews working to unload the spaceplane and prepare it for upcoming tests. In terms of a launch date, Sierra Space hasn’t yet released a specific date however they are absolutely targeting a launch this year. In a recent statement, the company was quoted saying, “Dream Chaser Tenacity, the first in a fleet of spaceplanes, remains on track for a 2024 launch on the first of seven missions to resupply the International Space Station for NASA under a Commercial Resupply Services-2 (CRS-2) contract.” This estimate along with current progress suggests a launch toward the end of this year is likely.

The other important aspect of this maiden flight is the launch vehicle itself. As partially mentioned before, Tenacity will fly on top of United Launch Alliance’s Vulcan Centaur. Not long ago this vehicle had its own maiden flight and is preparing for its second-ever launch with Dream Chaser. Thankfully, it seems ULA is ready and could even be waiting for Tenacity in order to launch. On May 14th, Tory Bruno, ULA CEO tweeted a picture of Vulcan’s Cert2 booster and its two BE-4 engines. This booster will be responsible for helping carry Tenacity into space. Someone even asked why Vulcan hasn’t launched a second time yet to which Bruno responded, “Waiting for the payload (DC).” This is a good sign and should mean that the second Tenacity is done with its tests and ready to be integrated, ULA and the launch vehicle should be as well.

Besides the tests that Dream Chaser is about to complete, they also pointed out that it needs a bit more work on its heat shield. Specifically, they said one of the remaining pre-flight activities involves the completion of work on the spaceplane’s thermal protection system. Images and videos of Tenacity highlight that a majority of its tiles are installed however some are still missing. This likely has to do with testing requirements and those tiles being installed when the vehicle is officially ready to launch. In total, Dream Chaser features thousands of individual tiles spread across the entirety of its body. Each is unique requiring a lot of precision and in some cases time when installing tiles. This is something to consider when thinking about its launch date but shouldn’t get in the way.

Thorough Testing

Any spacecraft or rocket goes through a lot of testing before a flight. That being said, when it’s the first time that vehicle has ever attempted a launch, the process is even more thorough and consists of a laundry list of checks. For reference, around 5 months ago in January, Sierra Space shipped Dream Chaser to Ohio for its initial round of testing. Here it spent nearly half a year just purely being tested.

They started with shock tests which helped simulate the initial launch. The two vehicles were stacked in launch configuration on the world’s most powerful spacecraft shaker table inside the test center’s Mechanical Vibration Facility. Sine Vibration testing – conducted over a five-week period – simulated the intense conditions and environment of a launch on a Vulcan Centaur rocket. After vibe testing concluded, the teams conducted another shock test – this time with the flight separation system between Dream Chaser and Shooting Star – to simulate the dynamic environment during separation of the two vehicles prior to de-orbit and re-entry.

Next, the Sierra Space and NASA test teams transported the vehicles to the In-Space Propulsion Facility at Armstrong for thermal vacuum or “T-VAC” testing. It’s important to point out that temperatures in space can range from extremely cold – hundreds of degrees below freezing – to several hundred degrees Fahrenheit due to radiation from the sun. TVAC testing is a realistic thermal simulation of the flight environment and is critical to ensuring mission success. For more than five weeks, Dream Chaser and Shooting Star were subjected to multiple cold-hot cycles in a vacuum environment, between -150F to +250F, with teams conducting functional tests at temperature plateaus to verify system performance. Sierra Space even shared images of the vehicle inside the chamber. These tests among others occupied most of this year.

While time-consuming, on this first flight, Tenacity needs a successful launch and landing. Dream Chaser is a lifting body design spaceplane that measures 30 feet long by 15 feet wide. The winged design allows it to transport cargo to and from low Earth orbit and maintain the ability to land on a runway in the style of NASA’s space shuttle. The 15-foot Shooting Star module can carry up to 7,000 pounds of cargo internally and features three unpressurized external payload mounts. The partially reusable transportation system will perform at least seven cargo missions to the space station as part of the agency’s efforts to expand commercial resupply services in low Earth orbit. Future missions may last as long as 75 days and deliver as much as 11,500 pounds of cargo. Even though Sierra Space is working on a second Dream Chaser, they are going to rely on Tenacity in the beginning.  

During the maiden flight, as part of the process to certify the vehicle system for future agency resupply missions, NASA and Sierra Space have said that they plan to put the spaceplane through its paces once in-orbit. They were quoted saying. “As Dream Chaser Tenacity approaches the space station, it will conduct a series of demonstrations to prove attitude control, translational maneuvers, and abort capabilities. After completing the maneuverability demonstration, space station astronauts will use the Canadarm2 robotic arm to grapple the spacecraft and dock it to an Earth-facing port. After remaining at the orbiting laboratory for about 45 days, the spaceplane will be released from the station and return for a landing at Kennedy’s Launch and Landing Facility. After landing, Dream Chaser is powered down, and the Sierra Space team will transfer it back to the processing facility to perform necessary inspections, offload remaining NASA cargo, and begin the process of preparing it for its next mission.”

This action-packed maiden flight will test Tenacity in many ways. Arguably the most challenging will be reentry. Across Dream Chaser’s body, they use a mix of white and black tiles depending on the heat signature and expected temperatures. Specifically, both versions of the tiles are used to help balance the heat absorbed on-orbit and the heat that the spaceplane will need to survive on reentry. The areas in black will have the hottest temps on reentry while the white tiles are more reflective and will be cooler. For years now Sierra Space has been working to develop and create a new and improved heat shield capable of protecting the spacecraft upon re-entry. To be specific, around 2,000 of these tiles will protect Dream Chaser from temperatures that could reach upwards of 3,000°F on entry, while keeping the vehicle itself at only 350°F. A process that will be put to the test not too long from now.

Conclusion

Dream Chaser Tenacity has arrived in Flordia and completed its initial testing campaign. At this point, it just needs to complete a few more tests before it’s integrated and launched for the first time. We will have to wait and see how it progresses and the impact it has on the space industry.