The First Dream Chaser Spaceplane Was Just Powered On
Things are starting to ramp up quickly as Dream Chaser gets closer to its maiden flight. Only days ago the company announced astronaut training and practice for the first launch. Now significant physical developments with the Tenacity test article are being completed.
For example earlier today, Sierra Space announced that for the first time, they powered on Dream Chaser. This is a big deal considering they have been constructing and working on Tenacity for years. The successful power-up means that final testing is right around the corner and then it will be time to launch.
Since 2021, teams have been putting Tenacity together, routing its wiring, and installing heat shield tiles, all for the first mission to the ISS scheduled late this year. Here I will go more in-depth into the new power milestone, exactly what still needs to be completed, what to expect in the coming weeks, and more.
Tenacity Powered On
Tenacity is the name of the first Dream Chaser test article that is set to lift off in December for a mission to the International Space Station. This specific model is a cargo variant and as expected it will be carrying different supplies during the first launch. While physical updates like attaching tiles or other structural components of the vehicle have been somewhat common, this morning’s update was the first of its kind. Only hours ago Sierra Space tweeted saying, “Dream Chaser has powered on.” This included multiple images of the process highlighting the test article being hooked up and large crowds seen in the background.
The company released a statement that said, “The power-up of Dream Chaser signifies the activation of its integrated systems, showcasing the culmination of years of rigorous engineering, design, and testing. Sierra Space simulated the power that will be generated from Dream Chaser’s solar arrays once on orbit. Test engineers plugged that power into Dream Chaser and began turning on systems. Sierra Space exercised flight computers, base processors, and low-voltage distribution units” they said.
The solar arrays the company is talking about will be from the Shooting Star module attached to the back of the spaceplane. Similar to the spacecraft itself they will be folded up during launch and then deploy once on orbit for the journey to the ISS. When operating they are expected to provide around 6 kW of electrical power. Enough to power various important systems like the ones mentioned by the company.
In addition, Sierra Space CEO Tom Vice commented, “This is a milestone that points to the future and is a key moment in a long journey for Dream Chaser. With this significant achievement, our Dream Chaser spaceplane is poised to redefine commercial space travel, opening up new possibilities for scientific research, technological advancements, and economic opportunities in space” he said.
The company finished with one final statement highlighting, “The successful test was a key moment for the progress of space technology after years of design and development across Sierra Space, enabled by the accomplishments of many teams from system level design to final assembly and test. With this test complete and teams starting to power on the test article, it brings up questions regarding what still needs to be completed. It’s important to point out that around two months ago the first mission was delayed from August to no earlier than December this year. Specifically, NASA updated its internal schedule to show that Sierra Space’s Dream Chaser spacecraft would berth to the ISS on December 17, 2023.
This suggests that a decent amount of work is still needed on Tenacity before its first launch. One specific area of concern that could be taking longer than expected is the heat shield. Late last year in October, Sierra Space tweeted saying, “Right now, our Dream Chaser team is hard at work affixing more than two thousand hand-cut thermal tiles. We’ll have more photos and close-ups of Tenacity coming soon.
Looking at the images from the power-up milestone, some show a barren bottom where the structure itself is still exposed without any applied heat shield tiles. As of right now, it’s not clear exactly what the company still needs to do but it likely is a combination of a few different things including finishing tile application. For one final hint at Tenacity’s progress, early this year in January the company said in a statement, “The first Dream Chaser, Tenacity, is nearing completion and will subsequently ship to NASA’s Neil Armstrong Test Facility in Cleveland, Ohio, for final space environmental testing ahead of its first mission to the ISS later this year.” This was over four months ago now and we haven’t heard anything from the company related to completed tests with NASA.
Ideally, the recent successful test and general progress are enough to launch within the December timeline with a complete and capable vehicle. This being said, from the information provided to us it looks as if more delays are not out of the question. Not to mention continued work on Vulcan, Tenacity’s launch vehicle, which is also running into different delays. Something we will have to keep up with in the coming months.
A lot of Work Left
At its core, Dream Chaser is a reusable, fully autonomous, orbital spaceplane designed to transport cargo to low-Earth orbit (LEO) destinations such as the International Space Station (ISS) and land at conventional runways. Measuring about one-quarter the size of the Space Shuttle, it features autonomous launch, flight, and landing capabilities with a smooth 1.5 low-G re-entry on compatible commercial runways worldwide.
Under NASA’s Commercial Resupply Services 2 (CRS-2) contract, Dream Chaser will provide a minimum of seven cargo service missions to and from the space station. With the help of the Shooting Star service module, Dream Chaser can deliver up to 5,500 kg of pressurized and unpressurized cargo to the space station, including food, water, supplies, and science experiments, before returning to Earth. The goal of designing the vehicle for high reusability was to reduce overall cost, providing quick turnarounds between missions. The ability to liftoff on top of multiple launch vehicles and land at a wide variety of runways is meant to make Dream Chaser a flexible option for reliable transportation.
While Tenacity is a cargo variant not meant for humans, under NASA’s Commercial Crew Program with SpaceX’s Crew Dragon and the Boeing Starliner, Dream Chaser was originally designed as a crewed spaceplane, capable of carrying up to seven astronauts to and from the space station and other low Earth orbit (LEO) destinations. The crewed version of Dream Chaser is approximately 85% common to the cargo system, limiting primary changes to environmental control, and life support systems. In addition, an integral main propulsion system is available for abort capability and major orbital maneuvers.
With this unique design comes different challenges and innovative solutions trying to solve them. The heat shield as partially mentioned prior has been a big focus of the company for years now. In the past, the Space Shuttle struggled with its heat shield design quite a bit. It used tens of thousands of individual tiles that would need to be replaced and repaired after each mission. Often times missions could be delayed solely by the work needed to replace damaged tiles across the body of this massive shuttle. While Dream Chaser is smaller and uses fewer tiles, they still wanted to improve on this system.
Much of the shuttle was covered with LI-900 silica tiles, made from essentially very pure quartz sand. The insulation prevented heat transfer to the underlying orbiter aluminium skin and structure. In contrast, Sierra Space is quoted saying, “SNC engineers have been able to update the TPS tiles from what was used during NASA’s shuttle program with more innovation, better technology, and utilizing lessons learned. They use more modern manufacturing techniques to increase strength and reduce cost. Another difference between the tiles is Dream Chaser tiles are about 10 inches by 10 inches, while those on the shuttle were six inches by six inches. Dream Chaser tiles are stronger and lighter weight than those used during the shuttle program and meet all Micro-Meteroid Orbital Debris (MMOD) requirements to ensure safe entry, descent, and runway landings for crewed or cargo missions. These among other changes are intended to make the tiles even more reliable and easier to refurbish.
While the current tile installation looks to be taking a bit longer than expected, this is the first ever Dream Chaser test article meant for space. The company is bound to take its time and make sure the application is perfect. As they get more experience and work on more spaceplanes, this process should only get faster and more effective.
In addition to tile application, the final main step is a host of different tests to make sure Tenacity is space ready. Assuming the results are good, the cargo for the ISS mission will be loaded into the spacecraft and it will be integrated on top of ULA’s Vulcan.
Conclusion
In just the last week alone we have gotten a few significant updates regarding Tenacity’s first launch. This includes astronaut training to unload the spacecraft and powering up the test article for the first time. We will have to wait and see how it progresses and the impact it has on the space industry.