Sierra Space’s Dream Chaser vehicle is one step closer to launching no earlier than the first half of 2024 following testing at NASA’s Neil Armstrong Test Facility, formerly known as Plum Brook Station, in Ohio.
NSF was among a select group of media members that received access to the vibration testing chamber where the vehicle completed testing.
For the first time, Tenacity, the first Dream Chaser vehicle scheduled to fly into space, was mated to its cargo module called Shooting Star. According to Sierra Space, the cargo module is capable of carrying 4,000 kilograms (9,000 pounds) of cargo internally. It also contains three external attachment points for additional cargo and/or experiments.
The spacecraft’s configuration will be the same during the launch atop the United Launch Alliance Vulcan rocket on the vehicle’s first mission to the International Space Station (ISS) this year.
Dream Chaser was selected by NASA as part of the second round of Commercial Resupply Services (CRS-2) contracts to send science, supplies, and more to the ISS regularly. The winged spacecraft joins SpaceX’s Cargo Dragon and Northrop Grumman’s Cygnus vehicle in that contract.
The vehicle will also become the second resupply craft to offer down mass capability, meaning it can return time-critical science experiments and research samples back to Earth. Following its ISS mission, Tenacity is scheduled to land at the Launch and Landing Facility at NASA’s Kennedy Space Center in Florida. The company has also discussed the potential for landing operations at Vandenberg Space Force Base in California with the potential to land at other airports in the future.
Phil Dempsey with NASA’s ISS program is excited not just at the amount of up and down mass, but also how that mass is being returned.
“Dream Chaser will deliver over 7,800 pounds of cargo on its first 45-day mission, with the potential to increase that on future missions as we learn more about how the vehicle flies,” Dempsey said. “So I do have to say I’m a little bit excited just because on a personal level, seeing a winged vehicle return to the space station, land on the runway, but also in my current job, carrying over 3,000 pounds of our research and cargo back at the same time.”
Dempsey referred to the space shuttle, which assisted in building the orbiting laboratory and bringing crew and cargo to and from the ISS until the program’s retirement in 2011.
Currently, Tenacity is located inside the mechanical vibration facility.
“For the last couple of weeks, we’ve been testing the vibration of the spacecraft, taking it in both the horizontal direction and the vertical direction,” said NASA Glenn Director Dr. James Kenyon. “This allows us to simulate the vibration environment that the spacecraft will experience during launch and then when it starts to re-enter the atmosphere near the end of its flight.”
With the vibration testing completed, the vehicle will now move to NASA Glenn’s In-Space Propulsion Facility just down the road. According to NASA, this is the only facility in the world capable of testing full-scale, upper stage launch vehicles and rockets in a space environment.
“For Dream Chaser… we’re going to pump down the pressure and the temperature to the very low pressures and very low temperatures that the spacecraft will experience as it enters orbit,” Kenyon said. “Then we’re going to use a dynamic heating element to go around and simulate the heating environment that would be experienced by the spacecraft due to the sun, the solar heating, while it’s there on orbit. These ground tests will allow us to reduce risk for the program and identify and resolve issues before launch.”
The vehicle will then be moved to the Kennedy Space Center to undergo launch preparations.
Before its launch, Sierra Space has been working with astronauts on the ins and outs of the vehicle as well as how to utilize the vehicle in orbit.
“Together, we’ve been training our astronauts already to look at what it’s like to have Dream Chaser on ISS,” Dempsey said. “We’ve been planning on joint operations, and we’re doing that while our engineers are working side by side with the Sierra Space team to go complete the final phase of the integration and testing and readiness of this vehicle.”
When asked about the number of ISS flights, Sierra Space officials said it is a joint decision between their company and NASA.
“As we go forward looking to get through the rest of the decade, we’ll take a look at the capabilities as well as the ISS needs and go determine them,” said Sierra Space CEO Tom Vice. “So there’s no set plan for the cadence that we need beyond that, but we don’t fly in excess of what the needs are of the space station.”
However, the company is still planning multiple flights for Tenacity as well as a second vehicle, Reverence, currently under construction.
“We designed [each vehicle] for 15 missions but we think we’re going to be well above that,” Vice said. “Tenacity is the first, Reverence is going to the factory, so we think we’re going to be able to service that, not only for NASA, but long term in terms of how we think about commercialization of the workforce.”
Sierra Space said the current plan is to fly Tenacity on the first four flights, with flight five being the debut of Reverence.
The company is also looking into launching from locations outside of the United States.
“We’ve had lots of discussions about launching from Japan and landing it at the airport, launching in other areas of the world that have the right launch latitudes, and landing back at runways in these locations,” Vice said. “It gives us massive leverage in terms of how we think about ushering in this new space era. It can’t be just from one or two sites in the United States. It has to be global.”
Vice noted that we are in what he calls the orbital age as commercialization of low-Earth orbit becomes more popular and more affordable.
“The orbital age is an existential revolution driven by the underlying technologies that are commercializing low-Earth orbit, connecting in new ways the surface of our planet with 250 miles above our head,” Vice said. “Existing companies in every segment of biotech and industrial sectors will operate the factories of the future in microgravity, extending our cities and communities into space.
“In the orbital age, the number of humans in space will reach critical mass and establish a permanent presence for civilizations around the world to continue the incredible leadership that NASA has demonstrated decade after decade after decade onboard the International Space Station. We collectively, NASA and Sierra Space, go to space to benefit life on Earth.”
(Lead image: Dream Chaser undergoes testing at NASA Glenn. Credit: Max Evans for NSF)