There is still some work to do to prepare Sierra Space's Dream Chaser spaceplane for its first mission, but the company says the winged resupply craft for the International Space Station will soon ship to its launch site in Florida.
The Dream Chaser will take off on top of a United Launch Alliance Vulcan rocket to head for the space station. A spokesperson for Sierra Space told Ars the spaceplane's launch is scheduled for the third or fourth quarter of this year.
But Sierra Space will transport the Dream Chaser to NASA's Kennedy Space Center in Florida with a to-do list. There are two more significant tests the spacecraft must complete at the launch site. Technicians must also finish work on Dream Chaser's heat shield before it is ready to go on top of its Vulcan launcher. It's unclear how long these activities will take to complete.
Nevertheless, the spaceplane is about to leave NASA's Neil Armstrong Test Facility in Ohio, where it has undergone environmental testing since December. Sierra Space conducted the tests in Ohio in several phases.
First, Sierra Space engineers conducted shock tests with ULA to check the spacecraft's response to the jolt of separation from the Vulcan rocket in orbit. Then, ground teams stacked the Dream Chaser spaceplane on top of its rear-mounted pressurized cargo module and placed the entire vehicle on a shaker table to simulate the vibrations the spacecraft will experience during launch.
AdvertisementSierra Space next performed another shock test using the separation system that will jettison the disposable cargo module from the reusable spaceplane before reentry and landing at the end of its mission. Lastly, engineers transferred Dream Chaser to a thermal vacuum chamber at the Ohio test facility, where, for five weeks, the spacecraft was subjected to the airless environment and the extreme temperature swings of low-Earth orbit.
"Successful completion of an incredibly rigorous environmental testing campaign in close partnership with NASA is a significant milestone and puts Dream Chaser on track for operations later this year," said Tom Vice, Sierra Space's CEO. "This is the year that we transition from rigorous research and development to regular orbital operations and—in doing so—transform the way we connect space and Earth."
Sierra Space's to-do list
Dream Chaser has been in development for more than 15 years, and the concept goes back further than that. NASA kick-started the current iteration of the commercial spaceplane with the award of a commercial cargo contract to Sierra Nevada, Sierra Space's parent company, in 2016.
This will be the first of seven resupply missions Dream Chaser will fly to the International Space Station under the NASA contract. The company is building a second reusable spaceplane to help meet its commitment to NASA and potentially service follow-on commercial space stations.
Finally, the finish line for Dream Chaser is now in sight. Last year, the first spaceplane, named Tenacity, left Sierra Space's factory near Denver for the journey to the Armstrong Test Facility in Ohio. Ars visited Sierra Space's factory to see Dream Chaser a few weeks before its departure. The spacecraft was mostly finished, but technicians continued to outfit the interior pressurized compartment of the spaceplane and add tiles for its heat shield.
There's still more work to do on Dream Chaser's heat shield. Sierra Space will transport the spaceplane to NASA's Space Station Processing Facility at Kennedy Space Center, where ground teams have prepared modules for the International Space Station before their launch on space shuttle missions. There, Sierra Space will finish installing custom-fitted ceramic tiles to the spaceplane's wings and fuselage.
Also, teams at the Florida launch site will put Dream Chaser through acoustic testing and electromagnetic interference and compatibility testing. A Sierra Space spokesperson told Ars the company has always planned to do this final work on-site at Kennedy. Ground crews also must load cargo into Dream Chaser and its attached "Shooting Star" cargo module and fuel the spacecraft with propellant for its maneuvering thrusters.
If everything goes perfectly to plan, there is an opportunity to launch Dream Chaser this fall. But spacecraft testing often takes longer than anticipated. For example, an official from Sierra Space told Ars last year that the environmental testing in Ohio would take one to three months; it ended up taking about five.
Last month, Vice told CNBC he was "very confident" Dream Chaser would fly before the end of this year. Aside from the testing and hands-on work needed to ready Dream Chaser for launch, Sierra Space must also work with NASA to find an opening in the space station's manifest of visiting vehicles.
Notably, Sierra Space must also obtain a reentry license from the Federal Aviation Administration, which announced last month it would no longer allow commercial reentry vehicles, like Dream Chaser, to launch before getting regulatory approval to return to Earth. The FAA announced this policy change after Varda Space Industries launched a returnable spacecraft last year without obtaining a reentry license. Varda's satellite remained in orbit more than seven months longer than expected as the FAA completed safety reviews.
AdvertisementThe Dream Chaser spaceplane is slated to fly on the second launch of ULA's Vulcan rocket, which had a successful inaugural flight in January. At that time, ULA officials aimed to launch the second Vulcan rocket in April. But Dream Chaser wasn't ready, and neither was Vulcan as ULA waited for delivery of the rocket's second BE-4 main engine from Blue Origin.
ULA, and its primary customer, the US Space Force, would like to fly the second Vulcan rocket as soon as possible. The Space Force and ULA consider the first two Vulcan launches as "certification flights" to demonstrate the rocket's performance and reliability before pricey military payloads hitch a ride on the new rocket. Vulcan will only be certified to launch military satellites after completing a second successful test flight, and there's a long list of Space Force missions waiting in the queue.
Last month, ULA confirmed both BE-4 engines were installed on the Vulcan booster for the second flight, and it appears conceivable that hardware for the second Vulcan launch could be in a position to fly by September. Will Dream Chaser be ready for launch by then?
Tory Bruno, ULA's CEO, said in a post on X this week that the company aims to launch Vulcan again in the fall "as soon as Dream Chaser is ready." But ULA doesn't want to wait for Dream Chaser and could fly another mission—either another commercial payload or a dummy satellite—if the spaceplane's schedule slips further.
"We have a backup if they have an issue," Bruno said.
