NASA and Sierra Space have mutually agreed to modify their contract for the Dream Chaser spaceplane, altering its initial mission profile and delaying its first flight. The inaugural launch, previously planned as a cargo run to the International Space Station (ISS), will now be a free-flying demonstration mission scheduled for no earlier than late 2026.
Key Takeaways
- The first flight of Sierra Space's Dream Chaser will no longer dock with the International Space Station.
- The mission is now a demonstration flight, pushed back to late 2026 due to launch vehicle availability.
- The contract change allows Sierra Space to explore national security applications for the spaceplane.
- NASA retains the option to order future cargo missions to the ISS if the demonstration is successful.
Contract Modification and New Mission Plan
Sierra Space was one of three companies, alongside SpaceX and Northrop Grumman, selected for NASA's Commercial Resupply Services 2 (CRS-2) program. Under the original 2016 agreement, the company was awarded seven missions to deliver supplies to the ISS using its Dream Chaser vehicle.
However, the two parties have now revised this plan. The first mission for the spaceplane, named Tenacity, will not involve a rendezvous with the space station. Instead, it will operate as a standalone demonstration to test the vehicle's capabilities in orbit.
According to NASA, this adjustment provides greater flexibility for both organizations. Dana Weigel, NASA's manager for the ISS program, commented on the change.
"Development of new space transportation systems is difficult and can take longer than what's originally planned. The ability to perform a flight demonstration can be a key enabler in a spacecraft's development and readiness."
If the free-flying test mission is successful, NASA can still order cargo delivery flights to the ISS under the existing CRS-2 contract. This change allows for thorough testing of the new vehicle before it is integrated into critical space station operations.
Launch Delays and Vehicle Readiness
The Dream Chaser spacecraft arrived at Kennedy Space Center in Florida during the spring of 2024. The initial plan was for it to launch later that year on the second flight of United Launch Alliance's (ULA) new Vulcan Centaur rocket.
Following its arrival, the vehicle underwent extensive testing at NASA's Neil Armstrong Test Facility in Ohio. However, issues that arose during this testing phase caused it to miss its scheduled launch window. With Dream Chaser not ready, its ULA rocket was reassigned.
Background on ULA's Vulcan Rocket
The Vulcan Centaur is the successor to ULA's Atlas V and Delta IV rockets. Its launch schedule, known as a manifesto, is increasingly crowded with high-priority missions for the U.S. national security sector. Due to these commitments, the next available launch slot for Dream Chaser is not until late 2026.
The delay underscores the challenges inherent in developing and certifying new human-rated or cargo spacecraft. Weigel noted that the revised plan aligns with the long-term strategy for low-Earth orbit, especially as NASA and its partners plan for the ISS to be deorbited in 2030.
Technical Specifications of Dream Chaser
The Dream Chaser is a lifting-body spaceplane that resembles a miniature version of NASA's retired Space Shuttle, measuring about one-quarter of its size. The uncrewed vehicle is approximately 30 feet long and has been in development for over 15 years.
Cargo and Landing Capabilities
- Cargo Capacity: Can deliver up to 12,125 pounds (5,500 kilograms) of pressurized and unpressurized supplies.
- Landing Method: Designed to land on conventional runways, similar to an airplane.
- First Landing Site: The inaugural mission is planned to conclude with a landing at the former Shuttle Landing Facility at Kennedy Space Center.
This runway landing capability is a key differentiator from other CRS-2 providers. SpaceX's Dragon capsules perform splashdowns in the ocean, while Northrop Grumman's Cygnus spacecraft are designed to burn up in the atmosphere upon reentry.
The ability to land on a runway allows for rapid access to returned cargo, particularly sensitive scientific experiments, and enables quicker turnaround for vehicle reuse.
Future Applications and Strategic Shift
While the immediate focus has shifted from ISS resupply, Sierra Space is positioning the Dream Chaser for a wider range of missions. The company's executive chair, Fatih Ozmen, stated that the change allows them to pursue opportunities in the defense sector.
"This transition provides unique capabilities to meet the needs of diverse mission profiles, including emerging and existential threats and national security priorities that align with our acceleration into the defense tech market," Ozmen said.
He emphasized the spaceplane's adaptability for rapid deployment and its ability to land on various commercial runways worldwide, which could be valuable for national security operations requiring quick access to payloads.
Long-Term Commercial and Crewed Versions
Sierra Space initially competed for NASA's Commercial Crew Program to transport astronauts but was not selected; those contracts went to SpaceX and Boeing. However, the company has not abandoned its goal of a human-rated Dream Chaser.
A future crew version is designed to carry up to seven astronauts. This vehicle could service the commercial space stations planned to succeed the ISS. Sierra Space is a partner with Blue Origin in developing one such station, known as Orbital Reef.
The successful demonstration of the cargo version is a critical step toward realizing these long-term ambitions. The 2026 test flight will be a crucial milestone in proving the vehicle's design and operational capabilities for both cargo and, eventually, human spaceflight in the emerging low-Earth orbit economy.