Colorado based Sierra Space has entered the final test and checkout campaign for their Dream Chaser spaceplane; delivering the first flight article, Tenacity, to NASA’s Armstrong Test Facility in Ohio. This represents a key milestone for integrated checkout and testing as the company eyes their first flight of the cargo system in mid-2024.
Dream Chaser will be integrated with Sierra Space’s cargo module, Shooting Star, which was delivered to NASA’s Armstrong test facility in November 2023. Both components of the Dream Chaser Cargo System will be stacked in launch configuration for the first time and undergo extensive environmental testing starting in the Mechanical Vibration Facility. The test will subject the combined stack to the extreme conditions of launch vibrations on the world’s most powerful spacecraft shaker table – a key component in final engineering validation for the system. The system will then be destacked for final checks, before shipment to Cape Canaveral where it will be stacked and launched atop a United Launch Alliance Vulcan rocket.
After losing an initial bid to launch astronauts as part of the Commercial Crew Program, Dream Chaser was selected by NASA for cargo delivery, return and disposal service for the International Space Station under the Commercial Resupply Services-2 (CRS-2) contract. This contract leverages the spaceplane’s high up-mass and down-mass capabilities to deliver and return greater volumes of cargo from the orbital laboratory. The low G-loading of a spaceplane planform enables much less intense stresses on cargo during entry, ensuring sensitive cargo is delivered intact. Dream Chaser is also unique in that it can land at any commercial runway, a capability which Sierra Space claims will drastically reduce turnaround times and shorten cargo delivery schedules.
SNC-1, or Demo-1, has been delayed numerous times due to slipping schedules for both the launch vehicle and the spacecraft, as well as knock-on impacts of the COVID-19 pandemic. These delays have resulted in other CRS-2 contracts for Northrop Grumman and SpaceX to be extended, while Sierra Space is yet to fly. Station scheduling conflicts have also resulted in headaches for the company, with limited spots available for berthing on the orbital laboratory. Despite this, the test campaign for launch remains well underway, and a second Dream Chaser spaceplane newly dubbed Reverence, has entered production. There is currently no stated date for when this second spacecraft will fly.
Sierra Space is currently contracted to fly six resupply flights under the CRS-2 contract, alongside Northrop Grumman’s Cygnus and SpaceX’s Cargo Dragon vehicles. The company aims to ultimately fly beyond the International Space Station, and has set its sights on becoming a primary support vehicle for Blue Origin’s Orbital Reef project – a multi-company space station aiming to compete in the Commercial LEO Destinations contract for NASA. This program, however, has been marred with improper funding and delays that threaten to result in a LEO spaceflight gap for the United States. Sierra Space has also repeatedly stressed their desire to develop a crew spacecraft, a larger version of Dream Chaser known as DC-200. This vehicle departs significantly from the mold line of the original spacecraft, likely to ensure abort criteria for crew operations – with the unfortunate drawback of added complexity.
With the final phase of checkouts underway, Tenacity looks to be in the home stretch before the company’s demonstration mission can take place – returning spaceplanes to the US spacecraft fleet. With the tenacity and courage of the Sierra Space team behind her, the latest cargo spacecraft to visit the ISS is nearly ready to take flight for the first time.
Edited by Scarlet Dominik