A bottle of whiskey and a software-defined radio have given Sierra Space’s Ghost cargo vehicle its first live tests in nearly two years, and both loads came back intact.
High above the Utah desert in May, a high-altitude balloon released the compact reentry vehicle from 35,000 feet in one test and 68,500 feet in another. Recovery crews found the payloads quickly, according to a report on the tests.
A rush job for Space Command
Sierra Space built a new Ghost vehicle from scratch in less than four months after U.S. Space Command called on the company for its Apollo Nexus exercise. Sierra Nevada supplied the radio to see whether electronics could survive a rough outdoor environment, while the whiskey stood in for liquid cargo.
Erik Daehler, a senior vice president at Sierra Space, said both cargoes arrived without incident and that the ground crew recovered them within a reasonable time. He described the exercise as being about getting U.S. forces and allies to work together on logistics under pressure.
How Ghost is meant to work
Ghost is a decelerator designed to move cargo from orbit to any point on Earth in roughly 90 minutes. Sierra Space unveiled it in April 2024 after years of behind-the-scenes development. The current version carries about 330 pounds (150 kilograms) of payload and has a five-year shelf life in space, so loaded vehicles can be prepared weeks in advance.
When a delivery is ordered, the vehicle turns around and fires a small motor to slow to about 7,000 meters per second, or roughly 15,700 mph. Atmospheric drag takes care of the rest.
Thermal protection packs that fold compactly for launch expand to shield the contents from temperatures up to 2,000 degrees Fahrenheit. During descent, the shield falls away and a parafoil steers the package toward a landing zone about 328 feet (100 meters) wide.
Earlier drop tests
The first drops, in Florida in February 2024, examined the final stretch of flight. One package fell from 2,000 feet without a parachute to gauge the impact, and another landed from 4,000 feet under a parachute. In a third, the shield was dropped and the parachute took over. The data helped engineers fine-tune the placement of the center of gravity and the vehicle’s control.
Military interest and bigger Ghost
The Air Force Research Laboratory awarded Sierra Space a fixed-price contract in October 2024 to study scaling Ghost up to 5 or 10 metric tons (about 5.5 to 11 U.S. tons) under its Rocket Experimentation for Global Agile Logistics program. The aim is to get critical supplies where they are needed faster than traditional airlift can, particularly in hot spots where large transport aircraft cannot fly without being shot at.
U.S. Transportation Command has also shown strong interest in how recovery, deployment and day-to-day operations would work once the vehicles return. Sierra Space expects lessons from its Dream Chaser spaceplane to carry over to the smaller design.
The balloon tests, which fall well short of an orbital return, gave the company valuable real-world experience.