The innovative concept is to drop the Ghost platform from orbit to Earth.
Sierra Space presented the concept of delivering cargo from low Earth orbit. The company plans to deliver important cargo anywhere on the planet within 90 minutes from the moment of request.
This concept can significantly reduce the time it takes to deliver critical supplies to remote areas, especially where traditional ground transportation infrastructure is lacking. The Ghost orbital delivery platform can also assist first responders in disaster-stricken areas and support humanitarian missions.
While several commercial launch providers such as SpaceX and Rocket Lab are discussing using rockets to quickly deliver cargo, Sierra Space's Ghost concept would allow cargo to land in areas without launch or landing infrastructure. This is especially useful for smaller loads, opening up new opportunities for civilian supply chains.
According to Sierra Space, the system will involve pre-loading certain supplies, such as survival kits, inflatables, rations and equipment, into various form factors, which will then be launched into orbit.
The Ghost platform will be able to remain in orbit for up to five years before pre-loaded supplies are sent back to Earth. When delivery is required, the deorbit engine will slow the satellite down enough for Earth's gravity to begin pulling it toward the planet's surface. At the same time, the system’s heat shield will protect the payload from overheating and combustion upon reentry.
After entering the Earth's atmosphere, the thermal protection will be reset, then a soft parachute, similar to an umbrella, will unfold. According to Sierra Space, they will be able to send the payload of «Ghost» within a radius of 100 meters from the target landing point.
Sierra Space's technology incubator, Axelerator, helped the team develop a prototype of the Ghost system in just 90 days, according to the company.
Speaking at the space symposium, Vice President of Orbital Missions and Services Eric Dahler noted that while the Ghost system can be scaled to various sizes, the payload range is from 250 to 750 kg — «golden mean» in terms of cost and payload quantity.
Each platform currently costs tens of millions of dollars to build, but Dahler said Sierra Space is working to bring that cost down to just a few million.
When asked whether the concept could be scaled up to return something as massive as the ISS module, Daler suggested that such a concept was possible, although it would require a slightly different design approach.
«For cool things like ISS segments, you can scale this platform. But perhaps we should consider another way of beautiful implementation. So instead of making a rigid structure like we did, which is very easy to create, you can make something inflatable», — Daler said.
«We originally started developing this platform because our cargo modules were going to burn up during NASA's debris disposal missions. We'd like to reuse them. Therefore, we consider scalability, — he continued.
A prototype of the Sierra Space Ghost delivery system was presented at the 39th Annual Space Symposium in Colorado Springs. The lower portion of the test sample was damaged due to a test drop at the historic LLF launch and landing facility in Florida, where NASA space shuttles previously landed.
Tests in February 2024 included the drop of seven different test samples from a Sikorsky S-76 helicopter — some with parachutes, others only with a soft retarder system, and others only with a payload, — from a height of 610 to 1220 meters.
Similar concepts for resupply have been discussed for years, except those involving rocket launches with reusable systems, such as the huge SpaceX Starship. This year, the US Air Force has committed $4,000,000 to the Rocket Cargo Vanguard, or Point-to-Point Delivery (P2PD) program. According to Breaking Defense, the program focuses on using space vehicles to transport Department of Defense equipment anywhere in the world in a tactically limited time frame.
However, such a system would probably not be able to land anywhere, as it would require the infrastructure to land rockets. A more compact concept, like the Sierra Space Ghost system, could provide targeted delivery to remote or contested areas without the need for specialized landing sites.
Sierra Space has not yet announced a planned go-live date for the system, but the company is actively testing to develop the Ghost concept and determine the necessary infrastructure, communications systems and other architectural aspects to turn the idea into reality.