Microgravity can enable manufacturing processes that are difficult to reproduce on Earth. Pharmaceutical companies are targeting the production of unusually pure or useful crystal structures in orbit; BioOrbit, for example, aim to improve cancer treatment with improved protein crystals. Other proposed applications include semiconductors, optical materials and advanced alloys.
For space-for-Earth manufacturing, production is not the only consideration: returning the products to Earth in a usable condition, and at scale, is a challenge. The commercial value of many of these products depends on preserving a particular temperature, mechanical condition or crystal structure. Return vehicles must therefore be suitable to protect these products from excessive heat and vibration.
As in-space servicing, assembly, and manufacturing (ISAM) develops from experimental research towards commercial production, scale becomes increasingly important. There is a strong commercial incentive to increase downmass – the amount of payload that can be returned to Earth. Larger payloads can potentially spread the fixed costs of a return mission across more product or multiple customers. There is therefore a trade-off between the size of the thermal protection, deceleration and recovery systems required for a safe descent, and the available payload. This has motivated the development of competing commercial return vehicles with different engineering solutions, at different scales. Three companies illustrate the contrasting approaches particularly well.
Varda: tightly controlled payload environment
Varda has concentrated on relatively small return capsules intended for high-value payloads such as pharmaceuticals. Their first W-series mission crystallised the HIV drug ritonavir in microgravity. To determine whether unstable crystal forms could survive the complete journey back to Earth, the mission carried samples of four ritonavir solid-state forms, including the metastable Form III polymorph.
Varda’s capsule solved two different thermal problems simultaneously. Its structure combined an ablative heat shield, which dissipated the severe external heating of atmospheric entry, with active thermal control which maintained a precise payload temperature. The heat shield was constructed of C-PICA, which NASA describes as “stronger, less expensive and more efficient” than earlier PICA materials. C-PICA can achieveup to 55% lower through-thickness thermal conductivity than conventional PICA, and is also more compliant, allowing it to tolerate greater thermomechanical strain as the capsule heats up during entry. Inside the capsule, Varda’s payload incorporated film heaters, Peltier devices and an aluminium heat spreader to impose a carefully controlled temperature profile on the pharmaceutical samples.
Throughout the extreme conditions of atmospheric re-entry, the temperature of the experimental vials was kept below 23°C, allowing the ritonavir to retain its metastable Form III structure. Although W 1 carried small (150 mg) samples, this mission demonstrated that a fragile payload can survive the complete orbital logistics chain. Varda’s W-series architecture is therefore well suited to products whose value per kilogram is extremely high and whose commercial utility depends on tightly controlled conditions.
The Exploration Company: scaling the conventional capsule to tonnes
TEC is applying the conventional capsule architecture to a different logistics requirement: multi-tonne downmass. The overall structure of TEC’s Nyx spacecraft is broadly similar to Varda’s, using ablative thermal protection and parachute recovery. However, TEC does this at an entirely different scale, and they advertise a return capability of up to 3,000 kg in a single journey.
For a multi-tonne return vehicle, surviving atmospheric entry is only part of the problem. The forces a vehicle experiences during splashdown are notably difficult to predict, varying with vehicle shape, wetted area and impact velocity, among other factors. In 2026, TEC therefore conducted 20 controlled splashdown tests using a 135 kg, 1:4-scale capsule, instrumented with pressure sensors, accelerometers and a gyroscope. The data from these experiments are being used to refine the hydrodynamic coefficients used to model the splashdown environment. This allows TEC to refine the structural margins of the full-scale vehicle and more accurately determine the restraints required to protect its payload from the impact.
Compared to Varda’s W-1 experiment, Nyx’s commercial proposition is scale. A single flight of a larger vehicle could aggregate payloads from several customers or return substantially larger production batches. For products that can be returned in larger batches, this creates the possibility of spreading the cost of a return mission across substantially more payload.
ATMOS PHOENIX: changing the entry architecture
While Varda and Nyx differ in scale, a third company, ATMOS, is pursuing a more fundamental change to the architecture of its capsule. Its PHOENIX spacecraft uses an Inflatable Atmospheric Decelerator (IAD), a flexible structure that acts as both an aerodynamic brake and a non-ablative thermal-protection surface. The clear advantage of this type of decelerator is that it can be deployed only when it is required. This means that it is not constrained in size by the fairing in the way that a rigid heat shield is.
The principle had been demonstrated by NASA's 6 m LOFTID inflatable aeroshell. LOFTID returned a 1,100 kg re-entry vehicle at approximately 8 km/s, remaining stable from hypersonic to subsonic flight before being recovered “in excellent condition”. ATMOS then developed its own IAD-based architecture with its PHOENIX series. PHOENIX-2 is designed for a 100 kg payload, with a pressurised cabin and a 4–40°C thermal-control range.
ATMOS, together with the ESA, recently completed a concept study evaluating a much larger PHOENIX-3 configuration capable of returning more than 1,000 kg of payload. PHOENIX therefore represents a competing technological route for scaling commercial orbital return. If ATMOS can successfully demonstrate the PHOENIX-3 model, ISAM operators would have an alternative to the rigid ablative capsule for returning manufactured products. At present, it is too early to say whether that alternative will prove cheaper, more reusable or otherwise commercially superior.
Different products may require different return vehicles
There is no indication that one company’s approach is becoming dominant across the ISAM market. Architectures are being specialised and scaled up in distinct ways.
Varda illustrates one end of the problem: a pharmaceutical polymorph may be extremely valuable in very small quantities, but only if its temperature and crystal structure are preserved throughout re-entry. Nyx addresses a different requirement, where returning tonnes of cargo could accommodate larger production batches or several customers' payloads within a single logistics service. PHOENIX, meanwhile, shows that the industry is not necessarily committed to the conventional rigid, ablative capsule as commercial return scales up.
The optimal vehicle for a temperature-sensitive pharmaceutical sample is unlikely to be the same as for other space-for-earth products, such as optical fibres and advanced alloys. As ISAM matures, return vehicles may differentiate in much the same way as terrestrial freight services: not simply by how much they can carry, but by what they can carry, the condition in which they can deliver it, and the economics of doing so repeatedly.
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