Human spaceflight has come a long way since Soviet cosmonaut Yuri Gagarin became the first person to orbit the Earth in April 1961. The field has advanced at a steady pace since, with humans orbiting and, subsequently, walking on the moon in the 1960s; creating the first manned U.S. and Soviet space stations in the 1970s; and placing the first resident crew on the International Space Station (ISS) in 2000. A year later, in 2001, the first space tourist, American engineer and business owner Dennis Tito, journeyed to the ISS on Soyuz TM-32, an event that would inspire six other space tourists to pay up to $25 million to visit the ISS that decade.

These flights took place in spacecraft funded, developed, and regulated by government agencies. In the United States, the National Aeronautics and Space Administration (NASA) managed all human spaceflight until 2004, when the privately designed, built, and crewed SpaceShipOne traveled 62.5 miles (100 kilometers) above the Earth’s surface. This distance is known as the Kármán Line and delineates where space begins.

Financed by aerospace engineer and entrepreneur Burt Rutan and tech entrepreneur Paul Allen, SpaceShipOne’s success propelled other private ventures, including British industrialist Richard Branson’s Virgin Galactic and The Spaceship Company, of which Rutan was an original co-owner. In a field where innovation and growth had taken years to finance and implement, things were now skyrocketing. 

In 2011, NASA ended its government-funded Space Shuttle program and began forming agreements with the private sector to transport people and cargo to orbiting spacecraft. The move further boosted the number of new businesses devoted to commercial spaceflight and the quest to send thousands into space.  

As more startups take on the mission of commercialized human spaceflight, the need for voluntary consensus standards has likewise increased. This is where ASTM International has stepped in. Created in 2016, the committee on commercial spaceflight (F47) is developing standards and best practices for the design, manufacture, and operation of spacecraft and human spaceflight safety.

Shift to Commercial Spaceflight

The committee on commercial spaceflight bridges the gap between the ever-expanding spaceflight industry and what is deemed standard for NASA, says Chris Ferguson, committee co-chair and a private contractor supporting developers of human spaceflight hardware.

“NASA has 60-plus years of building human-rated spacecraft, so there are plenty of NASA standards and we have a lot of proven data from which to choose,” he says. “However, industry is different than NASA. It has different objectives and risk tolerances, so there’s a delicate balance between safety and efficiency and profitability.”

This trifecta comes up frequently in conversations about commercial spaceflight. Many have voiced concerns over a shift from science-motivated missions to adventure-driven flights and the tremendous corporate profits garnered through the latter. Questions also abound regarding the safety of potentially ill-prepared civilians going into orbit. 

When it comes to passenger well-being, the U.S. Federal Aviation Administration's (FAA) Office of Commercial Spaceflight retains a level of authority over spaceflight safety, issuing commercial space licenses, regulating flight crew qualifications and training, and confirming launch and re-entry vehicles. This is where voluntary consensus standards come into play and the committee partners with industry. For standard practices and guides on everything from medical requirements for passengers to "Training and Qualification of Safety-Critical Space Operations Personnel," and even "Occupant Survivability," the technical committee is diligently bringing together industry experts in the development of international standards.

Voluntary consensus standards ease many of these worries. “These ASTM standards will provide guidance that most commercial providers are aligned with,” says Ferguson. “And when commercial spaceflight businesses start selling seats, they can point to these agreed-upon standards, which provide the right levels of fault tolerance, redundancy, and safety.”

Classifying Launch and Re-Entry Vehicles

In 2023, the commercial spaceflight committee published the standard classification for space launch and re-entry vehicles (F3388), which gives the commercial space industry a common vocabulary for classifying vehicles based on their operational flight envelope, which is the area within which an aircraft can safely operate. The FAA-H-8083-3C Airplane Flying Handbook discusses how pilots control an aircraft's altitude and airspeed within its flight envelope, which defines the boundaries of an aircraft's capabilities in terms of: airspeed, load factor, altitude, and maneuverability.

The FAA’s Code of Federal Regulations (CFR) Title 14 parts 400-460 on commercial space transportation served as the basis for the launch and re-entry classification standard.

“Through the review process, we realized that there were terms used both in space and aviation that meant different things and were codified in aviation,” says F47 member Lisa Loucks. Loucks is also the president of Ascendant Spaceflight Services. “The space launch and re-entry community was coordinating with FAA air traffic control, with different assumptions for the same words. Our goal was to establish a common baseline of communication between interfaces.” 

To further clarify terminology and ensure that everyone speaks the same language, the classification standard considers the mission being performed by the launch and re-entry vehicles and the vehicles’ range of capability. Because a specific mission could hamper or alter a vehicle’s capabilities, this dual focus is necessary. 

Andrew Nelson, vice-president of aerospace at RS&H Incorporated, notes that a given vehicle’s capabilities may include horizontal or vertical launch, vertical landings, gliding landings, or capsule landings on water or land. 

“Those types of permutations start to cross-fertilize. With the Space Shuttle or many of today’s commercial spacecraft, you have a vertical launch but a horizontal landing,” says Nelson. “The size of the vehicle, different safety criteria, and propulsion systems need to be considered, too. A dominant design hasn’t emerged from the space industry, so you need a playbook that allows people to state, ‘I’m this.’ From there, you can derive different requirements and operations and say, ‘I can accommodate this at my spaceport but not that.’”

Spaceports are testing and launch sites may or may not accommodate vehicle re-entry.

In the U.S., there are 14 FAA-licensed spaceports and approximately six other launch sites, two of which belong to SpaceX and one of which is owned by Blue Origin. Four of these sites can accommodate horizontal and vertical launches. Two permit orbital re-entry. The remaining allow for either vertical or horizontal launches.

Sharing Information Within the Industry

Along with establishing a common language for discussing spaceflight, F47 is working on a new guide for industry requirements for voluntary spaceflight safety information-sharing processes (VSS-ISP). Drafted by the subcommittee on cross-cutting (F47.05), the proposed standard (WK87972) would identify and define industry requirements for collecting, sharing, and creating a database of safety-related information. 

Presently, a uniform system for disseminating this type of information doesn’t exist. “We’re finding that unless you’re an avid consumer of space history, you probably don’t know all of the lessons learned in the 1960s,” says Ferguson. “NASA was very good about issue documentation, but industry is different and currently, there is no method for self-reporting incidents or lessons learned so that the rest of the industry can benefit. With the new guide, safety issues could be identified, studied, and corrected so that they don’t occur again. The data would be available to industry stakeholders for analysis, recommendations, safety alerts, and advisory circulars and would allow the spaceflight industry to learn from its predecessors’ mistakes and mishaps.”

Human Safety in Space

Common language and communication aren’t the only challenges the commercial spacecraft committee addresses. Human factors are being tackled, including the physiological, psychological, and ergonomic factors that affect human welfare and safety and how to apply human factors design principles to spacecraft. With the prospect of additional commercial passengers jetting off to space, it has become imperative to understand how spaceflight impacts the mind and body and to determine how best to ensure human health, safety, and performance in space. 
With this in mind, the subcommittee on cross-cutting (F47.05) has drafted the new practice for human factors in commercial spaceflight (WK84313). This work item identifies human factors considerations for all aspects of commercial human spaceflight, including design, qualifications screening, training, ground operations and maintenance, occupant protection, and risk assessment. Such a standard would be relevant for owners, operators, manufacturers, technicians, contractors, and supply-chain organizations involved in the development and maintenance of human-rated spaceflight vehicles, habitats, and related spaceflight activities.

The subcommittee on occupant safety (F47.01) has proposed a revision to its 2023 standard guide for crewed suborbital space vehicle design (F3658). The standard covers areas of vehicle design that ensure a high probability of safe human spaceflight and an equally sound return to Earth. It applies to the flight crew, spaceflight passengers, mission specialists, and any other people on suborbital trajectories. The revision to F3658 would address comments made during the approval process.

Human safety also comes into play with the standard guide for medical qualifications for suborbital vehicle passengers (F3568). Another standard written by the subcommittee on occupant safety, it describes the minimum recommended medical guidelines for suborbital flights and advises the commercial-spaceflight operators developing medical programs for them. These guidelines can be customized to fit a company’s specific spaceflight system, operational procedures, safety standards, and risk profiles.

“In a way, these medical standards help to drive the space industry,” says Loucks. “Because the space industry is in a learning period and the current regulations don’t necessarily reflect where industry is and is heading, F47 will be instrumental in creating consensus standards in advance of regulation. It will enable more of an industry-led safety model.”

Gloves, Suits, and Software

Space apparel is yet another concentration of the commercial spacecraft committee. Its subcommittee on cross-cutting has three work items dedicated to spacesuits and, particularly, to gloves: the new test method for measuring the insulation and contact temperatures change of an instrumented hand in glove assemblies worn on extravehicular activities (WK85993); the guide for evaluating impact abrasion resistance of textile fabrics used in spacesuits and spacesuit gloves—rotary tumbler method (WK85994); and the test method for measuring cut resistance of materials used in spacesuits and spacesuit gloves under cryogenic conditions with tomodynamometer test equipment (WK85995).

Gloves are reputed to be the trickiest part of a spacesuit. They must afford the astronaut enough dexterity to pick up and use tools while supplying adequate protection from the harsh environment of space.

“If you look at the original Apollo lunar gloves, they were designed to last about 12 days on the lunar surface,” says Nelson. “You see them at the Smithsonian National Air and Space Museum, and you see they’ve been destroyed by the lunar regolith. This is the extremely abrasive dirt on the moon. It has a lot of static and sticks to everything. Because gloves are the most challenging aspect of a spacesuit, parts of the lunar glove standards can be applied to the rest of the spacesuit as well.”

Another element of F47’s focus is software safety. The new test method for software safety standard (WK76298) sets up a process for system-level testing of commercial spaceflight software to verify its function and compliance with safety objectives. This test method would serve as one of several ways to verify compliance with the FAA’s 14 CFR Part 400. 

Although NASA has published standards on software testing, the subcommittee on occupant safety (F47.01) is evaluating these and the models included prior to the development of their standard. The abundance of proposed and new standards stems from the dearth of existing ones. At this point, Ferguson notes, no other private organization is writing standards for human spaceflight.

“It is important to speak the same language in space and as each commercial provider builds their system, they develop their own lexicon. Through its terminology standard, ASTM is attempting to drive a common language across the industry to ensure that the same term does not have conflicting meanings. A good example is the word ‘abort,’ which is clearly a very important capability, but it is currently used differently depending on the provider.”

“With international standards that govern interfaces and safety-related themes, everyone understands what everyone else has,” he adds. “And we know what we’re capable of building someday.”

For additional information regarding the committee on commercial spaceflight, see the F47 committee page.  ■