In the most recent development in the negotiations over President Trump’s contentious proposal to create a Space Force, acting Secretary of Defense Patrick Shanahan has proposed that the new organization follow the current Marine Corps/Department of the Navy model. Just as the Marine Corps is a military service within the Department of the Navy, this version of the Space Force would fall under the responsibility of the secretary of the Air Force.

Briefly, the overall purpose of a future Space Force, if it happens, will be twofold. First, it will organize, train, and equip its members to build, launch, and operate satellites and other capabilities that support U.S. government activities on Earth. The second major mission will be to prepare to operate those satellites when future conflict eventually extends its battlefields into space.

But whatever the formal structure of a sixth military service, if it happens, the Pentagon will have to decide what to call its uniformed members. Few decisions are as important in determining the long-term success, and public acceptance of this new organization could depend on this one choice. Choosing the wrong naming conventions, symbology, and other artifacts in the early days will have a lasting impact. Often, newly minted leaders will either overlook these small decisions or stubbornly defend a perceived poor choice. After the debate over creation of the Space Force in the first place, the last thing the military needs is a long news cycle ridiculing whatever name is chosen.

Most Americans can easily rattle off soldier, sailor, airman, and Marine. (Despite being the fifth military service, the Coast Guard doesn’t always make the list.) On the very first day that a space service comes into being, Americans will want to know what to call its members. The wrong moniker would affect the morale, confidence, and credibility of the entire organization.

The right name should be simple and should derive from a credible story—the explanation for it should make sense. It has to be grounded in military tradition of the past, but it also has to speak to the present and the future. Given all the memes that have circulated since Trump first talked about a Space Force, Americans would likely support a name that nods toward pop culture.

Three particular names have gained traction in space circles. In an informal poll recently conducted by the Army Space Professional Association, trooper, sentinel, and guardian were among those that received positive support. Spaceman was widely regarded as a nonstarter.

Space trooper is my personal favorite. With two syllables, trooper matches the flow of the soldier-sailor phrasing. Also, the Army refers to captain-led cavalry organizations as troops and their members as troopers. Furthermore, within military circles, the book and movie Starship Troopers is quite popular and on many official reading lists, so the name will resonate as a source of strength and inspiration, especially if we end up fighting aliens someday.

Space sentinel is a strong candidate as it evokes an image of a person standing watch over something, such as the Army’s Old Guard sentinel protecting the Tomb of the Unknown Soldier at Arlington National Cemetery. Since members of a Space Force will be operating and defending satellites that look across the entire globe, that imagery could work. Also, the Army, Air Force, and Coast Guard each have equipment (radars, drones, Coast Guard cutters) currently in their inventories known as sentinels, which would allow for certain types of lineage to carry into the new force. Finally, The Sentinel is an anthology of space-centric short stories by Arthur C. Clarke, one of the most well-known space-centric sci-fi authors.

A space guardian makes sense as well, in part because of the way it invokes the heavens. As the newest military service, some space professionals would prefer to use terminology that isn’t steeped in centuries of military history. Adopting the name guardian provides an opportunity to introduce a new term into the lexicon. And of course, the Marvel Cinematic Universe has turned the Guardians of the Galaxy into a household name.

The wrong moniker would affect the morale, confidence, and credibility of the entire organization.

Why are some military space professionals against the name spaceman? For one thing, it’s a little too close to airman. In 1947, Congress officially split the Army Air Forces out of the U.S. Army and consolidated them into the newly established Department of the Air Force. Members of the “new” U.S. Air Force didn’t want to be known as air soldiers and eventually settled on airman. Under Shanahan’s proposal, and similar to the history of the Air Force, the Space Force will be a separate and distinct branch of the military, although still within the Department of the Air Force. (Yes, I know that’s confusing.) Members will want their name to be different, especially knowing that one day, it will eventually transition out of the Air Force and become its own military department. Similarly, the space service deserves the opportunity to find terminology that is connected to, but not a carbon copy of, its origin. Spaceman as a name is as close to airman as you can get. And of course, it makes sense to avoid using -man in the 21st century, even though it’s long been accepted within the Air Force as gender neutral. Trooper, sentinel, and guardian offer an obvious distinction so that Space Force members will view themselves as different from their Air Force counterparts.

Eventually, the space community will find a name for its members that sticks. Internet memes and obvious references to Star Wars or Star Trek aside, people will find serious words and symbols that come to represent the new organization. But finding the right words and symbols is a serious and necessary conversation, one that shouldn’t be restricted to PowerPoint presentations within the Pentagon. The leaders and decision-makers of the new Space Force should actively seek input from the community. A relatively simple way to address this would be to utilize a series of focus groups that could include future targets for recruiting, congressional members and staff, industry, and existing service members who are designated as space professionals

But we can also do this more informally. What do you think we should call members of the Space Force if it comes to be? Leave it in the comments or tweet it with #RealSpaceForce.

All opinions expressed in this interview are those of the author and not those of the United States Army or the Department of Defense. Special thanks to Joe Guzman, Jason Kalainoff, Mark Cobos, and Joe Mroszczyk for their inspiration in the development of this piece.

Future Tense is a partnership of Slate, New America, and Arizona State University that examines emerging technologies, public policy, and society.