There are many unknowns in the field of space exploration. What came before the Big Bang? What is dark matter? Will we ever make contact with another civilization, or are we destined to remain alone, floating along on this tiny, insignificant speck in the universe?

The latest unknown to captivate the space community is something a little less grand: Where is that giant rocket going to land when it falls out of the sky?

The rocket in question belongs to China, and it is currently hurtling through the atmosphere, circling the planet about every 90 minutes, toward what is known as an “uncontrolled reentry” sometime this weekend. The expendable hardware was once part of a larger vehicle, the Long March 5B, which launched last month with the first piece of China’s new space station. Once the payload successfully reached space, the rocket, emptied of fuel, slipped away and became space junk.

Launch providers usually try to ensure that their discarded rocket bits descend soon after a flight, and the hardware mostly falls into the ocean, though some pieces, on rare occasions, hit land. But this empty rocket is different. The Long March 5B vehicle was designed in such a way that its expendable rocket ended up in orbit, tumbling around at more than 17,000 miles per hour. Parts of the rocket are expected to survive the fiery reentry through Earth’s atmosphere and reach the surface, and who knows where they might land? The U.S. military is tracking the object, but even the best available data can’t predict its final destination.

Considering the size of this thing—nearly 100 feet tall, more than 15 feet across, weighing 23 tons—the idea of even parts of it hurtling toward us is particularly unnerving, enough that a friend whom I haven’t seen in ages sent me this text message last night: “Are you following this China rocket thing? Are we doomed??"

No one is doomed! Not because of this, at least. While the chances are not zero, the likelihood that debris from the Long March 5B will drop onto a populated area is extremely low. Even without a controlled entry, it is far more likely to smash into the ocean, which our planet thankfully has a lot of. (Honestly, the reentry we should probably be more preoccupied with is the return to social interaction after vaccination.) Stuff falls into the atmosphere every day, burning up as it goes. You’re more likely to get struck by lightning than smacked with a piece of falling space debris.

“The chance of someone being hurt is maybe a percent or so,” Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who is well known in the space community for his expert monitoring of artificial space objects, told me. “The chance of you being hurt is 8 billion times smaller than that, so don’t worry about it.”

[Read: A graveyard of giant spacecraft spins through space]

Careening, out-of-control space debris is one of those problems that we hear about precisely because it’s so rare. It’s also quite solvable, McDowell said—just don’t build your rocket, as China did, to reach orbital velocity and start zooming around. The few times that very large pieces of space junk have come crashing down to Earth over the years—rockets, satellites, even entire space stations—no one was doomed.

In the 1970s, Skylab, the first American space station, came plummeting through the atmosphere. NASA astronauts had used the floating outpost to conduct science experiments and generally get the feeling of life in microgravity. By the end of the decade, the station, now abandoned, started losing altitude. The station wasn’t designed to maneuver itself into a higher orbit, and the space shuttles that NASA thought could help haul it up weren’t ready yet, so down the station went. NASA did have the power to give it a nudge or two, but mostly Skylab was carving its own path.

In 1979, as the public followed the station’s descent with, according to Time magazine, “varying degrees of fear, anger and fascination, but mostly with a detached kind of bemusement,” NASA controllers worried that some debris could hit North America. The Federal Aviation Administration even closed off airspace over Maine to protect planes. Hours before reentry, engineers commanded Skylab to fire some engines and produce a wobble that would adjust its path just a bit, bringing its descent over the ocean. The last-minute adjustment was partly successful; most of Skylab fell into the Indian Ocean, but some debris was scattered along the coast of western Australia. Suddenly, space litter became a souvenir, and people scoured the coast for remnants of Skylab, eager for a trophy or something to sell. The city council of Kalgoorlie even hauled a piece of the station into its town hall, which the mayor said was “very good for the tourist industry."

[Read: If everyone left the International Space Station]

When something is moving as fast as Skylab was—or the Long March 5B is now—even the slightest shift can change its trajectory by thousands of miles, bumping it from one continent toward another. NASA’s decision pushed Skylab “to fly safely over southern Canada and Maine, but may have been responsible for its Australia landing,” The New York Times reported. President Jimmy Carter even apologized to the Australian people for the mess.

An empty Soviet space station came down in 1991 in a similarly uncontrolled manner over Argentina, appearing as a fireball in the sky. Some debris managed to reach the ground, igniting small fires in a trash dump in a southern coastal city, but there were no injuries. More recently, a Chinese space station, Tiangong-1, fell back to Earth in 2018, burning up over the South Pacific, with remnants landing in the water near Tahiti. Chinese officials had lost contact with the spacecraft two years earlier, sparking anxious speculation about where the out-of-control station would come down. Last spring, a disintegrating Long March 5B rocket sailed directly over Los Angeles and New York City on its final orbit of Earth before entering the atmosphere over the Atlantic Ocean and raining debris in the Ivory Coast in Africa. Again, no one was injured.

So, yes, the Long March 5B does not threaten immediate catastrophe. But it’s still not great, and China isn’t doing much to alleviate worries. The country is known for being secretive about its space activities, both at home and abroad. Foreign-ministry officials declined to answer questions about the reentry at a press conference this week, saying only that China is “committed to the peaceful use of outer space and stands for international cooperation in this regard.”

[Read: The night sky will never be the same]

Already the White House press secretary has fielded questions about what the Biden administration would do if the rocket causes damage on Earth. Although one might imagine that fiery events that cross international borders would have inspired some kind of serious regulation, there’s no space law covering objects plunging to Earth. It’s up to nations to supervise their own space objects and where they fall. “In terms of the legal mechanisms governing reentry, there actually aren’t any obligations on this. There isn’t any international treaty,” Chris Newman, a space-law professor at Northumbria University at Newcastle, in the United Kingdom, told me.

But there are some rules about who’s responsible if space litter damages property or injures people. Many countries are party to the 1972 Space Liability Convention, which allows one nation to hold another financially responsible for space litter. In 1978, after a fallen Soviet satellite scattered radioactive debris over northwestern Canada, the Canadian government asked the Soviet Union to fork over $6 million to cover cleanup efforts; the Soviet Union waffled for a few years, but eventually paid $3 million. This rule comes with all sorts of political entanglements, Newman said; if the Long March rocket does cause damage somewhere inhabited, the leaders of that country may decide that seeking recompense isn’t worth the potential diplomatic ripple effects of challenging China. “This is going to be a foreign-policy decision as much as a legal one,” Newman said.

A more pressing concern about space debris involves the type that most people don’t notice or worry much about. The space around Earth is brimming with satellites, rocket parts, and other hunks of metal, and some objects occasionally pass dangerously close to each other and even collide. Space law doesn’t have much to say about space traffic either, but space is getting more congested every day, even without a rogue rocket.

Had Johnson & Johnson’s COVID-19 vaccine been the first to get the FDA’s green light, it might have been hailed from the get-go for what it actually is: a scientific and technological marvel. It requires just one injection to confer full immunity—a boon for needlephobes and tough-to-reach populations who can’t easily access a second dose. It’s relatively cheap and has forgiving refrigeration requirements, making it a breeze to ship and store. And clinical trials showed that it’s a knockout at guarding against hospitalization and death, and 66 percent effective at preventing moderate to severe cases of COVID-19, even amid the rise of antibody-dodging coronavirus variants. Johnson & Johnson accomplished all this in less than a year, granting the world a safe and effective vaccine crucial to hastening the pandemic’s eventual end.

That’s not how the J&J story played out.

By the time the authorization for the J&J vaccine went through, its mRNA-based counterparts, boasting clinical-trial efficacies of roughly 95 percent, had been in the field for months. Experts cautioned that differences in trial design and timing made the trio of vaccines impossible to accurately compare. But people pitted them against one another all the same, and time and time again, J&J appeared to lose out. The shot was labeled “second class” just as it surged into some of the disadvantaged populations hit hardest by the pandemic, raising discomfiting questions about whether the rich and privileged were hoarding the top-tier vaccines for themselves. Manufacturing snafus that compromised millions of doses quickly added to the ire. Last month’s 10-day hiatus, when the CDC and FDA linked the vaccine to a rare and unusual blood-clotting disorder, dealt the shot yet another blow, spurring a noticeable dip in confidence in the J&J formulation.

As vaccine supply starts to exceed demand in the U.S., researchers and health workers across the country are steeling themselves for what could be a rough rescue mission. A vaccine that’s thought of as “shitty,” experts told me, has little chance at being seen as truly equitable, and some of them worry that J&J’s product has already been snared in that trap.

“I think it’s going to be hard to dig our way out,” Abraar Karan, an internal-medicine physician at Brigham and Women’s Hospital in Boston, told me.

What the J&J shot now faces is a sort of branded vaccine reluctance, largely specific to one company’s product. But the reputation of other vaccines also hinge on this one, experts told me, making rehabilitation key. An important first step, they said, might be giving people the option not to take it at all.

The Johnson & Johnson vaccine is not, experts repeatedly told me, a “worse” vaccine. Among the three options available to Americans—Pfizer-BioNTech, Moderna, and J&J—“the best vaccine you can get is the one you can get in your arm as soon as possible,” Chrissie Juliano, the executive director of the Big Cities Health Coalition, told me.

But J&J’s vaccine is undeniably different, and its portability and convenience have prompted health departments to shuttle it into distinct populations, such as incarcerated individuals and people experiencing homelessness. In practice, this may be contributing to some unintended stratifications. David Lazer, a computer scientist at Northeastern University, told me his team has collected data showing that Black people are almost twice as likely to have received the J&J vaccine than white people, a disparity that doesn’t seem to be accounted for by preferences alone.

The hustle to allocate J&J immediately raised questions about whether America’s “problematic” vaccine was being earmarked for communities who are already distanced from medical resources and disproportionately pummeled by the virus, says Rachel Hardeman, a health-equity expert at the University of Minnesota. That stigma rapidly began to reinforce itself. In early March, Detroit Mayor Mike Duggan rejected a batch of J&J doses, saying that he wished to provide his residents with only “the best” vaccines. One physician told me that she’d received calls from reporters asking her to comment on J&J “being the poor person’s vaccine.” “There’s this undercurrent of tension,” Taison Bell, a critical-care physician at the University of Virginia Health System, told me. Many of the populations described as good J&J candidates “feel, rightfully so, that they receive second-rate care.”

This challenge, even if it has more to do with public perception than the vaccine’s intrinsic quality, can’t be dismissed: If people believe the vaccine is inferior, “that’s just as important as reality when people try to make healthy decisions for themselves,” Bell said.

Rehabilitating the Johnson & Johnson vaccine, experts told me, will require honest acknowledgments of its shortcomings, and validating, not combatting, people’s concerns. The rare blood clots that have been tied to the vaccine are serious, they said, but extraordinarily uncommon—a risk that’s far outweighed by the benefits of immunity.

The pause clearly did shake things up. Willie Bodrick II, a senior pastor of Twelfth Baptist Church in Boston, who’s heavily engaged in vaccine outreach to the city’s Black community, told me that, even before the pause, he had been fielding questions about the J&J shot for weeks. Some people who were unwilling to take a second dose, whether because of work constraints or wariness of side effects, saw the single injection as an ideal option; others “were really worried they would be receiving a subpar vaccine,” he said. Just days before the J&J halt, Bodrick felt he’d made progress. But news of the rare blood clots “resurfaced a hurdle I thought we were doing a good job moving beyond,” he said. Van Yu, a physician in New York City working to bring J&J vaccines to people experiencing homelessness, told me that, before the pause, many of his patients explicitly requested “the single-shot thing.” Now that J&J is available again, he and his colleagues have noticed that some people are citing the halt as a reason to turn it down.

The risk of clots has persuaded a few people to forgo vaccination entirely. Earl Potts, a 60-year-old IT-security specialist in Maryland, told me that he’s been skeptical of receiving any vaccines for decades. Although constant coaxing from family initially nudged him and his wife, Lori Renee Potts, toward getting J&J “because it was just one shot,” the pause reignited their fear that the vaccine-making process had been rushed. “I need more data; I need more time,” he said.

In many parts of the country, however, a simple message is still encouraging people to roll up their sleeves: Johnson & Johnson’s vaccine is “one of three excellent choices for protection against COVID-19,” as Hardeman puts it. In Columbus, Ohio, the health department’s on-site clinic vaccinates about 130 to 140 people each day, more than a third of whom are still queueing up for the one-and-done shot, Health Commissioner Mysheika Roberts told me. At another large site, where Pfizer and J&J doses are alternated throughout the week, “the J&J days are just as busy.”

Still, the pause prompted Roberts and her team to switch up their outreach tactics. Before the halt, city officials had brought only one brand at a time when inoculating off-site, prioritizing J&J allocations for the residents of homeless shelters and homebound individuals. When the vaccine returned with a warning label, “we thought it was appropriate to offer a choice,” Roberts told me, so no one felt cornered. Porting mRNA vaccines around requires a mobile freezer, which is “tedious to maintain,” she said, but removes a barrier. “Now when we go out to any location, it’s, ‘Which do you want, Pfizer or J&J?’”

This smorgasbord-of-shots strategy, experts told me, could be key to the next stage of the American rollout, especially as vaccine delivery moves past inoculating enthusiasts, and starts pointedly targeting those with reservations. The idea is to meet the unimmunized where they are, both literally and figuratively. And sending different brands of vaccines to different communities isn’t going to work in a culture set on believing one shot is “worse” than the rest. Biased allocation also puts the vaccination campaign as a whole at risk, Bell told me: If something should derail a shot that’s been doing most of the heavy lifting for certain demographics, those populations could be put in a sudden and irreversible bind.

“There should be no community without a choice of vaccines available to it,” Camara Phyllis Jones, a family physician and epidemiologist based in Atlanta, told me. “Giving options is another way of signaling we value people equally.” Sending J&J to places that lack the infrastructure to store and administer Moderna and Pfizer, for instance, might seem easier or more expedient in the short term. But it sidesteps the actual inequities at play, she said. And she doesn’t consider a lack of a freezer a good excuse for snubbing an mRNA vaccine: “Bring a freezer.”

An infrastructure of choice is now supporting the vaccine rollout among people experiencing homelessness in Los Angeles County, where close to 70,000 people are without stable housing. Heidi Behforouz, the medical director of Housing for Health, told me that her team has delivered doses to more than 3,500 people living in shelters or on the streets in the past three months. Most received the Moderna vaccine. The shot is cumbersome to trek into encampments, but with the help of specialized coolers and a vigilant follow-up protocol, “our second-dose return rate is about 93 percent,” she said. (The national average, meanwhile, is about 92 percent.) The team added J&J to its repertoire in early April, just days before the pause, and plans on offering both brands to all of its patients.

Two of Housing for Health’s recent recipients, Candy Acuña Rodriguez and Daniel Gilbert Trujillo, told me they gladly selected the one-and-done shots last Friday, after health workers assuaged their concerns about the pause. “Why would we want to have to go back and take two doses?” Rodriguez told me. “It should be all in one.”

None of these discussions are intended to erase the fact that the J&J may be well suited to, or preferred by, certain groups of people. Making assumptions about who those individuals are is what imperils a rollout. Roberts, in Columbus, told me that one of her region’s first outreach clinics brought J&J to a predominantly African American church, whose members rallied for the brand because it was familiar to them. “They said, ‘It’s a company we’ve heard of,’” she told me. In Los Angeles, however, Behforouz told me that some Black women regard J&J with reproach, citing concerns that the company had, in prior years, aggressively marketed baby powder to their demographic, even amid accusations of asbestos contamination. “It’s hard to predict which patients will want which vaccines,” Josh Banerjee, a physician working with the Street Medicine Program at USC, told me. As Yu, the New York physician, said: “It’s not like I can take a look at you and just guess.”

A big asterisk still hangs on this discussion. While millions of Americans quibble over their glut of three spectacular shots, residents of other countries are wrapped into a far worse conundrum: a paucity of any vaccines at all. High-income countries have already laid claim to more than half the globe’s available doses. As things stand, the rest of the world doesn’t have the luxury of choice. The U.S. has taken some limited steps in rectifying global disparities, by shipping out doses of the AstraZeneca vaccine (which resembles J&J in formulation but has yet to be cleared by American regulators), and moving toward waiving intellectual-property protections on the vaccines.

After failing to protect people for months, U.S. policies are finally reversing that trend with a successful vaccination campaign. The country now has another opportunity for global leadership: collectively opting back into a lifesaving shot. Choosing a J&J vaccine here doesn’t just benefit the person who receives it; it sends a reverberating message, Karar, of Brigham and Women’s, told me. “It highlights that perhaps this is not a worse vaccine at all.”