On the Florida coast, at Launch Complex 39A at NASA’s Kennedy Space Center, the SpaceX team is readying the historic Inspiration4 mission for liftoff. It will be the first all-private, all-civilian spaceflight into orbit. The four crew members—Jared Isaacman, Sian Proctor, Chris Sembroski, and Hayley Arceneaux—have trained intensely for this day, although none of them are professional astronauts. SpaceX’s Crew Dragon craft has previously ferried NASA astronauts to and from the International Space Station, but everyone aboard this flight is traveling as a guest of Isaacman, the billionaire CEO of Shift4Payments, who paid for all four seats and played a part in selecting the other passengers through a series of contests. (You can read more about the selection process and the mission here.)
The Inspiration4 crew have a five-hour launch window that opens at 8:02 pm Eastern on Wednesday night. If the weather cooperates and all systems are go, the team will blast off on their Falcon 9 rocket, and in a little more than eight minutes their space capsule will be propelled into orbit. They’ll fly about six times higher than Richard Branson and Jeff Bezos did during their edge-of-space jaunts earlier this summer, and stay in orbit for approximately three days.
As early as Saturday evening, the Dragon spacecraft will descend toward Earth and splash down at one of several possible landing sites off the Florida coast, where a SpaceX team will be waiting for them, ready to take the new astronauts ashore.
How to Watch
SpaceX’s webcast of the launch will go live at about 4 pm Eastern time on Wednesday, September 15, about four hours before the launch window opens. SpaceX’s preview coverage will include features on the crew and their lead-up activities. You can stream it below or on the SpaceX website.
Weather condition forecasts have recently been upgraded from 70 percent to 90 percent favorable, so a launch tonight seems likely. But if they have to scrub tonight’s attempt, they’ll try again tomorrow. Their backup five-hour launch window starts Thursday, September 16, at 8:05 pm Eastern.
As the Perseverance rover drilled into a rock on Wednesday to collect a sample from Jezero Crater on Mars, Justin Simon, a planetary scientist at NASA’s Johnson Space Center in Houston, felt both nervous and excited. He has the honor of serving as the “sample shepherd,” leading the effort from millions of miles away, but the pressure’s on. “These samples not only will allow us to understand the geology of the crater but also minerals likely related to the history of water there,” he said yesterday.
But first, the rover had to actually capture a chunk of rock in a test-tube-sized container. An initial attempt in early August had come up empty. That first rock, nicknamed “Roubion,” simply crumbled to dust as the drill bored into it, and none of those bits made it into the container.
Simon can now breathe a sigh of relief. Perseverance’s second try, with a different rock, appears to have successfully extracted a Martian core slightly thicker than a pencil.
“We got that image of just a spectacular-looking core, a fantastic-looking cylinder, broken off cleanly. It looks geologically very interesting, something scientists of the future will enjoy working on,” says Ken Farley, a Caltech geochemist and project scientist of the Perseverance mission, which is led by NASA’s Jet Propulsion Laboratory in Pasadena, California.
But the analysis of the new sample is going to take awhile, because NASA scientists haven’t been able to get clear photographs due to low lighting conditions, which makes the images tough to interpret. To add more drama for the scientists, when Perseverance did a “percuss-to-ingest” procedure—shaking the sample to make sure the tube wasn’t overfilled, which would make the system jam when it’s stored—one image appeared to show an empty sample tube. (They’re pretty sure they got the sample, but they’re going to try taking more images in better light over the next couple of days.)
Perseverance’s first drill attempt, which essentially pulverized the sample, wasn’t a complete failure, as it yielded evidence suggesting the rock had been weathered, worn down by a river flowing into the lake crater billions of years ago. “It always had been possible that this lake was a transient event, like maybe a comet, rich in water, hit Mars and made lakes, and then it boiled away or froze within tens of years. But that would not produce the weathering we see,” said Farley in an interview earlier this week.
Since that rock was too powdery, the scientists then piloted the rover to a new area, looking for a different kind of rock to sample, using the Ingenuity copter to scout ahead. Perseverance trundled slightly to the west, where on a ridgeline the researchers found a larger, boulder-like rock, which they nicknamed “Rochette” and which seemed less likely to disintegrate when the rover deployed its tools on it. “It looks like a rock that, if you could throw it, would clank down on the ground. A good, healthy rock,” Farley said.
Before each sampling attempt, Perseverance performs reconnaissance by snapping a bunch of photos of a candidate rock. Last weekend, it also performed an abrasion test to see if Rochette was durable enough to sample. The rover is equipped with a rotary percussive drill (with extra drill bits) that both spins and hammers into the rock. This tool helps clear away dust and chip through the weathered outer layer. The abrasion was spectacularly successful, according to Farley, so the scientists decided to go ahead with grabbing a sample. Perseverance extended its 7-foot-long robotic arm, fired up the drill, and carefully extracted a core sample. Then it rotated the arm’s “hand” so that the sample tube could be inspected.
Last week, NASA’s Perseverance rover shot for a new milestone in the search for extraterrestrial life: Drilling into Mars to extract a plug of rock, which will eventually get fired back to Earth for scientists to study. Data sent to NASA scientists early on August 6 indicated a victory—the robot had indeed drilled into the Red Planet, and a photo even showed a dust pile around the borehole.
“What followed later in the morning was a rollercoaster of emotions,” wrote Louise Jandura, chief engineer for sampling and caching at NASA’s Jet Propulsion Laboratory, in a blog post yesterday describing the attempt. While data indicated that Perseverance had transferred a sample tube into its belly for storage, that tube was in fact empty. “It took a few minutes for this reality to sink in but the team quickly transitioned to investigation mode,” Jandura wrote. “It is what we do. It is the basis of science and engineering.”
By now, the team has a few indications of what went wrong in what Katie Stack Morgan, deputy project scientist of the Mars 2020 mission, calls “the case of the missing core.”
“We’ve successfully demonstrated the sample caching process, yet we have a tube with no core in it,” she says. “How could it be possible that we have carried out all of these steps perfectly and successfully, yet there is no rock—and no anything—in the tube?”
One theory, of course, was that the rover had simply dropped the core sample. But there were no broken pieces on the surface. Also, Stack Morgan says, the tube was “very clean, not even dusty, suggesting that there was perhaps nothing that had ever gotten into the tube.”
NASA scientists now think that the core was actually pulverized in the drilling process, then scattered around the borehole. “That would explain why we don’t see any pieces in the hole and why we don’t see any pieces on the ground, because they have basically become part of the cutting,” says Stack Morgan. “So we started to think about why that happened, because that is not a behavior that the engineers saw in the very extensive test set of rocks that they cored prior to launch.”
Perseverance is drilling in Jezero Crater, which used to cradle a lake, and therefore may have been home to ancient microbial life. (It’s been relying on the Mars helicopter, Ingenuity, to scout ahead for spots to dig.) By digging into the rock instead of just sampling dust at the surface, the rover will provide vital clues about the geological history of the planet. The Curiosity rover, which landed on Mars in 2012, also drilled, but it was designed to grind the rock instead of extracting cores. This time, NASA engineers want samples that let them observe the rock as it was laid down so they can analyze it for hallmarks of life—some microbes, for instance, leave behind characteristic minerals.
For Perseverance, the drilling process actually begins inside the rover, in a section called the adaptive caching assembly. Here, a robotic arm takes a tube out of storage and inserts it into the “bit carousel,” a storage container for all of Perseverance’s coring bits. The carousel then rotates, presenting the tube—which is about the same shape and size as a laboratory test tube—to the 7-foot-long arm that’ll actually do the drilling. “We pick up that coring bit, and that has the tube inside,” said Jessica Samuels, surface mission manager for Perseverance, in an interview before the first drilling attempt. “And now at that time we’re ready to actually acquire the sample.”
The researchers found the core density to be surprisingly low, at only about 6 grams per cubic centimeter, which is much lower than what they’d expected of an iron-rich center. “It’s still a bit of a mystery how the core is so light,” Stähler says. There must be lighter elements present, though exactly what those may be is unclear. He and his team eventually hope to detect P-waves produced by a marsquake originating directly across the planet from where InSight is parked. Since they can pierce through the core-mantle boundary, they will carry information about the core’s composition to the lander’s receiver. But for that to happen, Stähler says, “Mars has to play along and give us this one quake on the other side of the planet.”
In Stähler’s team’s paper, they report a core radius of 1,830 kilometers. Another team, led by ETH Zürich geophysicist Amir Khan, found that this size is so large it leaves little room for an Earth-like lower mantle, a layer that acts as a heat-trapping blanket around the core. Earth’s mantle is divided into two parts, with a so-called transition zone in between; the upper and lower levels are composed of different minerals. “The mantle of Mars is—can I say flippantly—a slightly simpler version of the mantle of Earth, simply in terms of the mineralogy,” says Khan, lead author on the paper describing the mantle.
Previous estimates of the core’s radius using geochemical and geophysical data hinted at the absence of a lower mantle, but scientists needed InSight’s seismological readings to confirm it. Without this layer, the Martian core likely cooled much more readily than Earth’s. This is key to understanding the evolution of the Red Planet, and in particular why it lost its magnetic field, a barrier that would have protected the atmosphere—and potential life—from harsh solar winds. Creating a magnetic field requires a temperature gradient between the outer and inner core, high enough to create circulating currents that churn the core’s liquid and give rise to a magnetic field. But the core cooled so fast that these convection currents died out.
Khan’s analysis also shows that Mars has a thick lithosphere, the rigid and cold part of the mantle. This might be a clue as to why the Red Planet doesn’t have the plate tectonics that drive the frenzy of volcanism on Earth. “If you have a very thick lithosphere, it’s going to be very difficult to break this thing up and create the exact equivalent of plate tectonics on Earth,” says Khan. “Maybe Mars had it very early on, but it’s certainly shut down now.”
While InSight eavesdrops on the interior vibrations of Mars, Perseverance has been rolling around its dusty surface looking for signs of ancient life in the rocks, scoping out places to collect regolith samples, and learning about Jezero’s geological history. “Exploration is not a sprint, it’s a marathon,” said Thomas Zurbuchen, NASA’s associate administrator of science, who opened the press conference on Wednesday that highlighted early advances from the rover’s first few months in its new home. “Perseverance is one step in a long legacy of carefully planned Mars exploration that links robotic and human exploration for the time to come.”
The scientists at the press briefing laid out what Perseverance has been up to on its road trip so far. “The challenge is figuring out exactly where we want to go and how we’re going to fit everything into our schedule,” said Vivian Sun, a systems engineer at NASA’s Jet Propulsion Laboratory. Sun said they decided to detour Perseverance about 3,000 feet south of its landing site to extract its first rock samples, which will be stored in the belly of the rover and later cached on the planet’s surface for a future return mission that will ferry them to Earth.
This came on the heels of similarly dreamy exclamations by another space billionaire, Richard Branson, who also portrayed his own self-financed suborbital jaunt as something beyond human language. “I’m never going to be able to do justice to it,” he said at his own press conference. “It’s indescribably beautiful.” A word he kept using was “inspiration”—space, in his view, was not an infinite void but a life-changing mountaintop that symbolizes what humans could accomplish.
Even Virgin’s lead operations engineer, Colin Bennet, who was on the flight, hopped onto the awe train, depicting space as kind of a heaven. “It’s very zen,” he said. “It’s very peaceful up there as well. What jumped out at me were the colors and how far away it looked. … I was just mesmerized.”
Space travel, it seems, is all about inspiration, beauty, and returning … to our natural state?
Of course, we’ve already heard plenty about the intangible magic of gazing down at Earth from NASA astronauts who happened to experience spiritual moments in the course of their work. But as people increasingly visit space not to work, but to indulge in a life-changing experience, revelation moves from a serendipitous side effect to the point of the matter. The premise of space tourism isn’t exactly guaranteed satori, but it’s certainly implied. (That, and a lot of fun floating around. Video from RSS First Step, the capsule of New Shepard, showed the crew tumbling and playing, tossing a ball, and pitching gravity-free Skittles at each other.)
But even as Jeff Bezos was gushing about the amazeball-ness of his flirtation with space, the fact is that ultimately, all of that mumbo jumbo is secondary to him. The thrills and revelations of space travel are but enablers of the main reason he started Blue Origin: To begin a journey on which millions of human beings would leave the Earth to live and reproduce in space colonies, extending our species to over a trillion souls.
He was explicit about it when I spoke to him in 2018: “I like the adventure of space; that’s great,” he said. “But that pales in comparison to the importance of making sure that our grandchildren’s grandchildren don’t face a life of stasis. Basically, we have a choice to make as a civilization, which is do we expand into the solar system or do we accept stasis here on Earth? There have been many reasons over the years that people have given for why we need to go to space, and this is the only one that I personally find super motivating.”
Yesterday at his post-flight press conference, he repeated the message, though tactically avoided explicit talk of space colonies. “What we are doing is not only adventure,” he said. “It’s also important. Because what we are doing is something big. … We’re going to build a road to space so that our kids—and their kids—can build a future.”
He went on to insist that his goal wasn’t escaping Earth, but saving it, as it’s “the only good planet in the solar system.” But as I understood him from hours of conversation in 2018, he sees Earth as a preserve, a haven, that can be conserved once destructive manufacturing is moved to the unimaginable vastness of space so the natural ecology can prosper. People still living here will be Earth’s caretakers. The huge population of humans living in lush galactic colonies—think not of the cramped International Space Station, but massive verdant structures with lakes, shopping malls, and stadiums—can return to their home planet for visits or residencies.