On Thursday, a Soyuz rocket suffered a catastrophic failure at around the time the second stage began to separate from the first stage. At that moment, the spacecraft's escape system automatically fired, carrying NASA astronaut Nick Hague and Russian cosmonaut Aleksey Ovchinin into a ballistic return to Earth. They later landed safely in Kazakhstan.

The incident has raised a number of questions about what actually happened, what this means for the International Space Station going forward, and what this means for the commercial crew program. In this article, we're going to try to answer some of those questions based upon a NASA briefing that Ars attended in Houston as well as discussions with several officials including former astronauts and aerospace engineers.

What happened to the rocket?

No one is saying for sure, although a Russian investigation has already begun. What we know is that at about two minutes, there was some sort of failure with the first stage of the rocket and/or its strap-on boosters. (Rumors are circulating that perhaps one or two of the boosters didn't properly separate from the first stage).

What happened to the crew?

"We know during their ascent that, certainly, this happened very, very quickly," said NASA deputy astronaut chief Reid Wiseman during the agency's news conference. "On the order of less than a second, they had a booster-emergency light illuminate in the Soyuz. We know that that light came on, which signaled that there was an anomaly with the ascent stage. Their abort motor fired, and that's very quick. I would call that an acute onset of g. Very brief, but very high, to get them away from the booster.

(Note: There has been a lot of speculation as to whether the abort motor fired automatically, or whether the crew had to trigger an escape manually. Two well-placed sources said Thursday night that the Soyuz's automatic system worked as intended, as Wiseman describes here).

Wiseman continues: "So now they're in their reentry module, and the first thing we heard them report is that they had sensed weightlessness because they had been removed from the booster and they were now free-falling back to Earth. Then the next call that we had from them is that they were feeling fine. We are well-trained for all of these events, and the crew handled their procedures exactly as we had planned." Later, Hague and Ovchinin returned by plane to Baikonur in Kazakhstan and were united with their families. Soon, they will fly to Star City near Moscow and take part in the investigation.

How long will the investigation take?

In our experience, the Russians look at these things quickly. But Kenny Todd, the space station's mission operations integration manager, did not put a time frame on that during the news conference. "We'll expect to hear some details on that over the next few days from our Russian colleagues," he said. But it will take longer to determine precisely what had happened and how the Russians will get the Soyuz rocket and spacecraft back into service.

"Obviously, this is a high priority from a Russian standpoint to go try to understand what happened with this booster," he said. "It's my speculation that they will put a lot of resources into trying to understand exactly what happened. I would anticipate that they would try to do that sooner rather than later. But we'll have to see where the data leads, whether that's a month or two months. I really can't speculate on the length of it."

Who is on the station, and how long can they stay there?

Three people remain on the station: American astronaut Serena Auñón-Chancellor, German ISS Commander Alexander Gerst, and Russian Sergey Prokopyev. They were due to return to Earth in mid-December. "Talked to the crew this morning—they're doing great," the deputy astronaut chief, Wiseman, said. "Everybody is in good spirits. They're ready to serve at the will of the program. They will stay up there as long as we need them to."

The crew has consumables for months and could be re-supplied by two US cargo ships as well as a Japanese vehicle. The bigger question is the health of the Soyuz spacecraft docked to the station. Generally, these vehicles are rated to survive about 200 days on orbit, and the certified lifetime of the vehicle at the station ends in early January. That could be pushed back a little but not too much, officials said.

Could the Soyuz on orbit be replaced?

Yes. Three astronauts—American Anne McClain, Canadian David Saint-Jacques, and Russian Oleg Kononenko—were scheduled to launch to the station in mid-December aboard a Soyuz vehicle. If the Russians and NASA aren't fully confident in that launch vehicle, a Soyuz spacecraft could possibly be launched empty to the station and replace the existing Soyuz as a lifeboat for the three astronauts on orbit. This would give the on-orbit crew another 200 days.

"The vehicle that's going to bring up a replacement crew is moving through its normal development process," Todd said. "Our Russian colleagues would choose how best to handle that situation, and that's all still T.B.D."

Can the ISS be operated from the ground?

NASA's strong preference is to keep astronauts aboard the station. But Todd said NASA does have procedures for operating the station without crew on board. "That's something that we're always prepared for," he said. "I feel very confident that we could fly for a significant period of time."

There is no set period of time. As we understand it, the large space station can be controlled from the ground through its normal operations. However, the risk is that something goes wrong—perhaps with an ammonia pump or with the solar arrays—that cannot be fixed from the ground. In this case, the $100 billion space station would probably be lost. That would be a catastrophic outcome given that NASA and its partners spent 15 years building it, at great cost, and have only begun reaping its research rewards.

Where are the commercial crew vehicles?

They're not ready yet, and Todd was in no great mood to talk about possibly accelerating the availability of SpaceX's Dragon or Boeing's Starliner on Thursday. "We're about eight hours into what was a pretty major anomaly here with this Russian vehicle," he said. "I can promise you we haven't thought too far out for what it means for the commercial crew program. I'm thinking maybe some of the CCP people might be thinking about it."

One possibility floated is accelerating the uncrewed demonstration flight of the Dragon back into late 2018 and flying an operational crew on that spacecraft in mid-2019. This is probably the soonest we could expect either of the commercial crew spacecraft to carry people into space, and even that might be a stretch given NASA's relatively risk-averse posture when it comes to human spaceflight.

Do Roscosmos and NASA trust each other?

This is a question we asked Todd because of a problem with the last crewed Soyuz spacecraft, which launched in June. In August, the crew found a small leak in the vehicle's orbital module and patched it. Russian officials have been coy about how the leak was caused, even intimating shortly after the leak's discovery that a NASA astronaut may have drilled the hole while in space. This is a preposterous theory that caused significant heartache at Johnson Space Center and elsewhere in NASA. Todd sought to downplay any tensions resulting from this.

"Back in that time frame, certainly, we thought that the comments were premature in terms of statements that were made by the Russian side," Todd said. "But once our administrator and [Roscosmos Director Dmitry] Rogozin got together and compared notes—talked about how we approach this situation—it seemed to be there was a bit of a misunderstanding, and at least they worked through that problem."

Todd suggested the leak issue won't affect the current situation.

How did it come to this?

In 2014, I wrote a long story about NASA's drifting human spaceflight program, which dug into the appalling failure by the US government to prepare for the retirement of the space shuttle—it had nearly a decade's notice—and articulate a plan for what came next. Chris Kraft, NASA's legendary flight director, told me, "It’s fairly obvious that no one in the government thought through what they were about to bring about when they made that decision."

He's right. Congress dithered on supporting the commercial crew program, and then once SpaceX and Boeing were properly funded, those companies ran into the inevitable technical issues that arise with spacecraft. So we've been reliant on the Russians for more than seven years now, and having a single-point failure mode in a critical element like access to space has now burnt the spaceflight enterprise. Badly.

So what do you think will happen?

The NASA officials seemed pretty chill at today's news conference. They exuded confidence. I think they believe the Russians, who have flown the Soyuz vehicle for half a century, will identify the issue with Thursday's launch, fix what needs to be fixed, and get back into service within a few months.

Barring that, Russian and US engineers will probably look at sending up an empty Soyuz, or they will convince themselves the vehicle on orbit is safe to remain there as a return spacecraft until January or February of next year. Everyone we've talked to today has seemed confident that NASA won't get into a posture where it has to de-crew the station. Over the next few months, we'll see if they are correct.