This image provided by NASA shows the Orbital Sciences Antares rocket, with the Cygnus spacecraft onboard suffers a catastrophic anomaly moments after a 2014 launch from the Mid-Atlantic Regional Spaceport Pad at the Wallops Flight Facility in Virginia. The Cygnus spacecraft was filled with about 5,000 pounds of supplies slated for the International Space Station, including science experiments, experiment hardware, spare parts, and crew provisions. (AP Photo/NASA, Joel Kowsky)

When we last left off with the two companies hired to fly cargo to the International Space Station their unmanned rockets had exploded, incinerating thousands of pounds of cargo and leaving the astronauts on the orbiting lab in a bit of a lurch.

Suddenly, the so-called golden age of commercial space flight was more molten orange than gilded. And the widespread belief that the industry was finally, at long last, ready to take flight once again had to yield to questions about whether it really can be entrusted with a mission so difficult that traditionally only governments performed it.

Now the question is: can commercial flight rebound and endure?

Starting as early this week, there should be some answers. The two companies that saw their rockets explode on NASA missions are returning to the launch pad. On Thursday, Dulles-based Orbital ATK--which was Orbital Sciences at the time of the explosion, and has since merged with rocket-maker Alliant Techsystems--is set to fly a cargo resupply mission to the station for the first time since its Antares rocket blew up more than a year ago. Then later this month, SpaceX is slated to launch a commercial satellite from Cape Canaveral in its return to flight.

Both companies say they’ve fixed the problems that led to what they call mishaps, learned from the experience and emerged stronger and safer. But with both having explosions so close to one another, the pressure is on.

NASA also has a lot riding on the launches. Years ago, it decided to retire the space shuttle program and outsource the resupply missions to the commercial sector, so it could focus on deep-space missions.

There is no Plan B.

The failed attempts forced NASA to scramble; the station was ultimately resupplied by the Russian and Japanese. NASA has said that the astronauts were never in danger, and the agency has stood by the companies, saying it is confident with the way they have bounced back and handled the subsequent investigations.

“The mishap was very disappointing and a pretty big blow to the team,” Frank DeMauro, Orbital’s Vice President of Human Space Systems, said in an interview. “The day of the mishap, we licked our wounds and let ourselves grieve a little bit, but got right into the process of figuring out how we were going to return to fly.”

[Another major rocket failure for an industry out to prove itself.]

After SpaceX’s Falcon 9 rocket exploded in June, Gwynne Shotwell, SpaceX's president said it was, “a hiccup. It’s certainly a time to pause and make sure we’re doing everything we need to do.”

Elon Musk, the company’s billionaire founder, vowed to not just return to flight quickly but to restore some of the sense of urgency that propelled his struggling start-up to a disruptive, mainstream force in the space industry.

“To some degree I think the company as a whole maybe became a little complacent,” he said in July.

Still, Musk is marching back with swagger, signaling that the company will pick up right where it left off and again try to land the first stage of its Falcon 9 rocket. Being able to land and reuse rocket boosters has become a Holy-Grail quest in the industry, which would help it lower the cost of space flight.

Rocket boosters, which house the engines and are the most expensive part of the vehicle, are typically discarded into the ocean. Throwing them away is like junking planes after each commercial flight. But being able to reuse the rockets repeatedly would disrupt the economics of space flight.

Last week, amazon.com founder Jeff Bezos shook up the space world when his space company was able to launch its rocket to space and then land the first stage vertically.

[Jeff Bezos sticks rocket landing, stakes claim in billionaires' space race.]

In a series of tweets, Musk made it clear that what he is attempting is more difficult—trying to land a bigger, more powerful rocket designed to launch into orbit, not just the boundary of space as Bezos’ company had done. (Bezos also owns The Washington Post.)

In SpaceX’s two previous attempts, the 14-story-tall rocket hit a floating platform and exploded. This time, Musk indicated that SpaceX will try to land the booster on land. The company has taken over a launch pad at the Kennedy Space Center, and is also building a landing site nearby, which it has not yet publicly showed off.

As Orbital heads to its scheduled launch from Cape Canaveral Thursday, it won’t be using the company’s Antares rocket, which is still being upgraded with a new engine after the explosion. Instead, the Cygnus resupply capsule would launch atop the United Launch Alliance’s Atlas V rocket.

The launch will be “a tense moment,” said Lori Garver, the former NASA deputy administrator. But she said it was exciting that both companies “came so quickly to reflight. We all knew an early accident could derail the whole program. But obviously it has not done that.”

Now, NASA is looking ahead to the next round of contracts to resupply the space station, which it expects to award in January. And it is preparing for an even bigger milestone: the day when the United States can once again fly astronauts from American soil, a capability lost when the space shuttle was retired in 2011.

Boeing and SpaceX, the two companies that won that contract, are developing their vehicles, which would fly humans, and not just cargo, to the station. That makes the upcoming return-to-flight launches even more important—and the failures more consequential.

As the 3-2-1 countdown ticks to “lift off!” and the rockets ignite, it’s hard not to wonder: what if people were on board?