The third time was definitely not the charm for the International Space Station last week, as an unmanned cargo ship bound for the orbiting outpost exploded 2½ minutes after launch.

The catastrophe involving California company SpaceX's rocket was the third space station resupply mission to end in failure within the last year, and the second in a row.

In October, a rocket launched by U.S. company Orbital ATK erupted in flames seconds after launch.

Then in April, a freighter launched by Russia's space agency spun out of control before it could make its rendezvous with the station, and was left to burn up in the atmosphere with its 2.7 tonnes of fuel, water, food and other supplies.

The spate of mission mishaps is raising some serious questions. Will it hamper the rapid expansion of the multibillion-dollar commercial spaceflight industry? Was it wise to outsource space missions to private contractors like SpaceX and Orbital ATK, as NASA did when it retired its space shuttles in 2011?

It's still rocket science

But while aspiring space tourists might now think twice about booking a trip to the ionosphere, and stock market investors get spooked (Orbital's shares plunged 17 per cent after its rocket exploded), space industry veterans seem unfazed. To them, rocket science is still rocket science: complex, hazardous and prone to the occasional catastrophic error.

chris hadfield feature

Chris Hadfield, who flew on three space missions and commanded the space station, says failures are important to the industry because they can pinpoint errors before they become truly calamitous.

"I think it's a surprise to people that aren't in the business, because people sort of have a fond hope that things are going to go perfectly," said retired Canadian astronaut Chris Hadfield, who travelled to space three times between 1995 and 2013, including two months as commander of the International Space Station.  

"But in the actual business we recognize very clearly that it is very difficult, very hard to put a rocket in space."

Hadfield likened launching a rocket into orbit to crafting the perfect firework: You know all the theory, you make it according to spec, you might even test parts of it in controlled conditions — but ultimately, you only have one try at the real thing. And sometimes, it just doesn't go off as planned.

"Rocket launches are an immensely exaggerated version of that," he said.

Backup plan

The trick is to not put all the space eggs in one basket. For the space station resupply missions, none of the materials on any of the three doomed launches was in itself essential to the life or wellbeing of the astronauts living up above the Earth, or to the station. After the SpaceX rocket blew up, NASA said there is still a healthy cushion of four months of food, water and air aboard the outpost. Any highly sensitive equipment being sent up into space will often have a second, backup copy back on Earth just in case.

Space Station

The SpaceX Falcon 9 rocket and Dragon spacecraft break apart shortly after liftoff on Sunday, June 28. The rocket was carrying supplies to the space station. (John Raoux/Associated Press)

The other trick is not to use just one kind of basket to carry the eggs. Over the years, the space station has had a half-dozen different types of spacecraft come to provision it: the SpaceX and Orbital ATK rockets, Russia's Progress and Soyuz capsules, Japan's HTV, and the now-retired NASA shuttles and European Space Agency ATVs. That way, if a fatal flaw is discovered in one or two vehicle models, others can step forward and fill any gaps.  

"There's so many rockets going up," said Scott Larson, CEO of UrtheCast, a Vancouver-based company that has cameras installed on the outside of the space station to beam high-definition video back to Earth. "And it's getting easier and easier to get stuff into space than it was even a few years ago."

But easier doesn't mean easy.  

Take Larson's company, which had its own difficult moments. The camera system didn't work the first time spacewalking astronauts tried to install it. The cameras had to be removed and reinstalled a month later. Even then, one of them had telemetry problems while the other suffered some glitches with its robotic arm.

"Fundamentally, space is hard. I'm not sure there is a more difficult industry," Larson said.

Spaceflight still young

No less an authority than Buzz Aldrin, the second-ever man on the moon, agrees.

"Everyone in the launch business has failures — everyone," Aldrin wrote in a column last week for Time magazine after the SpaceX disaster.

That means public agencies like NASA and Russia's Roscosmos, but also the private companies that are now — to consternation in some quarters — handling more and more of the launches.

Neither Aldrin nor fellow astronaut Hadfield, though, say they have any concern that the recent SpaceX and Orbital ATK mission failures mean it was a bad idea to outsource spaceflight to the private sector.

"I don't think that's nearly as valid a concern as folks like it to be," Hadfield said. He pointed to the "long string of successes" SpaceX has had sending supplies to the space station and also launching satellites for other private companies.  

The fact is, spaceflight is still in its youth — it's been 57 years since the Soviet Union launched the first satellite, and 54 since the first human took to the stars. At the same point in the history of aviation, it was a risky business, too, Hadfield says.

"I'm really interested to see what we learn from all three of these accidents. Space exploration is going to benefit from these. We're going to have safer and better spacecraft as a result."