SpaceX the Alan Notes

SpaceX scrubbed Monday's scheduled launch of a robotic Dragon cargo capsule to the International Space Station, due to a helium leak on the Falcon 9 rocket's first stage.

Word of the postponement came a little more than an hour before the Falcon 9 was to lift off from Cape Canaveral Air Force Station in Florida.

Photographers focus on SpaceX's Falcon 9 rocket as it sits on its launch pad at Cape Canaveral Air Force Station in Florida on Monday. NASA

Forecasters had put the chance of acceptable weather for launch at 80 percent for Monday, but only 40 percent for Friday.

SpaceX's Dragon capsule is packed with about 4, 600 pounds (2, 100 kilograms) of supplies and equipment for the station. This is the third of 12 round-trip resupply flights that SpaceX is conducting under the terms of a $1.6 billion contract with NASA.

Billionaire's grand vision

This particular mission is notable because it's the first time the Falcon 9 has been outfitted with a set of four landing legs. The 25-foot-long (7.6-meter-long) foldable legs are part of a long-term experiment to see whether the Falcon 9 rocket can be recovered and reused.

This time around, the legs won't play a useful role. They're just part of a test to relight the rocket engines after stage separation and ease the first stage's fall into the Atlantic Ocean, so that it can be recovered intact by a SpaceX team.

SpaceX estimates the chances of a successful recovery at only 30 percent to 40 percent. But if the technology works, the Falcon 9 rocket of the future could fly itself back from a launch, unfold its legs and gently touch down on a landing pad. SpaceX has already tried out the prototype for such a system, known as the Grasshopper, at its Texas test facility.

SpaceX's Falcon 9 rocket has been outfitted with 25-foot-long (7.6-meter-long) foldable landing legs as part of an experiment in rocket reusability. Caroline Trump / SpaceX

Rocket reusability is a key part of SpaceX founder Elon Musk's vision for bringing the cost of spaceflight down to the point that missions to Mars become more affordable, not just for exploration but for colonization as well.

Musk, a 42-year-old billionaire who is also in charge of the Tesla electric-car company and the Solar City power-generating venture, has said his long-term goal is to make humanity a "multiplanet species." He thinks low-cost reusable rockets could reduce the cost of spaceflight to 1 percent of what it is today.

No stranger to delays

Dealing with 11th-hour launch delays is nothing new for SpaceX. It's all part of the California-based company's high-tech, low-cost business strategy. SpaceX's computers are designed to detect glitches and halt the countdown automatically, even after ignition.

Monday's scrub isn't the first postponement for the mission known as CRS-3 or SpaceX-3. Earlier launch dates were missed due to contamination in a payload area and problems with the Air Force's radar tracking system.