Hugh Pickens writes:
The cost of getting to orbit is exorbitant, because the rocket, with its multimillion-dollar engines, ends up as trash in the ocean after one launching, something Elon Musk likens to throwing away a [Boeing] 747 jet after a single transcontinental flight. That's why on Tuesday morning at 6:20 a.m. EST his company hopes to upend the economics of space travel in a daring plan by attempting to land the first stage of a Falcon 9 rocket intact on a floating platform, 300 feet long and 170 feet wide in the Atlantic Ocean. SpaceX has attempted similar maneuvers on three earlier Falcon 9 flights, and on the second and third attempts, the rocket slowed to a hover before splashing into the water. “We’ve been able to soft-land the rocket booster in the ocean twice so far,” says Musk. “Unfortunately, it sort of sat there for several seconds, then tipped over and exploded. It’s quite difficult to reuse at that point.”
After the booster falls away and the second stage continues pushing the payload to orbit, its engines will reignite to turn it around and guide it to a spot about 200 miles east of Jacksonville, Florida. Musk puts the chances of success at 50 percent or less but over the dozen or so flights scheduled for this year, “I think it’s quite likely, 80 to 90 percent likely, that one of those flights will be able to land and refly.” SpaceX will offer its own launch webcast on the company's website beginning at 6 a.m. If SpaceX’s gamble succeeds, the company plans to reuse the rocket stage on a later flight. “Reusability is the critical breakthrough needed in rocketry to take things to the next level."
You say with today's level of technology, but remember that Spacex's engines are at least 20 years newer technology. Also, with regards to fault tolerance, they already had a successful launch during which one of the nine engines failed.
You say with today's level of technology, but remember that Spacex's engines are at least 20 years newer technology
Not much changed in rocket science in last 20 years. Yes, SpaceX is riding on new computers and better models, which helps reduce costs somewhat. But the gain is not that significant, the launch and descent profiles are still harsh, and the space is still not within reach of a common man - it's not even within reach of a common business.
Also, with regards to fault tolerance, they already had a successful launch during which one of the nine engines failed.
There are different failure modes. Some are survivable, some are not (see Antares.) Generally speaking, the latest and greatest rocket engines are still terribly unreliable if you compare them to, say, civil aviation's jet engines. Car engines are another thousandfold reliability boost from that.