Any historical media that is exclusively digital can be forged. Once we have molecular level 3-D printers, all physical historical artifacts can potentially be forged and altered. We have to look at a possible future where there in no way to verify any historical fact, an historical fact being anything that happened more than a nanosecond ago.

The final approach is at 250 m/s. If I have this right, they'd be going about that fast if they started falling from zero velocity at 3 KM, ignoring air resistance. So, whatever parachute you use has to get you much lower and slower than that, and so precisely positioned above the barge that you can do the rest on the rocket.

Now, ULA plans to revive the Rogalo Wing from Gemini and combine it with the mid-air retreival from Corona, so this might not be completely absurd.

Sorry.

I guess then you were not so lucky as to have rocket scientists in the family. I guess I'm not unlike many techies my age, whose dads worked in aerospace. My dad worked on the lunar module at Grumman. My father in law worked in the blue cube for Lockheed.

People think of me an the Open Source guy. But I have been getting space spoon-fed to me since before first grade.

It's still slowing down during the last rocket length. That is really cutting it close, yes. I think the goal is to use an absolutely minimal fuel expenditure. The current configuration is not capable of landing after a GTO insertion. When they were considering doing the test for the DISCOVR flight, they were not going to have enough fuel for the normal recovery sequence, and were planning to delete the subsonic decel burn and come up to the barge at 1 KPS rather than the leisurely 250 m/s.

Armstrong did punch out of an LM trainer before that mission. It crashed and burned. They say that afterward, he went back to his office and quietly did some paperwork.

Well, it did what SpaceX was paid for reliably, which was to send the Cargo Dragon up to ISS in an expendable rocket. All of the NASA demo and supply flights they have done have been successful.

Recovery is so far a secondary and private mission of SpaceX, and Musk did say it had less than a 50% probability of success for this attempt (but a 75% to 80% probability of success for the year).

Me, I'm damned impressed that they can bring that thing from 78 miles high and suborbital speed, and touch the landing gear down on the barge at an acceptable descent rate. I think this is pretty good for the second try and they'll nail it soon enough.

Just look for one that says "Fallout Shelter"

If you think that's bad, read some of the comments to nontechnical news site articles on the recovery failure. Ignoramuses whining "how much of my taxes did this failure use". They aren't even smart enough to realize that it launched the Dragon to ISS successfully, and that NASA isn't footing the bill for recovery attempts. It's really enough to kill one's sympathy for the common man.

I was surprised by something in the re-entry profile. They use what they call "lift" from tilting the rocket body against the air stream to control horizontal motion. I call it "falling with style". So they can go back uprange some distance without an additional fuel expenditure.

All of their communication so far has been that they can get back to the pad with the F9 or the two outer stages of the F9 Heavy. The center stage of F9 Heavy would probably need the barge.

That would be hot for an aircraft, but it was the planned vertical speed profile for the rocket. The grid fins need speed to work and they are the main control surfaces. The cold gas thrusters don't have infinite gas behind them and the engine burns are very short.

They planned the fast approach. Consider that the main control surfaces are the grid fins. They don't work at slow speeds. It's all about landing with the minimum use of weight (thus fuel).

I must confess that most of my programs have bugs the first time I write them. I don't start over from zero when that happens.

The Wright Flier didn't get to San Francisco, but it started the path that led there. Actually touching down on the planned point, at the planned vertical velocity, is pretty good. They'll fix the rest.

The required longer burn to make up for a shut down engine does use extra fuel. It also changes the orbital injection point.

Speed and distance are the big problems. Rockets can do both. Things that are tied to ships or the ground have trouble keeping up with the rocket.

The first stage is most of the rocket by weight. The second stage has one engine, while the first has 9. And as you can see from a photo, the second stage is much smaller.

What makes it recoverable is that it doesn't take much fuel to bring an empty first stage back down. It's really light when empty. They only use one engine out of the 9, for very short burns, to do that.