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Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Ive been looking for info on the number of crashes of the reusable vertical landing one. Successful versus unsuccessful numbers. Ive been reading all the news media articles, but of course when it comes to technology, the media spoon feeds the masses info - even they don't understand.
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
So far there has been 1 success, as to the number of failures it depends on how you count. There have been a total of 21 launches of the Falcon 9, so you could say that there have been 20 failures but that would be disingenuous since they only even tried to land about half of them, in fact they did not even have the landing legs attached until the 9th flight.
There were also the Grasshopper, which was a modified Falcon 9, which was a test bed for the landing systems. That one flew 8 times with increasing heights each time, with the final flight reaching a height of about a half a mile, all with successful recoveries.
Most of the flight data is publicly available through their press releases, and details about the failures are usually released via tweet a few hours after a failed launch or recovery. There is a nice summary on wikipedia at
The thing that I would like is a bit more advance warning before launches take place, I think you are supposed to follow their twitter to listen for launch updates but that requires sifting through the rest of their publicity. At least the coverage they have of their launches, in my opinion, is a fair bit better than the shuttle launches were, especially considering that until nasa started streaming nasa tv online in the mid 2000's you either had to have one of the C-band satellite receivers (the bigass 10ft dishes) to get the over-the-air broadcasts or hope that your local cable provider carried the channel that showed launches.
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
As a company, they primarily rely on secrecy to protect their industrial designs. This ensures that: 1. They will usually be 3 years ahead of anybody else technologically 2. The huge legal cost can be reallocated into design expenses 3. Given 1 & 2 , like JPL they do not publish 99% of their accomplishments
A reusable launch stage is very difficult to model as the mass is always decreasing, and has partially filled liquid propellants sloshing around the tank baffles. Its the kind of control problem that gives Engineering physics people nightmares.
I was impressed they managed to get it to work once.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Carbon_Rod wrote ...
A reusable launch stage is very difficult to model as the mass is always decreasing, and has partially filled liquid propellants sloshing around the tank baffles. Its the kind of control problem that gives Engineering physics people nightmares.
I was impressed they managed to get it to work once.
yeah I was drawing the same conclusions over the past year or so. they must have ultra high speed - ultra sophisticated control models. even then, theyd have trouble keeping up with the unwanted changes. That's a lot of inertia to be standing straight up and down, and not have it be tilt-happy
I'm just wondering how much mass-fraction theyre losing as on orbit payload, due to this recovery and reusability business model.
Also the DC-X had a pyramid shape, with that wide base. I'm sure that made it more stable. Mr. Musk doesn't have that advantage.
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SpaceX Crashes.
