SpaceX's Falcon 9 Crashes Into Droneship (cbsnews.com)

SpaceX failed to successfully land its Falcon 9 on a drone ship at sea on Wednesday. Prior to today's crash, the company was able to conduct three successful experimental landing of its used rocket in a row. SpaceX founder Elon Musk noted that the booster rocket had a RUD (rapid unscheduled disassembly, he explained) on droneship. From a CBS News report: It was the California rocket company's fifth unsuccessful drone-ship landing after three straight successes, one in April and two in May. Including a successful landing at the Cape Canaveral Air Force Station last December, SpaceX's recovery record now stands at four successes in nine attempts. But the landing attempt was a strictly secondary objective. The mission's primary goal, the launch of two powerful all-electric communications satellites, was a complete success and regardless of the loss of the first stage, company engineers expected to collect valuable data as they continue their push to make such landings routine.

Comments

RUD FUD

[ColdWetDog]

I like that....

This is still lots better than what NASA is doing. Stressing the technology. Doing new things.

Going ka boom. Everybody needs an earth shattering kaboom now and again. I just wish they'd have audio on the drone ship.

Telemetry

[JamesPLynch]

Musk tweeted:
"Looks like thrust was low on 1 of 3 landing engines. High g landings v sensitive to all engines operating at max."
"Upgrades underway to enable rocket to compensate for a thrust shortfall on one of the three landing engines. Probably get there end of year."

Landing video froze at the last moment but it looked like a bulls-eye landing. There was flame climbing up the side of the stage. Telemetry should be helpful in making improvements.

Re:Telemetry

[Anonymous Coward]

Falcon 9 has 9 of those engines. they only use 1 to 3 of them for landing depending on the launch profile, using all 9 of them would make the rocket go back up instead of landing (technically if they left 1 of them turned on long enough it would make the rocket go back up, part of what makes landing a falcon so challenging compared to the blue origin's rocket)
Falcon heavy will have 9 on each core, with 3 cores, total of 27 of engines, but each core will have to land independently. So for the landing, not much actually changes, other than two of them happening at the same time (and one slightly later if they try to recover the center core, probably only going to be feasible on very heavy launches to LEO)

Re:All Electric? Cool!

[Anonymous Coward]

ion propulsion is NOT "all electric". Still need some particles to ionize.

Re:All Electric? Cool!

[ClayJar]

Also, chemical propellant is "heavy", meaning it takes much more mass to get an equivalent kick. If you want real words, the Isp (specific impulse) is lower for chemical propellant engines than for ion engines. With all electric satellites, you can carry much less propellant, meaning you can have a satellite of comparable capability in much less mass. In the case of these two satellites, the Boeing BSS-702SP platform they're built on means you can fit two on a "normal" GTO launch. That basically halves your launch costs.

The tradeoffs are that while all electric propulsion is very "fuel efficient", the thrust of ion engines is a very small fraction of that of the more conventional chemical propellant engines, so instead of taking days to settle in to your final orbit, it can take weeks of slow orbit raising. This is a "cost" that may or may not be worth the trade. Also, since the 702SP satellites are launched in pairs, a launch failure could take out two birds with one... rocket. To give a bit of insurance against this, Eutelsat and ABS chose to split two rockets. They'd each fly one satellite per launch, meaning they only risked one of their two each flight in case of a Very Bad Day.

Re:Someone is playing Kerbal Space Program

[ray-auch]

RUD = "Rapid Unplanned Disassembly" has been around a _lot_ longer than ksp.

See google books for one example from 1991, but it goes back much further than that.

Re:Someone is playing Kerbal Space Program

[Applehu Akbar]

"Also lithobreaking is used as a term for crashing."

No, that refers to a type of prison labor. You mean lithobraking.