Slashdot Mirror
SpaceX Plans Drone Ship Landing On January 17th (nbcnews.com)
Rei writes: With the world's first successful low-speed landing of an orbital rocket's first stage complete, SpaceX looks to continue that success by attempting its second landing — this time, on their new drone ship in the Pacific. While SpaceX has announced plans to turn their successfully-landed rocket, reportedly flight-ready, into a a museum piece, the stage they recover next may be SpaceX's first chance to prove the mudslinging of their competitors wrong and show that Russia's worries are well founded. That is, if they can successfully pull it off.
Just a guess, but they probably don't consider a splashdown-landed rocket viable to be relaunched, or that the refurbishment costs of a rocket that has been immersed-in and possibly flooded-by seawater is too high to justify doing that over building a new one.
This argument was made back when the Shuttle Program SRBs were ocean-landed and recovered, if I remember right they were never reflown either.
Do not look into laser with remaining eye.
Because you will be shocked at what happens next!
Shuttle SRBs were never reflown as the same unit, but they were disassembled for parts to use on later boosters - which were a combination of new and refurbished parts from various flights. Several booster components (structural/aerodynamic parts, mainly) from STS-1 were still being flown on STS-135, the final mission.
I can't speak for the actual economics of the practice, but on paper it looks like it has several obvious advantages, particularly when, as a solid rocket, the largest and most complex component is consumed during flight.
How many parts were used though? Did they limit reuse to just the structural connecting assembly that attached the SRB to the liquid tank, which presumably was a very durable, very hard, very corrosion-resistant part, or did they ship the segments back to Thiokol to get refurbished into fueled segments to then ship back to Florida for use?
Do not look into laser with remaining eye.
You can't reuse one until you learn to land them successfully. They have landed ONE. And I can see the rational about saving it for a future museum. When they have 2 or 3 more successful landings, it will then make sense to launch them again.
It's also not just about floating in seawater. The shuttle SRBs, for example, hit the water at highway driving speeds. It's basically a highway-speed crash.
But yes, floating in seawater is not exactly conducive to reuse of sensitive components ;) It's like saying, "Hey, toss your car in the ocean, have it bob around for a couple hours, then fish it out, dry it off and start it up, it'll surely be fine!" Only rockets have far tighter tolerances than cars - cars are sturdy, heavily built things while rockets are giant aluminum balloons that weigh a couple dozen times more when full than empty. Cars pump their fuel through tiny nozzles and drain a half dozen liters per hour of driving, while rockets can drain a swimming pool's worth of fuel and burn it in a manner of seconds. Cars roll down roads and face "some" air resistance, while rockets face so much that the compression heating burns the paint off of them. Etc.
He's the sort of person who would sell the Red Cross to Dracula.
With all due respect, they can waste their money in whatever fashion they want to - the primary mission is to launch something, if they accomplish that and then want to land the next 100 boosters so Elon Musk can make his own private modern version of Stone Henge out of them, thats his affair.
Or, you simply realise that landing and reusing are only loosely linked, in that you cannot reuse until you land, but you don't have to reuse just because you land.
Submitter here. I actually tried to come up with a better word but couldn't. They're really "slinging" doubt, but "doubtslinging" isn't a word. I thought of "FUD", but that implies a point of view, that the other side is deliberately trying to scare people off with misinformation, and that would be taking things too far.
Some of you with better English language skills than I can surely come up with better phrasing that's not overly wordy.
He's the sort of person who would sell the Red Cross to Dracula.
So, to confirm this, and yes, I know, I'm oversimplifying...
They're essentially reusing the steel cylinder. Presumably they strip it, media-blast it to remove all traces of its previous use down to bare metal, inspect it with sonic or magnaflux or X-ray or pressure test, along the way somewhere confirming its dimensions are still within spec and haven't ballooned due to use, then if it passes, clean again and build it in a similar fashion to if it had been a new steel cylinder being built as a rocket motor...
Don't get me wrong, it's not cheap to build a new steel cylinder capable of handling the pressures that the SRBs take, but if my assumptions about the reuse procedures are even somewhat in the ballpark it's more like recycling than a simple reuse. It saves money, but it's not a simple matter of recovering the spent SRBs from the ocean, checking a few things, buffing the paint and repainting anything that needs it, and casting a new propellant grain into them.
I'm assuming that SpaceX's goal is to collect the landed rocket, clean it, run diagnostics on its active systems, perform some materials tests at places that are known to have suffered load like where the legs attach and at the endcaps where the thrust pressures are highest, touch-up the paint, fill it with its liquid fuel again, and launch it again, possibly all at the same spaceport.
Do not look into laser with remaining eye.
All we really know is that it landed. We don't know how flight ready it was for another launch, I imagine neither did SpaceX. So this first one I don't think they had any other choice but to strip it completely apart and test everything and then putting it all back together might not make sense. Next landing they probably know what needs replacing and can relaunch the rest. Makes sense to me at least.
Live today, because you never know what tomorrow brings
NASAs money is there as progress payments to fulfil NASA contracts, and the ability to land a booster is not part of NASA's contracts with SpaceX. As long as SpaceX is fulfilling the contracts, NASA cannot complain.
The two things that are different between the Shuttles SRB situation and SpaceX's Falcon situation is that the SRBs underwent a significant impact with the ocean and a prolonged dip in salt water, so they literally needed to be stripped down, checked for stress issues etc etc, especially as there was a lot of rubber seals in there which are all suspect after that salt water bath. The Falcon undergoes none of that, so hopefully requires less stringent checks before it can be reused.
SRBs were firecrackers. No control once you start them. The Falcon 9 first stage has engines capable of throttle and relight and a computer that can bring it back autonomously. So, there is a lot besides the rocket in the Falcon that was not in the SRBs.
Bruce Perens.
As much as anything, SpaceX is a monument to Musk's ego.
...and if his little venture is sufficiently successful in getting mankind into space on a regular basis, let alone as permanent residents, I honestly don't give a damn if it pumps his ego or not.
Quo usque tandem abutere, Nimbus, patientia nostra?
A lot of the mission profiles don't work for return-to-launch-site. Heavy payloads to geosynchronous transfer orbit will not leave enough fuel, but they can still reach the barge. The center booster of F9 heavy goes too far downrange but not high or fast enough to make an orbit. So it must use the barge. We haven't heard of them planning to use any conveniently-placed land like San Nicolas Island from Vandenberg.
Bruce Perens.
They're really "slinging" doubt, but "doubtslinging" isn't a word. I thought of "FUD", but that implies a point of view
FUDslinging would actually be a pretty scrumtrulescent word.
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black