Author Topic: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3  (Read 815127 times)

Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #640 on: 04/25/2016 08:49 PM »
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

My source at McDonough Marine says all their big barges are rented out and he hasn't heard or seen anything locally to suggest SpaceX is expanding their ASDS fleet. If they did, it would have to be with a different company, elsewhere.

PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

Interesting... What is the lead time for new construction of this class of barge? And if new construction were commissioned, would it be this class or would SpaceX start applying learnings (integrated shielding instead of tacked on.. special thruster housings, etc... there are dozens of things one COULD do...)? It's possible it's too early to start customizing much, so by going for another Marmac 300 class, the barge could be returned to the lessor more easily...

Lead time for modifying an existing 300' x 100' barge would be 5-7 months according to my source. A new purpose-built barge could be around 12 months or more, depending on their specs.

Online abaddon

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #641 on: 04/25/2016 09:33 PM »
I wonder if SpaceX will at some point try and juggle their schedule to alternate ASDS and RTLS flights.  If we imagine the once every two week cadence they hope to hit (at least some of the time) later this year, back-to-back ASDS recoveries might be impossible, even with no damage to the drone ship.  I guess you can also start adding JRTI to the mix as VAFB flights start coming on-line later in the year.

Offline CameronD

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #642 on: 04/25/2016 11:42 PM »
Thank you!

That rohn tower does indeed have a combined anemometer/direction indicator, and it's ultrasonic.
.......
I'd also be willing to bet that somewhere aboard is an accelerometer/tiltmeter, to give them data on the exact attitude and motion of the ASDS at the moment of touchdown (for later analysis, not realtime use).  Might also be useful to know before launch if conditions are marginal (assuming they'd delay a launch for a landing issue). 

The high-res photos aren't quite high-res enough to work out exactly what they're using, but for completeness it is probably what is technically known as a "marine weather station", similar to this one:



These units use on-board GPS and gyros to compensate for movement of the platform giving precise true wind speed and direction - something I presume they'd need to know in the final seconds before touchdown - and the gyro outputs can be useful for motion recording also.  They're extraordinarily accurate.. to tenths of a knot!


PS:  Apologies for the viewing angle mix-up.  I've edited my original post accordingly.
« Last Edit: 04/26/2016 12:17 AM by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline CameronD

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #643 on: 04/26/2016 12:32 AM »
My source at McDonough Marine says all their big barges are rented out and he hasn't heard or seen anything locally to suggest SpaceX is expanding their ASDS fleet. If they did, it would have to be with a different company, elsewhere.

PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

Interestingly, the USCG never wiped their "Research Vessel" listing for MARMAC 300 - their Certificate of Documentation is valid to April 2017.  I'm not saying that implies anything.. only that, from a pure paperwork stand-point, it wouldn't be difficult to apply for this classification to be reinstated, should they choose to do so.

Personally, I can't see them increasing the SpaceX Navy for some time yet - the cost of barge upgrades, maintenance, berthing, man-power and tug support just does not seem to be warranted at this point.


« Last Edit: 04/26/2016 12:37 AM by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Online Herb Schaltegger


Personally, I can't see them increasing the SpaceX Navy for some time yet - the cost of barge upgrades, maintenance, berthing, man-power and tug support just does not seem to be warranted at this point.


Agreed. Once they reach a sustainable cadence, perhaps. But look at JCSAT-14 - the anticipated launch date has slipped approximately a week just since the CRS-8 flight. Until they need to sortie more than once every three - four weeks, there's no need for another barge, absent any SES-9 style rocket-punching through the deckplates.
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Offline CJ

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #645 on: 04/26/2016 03:03 AM »
I agree with those above who say they don't see the ASDS fleet increasing soon.

My take is it's way too soon; they're going to want to learn operational lessons, and also wait until they actually need more ASDS (that way, any new ones can be designed with lessons learned in mind).

Is one ASDS enough for the Cape? I think it is, even for FH - it looks like the early FH flights will have the side cores doing RTLS, leaving only the center core for ASDS to worry about.  As for F9 launches, the ASDS operational cadence could be increased in case of need (unless there are reasons why not?). The next flight, for example, has the ASDS approx 400 miles  offshore - further than usual. But, let's assume that's average. That's 69 hours one way from Canaveral at 5 knots. Let's say 12 hours on station, then 69 hours back.  150 hours round trip - 6.25 days. Is it reasonable to say an operational ASDS, after plenty of practice, could be unloaded and prepped for another mission in 3/4 of a day? If so, you've got an ASDS capability to support launches a week apart. If for some reason (say, launch dates 5 days apart) you need to do better on occasion, make sure of of them (the first one) has enough margin for a partial boostback burn to cut the distance offshore, or, temporarily hire a larger, faster tug that could handle the ASDS at, say, 8 knots, cutting outbound transit time down 43 hours.

IMHO, it'll be a long time before launch cadence (even if we assume no RTLS, ever) exceeds the capacity of one ASDS - and SpaceX has a track record of not completing new things before they are needed - why make a capital expenditure before it's needed?   


Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #646 on: 04/26/2016 03:19 AM »
Quote
?...and SpaceX has a track record of not completing new things before they are needed - why make a capital expenditure before it's needed?   

Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

Offline miscme

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #647 on: 04/26/2016 03:33 AM »
Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

I recall JRtI trying to catch the Jason-3 booster just 3 months ago.

Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #648 on: 04/26/2016 03:44 AM »
Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

I recall JRtI trying to catch the Jason-3 booster just 3 months ago.

OK, one attempt in a year. "Almost" nothing.

Point remains, the asset has been, shall we say, extremely underutilized.
« Last Edit: 04/26/2016 03:46 AM by Kabloona »

Offline The Amazing Catstronaut

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #649 on: 04/26/2016 04:41 AM »
Whoo-hoo, another exciting recovery then!
That doesn't follow. It's possible that they're going to do a ballistic reentry but not use the super max gonzo 3 engine landing option...

Lar, can I report you if your comment made me spill my hard-earned five AM hot chocolate on my crotch?
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Offline timverhoeven

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #650 on: 04/26/2016 11:39 AM »
Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

I recall JRtI trying to catch the Jason-3 booster just 3 months ago.

OK, one attempt in a year. "Almost" nothing.

Point remains, the asset has been, shall we say, extremely underutilized.

Accorinding to the manifest on http://forum.nasaspaceflight.com/index.php?topic=40049.msg1523417#msg1523417 there are 3 flights from the West coast planned for the remainder of this year. And the 6 months downtime because of CRS-7 didn't help of course.

Offline Scylla

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #651 on: 04/26/2016 01:42 PM »
Go Quest has moved near OCISLY.
http://portcanaveralwebcam.com/
« Last Edit: 04/26/2016 01:44 PM by Scylla »
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Offline the_other_Doug

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #652 on: 04/26/2016 02:48 PM »
Hypothetically, if launch cadence ramps up like the manifest says it might, could we get into a position where there is another GTO (or even FH) launch approaching and the drone ship is still carrying a stage back from the last launch attempt?

To put it more bluntly, what do we think is the fastest launch cadence we could see for launches which cannot use an RTLS trajectory for stage recovery?  Is three weeks between GTO launches too little time, or plenty?  Is two weeks pushing it too much?  Is a single week between GTO launches even do-able without designating the second GTO launch in a row as expendable, simply because the ASDS isn't ready to sail yet?

I'm thinking that SpaceX won't delay a launch just because the ASDS is still making its way back to Port Canaveral.  So, at what launch cadence will SpaceX require a second ASDS to be available on the ETR?  (Obviously, the WTR is not so much of an issue, as the launch cadence from Vandenberg isn't projected ot be nearly as busy as that from the Cape.)

Since moving JRtI from California to Florida would seem to require removing its wings before it will fit through the Panama Canal, I'm assuming in the question above that there is no operational flexibility available by using one of the current fleet of two as a "swing barge," able to pop over to the ETR when the cadence demands and pop back over to the WTR when it's needed.  In other words, I'm assuming that, for any kind of short-term planning purposes, an ASDS asset on one coast is unavailable for use on the other coast.  Unless Musk fits out one of them with Merlins, as he joked a couple of years ago...
-Doug  (With my shield, not yet upon it)

Offline cscott

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #653 on: 04/26/2016 03:18 PM »
Doug, your question was answered a few posts above yours.  And yes, our observations confirmed that Panama canal transit is a huge time (and money) sink in addition to the wing mods required; I think we can safely assume JRtI will not taste the Atlantic again.

Others: I agree with the general sentiment "too soon to massively increase ASDS fleet".  I wouldnt be too surprised to see *one* more ASDS on the east coast in the next, say, one to three years.  I suspect three-ASDS landings for FH will be pushing the limits of center core reentry speed and downrange distance for some time yet, so (in my possibly-crazy opinion) after the "easy" all-RTLS and side-RTLS/center-ASDS missions the next increment of performance would be side-ASDS/center-expendable.  That would only require a single new ASDS, and I think there are two MARMAC class barges still unaccounted for?  That extra ASDS could cover Boca Chica and provide some operational flexibility---the two/three year time frame is about when I'd expect the launch cadence to have come up and Boca Chica getting near completion.  As calculated above, a single ASDS is good for approximately weekly flights, and I don't see SpaceX achieving that (or anything other than RTLS of FH side cores) in less than a year.

(On the other hand, I wonder if they'll have dialed in landing accuracy enough in the two-ish year time frame that they feel comfortable landing both side cores on a single barge?  There is space along the long axis.  But if so that also enables them to try all-ASDS missions with a two-barge fleet, so maybe that's another reason the eventual Atlantic fleet size could grow to two?)
« Last Edit: 04/26/2016 03:25 PM by cscott »

Offline Alastor

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #654 on: 04/26/2016 03:33 PM »
what do we think is the fastest launch cadence we could see for launches which cannot use an RTLS trajectory for stage recovery?

As far as we have seen, assuming that ASDS does not sustain damage on landing (as seems to have happened last time), there is not much needed for the ASDS to be ready to sail again.

Coming back to shore did take less than a week, and as it was the first ASDS landing, we can assume that as was the case for port operations, they may have deliberately taken their time with it, in order to be sure they didn't make any mistakes.
Unloading operations did take no more than a few hours, once they arrived to port.
Preparing the ship to be ready to sail must be what, 1 or 2 days at most, I'd say.
Going from port to the landing zone is usually about 4 days.

In short, ASDS should be able to be recycled in about 10 days, maybe a bit more.
Going down to 7 days may be asking too much, since it would require the ASDS to go faster on the return trip than to go there, and would leave no margin. So it seems that this is definitely a no go for 7 days recycle.

So I'd say they will need a second ASDS on this coast at about the time when there will be an ASDS landing required once every two weeks. Two should be enough to be good for an ASDS landing once every week, maybe a bit less if they rush it. So it will be a long time before they need more than two (if ever).
Then, let's not forget that they can always decide to go expandable once in a while. I know it's tempting to believe that from now on, they will catch every single first stage they launch, and in the long run, that may be the aim, but until they can "safely" reuse a first stage, and until they seriously ramp up the storage capability, trying to catch every first stage they launch may cause them some serious logistics headaches, that may be solved by going expandable sometimes.

Online Lar

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #655 on: 04/26/2016 03:35 PM »
Then, let's not forget that they can always decide to go expandable once in a while. I know it's tempting to believe that from now on, they will catch every single first stage they launch, and in the long run, that may be the aim, but until they can "safely" reuse a first stage, and until they seriously ramp up the storage capability, trying to catch every first stage they launch may cause them some serious logistics headaches, that may be solved by going expandable sometimes.

Oh what exciting times we live in... "guys... splash this next one, we have too many first stages in the barn right now..."
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Offline Scylla

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #656 on: 04/26/2016 05:28 PM »
Spotted some workers on OCISLY. Possibly begining preperations for next launch.
http://portcanaveralwebcam.com/

Since we have this handy webcam, might be time to create a stand alone update/discussion thread for OCISLY.
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Offline IntoTheVoid

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #657 on: 04/26/2016 05:29 PM »
Oh what exciting times we live in... "guys... splash this next one, we have too many first stages in the barn right now..."

I still don't see that you'd really want to splash it on purpose. Why not try a really aggressive landing attempt with the first of the pair; something you expect to fail (like SES-9). If you pull it off then maybe you splash the second, but if you fail as expected then you've at least learned something from the lost S1. Sure you might damage the ASDS, but you could stage some steel and welders on Go _____ for on-site repair.

Online Lar

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #658 on: 04/26/2016 05:37 PM »
Alternatively (and this is really crazy) land one in one corner of the ASDS and the other one in the opposite corner.

That's such a silly idea I should self report...
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline OxCartMark

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #659 on: 04/26/2016 05:50 PM »
Wow, lots of good discussion here.  Hopefully our discussion on the need for more ASDSs is being done on a time available basis and doesn't cut into our staying on top of the real time ASDS events that Scylla is pointing out. 

I agree its not likely that the ASDS fleet is going to grow soon, particularly in light of abaddon's suggestion to juggle the launch schedule to have RTLS and ASDS alternate, its just that we're all here on this ASDS thread and it would be good for us to be ahead of whatever may be happening if it does so keep your eyes open.  As for Cameron's comment that the ASDS fleet is expensive I respond yes, but a) Part of that expense is Go Quest & Searcher, Port facility, crane, equipment rental, personnel that are not utilized much of the time with one ASDS, those expenses wouldn't increase appreciably with a 2nd ASDS, b) Having to juggle the launch schedule if a second ASDS becomes useful isn't an inexpensive option c) If the current ASDS becomes damaged which I've seen happen 4 times now out of ?6? you'd want another ASDS c) (somewhat indirictly related) The scale of expenses run up by the SpaceX navy is light compared to the cost of one lost stage.

Kabloona, good work in keeping in touch with your inside contact.

Hmm, now with a bit of time since writing above I am leaning a bit in favor of thinking a second east coast ASDS may be coming sooner rather than later.

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