Author Topic: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2  (Read 2435872 times)

Offline Ohsin

  • Full Member
  • ****
  • Posts: 1469
  • Liked: 1451
  • Likes Given: 2380
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #760 on: 01/08/2015 09:42 pm »
So many questions..
Lightning protection? Is there any? , Are 'tie downs' ballast tank hatches?, What is the exclusion area around ASDS? If its 10miles do they let it go out of this radius and then it covers distance and station keep unassisted? Were they just topping off the tanks or they  really needed refueling , how much fuel it can consume during each outing as delays can really mess up recovery operation if it needs to be refueled frequently.. we know how much those thrusters can consume, how much those two generators may burn....etc etc
"Well, three cheers to Sharma, but our real baby is INSAT."

Online Comga

  • Senior Member
  • *****
  • Posts: 4607
  • Liked: 1846
  • Likes Given: 1548
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #761 on: 01/08/2015 10:34 pm »
Have not seen this link here. A great compilation of video footage from multiple viewpoints of BargeX being towed to its destination today. In the last sequence, which starts at 1:19 and takes up the bulk of the total length, it takes a while for BargeX to become visible (it's finally fully visible at 2:42), but it's worth the wait.


Really cool
One thing to notice is the clear visibility of the tow line.  Granted that these images were from close range and at very low angle, but they show that the line would disturb the water enough to be visible.  There was some debate about the arial photo of the ASDS out near its "station".  Some insisted that it was moving itself.  Some thought that it could be under tow.  Not only does the length of the tow line in the video suggest that any tug would have been in the frame, the interaction of the tow line with the water would very likely have been visible.  So no tug, line, or waves from either weighs heavily in favor of the ASDS having been operating autonomously.

Be careful drawing conclusions.  The "figure 8 maneuvers" seem to indicate a change in towing configuration after the ASDS leaves the channel.  So you can't necessarily assume that the ASDS under tow in the open ocean would look like it does here.

In particular, the ASDS is being pushed by the Gregg McAllister in this video!  We know that Gregg doesn't leave the channel.
But if the tug is pushing it would have been within the frame of the picture.
"You can't push a rope."
We saw the ASDS being pushed AND towed.
The logical conclusion remains that the arial image showed the ASDS operating autonomously.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline akku

  • Member
  • Posts: 19
  • vienna austria europe
  • Liked: 3
  • Likes Given: 1
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #762 on: 01/08/2015 10:35 pm »
In November 2009, the STS-129 space shuttle mission attached two antennas—an AIS VHF antenna, and an Amateur Radio antenna to the Columbus module of the ISS. Both antennas were built in cooperation between ESA and the ARISS team (Amateur Radio on ISS). Starting from May 2010 the European Space Agency is testing an AIS receiver from Kongsberg Seatex (Norway) in a consortium lead by FFI (Norway) in the frame of technology demonstration for space-based ship monitoring. This is a first step towards a satellite-based AIS-monitoring service.[5]

http://en.wikipedia.org/wiki/Automatic_Identification_System

>> vesselfinder ;)

« Last Edit: 01/08/2015 10:47 pm by akku »

Offline cscott

  • Senior Member
  • *****
  • Posts: 2953
  • Liked: 2062
  • Likes Given: 666
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #763 on: 01/08/2015 10:59 pm »
But if the tug is pushing it would have been within the frame of the picture.

Exactly.  There was no tug pushing it in the open ocean.  There was a tug pushing it in the video taken in the channel.  Therefore video taken in the channel can't be used to make claims about what tow conditions in the open ocean are like.

Offline NotOnImpact

  • Member
  • Posts: 44
  • Texas
  • Liked: 36
  • Likes Given: 10
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #764 on: 01/08/2015 11:27 pm »
I am pretty sure that I see one or two people are on the ASDS as it leaves the port in the video.   That means that they have to get off of it at some point.  Perhaps that is part of the figure 8 that the tug does after it leaves the channel?  Or maybe they stay on until further out.
« Last Edit: 01/08/2015 11:28 pm by NotOnImpact »

Offline CameronD

  • Full Member
  • ****
  • Posts: 1510
  • Melbourne, Australia
    • Norton Consultants
  • Liked: 486
  • Likes Given: 348
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #765 on: 01/09/2015 01:12 am »
But if the tug is pushing it would have been within the frame of the picture.

Exactly.  There was no tug pushing it in the open ocean.  There was a tug pushing it in the video taken in the channel.  Therefore video taken in the channel can't be used to make claims about what tow conditions in the open ocean are like.

The channel will be considered to be restricted waters where the ability to manouver a vessel (a normal vessel at least) is limited.  It's likely that the Port Authority insisted that BargeX have an additional tug pushing for the duration of the voyage in the channel to guard against the ASDS going AWOL if the tow broke.

And if there are any guys on board seen jumping off at the river mouth, they're possibly harbour pilots/crew off the pushing (escort) tug.
 
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 robertross

  • Canadian Member
  • Senior Member
  • *****
  • Posts: 17842
  • Westphal, Nova Scotia
  • Liked: 505
  • Likes Given: 5202
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #766 on: 01/09/2015 02:06 am »
So many questions..
Lightning protection? Is there any? , Are 'tie downs' ballast tank hatches?, What is the exclusion area around ASDS? If its 10miles do they let it go out of this radius and then it covers distance and station keep unassisted? Were they just topping off the tanks or they  really needed refueling , how much fuel it can consume during each outing as delays can really mess up recovery operation if it needs to be refueled frequently.. we know how much those thrusters can consume, how much those two generators may burn....etc etc

I can probably answer one of those:
The plan was to weld plates over the landing pads to secure them to the deck.
Now if they are to tie down the stage from higher up, they can simply weld plates with U-bolts or shackles to the deck and attach cables at some pre-determined attach point. but I doubt that's needed.

As for lightning protection: if required I suppose they could mount a copper rod higher than the stage & ground it to the deck surface. Potential problem solved (excuse the pun).
Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

Offline Nomadd

  • Senior Member
  • *****
  • Posts: 4037
  • Boca Chica, Texas
  • Liked: 13377
  • Likes Given: 436
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #767 on: 01/09/2015 04:52 am »
So many questions..
Lightning protection? Is there any? , Are 'tie downs' ballast tank hatches?, What is the exclusion area around ASDS? If its 10miles do they let it go out of this radius and then it covers distance and station keep unassisted? Were they just topping off the tanks or they  really needed refueling , how much fuel it can consume during each outing as delays can really mess up recovery operation if it needs to be refueled frequently.. we know how much those thrusters can consume, how much those two generators may burn....etc etc

I can probably answer one of those:
The plan was to weld plates over the landing pads to secure them to the deck.
Now if they are to tie down the stage from higher up, they can simply weld plates with U-bolts or shackles to the deck and attach cables at some pre-determined attach point. but I doubt that's needed.

As for lightning protection: if required I suppose they could mount a copper rod higher than the stage & ground it to the deck surface. Potential problem solved (excuse the pun).
I doubt if they want a tall structure like that on the deck and just one wouldn't do the job anyway. I bet they'll just make a solid ground to the stage itself part of the securing procedure. The stage might have it's own rods and ground paths ready to hook to a deck point too. As long as the tanks have a solid path to ground they should escape damage. The controller might be at risk from the sensor/control paths picking up some ugly EMF, but those lines can all have their own protection if they're concerned.
 
« Last Edit: 01/09/2015 04:57 am by Nomadd »
Those who danced were thought to be quite insane by those who couldn't hear the music.

Offline dorkmo

  • Full Member
  • ****
  • Posts: 706
  • Liked: 334
  • Likes Given: 844
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #768 on: 01/09/2015 04:55 am »
In November 2009, the STS-129 space shuttle mission attached two antennas—an AIS VHF antenna, and an Amateur Radio antenna to the Columbus module of the ISS. Both antennas were built in cooperation between ESA and the ARISS team (Amateur Radio on ISS). Starting from May 2010 the European Space Agency is testing an AIS receiver from Kongsberg Seatex (Norway) in a consortium lead by FFI (Norway) in the frame of technology demonstration for space-based ship monitoring. This is a first step towards a satellite-based AIS-monitoring service.[5]

http://en.wikipedia.org/wiki/Automatic_Identification_System

>> vesselfinder ;)

So does this mean the off shore data is being collected iss? So when the iss Flys over we get a spike in data, then nothing till it comes around again? Might keep an eye out.

Offline avollhar

  • Full Member
  • *
  • Posts: 140
  • Liked: 38
  • Likes Given: 25
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #769 on: 01/09/2015 05:09 am »
What about AISSAT-1/2 and VESSELSAT-1/2 ? Possibly also AISat-1.
« Last Edit: 01/09/2015 05:11 am by avollhar »

Online Jarnis

  • Full Member
  • ****
  • Posts: 1161
  • Liked: 621
  • Likes Given: 165
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #770 on: 01/09/2015 07:02 am »
Look, on AIS;

- There are many satellites that receive AIS data. Yeah, they once used ISS to test AIS tech, but that was years ago.
- Satellite-based AIS information is still a "premium service" - shipowners pay good money to track their assets anywhere.
- Shore-based AIS receivers are "old tech" and required. That is the data most ship following sites have access to and are freely showing. Since AIS needs to be on when close to the shore for boats above certain size, this shows everything that is on the move pretty well up to certain distance from the shore.
- Free websites like vesselfinder may or may not be getting satellite-based AIS data. They may be getting it from only one source, which may or may not be available at any given time.

So in summary, for tracking SpaceX-related vessels, we generally can see them on the move near the shore. Beyond that it is a crapshoot and does not mean they turn off their AIS onboard to "hide". It may be on, but our crappy freebie sites just are not getting data from that area at the time.

Now if someone wants to have a better idea if they have actively shut down AIS aboard those vessels, first step would be to pay for global satellite AIS data access. Here you go - 269e a month, for 12 month subscription. Whoooops.

http://www.marinetraffic.com/en/p/satellite-ais

...and that one gives the data with 12 hour delay, except for a small number of "my fleet" ships that get live tracking.

If you ask me, I think vesselfinder may have ninja-enabled satellite AIS for that area and/or for those ships on the free site to get some more traffic/promotion during the first launch attempt, but then switched back to normal situation.
« Last Edit: 01/09/2015 07:03 am by Jarnis »

Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4343
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2581
  • Likes Given: 531
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #771 on: 01/09/2015 02:30 pm »
Quote
...for tracking SpaceX-related vessels, we generally can see them on the move near the shore. Beyond that it is a crapshoot and does not mean they turn off their AIS onboard to "hide". It may be on, but our crappy freebie sites just are not getting data from that area at the time.   

I have the MarineTraffic app that always lost track of the ships shortly after they left port. I had assumed the ships were turning their transponders off, then learned that the app doesn't show AIS satellite data, so you are correct.

And yes, both ships have disappeared from VesselFinder since Jan 7, so it looks like we are in the dark once again.

Offline sghill

  • Full Member
  • ****
  • Posts: 1471
  • United States
  • Liked: 1688
  • Likes Given: 2487
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #772 on: 01/09/2015 06:18 pm »
I am not a magnet professional (but I do use them in my dayjob to some extend) and what they dont like is shocks, temperature changes and stress. I dont know how expensive magnets would be that are strong enough to keep a F9 in place, or how heavy. I dont see fundamental show-stoppers other than maybe too much weight.

An other option would be to include iron feet, so ferromagnetic material but not a permanent magnet and use an electro magnet on the barge. But that also seems to be a huge investment. Not to speak of the power consumption that the barge would need or that.

You may be the crystal ball winner here!
Quote
In response to a question about the planned Falcon 9 first-stage rocket landing, Musk said the stage would use "mostly gravity" to stay on the robotic ship, with "steel shoes over the landing feet as a precautionary measure...

http://www.space.com/28215-elon-musk-spacex-mars-colony-idea.html
« Last Edit: 01/09/2015 06:18 pm by sghill »
Bring the thunder!

Offline cscott

  • Senior Member
  • *****
  • Posts: 2953
  • Liked: 2062
  • Likes Given: 666
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #773 on: 01/09/2015 06:19 pm »
An other option would be to include iron feet, so ferromagnetic material but not a permanent magnet and use an electro magnet on the barge. But that also seems to be a huge investment. Not to speak of the power consumption that the barge would need or that.

You may be the crystal ball winner here!

Uh, no.  Look at Elon's full quote.  No magnets involved.  Just a welder.

Offline ravedave

  • Member
  • Posts: 19
  • Liked: 9
  • Likes Given: 0
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #774 on: 01/09/2015 09:47 pm »
Quote
...for tracking SpaceX-related vessels, we generally can see them on the move near the shore. Beyond that it is a crapshoot and does not mean they turn off their AIS onboard to "hide". It may be on, but our crappy freebie sites just are not getting data from that area at the time.   

I have the MarineTraffic app that always lost track of the ships shortly after they left port. I had assumed the ships were turning their transponders off, then learned that the app doesn't show AIS satellite data, so you are correct.

And yes, both ships have disappeared from VesselFinder since Jan 7, so it looks like we are in the dark once again.

Use 'show tracks' on MarineTraffic and the path & last location of the EIII can be seen.


Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4343
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2581
  • Likes Given: 531
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #775 on: 01/09/2015 10:09 pm »
Quote
Use 'show tracks' on MarineTraffic and the path & last location of the EIII can be seen.
   


On both MarineTraffic.com and the MarineTraffic app, AIS data from both GO Quest and EIII stopped being shown Thursday afternoon as the ships moved offshore. Any tracking data shown is from Thursday or earlier, so not of much interest at the moment.

Vesselfinder.com is still dark, too.
« Last Edit: 01/09/2015 10:13 pm by Kabloona »

Offline Ludus

  • Full Member
  • ****
  • Posts: 1254
  • Liked: 664
  • Likes Given: 326
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #776 on: 01/10/2015 05:42 am »
Once the stages fly back to land the barge will still be around for FHR center core attempts.

It could be unused though during some historic SpaceX launches (as well as most of the time otherwise). I know what Tony Stark would do. Worlds largest robotic offshore party barge. That's a billionaire genius playboy version of a pontoon boat.

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28853
  • Minnesota
  • Liked: 9038
  • Likes Given: 5797
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #777 on: 01/10/2015 06:02 am »
It'll be needed for F9 launches which don't have quite enough performance for return-to-launchsite.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline IRobot

  • Full Member
  • ****
  • Posts: 1296
  • Portugal & Germany
  • Liked: 297
  • Likes Given: 263
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #778 on: 01/10/2015 08:32 am »
Wave height at the closest buoy is around 1.5 meters. Wind seems acceptable, around 15kn (8m/s).

http://www.ndbc.noaa.gov/station_page.php?station=41010&unit=M&tz=STN

Online OxCartMark

  • Full Member
  • ****
  • Posts: 1555
  • Former barge watcher now into water towers
  • Michigan
  • Liked: 1650
  • Likes Given: 1196
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #779 on: 01/10/2015 09:09 am »
EM: "Rocket made it back to drone spaceport ship, but landed hard. Close, but no cigar this time. Bodes well for the future tho."

Tags: