Author Topic: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2  (Read 2397414 times)

Offline cambrianera

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #160 on: 12/22/2014 11:03 AM »
The speculation around this was largely done before it was realised just how far down the COG is - being below the upper leg attach points.

Interesting post speedevil, only one thing:
COG of empty first stage should be about 12-13 m from bottom, 5-6 m over upper leg attach point.
Engines aren't that heavy compared to the 30+ meters tank.
Oh to be young again. . .

Offline Dudely

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #161 on: 12/22/2014 11:53 AM »
Well we have two attempts this January for a landing. CRS-5 and DSCOVR will both try to land.

No legs on DSCOVR per Jim.

The FCC application seems to have the barge on it. . .

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=63562

Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #162 on: 12/22/2014 12:19 PM »
^ So we don't reinvent the wheel, there's about 2 pages of discussion of the barge and support ship radio transmitters over here:

http://forum.nasaspaceflight.com/index.php?topic=35244.msg1284338#msg1284338

Now that we've seen photos, I'd guess the 61W support ship transmitter is the big dish seen on Go Quest's deck.

We also see what are probably two VSAT domes on the barge. From what I've read online, VSATs do require an FCC license. But they operate in C/Ku/Ka bands, all of which are higher freqs than the 2090 MHz listed in the FCC application, so that's a bit of a puzzle.
« Last Edit: 12/22/2014 12:46 PM by Kabloona »

Offline MTom

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #163 on: 12/22/2014 12:24 PM »
In addition to earlier discussion about containers on the barge. Seeing this picture I had an idea:

There are four big containers in the front-line.
IMHO these are simple containers mainly as some protection for the containers behind them (fuel, communication, control, etc.) + storing basic accessories within it. They have no special role on the barge.

Online douglas100

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #164 on: 12/22/2014 12:55 PM »
Well we have two attempts this January for a landing. CRS-5 and DSCOVR will both try to land.

No legs on DSCOVR per Jim.

The FCC application seems to have the barge on it. . .

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=63562

We'll see. I agree that their original intention was to attempt barge recovery on this flight. But Jim is working DSCOVR, has insight and is rarely wrong on ops matters. In the absence of direct information from SpaceX, I vote Jim.
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Offline mvpel

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #165 on: 12/22/2014 01:05 PM »
The FCC application seems to have the barge on it. . .

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=63562

Perhaps the barge has camera and communications capabilities that would be useful even if the stage is going to wind up in the water. After all, you can get an unmanned vessel and its cameras closer to the target splashdown site than a manned vessel.
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Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #166 on: 12/22/2014 01:09 PM »
The FCC application seems to have the barge on it. . .

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=63562

Perhaps the barge has camera and communications capabilities that would be useful even if the stage is going to wind up in the water. After all, you can get an unmanned vessel and its cameras closer to the target splashdown site than a manned vessel.

Not perhaps...definitely. The barge has two VSAT antennas for broadband satellite comms, and what looks like a binocular pan-tilt-zoom camera atop one of the containers for tracking the incoming stage.

No matter where the stage comes down, the bargecam should be tracking it visually and recording/streaming video.
« Last Edit: 12/22/2014 01:52 PM by Kabloona »

Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #167 on: 12/22/2014 01:15 PM »
In the absence of direct information from SpaceX, I vote Jim.

Except that we do have direct information from SpaceX, viz their FCC license app which clearly states "Launch vehicle sub-orbital first stage to be recovered downrange of Cape Canaveral."

Also, IIRC, Jim said earlier that F9 has plenty of performance margin for this mission, though my memory may be faulty...
« Last Edit: 12/22/2014 01:31 PM by Kabloona »

Offline mcoconnor

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #168 on: 12/22/2014 02:02 PM »
It looks like Jim has seen some new information suggesting the presence of legs on that vehicle too.

Seeing documentation that there are legs.  Some plans may have changed.

In the absence of direct information from SpaceX, I vote Jim.

Except that we do have direct information from SpaceX, viz their FCC license app which clearly states "Launch vehicle sub-orbital first stage to be recovered downrange of Cape Canaveral."

Also, IIRC, Jim said earlier that F9 has plenty of performance margin for this mission, though my memory may be faulty...

Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #169 on: 12/22/2014 02:09 PM »
What Jim has seen is the quote from the FCC application, I believe...
« Last Edit: 12/22/2014 02:10 PM by Kabloona »

Offline dgates

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #170 on: 12/22/2014 02:10 PM »
In addition to earlier discussion about containers on the barge. Seeing this picture I had an idea:

There are four big containers in the front-line.
IMHO these are simple containers mainly as some protection for the containers behind them (fuel, communication, control, etc.) + storing basic accessories within it. They have no special role on the barge.
It sure would be nice if SpaceX would simply give "the press" a straight up tour of the darn thing! It would sure answer a lot of questions, such as the basic process for ops, tie-down, grid deck, station keeping, comms / video, etc. etc. C'mon Elon, show us the new toy!
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Offline Brick_top

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #171 on: 12/22/2014 02:17 PM »
here is Jim's quote

Seeing documentation that there are legs.  Some plans may have changed.

http://forum.nasaspaceflight.com/index.php?topic=30543.msg1306074#msg1306074

sorry didn't notice the quote had been posted by mcoconnor
« Last Edit: 12/22/2014 02:19 PM by Brick_top »

Offline Jim

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #172 on: 12/22/2014 02:30 PM »
What Jim has seen is the quote from the FCC application, I believe...

No, there has been other documentation I have seen

Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #173 on: 12/22/2014 03:21 PM »
What Jim has seen is the quote from the FCC application, I believe...

No, there has been other documentation I have seen

Thanks, Jim, good to have your firsthand reports.

Online douglas100

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #174 on: 12/22/2014 03:22 PM »
Well we have two attempts this January for a landing. CRS-5 and DSCOVR will both try to land.

No legs on DSCOVR per Jim.

OK, looks from subsequent posts that I was wrong. Glad that was cleared up and we have two recovery attempts on the next two flights.
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Online meekGee

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #175 on: 12/22/2014 04:14 PM »
^ So we don't reinvent the wheel, there's about 2 pages of discussion of the barge and support ship radio transmitters over here:

http://forum.nasaspaceflight.com/index.php?topic=35244.msg1284338#msg1284338

Now that we've seen photos, I'd guess the 61W support ship transmitter is the big dish seen on Go Quest's deck.

We also see what are probably two VSAT domes on the barge. From what I've read online, VSATs do require an FCC license. But they operate in C/Ku/Ka bands, all of which are higher freqs than the 2090 MHz listed in the FCC application, so that's a bit of a puzzle.

It depends whether the FCC license is associated with the barge.  That's what I proposed in the beginning - that when you buy the equipment, which is COTS, the vendor gets you the license, and it might be under the name of whoever pulled out the credit card.
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Offline duh

Here are a few frames while leaving port.
FWIW, I placed the top 2 pictures side by side (top picture on left, other picture on right).
Then was able to look at it in 3D by crossing eyes well in front of pictures with aid of a pen
held in front of screen. Did get a good (IMO) 3D effect for much of the barge. Some other parts
of picture could have had better 3D effect.
thanks for posting the picture sequence.

Offline Nomadd

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #177 on: 12/22/2014 11:46 PM »
VSATs don't require FCC licenses. Since they're point to point and can't interfere with the wrong satellite on the same frequency unless they're seriously defective there's no reason for it. Where you're allowed to operate a particular remote is determined by the satellite operator.
 2090 Mhz sounds more like a radar frequency. It could be used for ranging or transponders. Depending on where they are, it can also be spread spectrum, which is a lot harder to listen in on.
« Last Edit: 12/22/2014 11:55 PM by Nomadd »

Online meekGee

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #178 on: 12/23/2014 02:24 AM »
VSATs don't require FCC licenses. Since they're point to point and can't interfere with the wrong satellite on the same frequency unless they're seriously defective there's no reason for it. Where you're allowed to operate a particular remote is determined by the satellite operator.
 2090 Mhz sounds more like a radar frequency. It could be used for ranging or transponders. Depending on where they are, it can also be spread spectrum, which is a lot harder to listen in on.

So that solves that mystery, but that's just detail.

The point was, no matter how much internet paperwork said otherwise, it was just very unlikely that SpaceX did not spend the dollars on COTS equipment for getting live video from off-shore.
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Offline Kabloona

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #179 on: 12/23/2014 03:34 AM »
2090 Mhz sounds more like a radar frequency. It could be used for ranging or transponders. Depending on where they are, it can also be spread spectrum, which is a lot harder to listen in on.

I doubt radar, 2090 MHz is cell phone/2-way radio/GPS/WiFi frequency (UHF band). Sounds like comms with the support boat, or maybe transponder as you say.

Radars are usually 8 GHz and higher.
« Last Edit: 12/23/2014 03:51 AM by Kabloona »

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