Yet another incredible show from SpaceX. At this point, if they said they were going to build a football stadium on Europa, my only question would be when does it open.
But I couldn't help but laugh at the fact that they can launch a massive rocket on the first try and land (at least) 2 cores, but the camera STILL cuts out on the drone ship.
I don't find that surprising. The communication link back is presumably by satellite since it is in the middle of the ocean, and probably a directional antenna because of the high bandwidth. You have any good suggestions for having a reliable connection via directional antenna on a flimsy barge that a rocket is landing on in this middle of the choppy north Atlantic?
Tow a cable from the barge to a nearby ship, buoy, or platform on which the antenna sits, that's out of range of the vibrations and faces a different direction?
I believe they are required as part of FAA regulations to ensure that no manned craft are within 15 miles of the landing zone? Something like that, at least, which would complicate a tether-based approach.
I think the suggestion was a separate but tethered unmanned platform, which would presumably have less vibrations. I would imagine it's just not cost-efficient for SpaceX, as they'll be able to recover the footage later regardless.
Who needs a tether? Ubiquiti makes gear capable of slinging 400+ Mbps over 25km in a straight line. For about $1500 they should be able to shove the "last mile" to a ship outside of the exclusion zone and put the sat uplink on the ship.
They have grid antennas with a slightly wider beam, or maybe a sector style with 20-30 degrees could be used. I just think it's easier to engineer a workable ship-to-ship stabilized radio solution rather than deal with the ship-to-sat dish which probably has much tighter tolerances.
On the pictures of the droneship the quite distinctive Inmarsat BGAN (which is in essence 3G bounced of geostationary satellite) antenna pod is plainly visible.
Edit: inside the pod is fairly high-gain directional antenna mounted on motorized positioner, but it is designed to track the satellite from slow (ie. ship) or predictably moving (ie. truck) platforms and certainly cannot cope with vibrations from the landing reliably. Man-portable BGAN terminals usually have fixed antenna and officially require quite lengthly positioning process (on the other hand it will work for some value of "work" when you just throw it into car trunk and park with trunk vaguely pointing to south, but you will be lucky to get reliable phone connection, not to mention video stream, in that case).
How about a camera feed from the tow ship (with a view like the two other boosters landing)? If you can film a rocket 300km in the air, you can surely spot a rocket landing 15 miles away. Unless ofcourse you don't want the world to see it crashing into the ocean live.
There aren't any nearby ships, for obvious safety reasons. Plus, any nearby ships would have the exact same issue - where exactly would you "feed" to, when any ship that far out is going to be using a commercial satellite data feed (ie, very slow and unreliable)?
The safety reasons don't hold, you can easily shoot from several kms away (there are people on land several kms away from the launch pad). In the worst case, you can pilot a drone from several kms away, close enough to the barge.
> any ship that far out is going to be using a commercial satellite data feed
The footage from the droneship always appears perfect seconds before the landings. So it's not simply the fact of being at sea.
Earlier in the feed they showed some ships that were presumably towing the drone out. I'm sure there are some that are within a mile or two.
To your second question, how about a camera on a boat closer in with a hard line to a boat farther out with the satellite connection? You act as if sending a video feed is an unsolvable problem despite them beaming living video through the rest of the mission when they are in space.
Yes, very hard to believe this was a technical failure/limitation. My money would be on a deliberate cut, possibly even automated, when the systems became aware of impending failure. It'd be important for SpaceX that any negative outcomes are delayed from public release in order to control what makes it into the headline news. The fate of the reusable components would be a particularly sensitive aspect of the PR campaign.
Nah, this is standard stuff for SpaceX. They always get signal dropouts and someone always says "conspiracy!"
They're not interested in the extra hassle of continuity for the sake of putting on a live show. The droneship has tons of cameras, the booster has tons of telemetry, that's all they're interested in.
(if you must spin a conspiracy, the one where they deliberately don't upgrade to keep their fans guessing is more credible - it's zero effort)
I have nothing to gain by SpaceX failing. I wish them all the best. I'm just stating what I think is pretty obvious - that this was a massive PR exercise, apart from anything else. My BS detector goes into overdrive at times like that.
When you mount cameras on a landing barge, you would expect there to be a high likelihood of them being damaged or affected in some way when your rocket lands. So you do the obvious thing, and setup a redundant camera feed somewhere at a distance. Previous test landings at sea had a chase plane. Where was that this time?
The landing barge is towed into position by tugs, and once the boosters are landed I presume it is towed back out, so there will be some tug boats nearby.
It has station-keeping thrusters to stay at precise GPS coordinates. But it can't move far under own power and is towed. The name ASDS is not really to be taken literally here.
It will likely be a proper dynamic positioning system so will more than likely use two independent reference systems for position, one could be a DGPS system the other could be as basic as a taughtwire....
They could perfect it, by having say an underwater wired data feed going to an ancillary ship which transmits it, which then is out of the thrust cone of the rocket. But it's probably just not worth it to get the footage 5 minutes early.
But I couldn't help but laugh at the fact that they can launch a massive rocket on the first try and land (at least) 2 cores, but the camera STILL cuts out on the drone ship.