Quote from: meekGee on 02/24/2018 10:02 amQuote from: aero on 02/24/2018 05:40 amI guess they could try to fly the fairing over at some low (very low) altitude then release the chutes at the right time. The fairing would drop predictably into the net. Maybe.Very low, yes. A near miss. This way you need to get less things right, since it doesn't matter how fast you're overtaking the boat. In exchange, you need to cut the cord when the ballistic IIP hits the net.Clearly the ship is helping to catch the fairing. Ships capable of 32 knots are expensive.The overtaking speed matters a lot. In the reference frame of the boat, the angle of the incoming fairing is tan-1(V_sink_fairing /(V_forward_fairing - Vship)). If the ship can keep up with the fairing, then it appears to descend vertically. Even if can only half keep up with the fairing, it roughly doubles the angle (from horizontal) and thus doubles the cross sectional area of the net.I think they will control the fairing all the way into the net. The tradeoff is the ability to make last minute corrections vs the chance of a last minute gust pushing you off course. Human parachuters control all the way to the ground without seeming problems, and the air should be even more predictable at sea, and high up like the net. Plus assuming the ship keeps a course into the wind, the large added constant component reduces the relative size of the gusts. In addition, with this approach you can stall the parachute for the last second of flight, which reduces impact loads. This is important for people, and might be a consideration for the fairing.
Quote from: aero on 02/24/2018 05:40 amI guess they could try to fly the fairing over at some low (very low) altitude then release the chutes at the right time. The fairing would drop predictably into the net. Maybe.Very low, yes. A near miss. This way you need to get less things right, since it doesn't matter how fast you're overtaking the boat. In exchange, you need to cut the cord when the ballistic IIP hits the net.
I guess they could try to fly the fairing over at some low (very low) altitude then release the chutes at the right time. The fairing would drop predictably into the net. Maybe.
Air gusts at sea will be worse than air in a stadium on a calm day.
Quote from: meekGee on 02/24/2018 11:43 amAir gusts at sea will be worse than air in a stadium on a calm day. There must be literally millions of hours of data on exactly this, since this is what aircraft carriers have done since they were invented. 32 knots into the wind, and then care a great deal about the air conditions a few tens of meters above the water. And they do this in all kinds of weather, not just calm days. They fly the plane right down to the deck.
So Elon said about 1-2 hours post-launch that the sats will fly over LA about 22 hours after launch and try to send down "Hello world".Do we know how this went? Radio silence as it usual with Starlink?
My SpaceX friends confirmed that the message was successful. Rajeev (VP of satellite development) emailed Elon informing him of its successful transmission, and Elon forwarded the email to the entire company with a congratulatory message to all.
I guess why wouldn't the ship move to where the parachute seems to be guiding the fairing, rather than hold a fixed position? Baseball analogy, the fielder moves to get under the ball as they understand the ball's likely arrival point better and better.
Quote from: Lar on 02/23/2018 04:04 pmI guess why wouldn't the ship move to where the parachute seems to be guiding the fairing, rather than hold a fixed position? Baseball analogy, the fielder moves to get under the ball as they understand the ball's likely arrival point better and better. A baseball isn't trying to guide itself to the glove. Both the ship and the fairing trying to guide themselves to the other could be a real mess. That parafoil has to be active control or it wouldn't hit within miles of the target.
Satellites have changed parameters since launch, is this due to propulsion or just normal drift?Tintin APerigee: From 500 to 505.3 km Apogee: From 517 to 525.7 km Tintin BPerigee: From 499 to 505.2 km Apogee: From 517 to 525.0 km
Can't "drift" upwards from LEO, so it was propulsion. Unless the changes represent a refinement of the tracked orbit by JSpOC, but given the length of time they have already been in orbit this seems unlikely. Any such refinement should have only taken a relatively small number of orbits, not a month of them.
Not to be one-upped by the fancy new Iridium-5 fairing half, PAZ's recovered fairing has made an appearance at Berth 240, SpaceX's prospective BFR factory and recovery facility. It's visibly being scrapped where it sits - all interior components are being removed and stacked on the ground. ¯\_(ツ)_/¯
Quote from: vaporcobra on 04/01/2018 08:58 pmNot to be one-upped by the fancy new Iridium-5 fairing half, PAZ's recovered fairing has made an appearance at Berth 240, SpaceX's prospective BFR factory and recovery facility. It's visibly being scrapped where it sits - all interior components are being removed and stacked on the ground. ¯\_(ツ)_/¯Or it's being prepped for helicopter drop tests mention by Elon. Otherwise that's quite the waste of the perfect test article.
Quote from: Flying Beaver on 04/01/2018 09:04 pmQuote from: vaporcobra on 04/01/2018 08:58 pmNot to be one-upped by the fancy new Iridium-5 fairing half, PAZ's recovered fairing has made an appearance at Berth 240, SpaceX's prospective BFR factory and recovery facility. It's visibly being scrapped where it sits - all interior components are being removed and stacked on the ground. ¯\_(ツ)_/¯Or it's being prepped for helicopter drop tests mention by Elon. Otherwise that's quite the waste of the perfect test article.Can't say more, but it's almost certainly no longer a viable structural test article.