SpaceX hasn't blown up a rocket since Falcon 1 flight 3; historically you're very lucky if your first 5 launches of a new launch vehicle succeed, and they've developed two of them since F1 and launched each over 5 times successfully. They're doing something right. Some of that is testing the crap out of their rockets, some of it is intense monitoring of different subsystems (this last part is nothing new, of course).It will take 100s of launches to get all these little bugs out, and they'll still happen. Frankly, given how many things have to go right for a launch to work, I'm always pleasantly surprised when a launch DOES go off without a hitch. (I admit Atlas V has done it enough times that I feel significantly less nervous, although it, too, has its glitches.)SpaceX is competing against two launch providers that have a nearly spotless record of late. ULA and Ariane. One launch failure would set them back significantly (since they've only done 13 F9 launches, only 8 v1.1), so a launch failure for SpaceX would be more damaging statistically than it would for their competitors which have a much longer track record. So SpaceX has to be incredibly conservative with this stuff. A scrub makes no difference long term, but even a single launch failure may (even though it's bound to happen eventually if you launch 100s of times), as we saw with Antares.
...Sorry, but they did have a flight abort with one of their older F9R's during flight tests. But that's fine because they were testing it until it broke, then brought out the new version.
Sorry, but they did have a flight abort with one of their older F9R's during flight tests.
Quote from: JasonAW3 on 01/06/2015 07:17 pmSorry, but they did have a flight abort with one of their older F9R's during flight tests. Huh what "flight abort" ? They shut down an engine and completed the primary mission. Was there another F9 anomaly I'm missing.
Unfortunate they did not go today, however as usual better safe than sorry. TVC drift not something you want to launch with ever. Hopefully its an easy fix and does not require physical work on the actuator, however I won't be surprised at all if they have to exchange that actuator entirely. If work is required, would be interesting to see what damaged it, if anything (shipping error?). In any case would not be surprised if they could still make Friday even if they needed to install a new one. Rolling back the vehicle is not *that* time consuming after all.
There would have to be a force physically causing the drift. Recalibration would be insufficient without determining where that force is coming from then either eliminating it or determining it can be withstood in flight.
A bad LVDT would be even worse since it's part of control logic. And if it's part of control logic and the F9 V1.1 is human-rated, it's triplicated. If it's triplicated, all three LVDTs would be showing the drift. I heard no equivocation in the press releases that sensors were in conflict.QED
Hopefully this is the most appropriate place to ask this. Sorry if it's been asked already:The drone ship needs to be at a specific position for 1st stage recovery, but the ship isn't circularly symmetric. It has a long and a short axis. That gives it one degree of rotational freedom. What are people's thoughts on which way the ship will be oriented during landing? What would be most optimal?My guess is, the most important thing will be to minimize rocking due to waves, and therefore the ship should be rotated so that the long axis points into the wind ("in irons" as some of us sailors like to say), or into the direction of the biggest waves. Being oriented into the wind would also give a little more room for error for the 1st stage (approx. +/- 150 feet vs +/- 85 feet) as it's pushed around by the wind during descent.
I haven't exactly been following the ASDS specs. I would think it would point such that the motors can compensate for wind and current. Unless the motors can thrust equally in all directions, then I would agree that the long axis of the deck would align with the wind.
on one of the first flights of falcon i think i remember the second stage spinning. was that caused by a drift issue? or was that something else? im a bit hazy on that.
Grazie archipeppe, molto bello!
