YazataJul 8, 2020 04:07 PM (This post was last modified: Jul 9, 2020 04:46 AM by Yazata.)
Latest is that SN5 static fire is scheduled for Friday July 10, with Saturday and Sunday as backup days. Then (assuming it doesn't blow up on Friday) a short Hoppy-style test-flight is planned for Monday July 13, with Tuesday and Wednesday as backup days. Hoppy and Zeus will be watching.
Mary reports that the Super Giant Crane (she calls it Bluezilla) is hard at work today. Construction of the High(er) Bay has started. Foundation work was done earlier, now they are assembling big prefabricated wall pieces. Note the lunch area with picnic tables under a white tent awning, plus a taco-truck. (I'm told that all the workers get as much free food as they want, just by showing their company ID card.) There are a number of these food stations scattered around with different food trucks. Great if you like Tex-Mex. (Photo by Mary from twitter.)
Edit: Lots of afternoon action from the flare stack. I speculate that they are playing with the methane recondenser they installed.
YazataJul 9, 2020 04:19 AM (This post was last modified: Jul 9, 2020 04:32 AM by Yazata.)
(Jul 7, 2020 03:15 AM)Yazata Wrote: I'm looking forward to SN5 (hopefully) flying. It will be entertaining to see it fly a little wonky since its single engine will be a little off-center. (Because the thrust dome on the bottom is designed for three engines.) So its flight won't look exactly right, since the cylinder will be flying at a slight angle to the vertical (as the engine thrusts up from off-center through its center of gravity). Everyone wants to know if it will do a power-slide off to the side as it rises off the test stand.
Here's a very good video render showing SN5 flying wonky with its off-center engine.
Someone on Twitter pointed out that as SN5 goes from vertical to flight attitude the fuel will slop about inside - this is exactly the kind of thing control systems have difficulty dealing with. I'll be watching for slop-wiggle-flop and hoping it doesn't happen.
YazataJul 10, 2020 06:35 PM (This post was last modified: Jul 11, 2020 03:34 AM by Yazata.)
(Jul 10, 2020 12:00 AM)confused2 Wrote: Someone on Twitter pointed out that as SN5 goes from vertical to flight attitude the fuel will slop about inside - this is exactly the kind of thing control systems have difficulty dealing with. I'll be watching for slop-wiggle-flop and hoping it doesn't happen.
Hi C2.
I'm not sure how they plan to deal with that.
The entire hop might be fueled off the smaller header tanks. That's my guess. That's why the header tanks are there, so that the thing can maneuver violently at landing without sloshing fuel and without the engines suddenly getting fed gas instead of liquid. So as the level of remaining fuel goes down in the main tanks, the remaining fuel feeds the headers which are full until the end. Or something like that.
I think that SpaceX has lots of experience with that from their Falcon 9's.
I don't think that they will fuel SN5 any more than they have to.
So the larger fuel and oxidizer tanks might be pretty much empty on this flight, just pressurized with gas or something for rigidity. Which will make SN5 very light. It needs to be heavier than the minimum thrust of a single Raptor when throttled down as low as it will safely go (about 60% thrust, I think), since otherwise the whole giant tin-can will go up instead of down and won't be able to land propulsively. That might explain why just yesterday they added the 20 tons of ballast to the top that we also saw with SN4.
Anyway, today's static fire seems to have been canceled. Next road closures are for Monday (with Tuesday and Wednesday as backup days). The application to the county for the road closures said hop test, but that wouldn't prevent them from doing a static fire instead. I don't know what their plan is, whether they plan a static fire at all or are just going for the hop.
Mary, Jack Byer and NSF have started putting out short video Boca Chica weekly updates in addition to their daily updates. Here's the first of them, just the thing to get you up to speed ahead of the SN5 tests (hopefully this week):
The SN5 test (believed to be a static-fire) planned for today has been pushed back to Wednesday July 15. It was originally planned for last Wed July 8, then pushed back to today, and now pushed back to next Wednesday (maybe...).
YazataJul 14, 2020 07:12 PM (This post was last modified: Jul 14, 2020 07:39 PM by Yazata.)
They have just stacked one of the multiple nosecones they have sitting around atop a 5-ring barrel to form a complete nose fairing. This is the first one that I recall seeing since the mark 1 nose that's been sitting there like a giant lawn ornament for approaching a year now. My assumption is that this nose fairing is indication of more ambitious flights to come if SN5's short Hoppy style hop on one engine is successful. Flights to more serious altitudes will require a more aerodynamic shape. (Fins and control surfaces will also be necessary to test out the full landing sequence. This particular nose is probably just a first-approximation and won't get nose fins.) Dunno which tank section this nose will go atop. Maybe SN6 which is currently awaiting its turn in the Midbay.
Note the seeming imperfection on the nose cone about 1/3 of the way down. If you look closely, these are four black dots in a line. These are reaction control thrusters, indicating that this nose is the real-deal and not just for fabrication practice.
Photo by Mary of the stacking in progress. (It's complete as I write this.) It's interesting that that they have found a use for the smaller triangular bay that's been there for a year and seemingly used very little. Its become the nose completion structure. Looks like they rolled the barrel out the minimum necessary to allow the crane to drop the cone atop it, then the combined thing will be rolled back in.
YazataJul 14, 2020 10:52 PM (This post was last modified: Jul 15, 2020 03:04 AM by Yazata.)
They have just canceled the SN5 test scheduled for tomorrow, Wednesday 7-15. Moved back to Thursday Thurs 7-16. (But don't bet anything valuable on that date holding, the way things have been going. Elon's playing with everyone's heads.)
YazataJul 16, 2020 06:04 AM (This post was last modified: Jul 16, 2020 06:38 AM by Yazata.)
Thursday's SN5 test is cancelled. This is getting frustrating for all the roadside rocket scientists.
But word is leaking out of Boca that a static fire is definitely on for the weekend sometime. Probably just one, not an extended test campaign like we saw with SN4. So a single static fire, then a few days to assess the results, then a hop flight sometime in the first half of next week.
Word leaking out is that if SN5's hop is successful, then beautiful SN6 waiting in the Midbay may simply be scrapped. They are keeping it on hand in case SN5 fails, but if SN5 succeeds the plan seems to be to power on directly to SN8, which will get a nose, fins and three engines. Much closer to the operational configuration and able to conduct the anticipated 20 km flight that will test the radical landing.
SN7 was just a test tank that ended up bursting. Reports are that SpaceX is more or less satisfied with the pressure it achieved, but they are constructing another test tank with various design and manufacturing improvements that they hope can outperform SN7. The new tank will be dubbed SN7.1. Presumably it will be up to bat after SN5 is finished. SN8 may or may not await its results to decide whether it should incorporate the SN7.1 improvements.
Talk from inside Boca is that Elon is cracking the whip.
Anyway, that's the talk. Of course it leaves the new nose fairing that they just stacked without a function. It isn't for SN5 which will hop without a nose, and it isn't for SN8 if that one will get fins and full aerodynamics, since that will require that it have a nose with header tanks, hard points and actuators for the nose fins. So I assumed this new nose was intended for SN6 which I expected to perform a higher altitude VTOL test flight of the sort depicted in the first half of this video: https://www.youtube.com/watch?v=QPXqKBHKM4U
YazataJul 17, 2020 12:51 AM (This post was last modified: Jul 17, 2020 12:57 AM by Yazata.)
A sad note: They have started cutting up the Mk.2 tank section that's been standing like a stalwart sentinel for months in Cocoa FL. The Cocoa site looked like the center of the Starship universe for a while there, but it's apparent now how small the site really is compared to Boca and how difficult it would be to move completed rockets through city streets to Cape Canaveral nearby. They still use the large building on site to construct their Octagrabber rocket-grabbing robots.
Jul 8, 2020 04:07 PM
(This post was last modified: Jul 9, 2020 04:46 AM by Yazata.)
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