YazataSep 3, 2020 03:15 PM (This post was last modified: Sep 3, 2020 08:08 PM by Yazata.)
Thursday Sept 3: SN6 hop slated for today. Weather looks calm and clear on the livestreams.
9:00 AM CDT -- Many people at launch site. Parking lot at launch site full. Two sheriffs SUVs, one sitting in each lane of the two lane road at road block. No sign of the wooden barricades they usually use, instead there are lots of orange traffic cones along sides of road but not yet placed on roadway. Evidently the sheriffs vehicles will move to allow SpaceX employees out, but aren't letting new vehicles in.
9:11 AM CDT -- I lied. The wooden barricades just went up. A vehicle was just let through to go down to the pad, evidently a SpaceX'er. (I wonder what kind of ID or pass they have to show to get through.) Another thing I've noticed: While SpaceX security still have their white Teslas, they have acquired a bunch of large white pickups as well, with light bars and 'SpaceX Security' on the doors. Perhaps Texans just don't take Teslas seriously. 'Y'all think that little thing's gonna stop me??' Also more useful for transporting stuff like the road barricades and orange traffic cones.
9:45 AM CDT -- Cars gradually leaving the launch site parking lot. Only a few cars there now. Pad still not clear though.
10:22 AM CDT -- Pad is finally clear. The dents have disappeared from SN6, so it might be lightly pressed with ambient temperature gas. Now awaiting activity in the tank farm indicating cryogenic fluids moving around. That's usually accompanied by lots of vapor.
11:38 AM CDT -- Still no tank farm activity
12:00 noon CDT -- Some venting has started at the tank farm. Right at noon, maybe they have a timeline they are following. If so, they like to launch at the top of the hour.
12:22 PM CDT -- Multiple cars parking along the road near the roadblock and the Rocket Diner. May be SpaceX employees come to watch.
12:42 PM CDT --
On this week's episode of Texas Tank Watchers!
Successful flight!
Not to be outdone by its compatriot SN5, SN6 aced its hop equally well! Didn't explode or crash, although it's sitting a little tilted on its landing pad. Another Leaning Tower of Boca Chica. Probably hard to prevent given the crush core landing legs and the cockeyed landing with a single off-center engine. Currently releasing pressure and safeing the vehicle. Watch this video clip with the sound on in full screen.
Twitter view was much better. On the Boca Chica video, moved forward to the point of launch. Since they were so silent, almost thought the commentator guys had left beforehand and missed the hop, but they finally said something.
(Sep 3, 2020 07:26 PM)C C Wrote: Twitter view was much better. On the Boca Chica video, moved forward to the point of launch. Since they were so silent, almost thought the commentator guys had left beforehand and missed the hop, but they finally said something.
I think that you are referring to Lab's livestreams. The commentators like to talk on that one, but they shut up a few minutes before the launch (based on the warning siren) so that viewers can watch in peace without them talking over it.
YazataSep 4, 2020 05:56 PM (This post was last modified: Sep 5, 2020 03:40 AM by Yazata.)
Here's SpaceX's own video of the SN6 hop, with views from their photographic drones and from on-board cameras.
Really shows the power slide takeoff due to the off-center engine thrusting through the vehicle's center of mass, and the correction from the flight computers to damp out the lateral motion, leaving the thing tilted as it flies.
These have basically the same Raptor powerhead, preburners, turbopumps, valves and combustion chamber, but with a different shaped and much larger rocket bell, optimized for operation in the vacuum of space. The plan is that operational production Starships will have six engines, three sea-level Raptors of the sort that we have already seen, and three R-vac vacuum engines for use in space. These Starships are the second stage of the SS/SH full stack. The Superheavy on the bottom will have 28 sea-level Raptors. These will be divided up into 20 thrust-optimized Raptors that won't gimbal or throttle, plus eight Raptors that will gimbal and throttle for control during launch and landings.
The Merlins have similar models. The Falcon 9 boosters each have nine sea-level Merlins, while the Falcon 9 second stage has one big-belled Merlin vacuum engine (often referred to by the commentators in the launch live streams as the M-vac engine.
SpaceX photo from Hawthorne with a sea-level Raptor on the left and the new Raptor vacuum engine on the right
Side by side, slo-mo, then a couple of very cool videos with them superimposed. That was possible because Mary filmed each of them from the same spot. It shows that all three flew almost identical trajectories, to the same altitude, but Hoppy ascended and descended more slowly than SN's 5 and 6.
YazataSep 7, 2020 03:30 PM (This post was last modified: Sep 7, 2020 04:29 PM by Yazata.)
SN6 took its victory lap early this morning and is now standing next to SN5 in the build area. SN8, which is destined to receive a pointy nose and flipper flappers and look like a proper spaceship, is inside the midbay to the right of these two pathfinder veterans. Unclear if 5 and 6 are destined for more hops, probably so. Just attaching SN8's control-surface fins will be a complicated and time consuming process. I don't have a clue how they are going to do it, but I'm sure that their engineers have a detailed plan. So 5 and 6 will probably keep flying in the interim.
All of this while the first Super Heavy is under construction. They are apparently already making lead items for it like rings and pressure domes. Everyone is waiting to see its thrust dome. If the plan is for Super Heavy to have 28 Raptors in its finished model (test models will have significanlty fewer for the first hop-tests) that thrust dome will be something to see. Nobody is sure how they are going to do that either, but again the engineers must have a detailed plan.
One of Mary's photographs, from twitter. Six on the left, five on the right. Note the white flower-like beauty mark near 6's bottom. This is where Space Shuttle style thermal tiles were attached. They are experimenting with different methods of attaching them and these appear to have been glued on with some kind of adhesive. And they all fell off! Guess that method is going to be crossed off the list.
In the photo below, note the landscaping! Not only will SN8 look like a proper spaceship, the Boca Chica build site is looking less and less like a droid junkyard on Tatooine (Elon once called it that) and more and more like a proper space industry factory. Reassuring to NASA I'm sure. Maybe Elon is less crazy than they thought. The better the build site looks, the more professionalism it communicates. Which will only make Starship seem more credible to Old Space and in Washington.
Maybe there's upside as well as downside in putting Science-Fiction nuts in charge of a space program.
YazataSep 15, 2020 04:49 AM (This post was last modified: Sep 15, 2020 04:56 AM by Yazata.)
Monday Sept 14, 10:45 PM CDT -- Road closed and pad cleared for a 7.1 pressure test. Don't think that they plan to pump it up until it bursts tonight though.
I think that they will press the tank to flight pressure tonight and leave it there to see if it can hold pressure over time. Then they will push ahead to see what its outer limits are on Thursday when another closure is scheduled. That's when I think that they will keep increasing the pressure until it comes apart.
The reason why they are doing all of this pressure testing again is that they are proving some design changes in the bottom thrust dome apparently. They are always tinkering and making changes as they go
Sep 3, 2020 03:15 PM
(This post was last modified: Sep 3, 2020 08:08 PM by Yazata.)
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