Starship tests: SN15 flight early May

[mfb]

The FAA has issued a NOTAM ("notice to airmen") to avoid a zone around the planned flight area from December 4 to December 6. This is a key requirement for a flight and SpaceX only gets a NOTAM when they are reasonably confident they can fly.
https://tfr.faa.gov/save_pages/detail_0_8423.html
https://www.google.com/maps/d/u/0/viewer?mid=1kQOqXZlh8VUqT_07NNnBNkaDuJlBORA-&ll=25.99185682202349%2C-97.10829015&z=11

Edit: NOTAM retracted, not earlier than Monday

Edit2: Now NET Sunday? Altitude was reduced a bit to 12.5 km.

 

[mfb]

It's getting serious.
SpaceX Livestream starts in 13 hours, Tuesday at 14:00 UTC, that's in the morning local time.

A launch might happen at any time during the day or the following two days, but there will be some ahead warning - first from fueling, then from a siren 10 minutes before launch. And of course SpaceX might talk about plans in the livestream.

Spectacular landing maneuver or spectacular crash - it's guaranteed to be interesting.

On a less serious note, here is a sped-up flap test, that looks like it would try to take off with them.

 

[mfb]

Now targeting liftoff 4:30 CST

That's in 12 minutes!

Edit: Abort just at ignition. No flight today, maybe another try tomorrow.

 

[mfb]

Starship is getting fueled again.
SpaceX livestream in 20 minutes

 

[mfb]

Livestream is running.

Countdown is being held at T-2minutes.

Edit: A ship is in the restricted area, new planned time 16:40 CST, 22:40 UTC, in 1:15.

 

[mfb]

We got everything! A takeoff, a flight to 12.5 km with three, two, then one engine, the skydiver maneuver to slow down, the flip maneuver, and then a big explosion as it hit the landing pad too hard.
It looks like one of the engines stopped working in the final landing burn?

They'll clean up and prepare SN9 for a repetition of that test. It should be fully assembled already.

Edit: Musk tweeted: Fuel header tank pressure was low during landing burn, causing touchdown velocity to be high & RUD, but we got all the data we needed! Congrats SpaceX team hell yeah!

 

[jackwhirl]

Awesome flight. I was a little worried when the engines started going out. I hadn't anticipated a staggered shutdown like that.

So will they try to fix the pressure loss in SN9 or move directly to a later test article?

 

[iVenky]

I have a basic question. The motivation behind belly flop is to use air as brakes with higher surface area? And this gives us better control over landing?
Pumped up for SN9!

 

[jackwhirl]

Yes, Musk discussed that in his 2019 presentation. (~16 minutes in) It's all about shedding velocity.

 

[iVenky]

Yes, Musk discussed that in his 2019 presentation. (~16 minutes in) It's all about shedding velocity.

Yes, I saw a video where SN8 was really slow with the belly flop maneuver. Can't believe with my own eyes. Seems like magic!

 

[jackwhirl]

They've got to be feeling good about their computational models right now. It was a beautiful dive, and looked just like the simulations.

 

[nsaspook]

The 'landing' reminds me of this:

 

[mfb]

The header tank with the lower than expected pressure contains methane. With a lower pressure you can't pump enough fuel. Typically engines run "fuel-rich", i.e. with more fuel than needed for an optimal combustion. What happens if you have hot oxygen without enough methane? The oxygen reacts with the engine. In particular, it reacts with copper parts, which makes the exhaust green. Running without enough fuel is jokingly called "running engine-rich".

Here is a video looking up from the landing pad. It's pretty clear where the problems start. Quickly afterwards one engine stops completely.

This should be relatively easy to fix. They'll certainly look over all other flight phases as well, but it looks like SN9 can make another attempt soon. Maybe even this month.

Ars Technica: So, it turns out SpaceX is pretty good at rocketing

Looking beyond the 12.5 km flights: If they mount six engines then Starship can go to space (suborbital), testing faster re-entry with significant heating, with or without heat shield (it's still much easier than orbital re-entry).
They work on the first prototype for SuperHeavy, that will make its own test flights starting with two engines. Eventually we'll see both together, probably when they try to reach orbit. At that time the heat shield needs to work.

 

[bob012345]

I worry about the stability of the tall and narrow design as far as landing on the Moon and Mars. If you look at the video from SN8 it was not perfectly vertical at 'landing'. Perhaps that was just due to lack of thrust? I also worry about a lot of big windows on the projected designs. I prefer mainly steel and not glass when I'm that close to an infinite vacuum.

 

[jackwhirl]

Do we know if the header tanks were pressurized autogenously for this test, or is that something they are still looking to add in the future?

 

[mfb]

If you look at the video from SN8 it was not perfectly vertical at 'landing'. Perhaps that was just due to lack of thrust?

Yes. The engines gimbal to change the orientation of the spacecraft . Less thrust means both slower rotation and faster impact with the ground.

The Moon variant will not have any aerodynamic surfaces and it won't do the bellyflop maneuver either, because it will never land in an atmosphere.

I don't think the window design is final. They'll see what works. The ISS is flying with several windows, so far without issues.

 

[mfb]

Pictures of the remainder of SN8

SpaceX got another road closure for the 14th (Monday), presumably to move SN9 to the launch pad.

 

[jackwhirl]

They sure aren't wasting any time. This means they've probably got a good idea what went wrong with the tank pressure and that they can fix it with minor adjustments on the pad. Perhaps even in software.

Or they need more room to stack new rockets. Maybe both...

 

[jackwhirl]

SN9 didn't take the news well.


That'll buff out, right?

 

[mfb]

One of the jacks below it failed, apparently.

It only contacted the building in the payload area which isn't facing large forces in flight, it might be fine. We don't know if the bottom is damaged, however.

 

[jackwhirl]

One of the arguments for stainless steel was ease of in situ repair, right? This is a good opportunity to test that.

 

[mfb]

I'm not sure if you could work on the main structure on the Moon/Mars. Replacing some heat shield tiles should be possible. The current prototypes are not 50% covered in heat shields yet, they only have a few of them for tests.

 

[mfb]

SN9 is vertical again, some flap damage and minor nose cone damage have been spotted. Flaps are probably easy to replace but if the hinges are damaged as well then repairs might take time.

 

[mfb]

SN9 got new flaps (taken from SN10) and it was moved to the launch pad. We can expect a cryogenic fueling test, a static fire test, and then a flight if nothing goes wrong in the tests. Most likely a repetition of the SN8 test, maybe with a slightly different flight profile to test more things. The goal is clear - land safely.

There is a road closure tomorrow (23rd) which might be the cryogenic test.

 

[jackwhirl]

Are those flaps are still being constructed off-site and shipped in?

 

[mfb]

As far as I know yes, at least their main parts. They are "dumb" metal parts that just need the right shape, not much Boca Chica would do with them.

The last road closure was cancelled. New road closures for the 28th to 30th.

Musk tweeted a first Super Heavy hop is a few months away. Add almost inevitable delays and we are looking at the second half of 2021. By that time SpaceX should have more experience flying Starship - going from a hop to a high altitude flight for the booster might be relatively fast. Orbital flights are an entirely different thing, however.

 

[mfb]

Short static fire of SN9.

Airspace restrictions exist for Jan 8, 9, and 10, these are possible flight dates. The plan is a repetition of the SN8 test, just with a safe landing this time.

 

[mfb]

SpaceX's Starship SN9 prototype fires up rocket engines three times in one day
Just ~1.5 hours between the tests each. It's not fast reuse yet, but it's one step towards it.

There are airspace restrictions January 14, 15 and 16 as possible flight dates.
https://tfr.faa.gov/tfr_map_ims/html/cc/scale6/tile_17_31.html

No earlier than Jan 19: https://everydayastronaut.com/starship-sn9-10-kilometer-flight/
Two Raptor engines need to be exchanged. There is a flight restriction for Jan 18 but it's almost certain that day will be used for another static fire test (or more than one).

 

[mfb]

Fifth static fire test, with replaced engines.

Flight restrictions exist for 25th, 26th, 27th (Monday to Wednesday).

There are also smaller low altitude flight restrictions before, its purpose is unclear. There is a test tank "SN 7.2" near the launch site, maybe they'll test that. It cannot fly but it can launch debris high up in the air if it explodes.

 

[mfb]

Boca Chica village is being evacuated at 8 am on Thursday morning for Starship SN9's test flight.
Time zone conversion: 8 am is 5 hours 15 minutes after my post.
The flight could be planned for any time during the day, but the afternoon is the most likely time.

Test announcement at the SpaceX website - the livestream will be added there, too. LabPadre and Everyday Astronaut will be streaming much earlier and keep viewers updated on tanking and similar preparations.

Edit: Moved by one day, apparently because FAA didn't approve the flight in time.

Another edit: No earlier than February 1
Meanwhile SN10 was moved to the launch site. Here are both in one picture

Apparently something about the SN8 flight violated the FAA approval. The Verge

 

[mfb]

SN9 flight to 10 km

Spoiler

One of the two engines used to land didn't ignite, another fireball. Everything before that went well, just like for SN8.

SN 10 is at the launch site already, ready to take over.

Concerning the FAA regulation, looks like they disagreed on the risk to the public.

 

[mfb]

The village near the launch site will be evacuated for a possible SN10 flight attempt tomorrow (March 1).
Tweet
March 2 and 3 are backup dates.

Musk has indicated that they changed the landing procedure. They will try to ignite all three Raptor engines, and then shut down one immediately. If all three ignite that's great, if one of them has a problem then the other two will do the landing.

Edit: No earlier than March 3.

 

[mfb]

It landed!

The landing seemed to be quite rough and Starship looks a bit tilted, but it landed in one piece and didn't explode immediately.

It exploded 10 minutes after landing.

First video is the flight from SpaceX, second video is the explosion coverage from EverydayAstronaut.Edit: Landing legs didn't lock properly.

 

[hutchphd]

I like Scott Manley's compendium:

 

[mfb]

SN11 looks almost ready...

The flight synchronized with "No time for caution" (from the Interstellar docking scene):