SpaceX Starship - IFT-3 - Starbase TX - Launch Thread and Post Launch Discussion

Launch Date: March 14
Launch Window: 7:00 am CDT (9:00 am EST, 13:00 UTC)
Launch site: LC-1 - Starbase, Boca Chica Beach, Texas
Core Booster Recovery: Expended in Gulf with a landing burn
Starship Recovery: A controlled reentry through the atmosphere to a terminal velocity splashdown in the Indian Ocean
Booster: Super Heavy Booster 10
Starship: Starship 28
Mass: No mass simulator mentioned
Orbit: LEO-ish
Yearly Launch Number: 26

A SpaceX Super Heavy and Starship launch vehicle will launch on its third not quite orbital integrated flight test designated IFT-3. The mission will attempt to place Starship into a nearly orbital trajectory that will attempt a controlled reentry through the atmosphere to a terminal velocity splashdown in the Indian Ocean . The Super Heavy booster will attempt a landing burn in the the Gulf of Mexico where it will likely be destroyed. This is a further test of Stage 0, the booster, full power ascent, Max-Q, stage separation using the new hot staging, a booster stage test of a hard turn and boostback, full burn boost of Starship to space and sub LEO, Starship will do one partial orbit, simulate a de-orbit burn, test tiles and heating from atmospheric reentry, until it has a splashdown in the Indian Ocean.

It has also been determined that for this test flight there will be a fuel transfer test done on Starship for NASA's Tipping Part contract. The Starship will also test its payload bay door in zero-G for a test of future Starlink 2.0 deployments.

 

[JohnnyEnglish]

I have to agree with @JB47394 on both points:

• At the start of the coast phase the ship was in a constant orientation but with one fin pointing towards earth. I was surprised by this until I noticed the shadows and realised that they had oriented so the tiles were facing the sun. This is more effective than a barbeque roll for reducing the amount of heat absorbed.
• The ship was not in a stable attitude prior to re-entry. This was clear from both the camera views and from the on screen info. When the plasma field became visible it was clear that the ship was not 'belly first' into the airflow and that untiled areas of the ship were being exposed. From the on screen graphic the pitch angle also seemed to go from stern down to nose down and then back to stern down. If this was a correct representation (seemed to fit with the visible plasma field) it was definitely not what would have been planned.

However, I don't want this to detract from an absolutely amazing flight with huge advances relative to IFT-2.

 

[scaesare]

Wow, incredible so far. Is the ship venting LOX right now?

Are you talking about the booster after it's initial boostback with all engines off?

I saw this too and wondered, I don't recall seeing that kid of venting at that point with F9 boosters. Given the issues associated with dumping LOX last time, it caught my attention...

 

[HVM]

Good test flight.

I would say that the ship did not maintain good attitude control after the raptor shutdown, which likely led to the decision not to proceed with the restart test and contributed to the failure during re-entry.

I blame (humorously) Everyday Astronaut for that... ; P

 

[JB47394]

I don't recall seeing that kid of venting at that point with F9 boosters.

It may be autogenous pressurization venting, which Falcon 9 boosters don't employ.

 

[HVM]

Falcons need to vent only the LOX boil off, when Starship needs to do that for the both propellants (also scale). But I have seen Falcon's second stage fly-over my own eyes and that thing vented like no other...

 

[JB47394]

Hot staging happened at 5750 km/h. The booster slowed to 5660 km/h before starting its boostback burn. So it looks like the propellants being unseated wasn't the problem.

They got a good relight on all 13 engines.

My guess for IFT-2 is that they really did tear up the interior of the LOX tank as a result of the sloshing, and that reinforcement was all they needed.

 

[scaesare]

Any thoughts on why the Raptor relight issues prior to splashdown?

At that point the propellent would be settled... I wonder if the rapid grid fin movement implies there was some violent sloshing...

 

[scaesare]

Also, Manley posted something I saw briefly as well, but forgot to mention... looks like mostly tiles:

https://twitter.com/x/status/1768278563890020435

 

[ecarfan]

Also, Manley posted something I saw briefly as well, but forgot to mention... looks like mostly tiles:

Yes I noticed that and was surprised because at that point the ship was at 112km so very little atmosphere and engines were off; why were those tiles falling off at that point in the flight? I can understand during ascent or reentry but not in the coast phase.

 

[Electroman]

Actually 3 briefly:

View attachment 1027868

No reentry burn for Booster to slow it down before it hits the atmosphere at 55M attitude ? ?

 

[mongo]

No reentry burn for Booster to slow it down before it hits the atmosphere at 55M attitude ? ?

Yep, no reentry burn for Superheavy.

 

[ecarfan]

SpaceX has already posted their summary of the flight. Here is the part about the booster after stage sep. Some new details.

• Following separation, the Super Heavy booster successfully completed its flip maneuver and completed a full boostback burn to send it towards its splashdown point in the Gulf of Mexico.
• Super Heavy successfully lit several engines for its first ever landing burn before the vehicle experienced a RUD (that’s SpaceX-speak for “rapid unscheduled disassembly”). The booster’s flight concluded at approximately 462 meters in altitude and just under seven minutes into the mission.
• Starship's six second stage Raptor engines all started successfully and powered the vehicle to its expected orbit, becoming the first Starship to complete its full-duration ascent burn.

 

[mongo]

You're right. I just watched the SpaceX feed again. It impacted, and it looks like you can even see the surface of the water. The altitude reading went straight to zero while still moving at 1100 km/h (about Mach 0.9). They very briefly had three engines showing as lit.

No wonder the grid fin looked like it wanted to rip off.

You were right
"Super Heavy successfully lit several engines for its first ever landing burn before the vehicle experienced a RUD (that’s SpaceX-speak for “rapid unscheduled disassembly”). The booster’s flight concluded at approximately 462 meters in altitude and just under seven minutes into the mission."

 

[ecarfan]

And here is the rest of SpaceX’s first public analysis:

• While coasting, Starship accomplished several of the flight test’s additional objectives, including the opening and closing of its payload door (aka the pez dispenser,) and initiating a propellant transfer demonstration. Starship did not attempt its planned on-orbit relight of a single Raptor engine due to vehicle roll rates during coast. Results from these demonstrations will come after postflight data review is complete.
• Starship went on to experience its first ever entry from space, providing valuable data on heating and vehicle control during hypersonic reentry. Live views of entry were made possible by Starlink terminals operating on Starship.
• The flight test’s conclusion came during entry, with the last telemetry signals received via Starlink from Starship at approximately 49 minutes into the mission.

“Initiated” the prop transfer, no indication it was successful.

Interesting about the “vehicle roll rates” stopping the engine relight test. So the roll was not intentional.

 

[Electroman]

Yep, no reentry burn for Superheavy.

Thank you. Any reason why a slow down is not necessary for SH before hitting the atmosphere, but needed for F9 booster ?

 

[HVM]

...
Interesting about the “vehicle roll rates” stopping the engine relight test. So the roll was not intentional.

Like I said before the ship's attitude control did not seem to work at all. (But it work fine at the SH booster).
And what I was ref. in the previous comment:

 

[mongo]

Thank you. Any reason why a slow down is not necessary for SH before hitting the atmosphere, but needed for F9 booster ?

It's built stronger and is carrying less velocity.
F9: 4,700 km/hr at reetry burn @ 60 km down to 2,200 km/hr
SH: peaks at ~4,300 @ 29 km and is 3,300 @ 60 km

 

[JB47394]

You were right

I'll have to ponder that possibility. It happens so rarely. I guess what looked like water ripples was engine exhaust.

Do you think they intended to relight engines at 500 meters and perform a full braking burn? That would involve almost a 10 g suicide burn.

“Initiated” the prop transfer, no indication it was successful.

I noticed that too. If it was successful, they would have said as much, including the words "Fulfilling the NASA Tipping Point contract".

So the roll was not intentional.

I might have believed it if it was purely roll, but it was actually a slow tumble. How does a Starship perform attitude control? With the cowbell thrusters?

 

[Pricee2]

Was this the first ever external video of reentry plasma? Pretty amazing.

 

[scaesare]

I'll have to ponder that possibility. It happens so rarely. I guess what looked like water ripples was engine exhaust.

Do you think they intended to relight engines at 500 meters and perform a full braking burn? That would involve almost a 10 g suicide burn.


I noticed that too. If it was successful, they would have said as much, including the words "Fulfilling the NASA Tipping Point contract".


I might have believed it if it was purely roll, but it was actually a slow tumble. How does a Starship perform attitude control? With the cowbell thrusters?

If so, it clearly... needed... more... cowbell... never can get enough cowbell!