posted 02-26-2024 05:36 PM               

The FAA has closed the SpaceX-led mishap investigation of the Starship Super Heavy Orbital Test Flight 2 (OTF-2) launch that occurred on Nov. 18, 2023.

SpaceX identified, and the FAA accepts, the root causes and 17 corrective actions documented in SpaceX's mishap report.

Seven corrective actions were identified for the Super Heavy Booster including vehicle hardware redesigns, updated control system modelling, reevaluation of engine analyses based on OTF-2 flight data, and updated engine control algorithms. Ten corrective actions were identified for the Starship vehicle including vehicle hardware redesigns, operational changes, flammability analysis updates, installation of additional fire protection, and guidance and modelling updates.

The closure of the mishap investigation does not signal an immediate authorization of the next Starship launch.

Prior to the next launch, SpaceX must implement all corrective actions and receive a license modification from the FAA that addresses all safety, environmental and other applicable regulatory requirements. The FAA is evaluating SpaceX's license modification request and expects SpaceX to submit additional required information before a final determination can be made.

The most likely root cause for the booster RUD was determined to be filter blockage where liquid oxygen is supplied to the engines, leading to a loss of inlet pressure in engine oxidizer turbopumps that eventually resulted in one engine failing in a way that resulted in loss of the vehicle. SpaceX has since implemented hardware changes inside future booster oxidizer tanks to improve propellant filtration capabilities and refined operations to increase reliability.

At vehicle separation, Starship's upper stage successfully lit all six Raptor engines and flew a normal ascent until approximately seven minutes into the flight, when a planned vent of excess liquid oxygen propellant began. Additional propellant had been loaded on the spacecraft before launch in order to gather data representative of future payload deploy missions and needed to be disposed of prior to reentry to meet required propellant mass targets at splashdown.

A leak in the aft section of the spacecraft that developed when the liquid oxygen vent was initiated resulted in a combustion event and subsequent fires that led to a loss of communication between the spacecraft's flight computers. This resulted in a commanded shut down of all six engines prior to completion of the ascent burn, followed by the Autonomous Flight Safety System detecting a mission rule violation and activating the flight termination system, leading to vehicle breakup. The flight test's conclusion came when the spacecraft was as at an altitude of ~150 km and a velocity of ~24,000 km/h, becoming the first Starship to reach outer space.

SpaceX has implemented hardware changes on upcoming Starship vehicles to improve leak reduction, fire protection, and refined operations associated with the propellant vent to increase reliability. The previously planned move from a hydraulic steering system for the vehicle's Raptor engines to an entirely electric system also removes potential sources of flammability.

posted 03-04-2024 11:52 AM               

Starship completed its rehearsal for launch, loading more than 10 million pounds of propellant on Starship and Super Heavy and taking the flight-like countdown to T-10 seconds.

posted 03-08-2024 07:22 PM               

The FAA has given license authorization for the third launch of the SpaceX Starship Super Heavy vehicle. The FAA determined SpaceX met all safety, environmental, policy and financial responsibility requirements.

posted 03-12-2024 09:29 PM               

Starship stacked for flight.

posted 03-13-2024 06:29 PM            

The FAA has given license authorization for the third launch of the SpaceX Starship Super Heavy vehicle.

posted 03-14-2024 06:21 AM               

Weather is 70% favorable for today's third integrated flight test of Starship.

The live webcast will begin about 30 minutes before liftoff, which is currently targeted for 7:30 a.m. CT.

posted 03-14-2024 06:52 AM               

New liftoff time is 8:02 a.m. CDT, team is clearing a few boats from the keep out area in the Gulf of Mexico.

posted 03-14-2024 07:13 AM               

Shifting T-0 a few more minutes to give boats time to clear the keep out area, now targeting 8:10 a.m. CT.

posted 03-14-2024 07:25 AM               

The Starship team is go for prop load but keeping an eye on winds, now targeting 8:25 a.m. CT for liftoff.

posted 03-14-2024 07:36 AM               

Propellant load of Starship's upper stage is now underway.

Prop load of the Super Heavy booster is underway.

posted 03-14-2024 08:02 AM               

quote:

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Originally posted by Jim Behling:
It will be orbital, just won't complete an orbit.

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If we get past a successful stage separation and a full ascent burn with the upper stage, it will be at an altitude and trajectory below orbital — meaning Starship won't have to fire its Raptor engines for a deorbit burn and it will naturally come back into the atmosphere no matter what.

It's important to note that what we'll attempt today is not a burn required for Starship to reenter on today's test. We are intentionally flying this new steeper trajectory so we can test things like engine re-light without substantially changing where we expect to splashdown.

posted 03-14-2024 08:42 AM               

Starship has cleared the pad! Vehicle is on a nominal flight path.

Starship’s Raptor engines have ignited during hot-staging separation. Super Heavy is executing the flip maneuver.

Super Heavy boostback burn complete.

Starship's Raptor engine burn is complete and Starship has entered a coast phase.

We did see what looked like a nominal boost back burn. And then we did make it all the way to the landing burn this time, but didn't light all the engines that we expected and we did lose the booster. We'll have to go through the data to figure out exactly what happened.

posted 03-14-2024 09:02 AM               

Propellant transfer demo complete.

Pez [payload bay] door checkout complete, door closing, and HD views are over.

It does sound like we are skipping past the on orbit relight demo this time. Again, we'll confirm all of this through our post-flight data review, but it did sound like we did pass through that. So now we're going to start setting up for reentry.

posted 03-14-2024 09:17 AM               

Starship re-entering Earth's atmosphere. Views through the plasma.

We are hearing through some of the telemetry that it does look like we lost Starlink and our TDRS data flows at the exact same time. If both of those signals are cutting out at the exact same time, that could mean we lost the ship.

It has been several minutes since we've gotten any data from Starship. We are waiting just a couple more minutes just to see if we can get any additional confirmation but that is one data point that we're tracking and that could indicate that we had a loss or a breakup of the ship during the reentry. So we might not make it all the way to splashdown today.

posted 03-14-2024 09:32 AM               

We are making the call now that we have lost ship 28. So, as we were possibly expecting, we lost the data a couple of minutes ago, we haven't heard from the ship up until this point and so the team has made the call that ship has been lost. So no splashdown today.

posted 03-14-2024 09:46 AM               

quote:

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Originally posted by Blackarrow:
...by reaching orbit

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posted 03-14-2024 11:25 AM               

To refine the point, the Saturn V S-1C didn't place a single payload into orbit, but it launched and sustained the upper stages of the Saturn V, whereby the S-IV stage did place payloads into orbit. Unlike the Soviet N-1 superlifter, which failed to deliver any kind of payload into either a suborbital trajectory or an orbit.

posted 03-14-2024 06:25 PM            

quote:

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Originally posted by Robert Pearlman:
Starship did not reach orbit. It was on a suborbital trajectory the entire flight.

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posted 03-14-2024 06:33 PM               

quote:

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Originally posted by SkyMan1958:
...is that in addition to the mass of Starship?

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quote:

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Originally posted by Headshot:
Will the loss of Starship trigger a FAA investigation?

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A mishap occurred during the SpaceX Starship OFT-3 mission that launched from Boca Chica, Texas, on March 14. The mishap involved both the Super Heavy booster and the Starship vehicle.

No public injuries or public property damage have been reported. The FAA is overseeing the SpaceX-led mishap investigation to ensure the company complies with its FAA-approved mishap investigation plan and other regulatory requirements.

Background
 
A mishap investigation is designed to further enhance public safety, determine the root cause of the event, and identify corrective actions to avoid it from happening again.
 
The FAA will be involved in every step of the mishap investigation process and must approve SpaceX's final report, including any corrective actions.

A return to flight is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety. In addition, SpaceX may need to modify its license to incorporate any corrective actions and meet all other licensing requirements.

posted 03-15-2024 08:10 PM               

quote:

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Originally posted by Blackarrow:
I concede that Starship was deliberately kept slightly below orbital velocity...

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From space launch statistician Jonathan McDowell (via X):

Let's talk about "orbital velocity."

Wait no, let's talk about "orbital energy" instead.

The sum of kinetic energy (related to velocity) and potential energy (related to height) is really more relevant to the question of 'are you in orbit?'. So...

Here is the plot of E_t, the specific energy (energy per unit mass) of the trajectory, versus apogee height, for: (1) circular orbit, (2) orbit with perigee just above the atmosphere, (3) orbit with perigee at the Earth's surface (bad idea). (2, 3 on top of each other at this scale.)

E_t = 62.5, or (on the right hand axis) C3 = 0, corresponds to Earth escape.

Here's a zoom in to low orbits. A recent flight of interest is plotted with a cross. To be considered 'orbital,' you for sure need to be above the red line, really above the green line, and it would be nice to be at the blue line.