SpaceX

[Chalkie]

I have no doubt a software change will fix the booster flip and burn-back manoeuvre. My bet is shut down all motors, flip, then restart as fuel settles down to base of fuel tanks. Falcon does it that way...

Unlikely. They stage above any significant atmosphere. So once they shut of the motors, it will be in free fall (0G). Which means that they will need thrust to provide acceleration to settle the fuel. But the only thrusters are the RCS thrusters, powered from ullage gas, which in turn is provided by the raptors...

So, they would need an entire new thruster system to pull that off.

OK, so keep 3 motors running for a slower vectored thrust flip.... to try to keep fuel settled and start 10 more if needed for deceleration... ?

[Chalkie]

OK, so keep 3 motors running for a slower vectored thrust flip.... to try to keep fuel settled and start 10 more if needed for deceleration... ?

Initial plan was as you had it - but they had hot gas RCS thrusters, which had enough impulse to settle the tanks.

Then they deleted the thrusters and went for the 'flip' manoeuvre on IFT-1, which did not work at all.

Then they added the hot-stage ring for a powered separation on IFT-2, which almost worked.

What next? Don't know. They might actually go back to hot gas thrusters and full cut-off. Or it could just be a simple software tweak of the current system to reduce slosh.

So far, there are no signs of major modifications for IFT-3, so my guess would be a software tweak.

[Patrick AL]

Falcon 9 is a reusable, two-stage rocket designed and manufactured by SpaceX for the reliable and safe transport of people and payloads into Earth orbit and beyond. Falcon 9 is the world’s first orbital class reusable rocket. Reusability allows SpaceX to refly the most expensive parts of the rocket, which in turn drives down the cost of space access.

Falcon Heavy is composed of three reusable Falcon 9 nine-engine cores whose 27 Merlin engines together generate more than 5 million pounds of thrust at liftoff, equal to approximately eighteen 747 aircraft. As one of the world’s most powerful operational rockets, Falcon Heavy can lift nearly 64 metric tons (141,000 lbs) to orbit.

Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1, Falcon 9 and Falcon Heavy launch vehicles. Merlin engines use a rocket grade kerosene (RP-1) and liquid oxygen as rocket propellants in a gas-generator power cycle. The Merlin engine was originally designed for recovery and reuse.

[/media]

[Patrick AL]

In this presentation Elon explains why Starship launch 2 failed

[Chalkie]

Yep. Starship set itself on fire by venting the oxidiser with the engines still running, leading to a big explosion in space.

One other video I watched explained the fuel slosh and emulsification of the fuel caused on the booster during the hot staging and flip manoeuvre. Hopefully a software tweak will make IFT3 work better.

My bet is IFT 3 will be a full orbit and 'soft' landing in the Atlantic.

[Patrick AL]

Falcon 9 launches Ax-3, Dragon’s 12th human spaceflight mission




SpaceX and Axiom Space successfully launched four private astronauts into orbit Thursday, marking the third commercial mission to the International Space Station (ISS).

Axiom Mission 3 (Ax-3) on board SpaceX’s Dragon spacecraft lifted off via a SpaceX Falcon 9 rocket at 4:49 p.m. EST from Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

Falcon 9 launches Ax-3, Dragon’s 12th human spaceflight mission pic.twitter.com/VaswQz7npo
— SpaceX (@SpaceX) January 18, 2024

On board the spacecraft is the first all-European commercial astronaut crew, which is scheduled to spend about two weeks aboard ISS conducting microgravity research, educational outreach, and commercial activities, according to NASA.

Ax-3 crew checks in from orbit on January 18. [Courtesy: Axiom Space]

“Together with our commercial partners, NASA is supporting a growing commercial space economy and the future of space technology,” NASA Administrator Bill Nelson said in a statement. “During their time aboard the International Space Station, the Ax-3 astronauts will carry out more than 30 scientific experiments that will help advance research in low-Earth orbit.”

READ MORE: First U.S. Moonshot in Decades Will Fall Short—What It Means

In a quick check-in shortly after liftoff, “Ax-3 commander Michael López-Alegría confirmed the crew’s well-being and safety,” according to Axiom Space.

The Dragon spacecraft is expected to autonomously dock with the forward port of the ISS Harmony module on Saturday around 4:19 a.m. EST.

“Hatches between Dragon and the station are expected to open after 6 a.m., allowing the Axiom crew to enter the complex for a welcoming ceremony and start their stay aboard the orbiting laboratory,” NASA said.

NASA is providing live coverage of the docking event starting at 2:30 a.m. EST. It may be viewed here.

The Ax-3 astronauts are scheduled to leave the ISS on February 3 for their return to Earth and will splash down off the coast of Florida.

[propstrap]

Booster 12 seems to have completed structural testing and going back for engine installation.

OFT-2 mishap investigation has been completed and submitted to FAA for evaluation.

OFT-3 license application has been submitted to FAA.

SpaceX has stated they intend OFT-3 for February, but as usual, we will need to wait and see when all the paperwork is done...

[Chalkie]

Booster 12 seems to have completed structural testing and going back for engine installation.

OFT-2 mishap investigation has been completed and submitted to FAA for evaluation.

OFT-3 license application has been submitted to FAA.

SpaceX has stated they intend OFT-3 for February, but as usual, we will need to wait and see when all the paperwork is done...

Judging by all the work going on, on and around the OLM, I guess they can afford to wait another week or two.

[Patrick AL]

Flight 3 stack:

https://twitter.com/seankd_photos/statu ... 4238220741

GGFM9zPWgAAhtQu.jpg

I assume this will be unmounted again though. Ship 28 has had all engines removed/replaced, and Booster 10 seems to have had some internal re-working of the tanks. So they will almost certainly do static fires of the two vehicles before flight.

[Patrick AL]

Space X sends first private lunar lander towards the moon.

Good luck!

[Patrick AL]

https://www.spacex.com/updates :

February 26, 2024

BUILDING ON THE SUCCESS OF STARSHIP’S SECOND FLIGHT TEST

The second flight test of Starship and Super Heavy achieved a number of important milestones as we continue to advance the capabilities of the most powerful launch system ever developed.

On November 18, 2023, Starship successfully lifted off at 7:02 a.m. CT from Starbase in Texas. All 33 Raptor engines on the Super Heavy Booster started up successfully and, for the first time, completed a full-duration burn during ascent. Starship then executed a successful hot-stage separation, the first time this technique has been done successfully with a vehicle of this size.

Following stage separation, Super Heavy initiated its boostback burn, which sends commands to 13 of the vehicle’s 33 Raptor engines to propel the rocket toward its intended landing location. During this burn, several engines began shutting down before one engine failed energetically, quickly cascading to a rapid unscheduled disassembly (RUD) of the booster. The vehicle breakup occurred more than three and a half minutes into the flight at an altitude of ~90 km over the Gulf of Mexico.

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.

The water-cooled flame deflector and other pad upgrades made after Starship’s first flight test performed as expected, requiring minimal post-launch work to be ready for vehicle tests and the next integrated flight test.

Following the flight test, SpaceX led the investigation efforts with oversight from the FAA and participation from NASA, and the National Transportation Safety Board.

Upgrades derived from the flight test will debut on the next Starship and Super Heavy vehicles to launch from Starbase on Flight 3. SpaceX is also implementing planned performance upgrades, including the debut of a new electronic Thrust Vector Control system for Starship’s upper stage Raptor engines and improving the speed of propellant loading operations prior to launch.

More Starships are ready to fly, putting flight hardware in a flight environment to learn as quickly as possible. Recursive improvement is essential as we work to build a fully reusable launch system capable of carrying satellites, payloads, crew, and cargo to a variety of orbits and Earth, lunar, or Martian landing sites.

[heisan]

https://twitter.com/MarcusHouse/status/ ... 3791454680

"Following a successful start-up of all engines and separation from B9, Starship Ship 25 (S25) had a nominal ascent until 13:09:55 UTC, when the planned pre-second engine cutoff Liquid Oxygen dump started. Over the next minute, several explosions and sustained fires were observed in onboard camera aft video streams, ultimately resulting in a loss of communication between the forward and aft flight computers. This resulted in a commanded shutdown of all six engines, and an Autonomous Flight Safety System flight termination triggering at 13:10:55 UTC per flight safety rules."

GHS4y1QawAA5Rr4.jpg

[Dan the Man]

FAA has closed the mishap investigation, and accepted the list of 17 corrective actions supplied by SpaceX.

Which means that now SpaceX must submit proof of implementing the corrective actions (probably already done) and apply for license modification.

Probably 2-3 weeks before the next launch then.

[scavanger]

That's great news. Thanks for the updates @heisan. Very much appreciated, as always.

Cannot wait for test flight 3!

[Patrick AL]

https://www.bbc.com/news/science-environment-68465056

SpaceX sends Dragon to space station



A SpaceX rocket carrying three US astronauts and one Russian cosmonaut has blasted off from Florida bound for the International Space Station (ISS).
They have a six-month mission, and space is one of the few areas where the US and Russia continue to co-operate closely despite the war in Ukraine.
The three men and one woman are in a capsule used in space four times before by Elon Musk's SpaceX firm.
They plan to do various experiments.
Their research will include growing artificial replicas of human organs to study degenerative diseases in the low-gravity environment - which is not possible on Earth.
The crew blasted off from the Kennedy Space Center in Florida at 22:53 local time (03:53 GMT Monday).