SpaceX Starship missions 1

[thebard3]

Starting a dedicated thread here. After a pretty smooth flight test today, assuming no big anomalies occurred with the ground systems, it looks like SpaceX is back on track with testing and development. We should see more flights in the near future.
Both vehicles were lost before completing their full mission but a huge step forward today to see both executing the primary flight goals.

Brad Waybright

The more you know, the more you know you don't know.

 

[WKTaylor]

RK...?... Your post, 15 Apr 24 10:32, make no [zero] sense without context...

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[thebard3]

Flight test 4 complete. It seemed to be pretty successful.
One engine out on the booster during ascent, another went out during the landing burn but it looked like the soft landing was achieved.
There was obvious and significant heating damage to Starship during re-entry, but despite that, it looks like the reentry trajectory and soft landing was successful.

Brad Waybright

The more you know, the more you know you don't know.

 

[rb1957]

damn ! spoiler alert !!

I was going to natter on about how optimistic Elon was in his view of the future. Establishing an independent self sustaining Mars colony in 20 years is "very optimistic". But he has accomplished a lot. Building a moon base in 20 years (not self-sufficient) is as optimistic as I can get.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[thebard3]

We used to call his vision of fully reusable hardware overly optimistic. Now boosters are being used 20+ times.

Brad Waybright

The more you know, the more you know you don't know.

 

[WKTaylor]

The flap that partly disintegrated was obvious in the single camera perspective. HOWEVER in my Mishap investigation experience... what happens on one side of a relatively symmetric structure WILL HAPPEN on the opposite side structure... to a lesser or greater degree... just hidden from view.

I presume that the Starship landed/sank out-of-sight of any video recording seaborne recovery vehicle... or could it have landed softly enough that it is still floating?

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[thebard3]

Test flight 5 occurred this morning. Booster stage flight profile and capture was just about perfect. There was a small fire at the bottom of the booster that went out after a while. Starship flight looked to be very similar to ghe last one. There was some obvious heating damage so there's more work to do with that. Spacex had a camera platform on station to record the landing so they were on target and it looked like a short hover before splashdown.

Brad Waybright

It takes competence to recognize incompetence.

 

[JayMaechtlen]

And it floated for a while after splashdown.
Tail up, but I guess that's not surprising?
Some kind of explosion at splashdown, but dumping three engines at operating temperatures into ocean water could have caused fuel-carrying things to rupture?
With the successful catch of superheavy and two soft splashdowns of the ship, they may try and land the ship next time?
Obviously more work to do on the fins/joint thermal protection.

Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[Brian Malone]

I am not criticizing SpaceX engineering with my next comment: impressive as the booster catch is, contrary to the hype and hoopala, this is hardly a major step toward making humans an interplanetary species or go to Mars. Or am I missing the special sauce? The distance between planets is so immense in comparison to the propulsion capacity of Starship that catching a booster for reuse really doesn't mean anything except for Earth-to-Moon excursions. SpaceX engineering is very impressive and they continue to solve many challenges.

 

[WKTaylor]

Paraphrasing what my dad use to say to us kids... a form of mild praise... SpaceX starship has earned Hero 3rd class status.... . More hard work to do.

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[thebard3]

Tough crowd here.

Brad Waybright

It takes competence to recognize incompetence.

 

[LiftDivergence]

Tough crowd here.

Possibly because these forums are used primarily by seasoned engineers who tend to be.. how should I say... more dour/cynical/"realistic" about these types of challenges than the average "techie" or cult-of-personality type follower of SpaceX that you might see on social media or tech news forums.

It's pretty cool for sure. And I get it... you can take some weight & complexity out of the flight vehicle if you offload some responsibility to the ground support structure "Stage 0". If you catch the booster, it no longer needs landing gear, systems, etc. Fine.

But something that has always left me pondering about SpaceX's "plan" (other than the fact that configuration control must be a nightmare)... their "plan", even for a moon mission, requires potentially up to 30 Starship launches, just to refuel the lunar config so that there's enough DeltaV. The actual number seems like it is not pinned down, but it seems like at least 15 launches.

So are they trying to catch all of these boosters? Their ground support system is exceedingly complex and susceptible to damage. And they are making the launch site the same spot as the catch site. So what happens if they "miss" a catch? That would jeopardize the entire mission schedule, no?

Is the whole idea of catching the boosters really that good? Maybe I'm missing something. It seems to astronomically increase the risk.

Keep em' Flying
//Fight Corrosion!

 

[racookpe1978]

Test flight 5 occurred this morning. Booster stage flight profile and capture was just about perfect. There was a small fire at the bottom of the booster that went out after a while.

I was told on a different thread on

http://www.freerepublic.com

that the excess fuel was burning off while being "drained" out the bottom of the stage by gravity after landing (being caught in the twin arms). Disconcerting to see open flames after a landing - Certainly NOT what I expect after an aircraft or the Space Shuttle landed.

Then again, the Space Shuttle was in a deadly/no walk quarantined exclusion zone for several hours after landing before it could even move from the runway due to explosives remaining and the dangerous left-over thruster (?) fuel still aboard. SpaceX intends to have refueled this booster, reloaded a payload, and taken off again in that same time needed to roll the Space Shuttle off of the runway just to start a six week overhaul and inspection!

 

[Sparweb]

There was a small fire at the bottom of the booster that went out after a while.

That was a deliberate purge of remaining methane still in the tank. They couldn't vent it without burning it off - risk of accumulations somewhere and explosion, which is worse than a fire.

Is the whole idea of catching the boosters really that good? Maybe I'm missing something.

Not sure but I think the booster catch today is just "one small step" and the long-game hasn't been played yet. They also say they will land Starships on the Moon and it's not clear to anyone how that's supposed to work, either. But SpaceX has figured out so many other novel developments in spaceflight, they have earned some trust that the plan on their drawing board could be a good one. So what could that be? The question of landing anything on the Moon or Mars has remained extremely risky and difficult, even after decades of trying by NASA, USSR, Japan, China, India and others. Seems to invite a novel solution since the tried-and-true solutions require very high complexity (Apollo LM) to be guaranteed successful. Considering all that, my guess (not sure if there's been an official statement from Spacex on this) is that SpaceX has decided that they will prefer to build infrastructure on the Moon or Mars before attempting to land humans on it. Their decades-long practice of guiding rockets to controlled landings with increasing precision and repeatability suggests this strategy is preferred. While other space agencies will probably try to continue landing spacecraft on raw terrain in the coming decade, I expect SpaceX will minimize that or avoid it altogether. Their landing system for the Moon/Mars probably won't look exactly like Mechazilla Chopsticks, and nothing like a drone ship on the ocean, but I'll bet they won't just drop down on open regolith.

 

[WKTaylor]

Some random thought by WK Taylor...

Interesting video regarding evolution/development of the simplified Raptor III [RIII] engines... for the Starship Booster. SpaceX and the Rocket engine team are rightfully proud of this simplified 'mighty-mite' engine.

https://www.youtube.com/watch?v=bG_394YKaOI

However, as I was watching the video, my wandering mind said"heyyyyy, stop-the-presses... that RIII engine looks vaguely familiar!" Hmmmm...

So Inquired about the Russian RD180 engines [

https://en.wikipedia.org/wiki/RD-180

] and this image of these workhorses, popped-up... which appear at first/side/upside-down/glancing view to be strikingly similar to the RIII... or vice-versa... including relative length and size and performance. Hmmm only significant differences appear to the propellant... RP1/LOX for the RD-180 and L-Methane/LOX for the RIII... which really isn't that giant of a difference... and hey... the Methane fuel burns cleaner and won't coke parts like RP1 for a return to launch site deceleration-to-landing.

... but here is the SpaceX RIII 'rebuff' of the aging RD-180...

https://www.youtube.com/watch?app=desktop&v=trhnA5QLEtM

Hmmm I keep wondering if SpaceX had a peek at the RD-180... before evolving the RIII.



Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[LiftDivergence]

That was a deliberate purge of remaining methane still in the tank. They couldn't vent it without burning it off - risk of accumulations somewhere and explosion, which is worse than a fire.



Not sure but I think the booster catch today is just "one small step" and the long-game hasn't been played yet. They also say they will land Starships on the Moon and it's not clear to anyone how that's supposed to work, either. But SpaceX has figured out so many other novel developments in spaceflight, they have earned some trust that the plan on their drawing board could be a good one. So what could that be? The question of landing anything on the Moon or Mars has remained extremely risky and difficult, even after decades of trying by NASA, USSR, Japan, China, India and others. Seems to invite a novel solution since the tried-and-true solutions require very high complexity (Apollo LM) to be guaranteed successful. Considering all that, my guess (not sure if there's been an official statement from Spacex on this) is that SpaceX has decided that they will prefer to build infrastructure on the Moon or Mars before attempting to land humans on it. Their decades-long practice of guiding rockets to controlled landings with increasing precision and repeatability suggests this strategy is preferred. While other space agencies will probably try to continue landing spacecraft on raw terrain in the coming decade, I expect SpaceX will minimize that or avoid it altogether. Their landing system for the Moon/Mars probably won't look exactly like Mechazilla Chopsticks, and nothing like a drone ship on the ocean, but I'll bet they won't just drop down on open regolith.

To be clear, I wasn't implying that they will try to "catch" anything on the moon. I'm just talking about their reusable boosters. I wasn't stating anything about their off-earth infrastructure at all.

What I'm saying is that their "stage 0" on earth, their launchpad, is the same infrastructure as their booster return collection system. Given the amount of time, effort, and cost associated with their development of the launch pad for starship, and complications associated with land use / site availability / orbital mechanics, I can't see them constructing more launch/catch sites elsewhere. I think Boca Chica is what they've got.

So they have to launch 15-30 rocket stacks from this launchpad. Sure they can have a slew of Starships but they need to use the same launch / catch infrastructure. And the mission can't proceed until they are all launch and deliver their fuel.

So what happens if an attempted catch fails and the launch pad is disabled? They now need 15-30 perfect launch + catch ops in a row for a successful mission. Like I said, seems like a huge risk.

Sure they could just abandon the catch and dump the booster in the ocean. But that defeats the whole purpose of their design philosophy.

I have to wonder what the trade study of removing the landing gear really looked like.

 

[btrueblood]

"I'll bet they won't just drop down on open regolith."

So, they will build a landing pad? What is going to land the landing pad, a Starship? Landing on open regolith? The hole plan is full of wholes.

Wil, I had the same thought awhile back but saw that video. But still, the RD180 has been used by the Atlas V, and a lot of Russian engineers came over here after the wall fell - and I would assume quite a few (along with a bunch of US ex-Rocketdyne and Pratt engineers) went over to Musk's shop. There's been a lot of technology transfer as a result. Some of the superalloys used by the RD-180 especially help for oxidizer-rich preburner and turbines.

 

[Sparweb]

So what happens if an attempted catch fails and the launch pad is disabled?

Oh, I see. That would be bad.

As for landing the Starship on the Moon, if SpaceX even does that, I don't think the first landing will have people in it. Starship is so automated that I think the humans are just "cargo" in almost all cases. So a couple of landings may be dedicated to preparing a site for the manned landing later.

You can still say there are lots of holes, of course. I'm trying to account for the many different design strategies I see from SpaceX, and putting them to use as I "spitball" about it.