SpaceX Starship - Integrated Flight Test #2 - Starbase TX - Including Post Launch Dissection

[ecarfan]

Normally, one would arm before stacking and stack close to flight. SpaceX only has so many stands for Starship, so they are storing it on the booster.

That assumes that there would be no full stack WDR before launch. Right now that is a necessary step. Someday Starship flights will be routine, like F9 launches are becoming, and after inspections and maintenance there will be just a brief static fire of both stages, then arm the FTS, stack and go.

But it seems to me that FTS arming should be something that can be done quickly and easily without having to take the vehicle apart. And I’m sure that SpaceX will achieve that.

 

[mongo]

That assumes that there would be no full stack WDR before launch. Right now that is a necessary step. Someday Starship flights will be routine, like F9 launches are becoming, and after inspections and maintenance there will be just a brief static fire of both stages, then arm the FTS, stack and go.

But it seems to me that FTS arming should be something that can be done quickly and easily without having to take the vehicle apart. And I’m sure that SpaceX will achieve that.

Yeah, WDR do require unstacking to arm, but like you mention, that is only a development operation. Static fires can take place separately, so Starship FTS can be armed pre-stacking.

FTS arming itself needs to be something protected and deliberate. I believe the system is currently protected by an external shroud that needs removed for access, not really taking the vehicle apart.

 

[JB47394]

I wonder about the applicability of a flight termination system on a Starship. The Space Shuttle didn't have one. The solid rocket boosters did, but not the shuttle vehicle itself. On ascent, if the Shuttle stack went haywire, they could detonate the SRBs and that would take out the stack. Once the SRBs separated, the Shuttle and external tank headed out without the possibility of destruction via FTS.

The SRBs separated at 45 km after a burn of 123 seconds. Starship stages after 170 seconds. The thrust to weight ratios at liftoff are very different, but I'm sure that Starship starts to really move as it dumps fuel. It's a very different launch, but I'm going to just assume that the staging altitude is comparable.

My question is whether flight termination matters once the vehicle is safely out over the ocean.

The FTS could ultimately be on the interstage (no, not an ideal location), pointed in each direction. If they have to terminate both vehicles, detonate while still stacked. If you only want to terminate the booster (e.g. it's a manned Starship), then you stage, wait a bit, then detonate. I was going to suggest that Starship should have a fuel dump system in case of a low altitude abort, but the darned thing can just hover until it's light enough to land.

Starship may have an FTS today because the entire stack is so experimental. In the future, there may not be an FTS, so coming up with a system to easily maintain it isn't considered necessary.

 

[ecarfan]

From the latest Ars technica Rocket Report:

The biggest outstanding piece of the puzzle before the second integrated flight test is the environmental review, done in partnership with the US Fish and Wildlife Service. The agency has up to 135 days to complete its review process, and the clock just started on October 19. However, the agency said it does not expect to take that much time. Ars has heard the current no-earlier-than launch date is November 13.

 

[scaesare]

The FTS could ultimately be on the interstage (no, not an ideal location), pointed in each direction. If they have to terminate both vehicles, detonate while still stacked. If you only want to terminate the booster (e.g. it's a manned Starship), then you stage, wait a bit, then detonate. I was going to suggest that Starship should have a fuel dump system in case of a low altitude abort, but the darned thing can just hover until it's light enough to land.

Given the previous FTS had a hard time rupturing the tanks inside, And a FTS located in the interstage would have to fire through the hotstaging dome reinforced to withstand Raptor thrust at point-blank range, I wonder how well that would work...

 

[mongo]

Mid-November-ish maybe?

https://twitter.com/x/status/1720523323212492904

 

[Grendal]

First post updated...

 

[ecarfan]

Mid-November-ish maybe?

See my post just above: “Ars has heard the current no-earlier-than launch date is November 13.”

 

[mongo]

See my post just above: “Ars has heard the current no-earlier-than launch date is November 13.”

Yah, but SpaceX as a source is more authoritative and has info at the link including updated launch progression
3 seconds on pad and a new definition for MECO
SpaceX

 

[JB47394]

3 seconds on pad and a new definition for MECO

Yeah, lots of good stuff on that page. They say that we can watch the launch through the SpaceX site as well as Twitter. As I recall, some of us were having difficulties seeing Twitter streams. I hope it comes through via the SpaceX site, and at better resolution than Twitter - though it'll probably be the exact same bits.

I thought it was interesting that the deluge system is going to run for seven seconds prior to engine ignition. I just went back to watch the deluge test after the wet dress rehearsal and it lasted about 20 seconds (conservatively), which I find incredible. So seven seconds to come up to full water flow, three seconds to get the engines up to full power, two seconds to liftoff, then eight seconds more to leave the launch mount. In the first launch, it took about 10 seconds to clear the tower with three engines out, and I'm guessing that's far enough that they don't have to worry about significant thrust reaching the deluge plate. Here's hoping that eight seconds is enough.

Also, if all goes well, it'll take an hour and 17 minutes before Starship begins its reentry.

Go Fish & Wildlife Service! Go Starship!

 

[ecarfan]

Yah, but SpaceX as a source is more authoritative and has info at the link including updated launch progression

Yep, great info!

And this time the graphic correctly shows the booster orientation during the flip maneuver.

 

[ICUDoc]

Most Engines Cut Off = Hot Staging is the new MECO? Nice!

 

[Electroman]

Yep, great info!

And this time the graphic correctly shows the booster orientation during the flip maneuver.

View attachment 987808

Something seems amiss with the boostback trajectory.

After MECO and separation the booster is shown flying west (reverse direction) for a short period. That means it has zeroed the eastward velocity and gained some velocity in the reverse (westward) direction. YET later the graphic shows the booster falling towards earth and moving eastwards again. How is that possible?

 

[miimura]

How is that possible?

Artistic License.

 

[ICUDoc]

Artistic License.

Most powerful force on Earth

 

[ecarfan]

Something seems amiss with the boostback trajectory.

I would not take that graphic literally.

It’s not possible to show accurate trajectories of both vehicles within the physical confines of a very small rectangle.

 

[ggr]

It doesn't show a burn for de-orbit, but my understanding (possibly incorrect) is that Starship is essentially in orbit, having gone more than halfway around the earth, and will need something to make it re-enter.

 

[mongo]

It doesn't show a burn for de-orbit, but my understanding (possibly incorrect) is that Starship is essentially in orbit, having gone more than halfway around the earth, and will need something to make it re-enter.

It's not sub-orbital based on federal definition (vacuum path), but perigee is inside the atmosphere so it's coming down before it gets back to Texas.

 

[Electroman]

is there a rentry burn to slow down ? And a landing burn?

 

[JB47394]

is there a rentry burn to slow down ? And a landing burn?

The booster is supposed to make a soft landing in the Gulf of Mexico, so there should be a landing burn. According to Elon back in 2021, the booster won't need a reentry burn to slow down.

https://x.com/elonmusk/status/1410325315835109378