Starship IFT-4, soon

They are ordering some road closures for SpaceX a week from now for testing
activities.
https://www.cameroncountytx.gov/wp-content/uploads/2024/05/05.28.2024-Press-Release-on-Order-of-Closure-Related-to-SpaceX-Flight.pdf
I've been told launches typically occur a few days after these tests.
Alain Fournier

Launch is NET "after Memorial Day", from the usual sources, with S29
just having rolled back from the Wet Dress Rehersal to complete tile
work.

SpaceX has ask the FAA to approve a launch license while the IFT3
mishap investigation still open, arguing that the failures were each in
a flight portion that did not represent a safety hazard.

/dps

--
"It wasn't just a splash in the pan"
-- lectricbikes.com

Alain Fournier

2024-05-22 19:32:57 UTC

Post by Snidely

Post by Alain Fournier
They are ordering some road closures for SpaceX a week from now for
testing activities.
https://www.cameroncountytx.gov/wp-content/uploads/2024/05/05.28.2024-Press-Release-on-Order-of-Closure-Related-to-SpaceX-Flight.pdf
I've been told launches typically occur a few days after these tests.
Alain Fournier

Launch is NET "after Memorial Day", from the usual sources, with S29
just having rolled back from the Wet Dress Rehersal to complete tile work.

Translation: NET means "not earlier than"; Memorial Day is a US code
word for the last Monday of May (in this case May 27).

Post by Snidely
SpaceX has ask the FAA to approve a launch license while the IFT3 mishap
investigation still open, arguing that the failures were each in a
flight portion that did not represent a safety hazard.

I agree with SpaceX about that.

Alain Fournier

Snidely

2024-05-29 03:23:33 UTC

They are ordering some road closures for SpaceX a week from now for testing
activities.
https://www.cameroncountytx.gov/wp-content/uploads/2024/05/05.28.2024-Press-Release-on-Order-of-Closure-Related-to-SpaceX-Flight.pdf
I've been told launches typically occur a few days after these tests.
Alain Fournier

Launch is NET "after Memorial Day", from the usual sources, with S29 just
having rolled back from the Wet Dress Rehersal to complete tile work.

It actually didn't roll back, hanging out next to the OLM while the
suction cups were being applied. (Harbor Freight has similar suction
cups sold as being for lifting countertops.)

The second WDR has now been completed, and we may be on track for June
5th.

SpaceX has ask the FAA to approve a launch license while the IFT3 mishap
investigation still open, arguing that the failures were each in a flight
portion that did not represent a safety hazard.
/dps

--
"What do you think of my cart, Miss Morland? A neat one, is not it?
Well hung: curricle-hung in fact. Come sit by me and we'll test the
springs."
(Speculative fiction by H.Lacedaemonian.)

The Running Man

2024-05-22 14:07:29 UTC

I'm still waiting for the incident report of the last flight. I'm very interested in how SpaceX's resolving the issues of Starship's uncontrolled tumbling. I'm also curious why Super Heavy failed to relight all of its engines during the landing burn, since SpaceX is doing this almost on a weekly basis with Falcon 9.

Alain Fournier

2024-05-22 19:33:35 UTC

In my opinion, both Starship's and the booster's erratic behaviour can
be corrected by a software update. The software used for Falcon 9 can't
be used for Starship and its booster, so even though SpaceX has much
experience on controlling spacecrafts, they still need to write new code
and glitches happen in new code. I'm not much concerned about the IFT-3
problems.

Alain Fournier

The Running Man

2024-05-25 04:54:50 UTC

<https://www.spacex.com/updates/#flight-3-report>

According to this update both the boostback burn and the roll-control loss were due to filter blockages.

Niklas Holsti

2024-05-25 09:06:32 UTC

<https://www.spacex.com/updates/#flight-3-report>
According to this update both the boostback burn and the roll-control loss were due to filter blockages.

But they don't say what kind of stuff was blocking the filters. Hm.

For IFT-4, they say that there are "operational changes including the
jettison of the Super Heavy’s hot-stage adapter following boostback to
reduce booster mass for the final phase of flight." What, so that part
will fall into the ocean and not be reused? This is a surprising
departure from earlier principles. Perhaps it is only a temporary
work-around.

Alain Fournier

2024-05-25 13:23:19 UTC

Post by Niklas Holsti

I'm still waiting for the incident report of the last flight. I'm
very interested in how SpaceX's resolving the issues of Starship's
uncontrolled tumbling. I'm also curious why Super Heavy failed to
relight all of its engines during the landing burn, since SpaceX is
doing this almost on a weekly basis with Falcon 9.

<https://www.spacex.com/updates/#flight-3-report>
According to this update both the boostback burn and the roll-control
loss were due to filter blockages.

But they don't say what kind of stuff was blocking the filters. Hm.
For IFT-4, they say that there are "operational changes including the
jettison of the Super Heavy’s hot-stage adapter following boostback to
reduce booster mass for the final phase of flight." What, so that part
will fall into the ocean and not be reused? This is a surprising
departure from earlier principles. Perhaps it is only a temporary
work-around.

Indeed, it is a surprising departure from earlier principles. I don't
think that would be only a temporary work-around if they do so to reduce
mass. IFT-4 having no payload, they don't really need to reduce mass, so
they don't need to do it at all now. Perhaps this piece of hardware gets
severely damaged during flight (during hot-staging) and it is easier to
build a new one for each flight than to redesign it to survive intact.

Alain Fournier

Niklas Holsti

2024-06-04 09:51:26 UTC

[ snip ]

Post by Niklas Holsti
For IFT-4, they say that there are "operational changes including the
jettison of the Super Heavy’s hot-stage adapter following boostback to
reduce booster mass for the final phase of flight." What, so that part
will fall into the ocean and not be reused? This is a surprising
departure from earlier principles. Perhaps it is only a temporary
work-around.

There is some good discussion by "CSI Starbase" in this video:

The main suggestion is that fixing other issues by additions to the
booster HW increased booster mass so much that the LOX header tank
capacity became insufficient for booster recovery. The header tanks are
already built for the next few boosters and cannot easily be made
larger. Discarding the hot-stage adapter, to reduce mass, may thus be a
work-around for this header-tank issue, and may not be needed for future
boosters with larger LOX header tanks.

The video also presents evidence that the hot-stage adapter actually
tore itself loose during the last minutes of IFT-3 booster flight. This
may have been a factor in the booster's attitude-control problems during
its return.

Alain Fournier

2024-06-04 12:43:42 UTC

[ snip ]

Post by Niklas Holsti
For IFT-4, they say that there are "operational changes including the
jettison of the Super Heavy’s hot-stage adapter following boostback
to reduce booster mass for the final phase of flight." What, so that
part will fall into the ocean and not be reused? This is a surprising
departure from earlier principles. Perhaps it is only a temporary
work-around.

Indeed, it is a surprising departure from earlier principles. I don't
think that would be only a temporary work-around if they do so to
reduce mass. IFT-4 having no payload, they don't really need to reduce
mass, so they don't need to do it at all now. Perhaps this piece of
hardware gets severely damaged during flight (during hot-staging) and
it is easier to build a new one for each flight than to redesign it to
survive intact.

http://youtu.be/Ytl1efG1sBw
The main suggestion is that fixing other issues by additions to the
booster HW increased booster mass so much that the LOX header tank
capacity became insufficient for booster recovery. The header tanks are
already built for the next few boosters and cannot easily be made
larger. Discarding the hot-stage adapter, to reduce mass, may thus be a
work-around for this header-tank issue, and may not be needed for future
boosters with larger LOX header tanks.
The video also presents evidence that the hot-stage adapter actually
tore itself loose during the last minutes of IFT-3 booster flight. This
may have been a factor in the booster's attitude-control problems during
its return.

Thank you. The "CSI Starbase" video is cool.

Alain Fournier

Snidely

2024-06-04 18:17:40 UTC

[ snip ]

http://youtu.be/Ytl1efG1sBw
The main suggestion is that fixing other issues by additions to the booster
HW increased booster mass so much that the LOX header tank capacity became
insufficient for booster recovery. The header tanks are already built for
the next few boosters and cannot easily be made larger. Discarding the
hot-stage adapter, to reduce mass, may thus be a work-around for this
header-tank issue, and may not be needed for future boosters with larger
LOX header tanks.
The video also presents evidence that the hot-stage adapter actually tore
itself loose during the last minutes of IFT-3 booster flight. This may have
been a factor in the booster's attitude-control problems during its return.

Thank you. The "CSI Starbase" video is cool.
Alain Fournier

Zack doesn't do many videos, but he does excellent videos.

/dps

--
Trust, but verify.

Alain Fournier

2024-05-25 13:12:53 UTC

<https://www.spacex.com/updates/#flight-3-report>
According to this update both the boostback burn and the roll-control loss were due to filter blockages.

Interesting. Thank you.

Alain Fournier

Snidely

2024-05-24 07:20:48 UTC

They are ordering some road closures for SpaceX a week from now for testing
activities.
https://www.cameroncountytx.gov/wp-content/uploads/2024/05/05.28.2024-Press-Release-on-Order-of-Closure-Related-to-SpaceX-Flight.pdf
I've been told launches typically occur a few days after these tests.
Alain Fournier

Elon has just (as in May 23rd sometime around the launch of Starlink
6-63) twixxed that "Flight 4 in about 10 days", so expect Jun 01 or 02.

/dps

--
As a colleague once told me about an incoming manager,
"He does very well in a suck-up, kick-down culture."
Bill in Vancouver

Snidely

2024-05-25 04:47:09 UTC