Starliner back at pad

Post by Snidely
Starliner is again at SLC-41 ahead of crewed launch, L0 currently June
1st 12:25 pm EDT.
/dps
--
Killing a mouse was hardly a Nobel Prize-worthy exercise, and Lawrence
went apopleptic when he learned a lousy rodent had peed away all his
precious heavy water.
_The Disappearing Spoon_, Sam Kean

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue mission since it's not modified to perform an EVA. Only the Crew Dragon capsule being used for the Polaris Dawn mission is fitted (or being fitted) for EVA.

Snidely

2024-05-31 01:35:42 UTC

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue mission
since it's not modified to perform an EVA. Only the Crew Dragon capsule being
used for the Polaris Dawn mission is fitted (or being fitted) for EVA.

Why are you talking about rescue missions? Starliner's heat shield is
intact.

/dps

--
potstickers, Japanese gyoza, Chinese dumplings, let's do it

The Running Man

2024-05-31 23:43:04 UTC

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue mission
since it's not modified to perform an EVA. Only the Crew Dragon capsule being
used for the Polaris Dawn mission is fitted (or being fitted) for EVA.

Why are you talking about rescue missions? Starliner's heat shield is
intact.
/dps
--
potstickers, Japanese gyoza, Chinese dumplings, let's do it

Because they said there's about a 0.75% chance that the helium leak could result in a failure to initiate the retro-burn.

Snidely

2024-06-01 07:11:16 UTC

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue mission
since it's not modified to perform an EVA. Only the Crew Dragon capsule
being used for the Polaris Dawn mission is fitted (or being fitted) for
EVA.

Why are you talking about rescue missions? Starliner's heat shield is
intact.
/dps
--
potstickers, Japanese gyoza, Chinese dumplings, let's do it

Because they said there's about a 0.75% chance that the helium leak could
result in a failure to initiate the retro-burn.

Yes, and a Falcon 9 second stage may fall on your house. Multiple
failures have to happen for the retro burn to be missed. If any one of
those failures show up on the way to ISS, ISS becomes a safe haven.
And on departure, expect serious checkout of systems before the capusle
leaves the vicinity of the station.

/dps

--
You could try being nicer and politer

Post by The Running Man
instead, and see how that works out.

-- Katy Jennison

Snidely

2024-06-02 21:22:10 UTC

On Friday or thereabouts, The Running Man declared ...

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue mission
since it's not modified to perform an EVA. Only the Crew Dragon capsule
being used for the Polaris Dawn mission is fitted (or being fitted) for
EVA.

Why are you talking about rescue missions? Starliner's heat shield is
intact.
/dps
--
potstickers, Japanese gyoza, Chinese dumplings, let's do it

Because they said there's about a 0.75% chance that the helium leak could
result in a failure to initiate the retro-burn.

Was that 0.75% before or after the new backup backup procedure was
implemented (using 4 RCS thrusters twice)?

/dps

--
Who, me? And what lacuna?

The Running Man

2024-06-04 11:20:05 UTC

Post by Snidely
On Friday or thereabouts, The Running Man declared ...

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue mission
since it's not modified to perform an EVA. Only the Crew Dragon capsule
being used for the Polaris Dawn mission is fitted (or being fitted) for
EVA.

Why are you talking about rescue missions? Starliner's heat shield is
intact.
/dps
--
potstickers, Japanese gyoza, Chinese dumplings, let's do it

Because they said there's about a 0.75% chance that the helium leak could
result in a failure to initiate the retro-burn.

Was that 0.75% before or after the new backup backup procedure was
implemented (using 4 RCS thrusters twice)?
/dps
--
Who, me? And what lacuna?

Here's your answer:

"As it turned out, there was something to be concerned about. The review turned up what he called a ?design vulnerability? with Starliner?s propulsion system that had not been recognized. Starliner?s service module has four areas called ?doghouses? spaced 90 degrees apart that host both larger Orbital Maneuvering and Attitude Control (OMAC) thrusters and smaller reaction control system (RCS) thrusters. If two adjacent doghouses failed for some reason, though, it would prevent the spacecraft from doing a deorbit burn even though the spacecraft is designed with multiple ways to carry out the deorbit burn using combinations of OMAC and RCS thrusters."

<https://www.thespacereview.com/article/4805/1>

Snidely

2024-06-04 17:17:14 UTC

Post by Snidely
On Friday or thereabouts, The Running Man declared ...

AFAIK the Crew Dragon docked at the ISS isn't suitable for a rescue
mission since it's not modified to perform an EVA. Only the Crew Dragon
capsule being used for the Polaris Dawn mission is fitted (or being
fitted) for EVA.

Why are you talking about rescue missions? Starliner's heat shield is
intact.
/dps
--
potstickers, Japanese gyoza, Chinese dumplings, let's do it

Because they said there's about a 0.75% chance that the helium leak could
result in a failure to initiate the retro-burn.

Was that 0.75% before or after the new backup backup procedure was
implemented (using 4 RCS thrusters twice)?
/dps
--
Who, me? And what lacuna?

"As it turned out, there was something to be concerned about. The review
turned up what he called a ?design vulnerability? with Starliner?s propulsion
system that had not been recognized. Starliner?s service module has four
areas called ?doghouses? spaced 90 degrees apart that host both larger
Orbital Maneuvering and Attitude Control (OMAC) thrusters and smaller
reaction control system (RCS) thrusters. If two adjacent doghouses failed for
some reason, though, it would prevent the spacecraft from doing a deorbit
burn even though the spacecraft is designed with multiple ways to carry out
the deorbit burn using combinations of OMAC and RCS thrusters."
<https://www.thespacereview.com/article/4805/1>

I believe, from my sources, including NSF and Ars Technica, that that
finding was from before the additional mode was added. The review that
revealed the above issue was what prompted the software update.

/dps

--
"That's a good sort of hectic, innit?"

" Very much so, and I'd recommend the haggis wontons."
-njm

Snidely

2024-06-01 14:57:21 UTC

Starliner is again at SLC-41 ahead of crewed launch, L0 currently June 1st
12:25 pm EDT.

Working around GSE issues with LOX topping. L-01:29:01, and still
within the built-in hold.

-d

--
Let's celebrate Macaronesia

Alain Fournier

2024-06-01 17:26:15 UTC

Post by Snidely
Starliner is again at SLC-41 ahead of crewed launch, L0 currently June
1st 12:25 pm EDT.

Working around GSE issues with LOX topping. L-01:29:01, and still
within the built-in hold.

Scrubbed. Darn.

Alain Fournier

The Running Man

2024-06-02 11:33:26 UTC

Post by Alain Fournier

Post by Snidely
Starliner is again at SLC-41 ahead of crewed launch, L0 currently June
1st 12:25 pm EDT.

Working around GSE issues with LOX topping.? L-01:29:01, and still
within the built-in hold.

Scrubbed. Darn.
Alain Fournier

One of the three redundant computers failed to start up properly (took too long to start up). They want to investigate before giving the go.

Snidely

2024-06-02 21:20:40 UTC

Post by Alain Fournier

Starliner is again at SLC-41 ahead of crewed launch, L0 currently June 1st
12:25 pm EDT.

Working around GSE issues with LOX topping. L-01:29:01, and still within
the built-in hold.

Scrubbed. Darn.
Alain Fournier

Ground-based sequencer computer didn't sequence?

/dps

--
Rule #0: Don't be on fire.
In case of fire, exit the building before tweeting about it.
(Sighting reported by Adam F)

The Running Man

2024-06-03 13:19:49 UTC

Post by Alain Fournier

Starliner is again at SLC-41 ahead of crewed launch, L0 currently June 1st
12:25 pm EDT.

Working around GSE issues with LOX topping. L-01:29:01, and still within
the built-in hold.

Scrubbed. Darn.
Alain Fournier

Ground-based sequencer computer didn't sequence?
/dps
--
Rule #0: Don't be on fire.
In case of fire, exit the building before tweeting about it.
(Sighting reported by Adam F)

<https://www.theregister.com/2024/06/03/boeing_starliner_launch_scrubbed/>

Turned out to be a redundant power supply of the ground sequencer computer that needs to be replaced. Not anything major. They should be back on the pad within a few days.

Snidely

2024-06-05 14:48:28 UTC

Starliner is again at SLC-41 ahead of crewed launch, L0 currently June 1st
12:25 pm EDT.

Working around GSE issues with LOX topping. L-01:29:01, and still within the
built-in hold.
-d

Seems to be a clean count on the third try as of L-4:02.

-d

--
Let's celebrate Macaronesia

Snidely

2024-06-05 15:07:51 UTC

Starliner is again at SLC-41 ahead of crewed launch, L0 currently June 1st
12:25 pm EDT.

Working around GSE issues with LOX topping. L-01:29:01, and still within
the built-in hold.
-d

Seems to be a clean count on the third try as of L-4:02.

Still clean at Starliner separation at L+14:52

-d

--
"This is all very fine, but let us not be carried away be excitement,
but ask calmly, how does this person feel about in in his cooler
moments next day, with six or seven thousand feet of snow and stuff on
top of him?"
_Roughing It_, Mark Twain.

Snidely

2024-06-05 15:28:28 UTC