• Dragot de-Orbit

    From JF Mezei@21:1/5 to All on Sat Sep 18 18:22:40 2021
    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    I was under the impression the standard was to fire de-orbit engines and
    then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    --- SoupGate-Win32 v1.05
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  • From Snidely@21:1/5 to All on Mon Sep 20 10:48:28 2021
    Thus spake JF Mezei:

    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    SOP.

    Orbit was lowered in 2 steps before jettison and the rest of the
    landing sequence; this was described by the SpaceX commentators.

    And the trunk is very light, so sensitive the slight atmospheric drag.

    I was under the impression the standard was to fire de-orbit engines and
    then separate which ensures both portions de-orbit with the capsule distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    Standard? You mean like ISO?

    /dps

    --
    "First thing in the morning, before I have coffee, I read the obits, If
    I'm not in it, I'll have breakfast." -- Carl Reiner, to CBS News in
    2015.

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  • From Snidely@21:1/5 to All on Wed Sep 22 00:00:00 2021
    Snidely presented the following explanation :
    Thus spake JF Mezei:

    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    SOP.

    <URL:https://youtu.be/fZrSnM2xZzc?t=20632>

    Orbit was lowered in 2 steps before jettison and the rest of the landing sequence; this was described by the SpaceX commentators.

    And the trunk is very light, so sensitive the slight atmospheric drag.

    I was under the impression the standard was to fire de-orbit engines and
    then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    Standard? You mean like ISO?

    /dps

    --
    The presence of this syntax results from the fact that SQLite is really
    a Tcl extension that has escaped into the wild. <http://www.sqlite.org/lang_expr.html>

    --- SoupGate-Win32 v1.05
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  • From Snidely@21:1/5 to Snidely on Sun Oct 3 15:11:29 2021
    On Wednesday or thereabouts, Snidely asked ...
    Snidely presented the following explanation :
    Thus spake JF Mezei:

    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    SOP.

    <URL:https://youtu.be/fZrSnM2xZzc?t=20632>


    I'd give a similar pointer to Cargo Dragon flights, but neither NASA
    nor SpaceX leave longterm copies of recent cargo landings on Youtube.
    The NASA livestream only goes back 12 hours, and at 8pm yesterday I
    wasn't at my computer to grab anything.

    /dps


    --
    Trust, but verify.

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  • From Snidely@21:1/5 to All on Mon Nov 8 10:55:09 2021
    JF Mezei suggested that ...
    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    I was under the impression the standard was to fire de-orbit engines and
    then separate which ensures both portions de-orbit with the capsule distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    This evening, we're expecting /Endeavour/ to proceed through trunk
    separation, nosecone closure, and the deorbit burn.

    [Crew2 just got "Dragon is go for undocking"]

    /dps

    --
    "That’s where I end with this kind of conversation: Language is
    crucial, and yet not the answer."
    Jonathan Rosa, sociocultural and linguistic anthropologist,
    Stanford.,2020

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  • From Snidely@21:1/5 to All on Mon Nov 8 14:43:00 2021
    Monday, Snidely murmurred ...
    JF Mezei suggested that ...
    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    I was under the impression the standard was to fire de-orbit engines and
    then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    This evening, we're expecting /Endeavour/ to proceed through trunk separation, nosecone closure, and the deorbit burn.

    [Crew2 just got "Dragon is go for undocking"]

    Fly around complete, now in free flight, with the departure phasing
    burn next.

    -d

    --
    "Inviting people to laugh with you while you are laughing at yourself
    is a good thing to do, You may be a fool but you're the fool in
    charge." -- Carl Reiner

    --- SoupGate-Win32 v1.05
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  • From Snidely@21:1/5 to Snidely on Mon Nov 8 18:42:06 2021
    On Monday or thereabouts, Snidely asked ...
    Monday, Snidely murmurred ...
    JF Mezei suggested that ...
    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    I was under the impression the standard was to fire de-orbit engines and >>> then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    This evening, we're expecting /Endeavour/ to proceed through trunk
    separation, nosecone closure, and the deorbit burn.

    [Crew2 just got "Dragon is go for undocking"]

    Fly around complete, now in free flight, with the departure phasing burn next.

    That was done, now claw separation confirmed, and then "Nominal trunk
    jettison"

    -d

    --
    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

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  • From Snidely@21:1/5 to All on Mon Nov 8 19:05:04 2021
    Snidely used thar keyboard to writen:
    On Monday or thereabouts, Snidely asked ...
    Monday, Snidely murmurred ...
    JF Mezei suggested that ...
    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission >>>> (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long >>>> time (since that orbit was bery high) ?

    I was under the impression the standard was to fire de-orbit engines and >>>> then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics >>>> kick in.

    This evening, we're expecting /Endeavour/ to proceed through trunk
    separation, nosecone closure, and the deorbit burn.

    [Crew2 just got "Dragon is go for undocking"]

    Fly around complete, now in free flight, with the departure phasing burn
    next.

    That was done, now claw separation confirmed, and then "Nominal trunk jettison"


    [This reduces the mass the Dracos have to apply delta-vee to, as well
    as reducing the parachute load]

    "de-orbit burn complete, performance nominal, [nose cone] closure
    intiated"

    [de-orbit burn was about 15 minutes]

    -d

    --
    "I am not given to exaggeration, and when I say a thing I mean it"
    _Roughing It_, Mark Twain

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  • From Snidely@21:1/5 to All on Mon Nov 8 19:47:59 2021
    Lo, on the 11/8/2021, Snidely did proclaim ...
    Snidely used thar keyboard to writen:
    On Monday or thereabouts, Snidely asked ...
    Monday, Snidely murmurred ...
    JF Mezei suggested that ...
    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission >>>>> (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long >>>>> time (since that orbit was bery high) ?

    I was under the impression the standard was to fire de-orbit engines and >>>>> then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics >>>>> kick in.

    This evening, we're expecting /Endeavour/ to proceed through trunk
    separation, nosecone closure, and the deorbit burn.

    [Crew2 just got "Dragon is go for undocking"]

    Fly around complete, now in free flight, with the departure phasing burn >>> next.

    That was done, now claw separation confirmed, and then "Nominal trunk
    jettison"


    [This reduces the mass the Dracos have to apply delta-vee to, as well as reducing the parachute load]

    "de-orbit burn complete, performance nominal, [nose cone] closure intiated"

    [de-orbit burn was about 15 minutes]

    Splash down 7:33 PST, 10:33 EST off Pensacola FL.

    Great views from the WB-57.

    /dps

    --
    "Inviting people to laugh with you while you are laughing at yourself
    is a good thing to do, You may be a fool but you're the fool in
    charge." -- Carl Reiner

    --- SoupGate-Win32 v1.05
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  • From Snidely@21:1/5 to JF Mezei on Mon Nov 8 21:03:34 2021
    Remember Monday, when JF Mezei asked plaintively:
    On 2021-11-08 22:05, Snidely wrote:

    [This reduces the mass the Dracos have to apply delta-vee to, as well
    as reducing the parachute load]

    Are what altitude is the trunk jettisoned? It is allowed totally
    uncontroled re-entry anywhere at any time because they are confident it
    fully burns up?

    It's between the departure phase burn (aka landing phase burn) and the
    deorbit burn. This flight also included an out-of-plane burn that was
    a fuel dump, and this was also before trunk separation.

    However, we don't get the "speedometer" data for height and velocity at
    any point (except when we get a few views of the consoles).

    On other ships the excess weight is ditched after de-orbit burn to force
    it down in same orbit. But those happen to have de-orbit engines and
    tanks on the "trunk" portion, so keeping the trunk attached for de-orbit
    burn is sort of mandatory.

    Most Apollo reentries were basically set up from the moon, so SM
    separation happened well after the "de-orbit" burn. Skylab and ATSP
    provide the return-from-orbit scenario, and it appears for ATSP that
    the SM separated after the de-orbit burn (no scare quotes). Skylab was probably the same, but I don't see confirmation of that in a quick
    search.

    Remember, though, the SM had a pretty big engine ... that rocket motor
    was capable of doing the lunar return burn.

    <URL:https://history.nasa.gov/apollo/apsoyhist.html>

    Soyuz separated the orbital and descent modules after the de-orbit
    burn, too.

    [I'd expect a similar description of the Chinese capsules, based on the
    "they copied the Soyuz" trope]

    Gemini had the reentry rockets ("retrograde rockets") on the Adapter
    Module, so that had to be jettisoned after the deorbit burn.
    Astronautix says, "The sections of the adapter module remained in
    decaying orbits and were burned up during reentry." That hints that
    the AM might not have entered as quickly as the Reentry Module.

    <URL:http://www.astronautix.com/g/geminitechnaldescription.html>

    Yet once detached both parts follow their own trajectory and the
    parachutes never worry about the trunk/service module because it only
    needs to support the small capsule.

    Sure, so the NASA/SpaceX commentary is kinda being redundant about the
    jettison making it easier on the parachutes, but still.

    /dps

    --
    There's nothing inherently wrong with Big Data. What matters, as it
    does for Arnold Lund in California or Richard Rothman in Baltimore, are
    the questions -- old and new, good and bad -- this newest tool lets us
    ask. (R. Lerhman, CSMonitor.com)

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  • From JF Mezei@21:1/5 to Snidely on Mon Nov 8 23:18:35 2021
    On 2021-11-08 22:05, Snidely wrote:

    [This reduces the mass the Dracos have to apply delta-vee to, as well
    as reducing the parachute load]

    Are what altitude is the trunk jettisoned? It is allowed totally
    uncontroled re-entry anywhere at any time because they are confident it
    fully burns up?

    On other ships the excess weight is ditched after de-orbit burn to force
    it down in same orbit. But those happen to have de-orbit engines and
    tanks on the "trunk" portion, so keeping the trunk attached for de-orbit
    burn is sort of mandatory.

    Yet once detached both parts follow their own trajectory and the
    parachutes never worry about the trunk/service module because it only
    needs to support the small capsule.

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  • From Anthony Frost@21:1/5 to Snidely on Tue Nov 9 10:28:57 2021
    In message <mn.44ef7e5bf35f870a.127094@snitoo>
    Snidely <snidely.too@gmail.com> wrote:

    Gemini had the reentry rockets ("retrograde rockets") on the Adapter
    Module, so that had to be jettisoned after the deorbit burn.
    Astronautix says, "The sections of the adapter module remained in
    decaying orbits and were burned up during reentry." That hints that
    the AM might not have entered as quickly as the Reentry Module.

    Gemini had the adapter module in two sections. The first section was
    dropped off in orbit which exposed the re-entry motors, the section
    holding the motors was then dropped after the burn.

    Anthony

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  • From Snidely@21:1/5 to All on Wed Nov 10 22:19:55 2021
    On Tuesday, Anthony Frost queried:
    In message <mn.44ef7e5bf35f870a.127094@snitoo>
    Snidely <snidely.too@gmail.com> wrote:

    Gemini had the reentry rockets ("retrograde rockets") on the Adapter
    Module, so that had to be jettisoned after the deorbit burn. Astronautix
    says, "The sections of the adapter module remained in decaying orbits and
    were burned up during reentry." That hints that the AM might not have
    entered as quickly as the Reentry Module.

    Gemini had the adapter module in two sections. The first section was
    dropped off in orbit which exposed the re-entry motors, the section
    holding the motors was then dropped after the burn.

    Thank you. You sent me back to Astronautix and the search engine. I
    see I misread the article, not catching that the "retrograde module"
    was a separate section.

    I've also found a NASA illustration: <URL:https://history.nasa.gov/SP-4002/images/fig23.jpg>
    from
    <URL:https://history.nasa.gov/SP-4002/figures.htm>

    There seem to be more pictures/illustrations of the Air Force version
    of Gemini, Gemini-B, the commuter van for the Manned Orbiting
    Laboratory.

    Here's an article (and pictures) of the MOL/Gemini-B retrograde module: <URL:https://www.thespacereview.com/article/3158/1>
    (one of the photographers has several more pictures, too)

    This has a comparison of the retrograde modules between NASA and
    Gemini-B: <URL:http://www.astrocryptotriviology.com/blog/2016/6/18/a-jones-for-mol-11-the-retroactivity-of-mol-part-1>
    [there's also a bit of de-orbit analysis therein]

    That last reference suggests that the MOL would have de-orbited
    separately, perhaps a few hours later than the GeeBee.

    /dps

    --
    But happiness cannot be pursued; it must ensue. One must have a reason
    to 'be happy.'"
    Viktor Frankl

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  • From Snidely@21:1/5 to All on Fri Dec 31 04:43:13 2021
    Snidely submitted this idea :
    Thus spake JF Mezei:

    Looking at Inspiration4 landing.
    They were the highest a human has been since last Hubble repaid mission
    (and may have been higher).

    They jettisomed the "trunk" before de-orbit burn. Is this SOP for
    Dragon or special for this mission? By detaching before de-orbit,
    doesn't that create space debris with trucnk staying high up for a long
    time (since that orbit was bery high) ?

    SOP.

    Orbit was lowered in 2 steps before jettison and the rest of the landing sequence; this was described by the SpaceX commentators.

    And the trunk is very light, so sensitive the slight atmospheric drag.

    I was under the impression the standard was to fire de-orbit engines and
    then separate which ensures both portions de-orbit with the capsule
    distancing itself from the trunk/service module as soon as aerodynamics
    kick in.

    Standard? You mean like ISO?

    /dps

    BTW, Soyuz does re-entry burn, discards *2* sections, and then feels
    for the atmosphere.

    <URL:https://twitter.com/NASASpaceflight/status/1472754748805812225>

    /dps

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

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

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