View Poll Results: Which Orion is better? A (smallSM) "CorkScrew Orion" or a (bigSM) "SwissKnife Orion&q

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Thread: Which Orion is better? A (smallSM) "CorkScrew-Orion" or a (bigSM) "SwissKnife-Orion"?

  1. #271
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    Gaetano, you seem to have a misconception as to what is meant by angle of attack. You seem to think that it is simply the angle at which the capsule enters the atmosphere away from horizontal. This is incorrect. Angle of attack is the angle at which the capsule is traveling compared to the capsule's orientation - an angle of attack of 20 degrees would mean that the capsule would be traveling in a direction 20 degrees off of directly blunt-end forward. So, Bob's drawings are precisely correct,a s far as capsule orientation to the direction of travel. Since it will be at an angle of attack of >20 degrees, it will be rotated more than 20 degrees off of the direction of travel when reentering.

    Here is an image to demonstrate:


    This is a wing, not a capsule, but the same principles apply. Think of the chord line as a line running straight down the middle of the capsule vertically. Think of the relative wind as the direction of travel. You can see that at an angle of attack of 20 degrees, bob's drawing is a perfect representation of reality, while all of your drawings show an angle of attack of 0 degrees.

    As for bob's first drawing, it can be roughly approximated as showing the areas of high and low pressure on the design. The standard capsule has high pressure only on the heat shield area, while yours has it extending to the side of the capsule itself. Since these areas are most influenced by aerodynamic heating, clearly, the side of your proposed capsule would have a greater need for shielding than the apollo-style design.

  2. #272
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    Quote Originally Posted by gaetanomarano View Post
    that may be true fro cars, airplanes, etc. (designed in hundreds models every year) but not for capsules (of which NASA build ONE every 50 years!!!) ...with (near) all Apollo-guys retired or dead, great part of the experience is lost and must be rebuilt
    .

    So everything we know about fluid dynamics, about lift, and about stress must be reinvented simply because a different shape is being used, despite it relying on the exact same principles as supersonic jet fighters, which we build all the time

  3. #273
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    Quote Originally Posted by gaetanomarano View Post
    as I've said in my previous post, both capsules in your drawing appear rotated around their horizontal axis, while, the (real) "angle of attack" (not clearly shown without the line of earth) may be correct
    Angle of attack is the angle between the spacecraft axis and the velocity vector. It is implied from my drawings that the velocity vector is in the vertical direction, thus the angle of attack is simply how much from the vertical the capsule is rotated. The orientation of the capsule with respect to the Earth is irrelevant to this discussion.

    Quote Originally Posted by gaetanomarano View Post
    sorry, but that can be said of YOUR first drawing (with "my capsule" entirely submerged, from its feet to its belt, with a liquid fused-steel-like orange color...) while I've made my drawing in a few minutes (as clear from its low quality) ONLY to show that a capsule can't be "half-hot and half-cold" at reentry but has different temperatures in different places of the ship (values that nobody can know to-day)
    My drawing was accompanied with a narrative explaining what it depicts. I explained that the orange color represents the surfaces that are “directly exposed to the flow stream”, that is, the surfaces forming the leading side as the capsule moves through the atmosphere. I didn’t think it was necessary to explain that there isn’t a sharp line of demarcation between hot and cold surfaces because I thought it was obvious. I am somewhat astounded you think I was trying to say otherwise. The only purpose for the drawing was to show that, as the angle of attack increases, wall surfaces will begin to form a portion of the leading side sooner when the sidewall is steeper. With a more greatly sloped sidewall, larger angles of attack are possible while the wall surfaces remain on the trailing side.

    Quote Originally Posted by gaetanomarano View Post
    shown your drawing, BOTH capsule may survive (if they can reentry with that inclination) or may BURN in the atmosphere, if the attidude jets don't correct this bad inclination around its horizontal axis ...however, it's not clear the reason of a so bad inclination (at reentry) of both capsules (without a right correction made on time)
    You seem to incorrectly assume the orientations of the figures in my illustration are drawn with respect to the Earth horizon; they are not. Angle of attack has nothing to do with the location of the Earth as I’ve already explained. For illustration purposes I can orient the velocity vector in an arbitrary direction and it doesn’t change the argument. In my drawings the capsules are depicted as moving downward and/or the plasma stream moving upward. The capsules are rotated 20 degrees from vertical (i.e. from the velocity vector), therefore the angle of attack is 20-degrees (or 160 degrees if the zero degrees is defined as nose forward). This is not a bad or excessive inclination, it is quite normal for a lifting trajectory.

  4. #274
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    Quote Originally Posted by gaetanomarano
    Quote Originally Posted by Nicolas
    if Bob says he did not intend to show half hot and cold with that figure, he did not intend to show half hot and cold with that figure.
    read again my post... I've simply said that "was not clear in the first drawing" (that's the reason I've posted a different drawing)
    Let's see what you said on Bob B's first sketch in the posts up to the one where I made the remark you posted the above reply to:

    Quote Originally Posted by gaetanomarano
    to show that a capsule at reentry is not "half hot and half cold" (like in the Bob B. sketch)
    Quote Originally Posted by gaetanomarano
    the sole purpose of my drawing is to show that a capsule is NOT "half hot and half cold" at reentry
    Quote Originally Posted by gaetanomarano
    my intention was only to show that a capsule can't be half-hot and half-cold at reentry
    Quote Originally Posted by gaetanomarano
    Quote Originally Posted by Nicolas
    Bob explained that his drawing did not intend to show half hot and half cold.
    but not in the first post with the drawing
    You very clearly said that Bob B drew the craft as half hot and half cold. Now you're also twisting your own words.
    Last edited by Nicolas; 2007-Feb-09 at 12:15 AM.

  5. #275
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    .
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    times ago I've read in a .pdf document (I'm searching again googling) that the Apollo-CM angle of attack was 6.5 degrees

    if that is true, my sketch is much close to reality than Bob B. sketch ...however, this is not the main problem to solve

    the "angle of attack" argument is used to demontrate that a TBS-Orion may become too hot at reentry and can't survive

    so, to have an answer about this point (without do real tests) we need (if exists) the Apollo-CM's body temperatures' map

    infact, also assuming that Bob B.'s full-hot-red colored shape is correct, we must know "HOW MUCH HOT" is that "HOT"

    my opinion is that it's NOT a problem, mainly looking at the 40 years old Soyuz that accomplished 100+ successful reentries

    despite the Soyuz's shape is very close to a cylinder, it doesn't have its body entirely covered with a thick and heavy TPS

    its TPS is just slightly higher than Apollo/Orion, and, don't forget that Soyuz is made with '60s technologies and materials!

    so, a (less sloped) TBS-Orion (built with MOST advanced materials and alloys than Soyuz) can SURELY reenter SAFELY

    of course, everything needs (wind-tunnel and real vehicles) tests, tests, tests... but I'm confident that my TBS-Orion CAN work fine

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  6. #276
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    Your memory, just like the text colour, seems to be quite rusty. They investigated Apollo capsule heating mainly for 33° aoa.

    Want to check for yourself, read this little gem. It even includes the Schlieren photography data on the bow shock.

    http://ntrs.nasa.gov/archive/nasa/ca...1979076616.pdf

  7. #277
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    Quote Originally Posted by gaetanomarano View Post
    times ago I've read in a .pdf document (I'm searching again googling) that the Apollo-CM angle of attack was 6.5 degrees
    I’m pretty sure the 6.5-degree number you are remembering is the capsule’s flight path angle at entry interface. Fight path angle is the angle between the velocity vector and the local horizon, while angle of attack is the angle between the velocity vector and the spacecraft axis. They are different measurements that shouldn’t be confused.

    Quote Originally Posted by gaetanomarano View Post
    if that is true
    It is not.

    Quote Originally Posted by gaetanomarano View Post
    the "angle of attack" argument is used to demontrate that a TBS-Orion may become too hot at reentry and can't survive
    No, the angle of attack argument is to show that your TBS-Orion will likely require greater sidewall thermal protection than the Apollo-Orion. I never said it can’t survive, but in order to survive it must be adequately protected.

    Quote Originally Posted by gaetanomarano View Post
    so, to have an answer about this point (without do real tests) we need (if exists) the Apollo-CM's body temperatures' map

    infact, also assuming that Bob B.'s full-hot-red colored shape is correct, we must know "HOW MUCH HOT" is that "HOT"
    Agreed. A complete thermal analysis must be done to determine the thermal protection requirements. This is what I’ve been trying to tell you. You simply declared your design required less thermal protection without performing any analysis whatsoever other than comparing the area of the capsule base.

    Quote Originally Posted by gaetanomarano View Post
    my opinion is that it's NOT a problem
    It certainly is a problem, but it’s not an unsolvable one. I have no doubt your TBS-Orion shape can be made to work. The question is, will it be lighter than the Apollo-Orion shape? My concern is that the TBS shape will experience greater thermal loads on the sidewalls and will therefore require heavier thermal protection in this area. This could make the TBS shape heavier rather than lighter as you claim. In the final analysis the TBS-Orion may be lighter or it may be heavier, however determining which requires far more analysis than just a casual glance.

    Quote Originally Posted by gaetanomarano View Post
    mainly looking at the 40 years old Soyuz that accomplished 100+ successful reentries
    Soyuz reenters from Earth orbit while Orion will return from the Moon. The velocity on a lunar return mission is 1.4 times that of an Earth orbit return, thus resulting in much greater thermal loads. Comparisons to Soyuz’s thermal protection system are really not valid because Soyuz and Orion are built to perform different missions.
    _

  8. #278
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    Quote Originally Posted by Nicolas View Post
    ...read this little gem. It even includes the Schlieren photography data on the bow shock...
    a little complex to read ...do you have something simpler? (like a multi-color CM-body temperatures' map)
    .
    Last edited by gaetanomarano; 2007-Feb-09 at 05:09 PM.

  9. #279
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    Quote Originally Posted by Bob B. View Post
    ...the angle of attack argument is to show that your TBS-Orion will likely require greater sidewall thermal protection than the Apollo-Orion. I never said it can’t survive, but in order to survive it must be adequately protected...
    it's an indirect way to say the same thing: "angle of attack = too much hot on sidewall = your (standard sidewall) lighter TBS-Orion can't survive"
    ...simply declared your design required less thermal protection...
    never said that ...the TBS-Orion must have (at least) the SAME thermal protection of the standard Orion
    ...certainly is a problem...
    maybe... I think it's not a problem ...BOTH (standard and TBS) Orion are not made of butter! ...their sidewalls will be THICK, made with the BEST alloys and (already) designed to resist the hot-plasma! ...so, it may work well AS IS (without any increase of TPS and sidewall size and weight)
    ...velocity on a lunar return mission is 1.4 times that of an Earth orbit return...
    that's true in the vacuum, while, after the first impact with the atmosphere, the Orion speed will slow quickly ...then, it IS (also) a problem for the thermal shield, but (mainly) aproblem for the astronauts (that must experience an high negative-G) ...also, I don't think that +40% speed directly means a full +40% increase of TPS/capsule temperature ...however, despite a comparison with a Soyuz CAN be made (although it doesn't come from the moon, the Soyuz's sidewall is not an ice-cream at reentry...) my TBS-Orion design is NOT "Soyuz-derived" but "Orion-derived" (then, it has the SAME moon-ready TPS)
    .

  10. #280
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    Quote Originally Posted by gaetanomarano View Post
    a little complex to read ...do you have something simpler? (like a multi-color CM-body temperatures' map)
    .
    It's simple enough to see 33° alfa all over the place.

    I don't have a more accessible thermal analysis. You'd have to find some press conference leaflets from that time to find that, I assume.

  11. #281
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    [re-entry velocity = 1.4 times that from LEO] that's true in the vacuum, while, after the first impact with the atmosphere, the Orion speed will slow quickly ...then, it IS (also) a problem for the thermal shield, but (mainly) aproblem for the astronauts (that must experience an high negative-G)
    Why do you think Apollo went for the bunny hop re-entry? Because it really needed to bleed off velocity in order not to burn up. G loads were not the main problem of a direct re-entry, a CM becoming a great ball of fire was at least as important.


    I don't think that +40% speed directly means a full +40% increase of TPS/capsule temperature
    And you think that because? The kinetic energy is 1.96 times larger, as well as the dynamic pressure (the part that heats when slowed to stagnation), as well as the friction force. The stagnation layer protects the cabin (ironically) due to reducing friction of air streaming against the capsule. At higher velocity, this layer changes. I don't know if it changes in thermically advantageous manner or not, that is too complex for me to say just like that. The bow shock moves closer to the body, thereis more enrgy slope in the boundary layer..all vey complex things so I don't know that part. That said, I also don't know the total result but have given 3 factors that will become roughly twice as large.

  12. #282
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    Quote Originally Posted by gaetanomarano View Post
    it's an indirect way to say the same thing: "angle of attack = too much hot on sidewall = your (standard sidewall) lighter TBS-Orion can't survive"
    All I’m saying is that increasing the slope of the sidewall without appropriately modifying the sidewall TPS could be a problem. If a detailed thermal analysis shows that the sidewall TPS used on the standard-Orion capsule is inadequate for use on the TBS-Orion capsule, then the TBS-Orion capsule may have survivability issues.

    Quote Originally Posted by gaetanomarano View Post
    never said that ...the TBS-Orion must have (at least) the SAME thermal protection of the standard Orion
    Please define “same” as you use it here. Same mass, same thickness, or same performance? It is my understanding you mean the same thickness based on the following quote…

    Quote Originally Posted by gaetanomarano View Post
    while evaluating the TBS-Orion's weight reduction, I've assumed that the standard-Orion ALREADY includes an Apollo-like (thick) thermal shield, then, a 20% smaller surface TPS has (at least) 20% less weight
    My point is that for the TBS-Orion to have the same survivability as the standard-Orion, it requires the same TPS performance. There are valid reasons to believe that thicker sidewall protection may be required for the TBS-Orion to meet the same performance requirements. To determine for certain whether or not this is true requires a complete thermal analysis. You just can’t assume that what is adequate in one case will be adequate in another.

    Quote Originally Posted by gaetanomarano View Post
    ...so, it may work well AS IS (without any increase of TPS and sidewall size and weight)
    I’m glad to see that you have begun to use the word “may”.

    Quote Originally Posted by gaetanomarano View Post
    that's true in the vacuum, while, after the first impact with the atmosphere, the Orion speed will slow quickly ...then, it IS (also) a problem for the thermal shield, but (mainly) a problem for the astronauts (that must experience an high negative-G) ...also, I don't think that +40% speed directly means a full +40% increase of TPS/capsule temperature
    On a lunar return the spacecraft has twice the kinetic energy as one returning from earth orbit. This energy must be dissipated, which is done by converting the kinetic energy to thermal energy, or heat. (Heat is not the same thing as temperature.) The purpose of the heat shield is to protect the capsule from the heat generated during reentry. It does this by burning away and carrying the heat away with it. A shield of this type is called an ablative heat shield. So as you can see, the heat shield is sacrificial and not just an insulating barrier. The greater heat produced during a lunar return requires more ablative material than is required during an earth orbit return.

    One of the reasons* a lifting trajectory is used is to decrease the g-forces. Lift causes the capsule to descend more slowly resulting in a smaller deceleration spread out over a longer period of time. The duration of a lunar return reentry is considerably longer than one from earth orbit.

    * (EDIT) Change "The reason" to "One of the reasons". Of course another major factor for using a lifting trajectory is to reduce the thermal loads on the capsule.

    Quote Originally Posted by gaetanomarano View Post
    ...however, despite a comparison with a Soyuz CAN be made (although it doesn't come from the moon, the Soyuz's sidewall is not an ice-cream at reentry...) my TBS-Orion design is NOT "Soyuz-derived" but "Orion-derived" (then, it has the SAME moon-ready TPS)
    Again you use the word “same”. The use of that word is fine as long as you’re referring to performance specifications. You need to concern yourself with performance and not any particular TPS thickness. The thickness will be what it needs to be. My gut feeling is that the total TPS mass will be about the same regardless of the capsule shape.
    Last edited by Bob B.; 2007-Feb-09 at 09:39 PM.

  13. #283
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    The reason a lifting trajectory is used is to decrease the g-forces. Lift causes the capsule to descend more slowly resulting in a smaller deceleration spread out over a longer period of time. The duration of a lunar return reentry is considerably longer than one from earth orbit.
    Do you have info on whether this reduction in G forces was the main goal, or a way of achieving less thermal loads, or both were equally important goals of the bunnyhop re-entry?

    Seeing a plot of this re-entry trajectory always amazed me; it requires quite some understanding of the subject to come up with that and put people inside a craft doing such a trick.

  14. #284
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    Quote Originally Posted by Nicolas View Post
    Do you have info on whether this reduction in G forces was the main goal, or a way of achieving less thermal loads, or both were equally important goals of the bunnyhop re-entry?
    I mentioned g-forces because Gaetano brought it up, but you are correct in that reducing the thermal loads was definitely a huge part of it as well. I'm not sure which, g-force or heating, was the primary factor, though I think they pretty much go hand-in-hand (lessen one and you'll lessen the other). It is my understanding the 'skip' in the middle of the trajectory was to reduce the thermal load on the capsule and give it a chance to cool down a bit before resuming the descent.

  15. #285
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    I think I also remember learning that.

    That would hint at the thermal loads being a larger problem than G loads for the humans (just for G loads, you don't really need a cool down problem).

    But indeed they go hand in hand, and there's only so much you can do during a ballistic re-entry.

  16. #286
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    Quote Originally Posted by Nicolas View Post
    That would hint at the thermal loads being a larger problem than G loads for the humans (just for G loads, you don't really need a cool down problem).
    I agree it seems most likely thermal loads was the more critical factor. I suspect they probably established allowable limits for both factors and when the more critical factor was designed for, the less critical factor naturally fell below the limit as a consequence.

  17. #287
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    Quote Originally Posted by Nicolas View Post
    ...factors that will become roughly twice as large...
    that's true in first minutes, but the atmosphere quickly slows the capsule
    .

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    Quote Originally Posted by Bob B. View Post
    ...define “same” as you use it here...
    "the same" but in proportion with the reduced diameter (4.5 m) and mass (~8 mT) of the TBS-Orion (like a 4.5 m cone-shaped Orion)
    To determine for certain whether or not this is true requires a complete thermal analysis.
    agreed
    You just can’t assume that what is adequate in one case will be adequate in another.
    true, but, since the entire capsule will be made of the best materials, I believe that a positive result (or the need of minimal change) is most probable
    The greater heat produced during a lunar return requires more ablative material than is required during an earth orbit return.
    infact my design is Orion-derived
    The duration of a lunar return reentry is considerably longer than one from earth orbit.
    that's true, but, despite the long trajectory, I've read that a capsule reaches 6G in some points
    You need to concern yourself with performance and not any particular TPS thickness.
    of course, if the TPS is -20% in surface and the TBS-Orion mass only -15% (vs. the standard Orion) the TPS thickness reduction can't be -20% but less
    .

  19. 2007-Feb-10, 11:02 AM
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  20. #289
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    The CSM shape for Apollo was an amazing aerodynamic design. Due to an offset lateral CG, the craft reentered at an angle relative to the airflow, and thus actually created lift. This lift was used, by rolling the craft left and right along it's longitudinal axis, to create "crossrange" capability. Nothing near the Shuttle's capability, but at 20000mph+, it was still significant. The pinpoint landings of the program are testament to this very understood, and controllable, capability. The "double dip" of the reentry used this.
    So, the whole notion that the cone shaped capsule comes in at zero degrees AOA is inaccurate. Even the ablative material was designed thicker at the "leading edge" of the base heat shield. (basically the edge "under" the astronauts, they reentered heads down)
    Yes, the Apollo CM could actually "fly", in a manner of speaking. Not a bad accomplishment for a generation using very rudimentary computers and sliderules.

  21. #290
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    Quote Originally Posted by gaetanomarano View Post
    that's true in first minutes, but the atmosphere quickly slows the capsule.
    Quote Originally Posted by gaetanomarano View Post
    that's true, but, despite the long trajectory, I've read that a capsule reaches 6G in some points
    I don’t understand what you’re driving at, what’s your point?

    Quote Originally Posted by gaetanomarano View Post
    "the same" but in proportion with the reduced diameter (4.5 m) and mass (~8 mT) of the TBS-Orion (like a 4.5 m cone-shaped Orion)
    Well then, you have the burden of proof to show that this is adequate to protect your capsule from the heat of a lunar return reentry.

    Quote Originally Posted by gaetanomarano View Post
    infact my design is Orion-derived
    What is this supposed to mean? You’ve presented an entirely different geometric shape and then you try to evade responsibility for showing it will actually work by simply saying it is “Orion-derived”. What a copout.

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    Quote Originally Posted by Bob B. View Post
    ...what’s your point...
    every month I open thousands (space and non space) pages, threads, blogs and documents on the web and, of course, I can't save all links nor remember the argument of all saved links ...times ago I've seen a drawing of the trajectory of Apollo at reentry and, in a document, a graph of the G-force at reentry ...well, that force was not constant for the entire trajectory but varied, peaking 6G in some points (IIRC)
    ...proof to show that this is adequate to protect your capsule from the heat of a lunar return reentry...
    since it derive from Orion, I'm confident it can ...of course, to proof that 100%, I need a lot of million$, a wind-tunnel and a team of expert space engineers...
    ...“Orion-derived”...
    it's Orion-derived since all dimensions, mass, TPS, ecc. are very close to a resized-Orion (a capsule designed for lunar travel and direct reentry) not a (orbital-only) Soyuz ...of course, the shape is different, and that needs tests, research, etc.
    .

  23. #292
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    Quote Originally Posted by gaetanomarano View Post
    every month I open thousands (space and non space) pages, threads, blogs and documents on the web and, of course, I can't save all links nor remember the argument of all saved links ...times ago I've seen a drawing of the trajectory of Apollo at reentry and, in a document, a graph of the G-force at reentry ...well, that force was not constant for the entire trajectory but varied, peaking 6G in some points (IIRC)
    Yes, the Apollo reentry peaked at about 6g on a lunar return. It actually had two peaks due to the lifting reentry. On an Earth orbit return the peak deceleration was about 3.5g. So what’s your point? We where talking about thermal loads and suddenly you start talking about g-loads. Why is this pertinent to the discussion?

    Quote Originally Posted by gaetanomarano View Post
    since it derive from Orion, I'm confident it can ...of course, to proof that 100%, I need a lot of million$, a wind-tunnel and a team of expert space engineers...
    If you have no proof your capsule shape is better, then please stop declaring that it is.

    Quote Originally Posted by gaetanomarano View Post
    it's Orion-derived since all dimensions, mass, TPS, ecc. are very close to a resized-Orion (a capsule designed for lunar travel and direct reentry) not a (orbital-only) Soyuz ...of course, the shape is different, and that needs tests, research, etc.
    Yes, it is a different shape, which means it is structurally and aerodynamically different from the Apollo shape. The shape change may seem trivial to you but it looks like a radical change to me. You simply don’t have enough information to say with certainty that your shape will weigh less than the Apollo shape while maintaining the same performance. And of course trying to save weight is the whole reason you proposed the shape in the first place.
    Last edited by Bob B.; 2007-Feb-11 at 06:11 AM.

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    Quote Originally Posted by Bob B. View Post
    Soyuz reenters from Earth orbit while Orion will return from the Moon. The velocity on a lunar return mission is 1.4 times that of an Earth orbit return, thus resulting in much greater thermal loads. Comparisons to Soyuz’s thermal protection system are really not valid because Soyuz and Orion are built to perform different missions.
    For the sake of completeness and correctness - the Soyuz CM shape really seems suitable for return from the Moon as demonstrated by the L1-7K in the Zond series. Since they also went on a repelling trajectory, I think they came in in a hyperbolic fashion too. Don't know if and how the TPS differed from the orbital version, though.

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    Quote Originally Posted by gaetanomarano View Post
    I've seen a drawing of the trajectory of Apollo at reentry and, in a document, a graph of the G-force at reentry ...well, that force was not constant for the entire trajectory but varied, peaking 6G in some points (IIRC)
    6g isn't that much, especially when dealing with a hyperbolic reentry. If done the wrong way you can easily exceed 20g by far.

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    How could Gaetano's shape possibly weigh less than the Apollo shape?

    As a simple matter of geometry, it's got more surface area, which means more material, which means more weight.

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    Quote Originally Posted by JeDi View Post
    For the sake of completeness and correctness - the Soyuz CM shape really seems suitable for return from the Moon as demonstrated by the L1-7K in the Zond series. Since they also went on a repelling trajectory, I think they came in in a hyperbolic fashion too. Don't know if and how the TPS differed from the orbital version, though.
    Yes, there have been lunar versions of the Soyuz spacecraft that flew under the name Zond, and from what I've read, these included increased heat shield protection. Earlier in this thread Gaetano was drawing comparisons Soyuz. To my knowledge everything that flew under a Soyuz designation was an earth-orbit version that lacked the thermal protection needed for lunar return. Therefore any comparison between Gaetano's TBS-Orion and a "Soyuz" (meaning earth-orbit version) is not valid.

    As I have said, I see no reason Gaetano's capsule couldn't work provided it has adequate thermal protection. My problem is that Gaetano has implied his design will work if it is provided with the same thickness of protection as on Apollo or Soyuz because both Apollo and Soyuz work. This is faulty logic because his design is neither Apollo (cone shaped) nor Soyuz (earth orbit return). Historically Zond is most analogous to Gaetano's design, having both a steep sidewall and performing a lunar return reentry.

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    Quote Originally Posted by Bob B. View Post
    If you have no proof your capsule shape is better, then please stop declaring that it is.
    1. this is my opinion and... 2. if my design doesn't need extra TPS on sidewall, absolutely IS better
    ...different from the Apollo shape. The shape change may seem trivial to you but it looks like a radical change to me...
    already said in many posts that my design needs tests & tests (like everything in the ESAS plan)
    .

  29. #298
    Join Date
    Apr 2006
    Posts
    1,834
    Quote Originally Posted by stutefish View Post
    ...more surface area...
    it has a 4.5 m diameter (not 5 m like the standard Orion) then everything is smaller, while, the new shape may give a similar (real) habitable space
    .

  30. #299
    Join Date
    Apr 2006
    Posts
    1,834
    Quote Originally Posted by Bob B. View Post
    ...Zond, and from what I've read, these included increased heat shield protection...
    this is obvious ...the point we need to know is if they (simply) increased the Soyuz's heat shield thickness or added (also) an extra protection on sidewalls
    ...his design is neither Apollo (cone shaped) nor Soyuz (earth orbit return)...
    infact, my design (a 4.5 m resized and modified lunar-Orion) ISN'T nehiter Apollo (since the TBS-Orion has a bigger shield) nor Soyuz (since it's Orion-derived)
    .

  31. #300
    Join Date
    Sep 2004
    Posts
    14,076
    that's true in first minutes, but the atmosphere quickly slows the capsule
    And what happens when an atmosphere quickly slows a capsule?

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