Posts by Cboldt

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  • NASA: DEBRIS NOT TO BLAME

    02/06/2003 5:42:33 AM PST · 30 of 54
    Cboldt to Falcon4.0
    Indeed. Just check out the kinetic energy of one common rifle round.

    150 grain 30-06 at muzzle, 2970 ft/sec has 2938 ft-lb of kinetic energy, and at 400 yards and about 1900 ft/sec, still has 1232 ft-lb of kinetic energy.

    But, to be fair, the foam-to-insulation situation is tougher to cipher. Each of the items can lose energy to deformation, or to cutting (sharp edge might slice off a piece of tile rather than crush it), so we have to consider the shape of the impacting object; the angle of impact, relative hardness (in a bullet-to-tissue event, tissue loses, but in a bullet-to-steel plate event, the bullet loses), and many other factors.

    I think the indications all point to increased drag on the left wing, and hope that we will someday have information that permits us to have some certainty regarding the cause of this disaster.

  • NASA: DEBRIS NOT TO BLAME

    02/06/2003 4:43:12 AM PST · 18 of 54
    Cboldt to Cboldt
    Physics classroom URL went missing on me.

    Link here -> The Physics Classroom

  • NASA: DEBRIS NOT TO BLAME

    02/06/2003 4:39:27 AM PST · 17 of 54
    Cboldt to Falcon4.0
    By my calculations of 1/2 mass X velocity squared, the 2.67lbs foam with an impact speed of 1500 feet per second gives you a force of 3375000lbs or 1687.5 tons of force. Sounds like a resonable explination for tile damage to me.

    First, your incorrect calculation of 0.5 x m x v**2 has a math error.

    Second, you missed an important factor (I'll point it out below).

    Third, Force is mass time acceleration, your equation is for kinetic energy. The amount of damage caused will certainly be affected by the amount of kinetic energy the object has, but this object did not give up all of its kinetic energy to the orbitor. Also, the amount of damage is sometimes dependent on the RATE the kinetic energy is given up.

    OK, first, 1500*1500 = 2,250,000, times 2.67 is 6,007,500, and half of that is 3,003,750. But, this number is not a proper engineering calculation for kinetic energy. A common mistake made is to take a weight figure (2.67) and equate that to "mass." The two units (weight and mass) are not equivalent for calculating kinetic energy.

    In order to convert between them (weight and mass), one uses the acceleration due to gravity, and using the units of choice, that unit is 32.2 feet per second per second. An object that exerts 2.67 pounds of force when resting on the earth has a mass of 0.0829 lb*sec*sec/ft (2.67 divided by 32.2). This same object is weightless in space, and would exert a heavier force if resting on Jupiter, etc.

    Using the correct calculation of kinetic energy: 0.5 times 0.0829 lb*sec*sec/ft times 1500 ft/sec times 1500 ft/sec gives this moving object 93,300 foot-pounds of kinetic energy.

    One can "figure" the units without using numbers, by the way, and it is a good thing to do to determine whether the calculation is giving an answer in the units you expect (e.g., are we looking for force, pressure, temperature, or something else?). In this case, the sec*sec in the numerator cancels the sec*sec in the denominator, the ft*ft in the numerator divided by the ft in the denominator leaves just ft in the numerator, so the final answer is expressed in ft-lb.

    Check out The Physics Classroom.

  • NASA: Foam Probably Not Cause of Shuttle Disaster

    02/05/2003 4:30:30 PM PST · 129 of 324
    Cboldt
    STS-105 : Aug 10-22, 2001 : ET-110 Ship 7/26/00, On NASA dock 11/8/00
    STS-108 : Dec 5-17, 2001 : ET-111 Ship 9/22/00, On NASA dock 3/22/01
    STS-109 : Mar 1-12, 2002 : ET-112 Ship 3/8/01, On NASA dock 5/10/01
    STS-110 : Apr 8-19, 2002 : ET-114 Ship 6/18/01, On NASA dock 9/5/01
    STS-111 : Jun 5-19, 2002 : ET-113 Ship 4/30/01, On NASA dock 5/23/01
    STS-112 : Oct 7-18, 2002 : ET-115 Ship 9/26/01, On NASA dock 12/19/01
    STS-113 : Nov 23 - Dec 7, 2002 : ET-116 Ship 11/28/01, On NASA dock 2/6/02
    STS-107 : Jan 16 - Feb 1, 2003 : ET-93 Ship 11/2/00, On NASA dock 12/20/00

    STS is the flight designation, STS-107 was the 113th mission.

    ET is the external tank designation.

    STS-87 : Nov 19 - Dec 5, 1997 : ET-89 Ship 11/22/96, On NASA dock 4/1/97
    STS 87 was also by Columbia, is the previous flight that Kalpana Chawla was on. The notes in Lockheed Martin / Michoud's book recite "Columbia sustained extensive tile damage during launch." Probably a coincidence.

    The Free Republic link I referred to in my earlier post is: NASA Knew in 1997, Columbia sustained haevy tile Damage

    Michoud mission data book is at: http://www.lockheedmartin.com/michoud/et/shuttle_flight_info.pdf

  • NASA: Foam Probably Not Cause of Shuttle Disaster

    02/05/2003 3:45:03 PM PST · 72 of 324
    Cboldt to isthisnickcool
    I assumed they were in order too, but some other Freeper provided some real research, and a link to more useful data. There are many variables (duh), such as the existence of at least three different external tank designs, two different leading edge designs (Columbia has one design for carbon-carbon leading edge, the other orbiters are different in this regard), and a variety of changes made to address observations from previous flights.

    BTW, I assume no need to correct my obvious typo (STS-107 more than two after STS-107, should have said more than two after STS-105!)

    There is actually a lot of information out there. I have not tried to put it together in any sensible form.

  • NASA: Foam Probably Not Cause of Shuttle Disaster

    02/05/2003 3:31:11 PM PST · 50 of 324
    Cboldt to isthisnickcool
    STS-107 was not the second mission after STS-107 . . .

    In sequential order (per External Fuel Tank Manufacturer)

    STS-105 : Aug 10-22, 2001
    STS-108 : Dec 5-17, 2001
    STS-109 : Mar 1-12, 2002
    STS-110 : Apr 8-19, 2002
    STS-111 : Jun 5-19, 2002
    STS-112 : Oct 7-18, 2002
    STS-113 : Nov 23 - Dec 7, 2002
    STS-107 : Jan 16 - Feb 1, 2003

  • Video shows shuttle may have shed debris over Arizona - check out this video taken by amateurs

    02/04/2003 4:27:52 AM PST · 17 of 78
    Cboldt to Howlin
    Know you are interested, and that you have a sizable 'ping' list.
  • WILLIAM COHENíS LEGACY OF FAILURE [For All The Rumsfeld Haters]

    02/03/2003 5:45:59 PM PST · 10 of 11
    Cboldt
    .
  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 4:29:53 PM PST · 488 of 496
    Cboldt to Howlin
    Miss Marple: There are some here who are pushing the idea that NASA deliberately let astronauts fly on a craft that was known to be faulty, in essence letting them go to their doom.

    Howlin: I'm all confused here; if we disagree with that, are we bickering? Are we just suppose to let them SAY that without it being refuted?

    I'll speak for myself (not that any of you have tried to put words in my mouth, I am just offering my opinion). I don't have an answer, but it is my sense that many of these threads contain exchanges that are hostile and repetitive. I suppose, given the subject, that is inevitable.

    After a time, the facts (regarding the tragic loss of the crew of the Columbia, and the vessel too) will speak for themselves, and put a good number of "conclusion jumpers" in a bad light.

    I totally agree with your sentiment regarding NASA bashing. I am impressed with Dittemore's and NASA's response so far. I believe NASA was careful with this. Even though their gut told them the orbitor tiles were okay, they studied the potential effect of liftoff strikes against the tiles. Then, after the loss, they admitted that perhaps their study was flawed, and that they were reviewing that. When a big organization like NASA is open with facts like that, I develop trust in their statements.

    I have to admit, I have expressed difference of opinion with a few who were claiming NASA had been negligent (that is, I haven't followed my own advice to keep my mouth shut), then I figured it was a waste of my energy, and in many cases, only served to encourage the other side to post a response.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 4:07:36 PM PST · 483 of 496
    Cboldt to Joe Hadenuf
    And I would guess that this bickering has really turned off more than a few readers and is very distracting.

    Hear Hear! The bickering has scarred the threads. Signal to noise ratio has plummeted. I chalk much of it to stress of the moment, but also sense that there was a great deal of latent tension. Hopefully the place will regain most, if not all, of the quality it had.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 3:25:14 PM PST · 462 of 496
    Cboldt to lepton
    The point of my original message, that you and I are discussing, was to give more specific definition to the term "coming apart" or "break up". Many people were using those terms loosely, and arguing, and it is my continuing impression there are many ongoing arguments over semantics rather than talking substance.

    That problem can be solved by saying more precisely, what one means. For example, NASA is saying that it is possible (but they don't know) that parts of the shuttle came off over CA, and that this set in motion a chain of events that ended over TX.

    Now, some people here say the shuttle started to "break up" over CA, and voila, argument ensues between that person, and another who insists that break-up was over TX, and they never explain what they mean.

    Anyway, you and I are in agreement.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 3:13:57 PM PST · 446 of 496
    Cboldt to lepton
    It is unlikely that the Astronauts were able to talk calmly after the shuttle came apart.

    Depends on how far apart you mean. If you mean after 8:04, I'd modify your statement to simply, "It is unlikely that the Astronauts were able to talk after the shuttle came apart." But the shuttle was flown in on every previous mission, 100% of them, incomplete, with pieces missing, with tiles missing, and with tiles damaged.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 3:09:11 PM PST · 434 of 496
    Cboldt to Howlin
    It sounded to me like they used their own database extensively to "game" what might have been the outcome!

    That is exactly what they did, although I'd use a word a bit more respectful that "game." They knew shed ET insulation occurs, had measured its extent on numerous occasions, and were actively engaged in reducing or eliminating it (reduction via sanding hard outer layer of ET insulation off, in certain areas of ET, elimination by understanding mechanism that causes ET insulation to shed). NASA (I think) honestly believed, based on experience, that any damage due to ET insulation shed was only a matter of turnaround, and not any risk to mission integrity. They also reviewed information relating to this specific flight.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 3:02:44 PM PST · 417 of 496
    Cboldt to Howlin
    Good tile question here . . . ET (external tank) has shed insulation in the past. There is a good deal of info already out on this. NASA did testing related to the extent of damage possible by ET insulation striking the orbiter tiles.
  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 2:53:42 PM PST · 387 of 496
    Cboldt to justshe
    I'm monitoring another thread....too bad some of those folks aren't listening to this.

    Don't invite them, they don't just listen, they ask the same questions over and over, etc.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 2:49:50 PM PST · 376 of 496
    Cboldt to PhiKapMom
    If the shuttle were breaking up in CA, I would assume NASA would have known about it!

    Depends on the definition of "breaking up." If it means some small part came off, not enough to cause "immediate disintigration," but enough to start a chain of events, then I have the impression NASA is open to that theory. Their instrument readings, etc. were not "typical" at that point, and they are hungry for an explanation.

    If "breaking up" means breaking the shuttle into two or three big pieces, etc, then I think all will agree that event happened over TX.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 2:45:39 PM PST · 371 of 496
    Cboldt to Howlin
    Actually, that's not the impression I got from what he said; I thought he meant he had SEEN those reports and they were going to LOOK in the areas where the people say that they "saw" something.......like they were going to prove that it didn't happen.

    I get the opposite impression. Not that I've been listening all that closely, typing, etc. gets in the way! But I am pretty sure his technical comments indicate interest in events over CA, i.e., he is very open to the idea that something happened over CA that was anomolous, and possibly relevant to the eventual demise of the Columbia.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 2:38:34 PM PST · 357 of 496
    Cboldt to PhiKapMom
    Don't know where the thermal event is coming from -- wonder if it is computer software giving false readings

    IMO, no. The thermal readings are not apt to be incorrect based on software. Perhaps in error based on hardware failures, but not software. But then, the number of high temperature readings, plus consistent, related onbservations, points toward elevated temperature on the left side. The high "bond line" temperature readings are at the top side of the wing.

  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 2:36:04 PM PST · 348 of 496
    Cboldt to Howlin
    All of the press conferences made that point clear, the external tank insulation shed event has happened in the past, has been analyzed in detail (so there is a substantial knowledge base). I am impressed that they so openly questioned their deeply reasoned assumption, right from the start.
  • Live Thread: NASA PRESS CONFERENCE

    02/03/2003 2:32:35 PM PST · 335 of 496
    Cboldt to Howlin
    Post a transcript. I've been looking for one, and I am sure that comments based on the transcript would be considerably more valuable than the repetitive questions and uninformed speculation that has been rampant on this subject.