Apollo Re-entry another exposé from Aulis

[Bryanpoprobson]

 http://www.aulis.com/re-entrymatters.htm

Having read this through the one thing that shines through is, the Authors unfamiliarity with the subject matter. The whole diatribe seems to, basically point to missing L&D data for Apollo's 7 and 9's return trajectories. I'm sorry does the author know what type of missions 7 and 9 were? And the use of the word skip, instead of double dip by one person. What do people know about the author Mary M D Bennett, as far as I can ascertain, she is just a writer, with no knowledge of physics, maths or science. I know she co-wrote David Percy's claptrap, "Dark Moon" beyond that I can find out little about her, apart from she was brought up in Thaxted a couple of miles away from where I live. Perhaps I should go pay her a visit and ask her directly.
The other glaring omission from the article, was the use of the FIRE 1 and FIRE 2, rigs in 1964 and 1965 to simulate lunar return trajectories and speed and the wind tunnel tests on the capsule. She seems to think that they launched  4 and 6 with 4 giving the only relevant data, then proceeded straight to manned flights.

edit:- The other problem seems to be missing Maximum Entry velocity from Apollo 12 onwards, even though the "actual" velocities are given, I can only surmise that the max figure was a estimated figure for the given return angle and was not given after experience with 8, 10 and 11? I don't know..


Any thoughts?

[onebigmonkey]

I read this but as a non-rocket scientist don't feel qualified to comnent. Pity the author didn't feel the same.

What I will say is that the Kraft quote is not seemingly found outside the Popular Mechanics article and isn't attributed there so we have no real idea of context.

What context we do have suggests that Kraft is referring only to Apollo 11 and the article is making much play out of generalising to all missions.

What she also seems to be proving is that these ways of carrying out re-entry worked just fine.

[Bryanpoprobson]

What she also seems to be proving is that these ways of carrying out re-entry worked just fine.

Which is why I have asked Adrian to give a synopsis on this from his, lauding of this article on infowars. I know for a fact that he doesn't understand one iota of the linked article, I was hoping to expose his lack of knowledge, but as per, he simply avoids the question, no change there then.

[onebigmonkey]

You'd also think, in relation to some of the comments under that article, that the existence of TV coverage of the splashdowns might be a teensy weensy clue that there were ships nearby when they re-entered

[Allan F]

The point not understood by that article is the matter of different coordinate systems in the graphs. The re-entry phase was (as I understand it) a "near miss" if the Earth had no atmosphere, and the "rise" in the trajectory was the CM passing through the atmosphere and climbing because the Earth curved away beneath it. Slowing down, the CM then fell into denser atmosphere.

One graph shows the CM's distance to the Earths surface. This looks like a "flat" Earth. In this graph, the CM clearly increases it's altitude after EI. I would much like to see a trajectory with a curved Earth at the bottom.

[Echnaton]

So Bennett's back in the game.  To bad she stays in the walled off ........ that is Aulis.  I would love to see her defend this analysis of  "the vocabulary used by NASA and its associates" here.  Quote mining at its finest.....er....lowest...er....whatever. 

[Count Zero]

So Bennett's back in the game needs money/attention.

ftfy

[Count Zero]

What she also seems to be proving is that these ways of carrying out re-entry worked just fine.

Which is why I have asked Adrian to give a synopsis on this from his, lauding of this article on infowars. I know for a fact that he doesn't understand one iota of the linked article, I was hoping to expose his lack of knowledge, but as per, he simply avoids the question, no change there then.

Wait... So you're asking Adrian for his analysis of something he doesn't understand that was written by someone who has no knowledge or understanding of what she's writing about?  I think I'm getting a "Scanners"-level recursive-ignorance headache.

[Bryanpoprobson]

Wait... So you're asking Adrian for his analysis of something he doesn't understand that was written by someone who has no knowledge or understanding of what she's writing about?  I think I'm getting a "Scanners"-level recursive-ignorance headache.

Exactly, I read the article and gauged a basic lack of understanding by the author, so as Adrian had linked the article, as an example of the growing whimper, I asked him to explain what he understood to be the problem with Apollo, as expressed in the article. Trouble is I know that, idiot though he is, he will not walk into so obvious a trap, so he ignores the question.

[gwiz]

She appears to think that there is something suspicious in quoting more than one figure for a re-entry speed.  Even ignoring rounding errors and conversion to different units, there is no discrepancy at all in quoting both a speed at 400 kft and different maximum speed, as the maximum speed can occur at a different altitude to 400 kft.  It's comparable to a racing car having a difference between the maximum speed down the straight and the speed as it crosses the finish line.

[Bryanpoprobson]

Does anybody know why the max speeds were not quoted after Apollo 12?¿

[Echnaton]

So Bennett's back in the game needs money/attention.

ftfy

She seems to be personally offended that a friend was thrown out of Autographica for putting hoax questions to astronauts.   Well she's now shown 'em not to do that again. 

[Bob B.]

That's one of the most useless articles I've ever read.  For half the article all she does is complain about inconsistency in terminology.  Well welcome to the real world.  Based on my understanding, Apollo did not technically perform a "skip" reentry, though I understand why someone might call it that.  I believe a skip reentry is one in which the spacecraft skims through the atmosphere and exits before performing a second crossing of the entry interface.  Although Apollo did perform a rise in altitude, it never rose above the entry interface altitude.  A "double-dip" is probably a more correct description.  Nonetheless, it is clear that everybody is describing the same thing, which is obvious when you understand what it is that they are talking about.

The next big thing that Bennett complains about is that the Apollo missions apparently never performed a double-dip reentry because the Apollo records she's looking at lists only one acceleration peak.  The records she's looking at lists the maximum g.  Only one of the two peaks can be the maxiumum, so that is the one that is listed.  Just because they don't list the smaller second peak doesn't mean it didn't happen.  Bennett is interpreting the absence of evidence as the evidence of absence.  The problem is that Bennett didn't look hard enough.  The Apollo entry postflight analysis reports clearly show that there were two peaks.  Below is an example for Apollo 10.

Apollo 10 Mission Report, Supplement 10 - Entry Postflight Analysis

Toward the end of the article Bennett complains about why there are "different entry interface speeds" listed.  Entry velocity is the velocity at entry interface, i.e. an altitude of 400,000 feet.  Maximum velocity is just that, the maximum.  They are not the same thing.  The spacecraft continued to speed up after crossing entry interface until the air became dense enough that drag started to slow it down.

[gwiz]

Does anybody know why the max speeds were not quoted after Apollo 12?¿

The person who compiled the table couldn't find them?

[Echnaton]

 

Does anybody know why the max speeds were not quoted after Apollo 12?¿

The person who compiled the table couldn't find them?

Do you mean they didn't have a maximum speed?