<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>philipkglass</author><text>Titanium is very common in the Earth&amp;#x27;s crust. But turning titanium minerals into pure, ductile titanium metal is more energy intensive and complex than making most other metals:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;chem.libretexts.org&amp;#x2F;Bookshelves&amp;#x2F;Inorganic_Chemistry&amp;#x2F;Supplemental_Modules_and_Websites_(Inorganic_Chemistry)&amp;#x2F;Descriptive_Chemistry&amp;#x2F;Elements_Organized_by_Block&amp;#x2F;3_d-Block_Elements&amp;#x2F;Group_04%3A_Transition_Metals&amp;#x2F;Chemistry_of_Titanium&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;chem.libretexts.org&amp;#x2F;Bookshelves&amp;#x2F;Inorganic_Chemistry&amp;#x2F;...&lt;/a&gt;&lt;p&gt;At the time, the USSR had already invested significant resources into making titanium for submarines. Buying titanium under false pretenses was easier than increasing the domestic industrial capacity for making titanium, particularly when the plane was not going to be produced in large numbers.</text><parent_chain><item><author>ben7799</author><text>Which is really odd, as Titanium is not that rare.&lt;p&gt;Are we sure that story about the Titanium coming from the USSR is accurate?</text></item><item><author>dghughes</author><text>Also incredible most of the titanium came from the USSR but through indirect routes and suppliers with the Soviets being unaware.</text></item><item><author>geocrasher</author><text>Indeed, Mach 3.5 is the &lt;i&gt;declared&lt;/i&gt; top speed in this story, but higher speeds are implied.&lt;p&gt;&lt;pre&gt;&lt;code&gt;     The Mach eases to 3.5 as we crest 80,000 feet... Screaming past Tripoli, our phenomenal speed continues to rise... I realize that I still have my left hand full-forward and we&amp;#x27;re continuing to rocket along in maximum afterburner... The TDI now shows us Mach numbers, not only new to our experience but flat out scary.
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He mentions unusually cool temperatures allowing higher speeds than usual, and the aircraft is performing better than ever. So who knows. 3.6? Did a perfect set of circumstances, mixed with a rather urgent need to depart, take them closer to 3.7?&lt;p&gt;It&amp;#x27;s truly incredible that the A12&amp;#x2F;SR-71 aircraft was designed without the benefit of modern computing. In Ben Rich&amp;#x27;s book &amp;quot;Skunk Works&amp;quot; I recall there a bit about a comment that somebody once made regarding Kelly Johnson, something like &amp;quot;That Swede can &lt;i&gt;see&lt;/i&gt; air&amp;quot;. Truly a compliment to Johnson&amp;#x27;s almost uncanny ability to design aircraft for a specification. The U2 was another example of such ability.</text></item></parent_chain></comment><story><title>Mach 3.5 Over Libya in an SR-71 Blackbird</title><url>https://www.thesr71blackbird.com/Aircraft/Stories/mach-35-over-libya-in-an-sr-71-blackbird</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>smburdick</author><text>I think it&amp;#x27;s mostly anecdotal (I have heard it too, but I can&amp;#x27;t think of where)&lt;p&gt;Not a metallurgist, but if I had to guess it was hard to find in large enough quantities at the time. I also understand that it&amp;#x27;s a lot harder to work with than say aluminum or steel&lt;p&gt;Speaking of which, King Louis served his guests with aluminum silverware, since at the time it was more valuable than gold due to the difficulty of extracting it at the time, despite its abundance.</text><parent_chain><item><author>ben7799</author><text>Which is really odd, as Titanium is not that rare.&lt;p&gt;Are we sure that story about the Titanium coming from the USSR is accurate?</text></item><item><author>dghughes</author><text>Also incredible most of the titanium came from the USSR but through indirect routes and suppliers with the Soviets being unaware.</text></item><item><author>geocrasher</author><text>Indeed, Mach 3.5 is the &lt;i&gt;declared&lt;/i&gt; top speed in this story, but higher speeds are implied.&lt;p&gt;&lt;pre&gt;&lt;code&gt;     The Mach eases to 3.5 as we crest 80,000 feet... Screaming past Tripoli, our phenomenal speed continues to rise... I realize that I still have my left hand full-forward and we&amp;#x27;re continuing to rocket along in maximum afterburner... The TDI now shows us Mach numbers, not only new to our experience but flat out scary.
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He mentions unusually cool temperatures allowing higher speeds than usual, and the aircraft is performing better than ever. So who knows. 3.6? Did a perfect set of circumstances, mixed with a rather urgent need to depart, take them closer to 3.7?&lt;p&gt;It&amp;#x27;s truly incredible that the A12&amp;#x2F;SR-71 aircraft was designed without the benefit of modern computing. In Ben Rich&amp;#x27;s book &amp;quot;Skunk Works&amp;quot; I recall there a bit about a comment that somebody once made regarding Kelly Johnson, something like &amp;quot;That Swede can &lt;i&gt;see&lt;/i&gt; air&amp;quot;. Truly a compliment to Johnson&amp;#x27;s almost uncanny ability to design aircraft for a specification. The U2 was another example of such ability.</text></item></parent_chain></comment><story><title>Mach 3.5 Over Libya in an SR-71 Blackbird</title><url>https://www.thesr71blackbird.com/Aircraft/Stories/mach-35-over-libya-in-an-sr-71-blackbird</url></story>