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Fascinating buried lead: > A NASA history of the Hubble,[24] in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter design, states:
by slipframe 5y ago
Fascinating buried lead:
> A NASA history of the Hubble,[24] in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter design, states: "In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites."
Hubble was derived from these spy satellites.
- perl4ever 5y agoWhat's mindboggling to me is the sheer number of spy satellites that were more or less each equivalent to Hubble. There are estimated to have been something like seventeen of the KH-11 satellites, each one of which cost something like 2/3s of a Nimitz class aircraft carrier. https://en.wikipedia.org/wiki/KH-11_Kennen https://en.wikipedia.org/wiki/KH-11_Kennen And there are an unknown number of its successor, but probably at least 3, where they updated it for stealth. https://en.wikipedia.org/wiki/Misty_(satellite) https://en.wikipedia.org/wiki/Misty_(satellite) It feels like a parallel universe where what is a technical struggle and tour de force here, is churned out by the dozens.
- slipframe 5y agoHubble was botched initially, they had to send astronauts up to fix it before they could get usable images out of it. I wonder what the success rate for those spy satellites was. Maybe some of them were replacements for others, replaced instead of repaired?
- wmf 5y agoIf you go back a little more, they used to launch one or two film-based disposable spy satellites per month.