supergeek 8 hours ago | next |

I find this passage quite amusing:

"Schöfbänker has also cross-haired with his equipment the "KH-11 Kennen" electro-optical satellites that were first introduced in 1976. "They are somewhat similar to the Hubble Space Telescope, but optimized to look down to Earth, instead of studying space," he said."

It's fairly well documented that the Hubble was effectively a US spy satellite pointing towards space, not the other way around. Or at least, it used all of the infrastructure in place to manufacture spy satellites.

Same maximum mirror size, same set of contractors/facilities, etc. It had a very different set of sensors, data systems, and focal range, but more or less demonstrated the US's spy satellite capabilities at the time.

mandevil 7 hours ago | root | parent | next |

The size being the same was not because of design reuse, but because that's the size limits imposed by the Space Shuttle payload bay. (1) Many of the contractors were the same, but that's because they won a competitive bidding process with a CCD design against a different set of contractors vidicon tube technology. Now, their experience with CCD's did come from the KH-11 process, but their bid did have competition.

1: Speculation but reasonably informed: in 1970 when the USAF was asked to set the size of the payload bay (in exchange for USAF political support on a program that had just survived by one vote, their parameters became the design guidelines for the STS) they basically went with their latest design at the time, the KH-10 Manned Orbiting Laboratory, which had already been canceled but was the latest thing anyone had. If the people at NRO who provided the specs had known how the future was going to go, they would have probably wanted a shorter but wider payload bay, so you could put bigger main mirrors into space. But, and this is total speculation, in 1970 when they are committing to this the KH-11 is far enough in the future that they don't have a good understanding of what it should be like. The KH-11 was designed to be carried into space by the STS, but the STS was delayed so its first flights were on unmanned rockets, and then after Challenger the NRO tried to get all of their satellites off the STS and go fully unmanned. A couple of satellites were far enough along that they were committed to the Shuttle after Return to Flight, but no more were committed after that point.

Loughla 8 hours ago | root | parent | prev | next |

So that was how long ago? I guess the super zoom satellite footage from movies might not be unrealistic like I thought. . .

sbierwagen 8 hours ago | root | parent | next |

There's a hard physical limit (the Rayleigh criterion) on the resolution of an optical system by how big the open end is. You won't get "super zoom" capabilities without a satellite the size of a stadium. https://en.wikipedia.org/wiki/KH-11_KENNEN#Resolution_and_gr...

alganet 7 hours ago | root | parent |

What about multiple satellites working to get one image?

Like the arrays we have on Earth pointing to space, but instead, arrays on space pointing to Earth.

I know there probably isn't that many KH-style satellites to do it, but would it be possible?

GlenTheMachine 7 hours ago | root | parent |

The alignment has to be better than half a wavelength. That's doable for RF, but for optical telescopes you're talking nanometers. That's not possible (currently or in the foreseeable future) for a spacecraft constellation.

sbierwagen 6 hours ago | root | parent |

Amusingly enough, there's been some groundwork laid here by gravity wave interferometer constellations: https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Ant...

You could imagine a deep-infrared mission (longer wavelength, to soften the alignment requirements) launched into deep space (Jupiter+) where both the solar wind density is lower (reducing space weather perturbations) and reduced solar flux would reduce heat loads on the structure, (objects in Jupiter orbit get 3.6% as much light as in Earth orbits) making cooling easier. An interferometer design would also improve resolution. A not-widely advertised feature of the JWST is that, due to the same Rayleigh limits, its far infrared modes have dramatically lower resolution than its near infrared camera. A problem with a 6 meter mirror, less of a problem with a kilometer mirror.

coolspot 7 hours ago | root | parent | prev |

In 2022 Trump declassified this satellite picture showing amazing resolution of current generation: https://media.npr.org/assets/img/2019/09/05/ap_1924315303447...

rafram 7 hours ago | root | parent | prev |

That looks about as high-resolution as Google Maps to me. I’m sure the government can do much, much better, but this isn’t a good showcase.

defrost 7 hours ago | root | parent |

Apples to oranges comparison there.

A great deal of Google Map imagery over urban areas is from relatively low level aerial survey aircraft that run lines over cities in summer.

The resolution is better and stitched together often provides a better bang for the buck than satellite imagery.

That said, Trump's image may have been from a sat or from a high altitude spy plane - they'd have ballpark optics but the aircraft would be closer in and more maneuverable .. I'd personally discount whatever Trump had to say about the source and want to hear from a third party military reconnaissance expert.

rafram 7 hours ago | root | parent |

Yeah, I’m referring to Google Maps satellite imagery, not the super-saturated and detailed urban area coverage. I mean, check out the satellite view here [1]. It’s not perfect, but you can make out building-sized objects and cars just as well as you can in the Trump image.

[1]: https://maps.app.goo.gl/Fic93Bhf8X8CA5De6

red369 6 hours ago | root | parent | prev |

I think also part of the KY-11 were the two telescopes the NRO (National Reconnaissance Office) donated to NASA in 2012. I forget the details I read, but as I remember they were roughly equivalent to Hubble, but obselete for the NRO.

slicktux 7 hours ago | prev | next |

Anyone else getting a prompt on Safari when visiting the page asking them; “Do you want to download “sync”?”

And the only option on prompt being Download… Anyone??

robinsonrc 6 hours ago | root | parent | prev | next |

Not seeing it in Safari on iOS at least (although I may have missed it amongst the thousands upon thousands of adverts… I really should look into alternatives again)

avalys 7 hours ago | prev | next |

Speaking of secret spacecraft - has anything interesting ever been revealed about the “Zuma” satellite, which failed to reach orbit a few years ago? It was supposedly a very expensive, very important program, but so secret that no agency ever admitted to owning it.

https://en.m.wikipedia.org/wiki/Zuma_(satellite)

adamredwoods 9 hours ago | prev | next |

I would have read the article, but after a few nag-popups and ads, my laptop fan kicked on, so I closed it. Space.com is one of the few websites I care about that I would like to be a bit more browser-friendly.

TacticalCoder 8 hours ago | root | parent | prev |

> ... but after a few nag-popups and ads, my laptop fan kicked on

On my Linux I have 12 workspaces or so and my main browser is always on a specific workspace. Then I configured my system to always put the CPU in "powersave" mode when I'm switching to that workspace. Actually all my workspaces besides the one where I do dev are in powersave. Fixes the fan issue. Works for GPUs too (there are tools to configure the max TDP of a GPU: even if approximative, it works).

I'm also blocking ads / millions of domains at the DNS (I'm running both unbound and dnsmasq).

binkHN 6 hours ago | root | parent |

How does powersave mode help here? All it does is slow everything down when you're in that workspace.

ipv6ipv4 8 hours ago | prev | next |

What about Chinese satellites?

Somehow, I feel that would be more interesting as there is even less public information about them.