KH-11 KENNEN

[LittleBird]

K-9 and K-11 used the same boosters.

Indeed they did, but I don't think that invalidated the rest of it. Do you ?

[Blackstar]

Interestingly he also said that they had been confused by US press reports and were expecting the readout feature to appear on the KH-9, in its different orbit from the KH-11's. This may refer to the second of the Aviation Week items in 1972 which said Lockheed were going to modify the "Big Bird" to include this (second grab). It's a reminder that the multiple contradictory open press reports may well have functioned as a type of disinformation, whether deliberate or accidental-I have to constantly remind myself when reading old press coverage that I am doing so through a filter of whet we know (or think we know) now.

I'd note that the AWST short article was wrong on a number of accounts, including TRW.

Ironically (no?), there was a plan to add a real-time capability to the last few HEXAGONs, although this was added in the early 1980s, not 1970s. It would have made the observers really confused if that had actually happened on the last mission.

Some guy wrote about that:

https://www.thespacereview.com/article/3662/1

[hoku]

<snip>
Interestingly he also said that they had been confused by US press reports and were expecting the readout feature to appear on the KH-9, in its different orbit from the KH-11's. This may refer to the second of the Aviation Week items in 1972 which said Lockheed were going to modify the "Big Bird" to include this (second grab). It's a reminder that the multiple contradictory open press reports may well have functioned as a type of disinformation, whether deliberate or accidental-I have to constantly remind myself when reading old press coverage that I am doing so through a filter of whet we know (or think we know) now.

Might have been part of an obfuscation effort by "leaking" semi-truth to the press? I seem to recall that someone wrote about KH-9 changing its film-based stellar index camera to the S³ camera (aka "Star Sensor System" or "Stellar Solid State" or "Solid State System") with its solid-state detector(s).

https://www.thespacereview.com/article/3662/1

[Blackstar]

I'm forgetting the details (they're probably in my article and I'm too lazy to look) but the S3 camera was carried on two missions where the plan was to rotate the satellite after the last bucket was deployed and use it to look downward, using its CCD array that was designed to look at stars to instead look at the ground. Something went wrong on those two missions and it was not used for that purpose.

On the very last HEXAGON mission, they mounted an S3 looking downward. (It is possible that they also had an S3 looking upward on this mission too.) The plan was that after the last bucket was deployed, the spacecraft would continue to operate for possibly up to half a year, using that special S3 camera to operate as a near-real-time imaging system. However, the rocket blew up during launch.

[LittleBird]

Thanks both. Blackstar will remember that there are at least two versions of how Av Leak actually got the real story on the KH-11 and agreed to spike it. One was recounted back in 1992 1990 in Richelson's "Secret Eyes" and concerned Clarence Robinson (first grab), while the other was told more recently by Craig Covault (https://www.americaspace.com/2012/06/06/top-secret-kh-11-spysat-design-revealed-by-nros-twin-telescope-gift-to-nasa/) -they may of course correspond to two separate incidents, but they sound to me like the same event, occurring sometime just after the launch in 1976. Reading them again I wonder if Jeff R got the story right and just got its protagonist wrong, perhaps having  heard it second hand [Source is just give as "interview"].

The later story said the quid pro quo was that Av Leak would receive regular backgrounders on what was known about Soviet weaponry space.  In addition to voluntary  self-censorship  it would of course be interesting to know if Av Leak was ever a (witting or otherwise) party to deliberate disinformation, but I doubt we'll ever hear about that.

[LittleBird]

"For example, the Feb. 23 battlefield document names one of its sources as “LAPIS time-series video.” Officials familiar with the technology described it as an advanced satellite system that allows for better imaging of objects on the ground and that could now be more susceptible to Russian jamming or interference. They indicated that LAPIS was among the more closely guarded capabilities in the U.S. intelligence arsenal."
https://www.washingtonpost.com/national-security/2023/04/08/intelligence-leak-documents-ukraine-pentagon/
Was this a known capability of KH-11 or is there also another imaging system out there?

No idea re specific question, or exactly what is meant by "time series video" here, but was interested to be reminded that 1m resolution commercial video from a few hundred km has been around for a while, e.g. the Carbonite satellites

 https://www.engadget.com/2018-01-13-prototype-satellite-earth-observation-full-color-motion-video.html

and the nice showreel that was put together for them:

[hoku]

<snip>
Following up on this, I think the things that would be interesting to know, but that we'll probably never know, are the details of the large, high-precision optics. How difficult was this? What were the key developments? If you compare the mass of the Hubble mirror with the mass of the FIA (WFIRST--Nancy Grace Roman Space Telescope) mirror, there was a dramatic improvement. But what happened in the period 1966-1972? Were there any major complications when they developed the KENNEN mirror?

The mass per collecting area of the primary mirror is definitely one of the main design drivers both for ground and space-based telescopes. The refinement of the "egg-crate" support structure seems to be one of the main technological achievements - see the attached images of the uncoated primary mirrors of the Palomar 200" and Hubble, and a back-side view of the Roman/WFIRST OTA.

It might be interesting to add the specifics of the primary mirrors for KH-7/8 and KH-10 to the following compilation:

Palomar 200": 627 kg/m^2 (12 700 kg total mass)
KH-10 (MMT): 207 kg/m^2 (544 kg total mass)
Hubble Space Telescope: 181 kg/m^2 (818 kg total mass)
Roman Space Telescope: 41 kg/m^2 (186 kg total mass)
James Webb Space Telescope: 21 kg/m^2 (705 kg total mass for PMSA segments + support structure)
<snip>

The Corning Museum of Glass has a number of "lightweight" (LW) and "ultra lightweight" mirror blanks in their collection. It is quite interesting to see how the design of the interior structure evolved from HST (1st image) to a much more recent 2.4m diameter "lightweight fused-silica mirror (...) made to be launched into space" (2nd image).

Hubble mirror has a square support structure, while this one has a triangular support structure. The mirror for Roman on the other hand has a hexagonal (honeycomb) structure. Makes one wonder about the various trade-offs (stability, weight, residual wavefront error, ...)?

The image caption mentions that the blank was gifted by Raytheon Optical Systems, Inc (ROSI) in 1999:
https://www.cmog.org/artwork/ultra-lightweight-mirror-blank

[Blackstar]

One thing that Davies' 1967 idea highlights is that resolution might not be as high priority for crisis management as it is for intel. VHR and real time tend to be run  together in histories and in discussions of MOL for example, but this is a reminder that real time imagery can sometimes be much more important than resolution. It's interesting that he was imagining a world were many "third party" countries would have imagery.

I'm now going to dip my feet back into the crisis response subject.

Something that I noted in one of the documents (which I'll refer to later) is that although resolution was not as high priority for crisis management as it was for strategic intelligence, there apparently was a bottom limit for it. I think that was around 4-5 feet; any worse than that and it did not provide the information that was required. I don't know what that limit was, but I think it was vehicles, like the ability to determine difference between a tank and an armored personnel carrier. A bunch of APCs could indicate putting down civil unrest (bringing in a lot of troops) whereas a bunch of tanks would indicate offensive operations.

More as I get to it.

[LittleBird]

To be honest I'm quite pleased even to have this cartoon, which appears to show the famous "stubby Hubble" shape, two solar arrays and what I assume are the two antennae that talk to the SDS relays. Antennae look smaller than I'd expect, but maybe somewhere in the huge pile of EOI docs the signal strengths etc are discussed.

It would only have one antenna since only one SDS is in view at a time.

Belatedly realised what the deely bobbers in both the NRO-sourced image below (see https://en.wikipedia.org/wiki/Deely_bobber for anyone under 60 50 ;-)) and some of those rather contentious photos from the ground discussed
upthread might be ...

... control moment gyros.

[LittleBird]

Thanks for th up Hoku. I remember Jim saying that HEXAGON didn't use CMGs, and I thought that I'd read in an NRO source that GAMBIT didn't but I'm now wondering if that's true, especially for the later G3 etc.

[Jim]

Thanks for th up Hoku. I remember Jim saying that HEXAGON didn't use CMGs, and I thought that I'd read in an NRO source that GAMBIT didn't but I'm now wondering if that's true, especially for the later G3 etc.

no place for them on the Agena

[Blackstar]

Thanks for th up Hoku. I remember Jim saying that HEXAGON didn't use CMGs, and I thought that I'd read in an NRO source that GAMBIT didn't but I'm now wondering if that's true, especially for the later G3 etc.

no place for them on the Agena

There's a story there that I don't think is in the official records (it may be that I have not seen it), which is that when they started work on the G3, there was concern that the Agena could not provide the fine pointing and stability required for the higher resolution. So somebody did an analysis of that to prove that it could. Maybe that's mentioned in the official histories somewhere.

[LittleBird]

Thanks for th up Hoku. I remember Jim saying that HEXAGON didn't use CMGs, and I thought that I'd read in an NRO source that GAMBIT didn't but I'm now wondering if that's true, especially for the later G3 etc.

no place for them on the Agena

There's a story there that I don't think is in the official records (it may be that I have not seen it), which is that when they started work on the G3, there was concern that the Agena could not provide the fine pointing and stability required for the higher resolution. So somebody did an analysis of that to prove that it could. Maybe that's mentioned in the official histories somewhere.

All I can recall is a statement in the GAMBIT story [*] which (I think-I need to check this) said that jets were used for coarse pointing and then switched off, and the momentum wheel [i.e. the one in the roll joint if I've understood ?], not  CMGs, was used for fine pointing. Description seemed to imply that there was a fair amount of time between picture taking sessions, which again others could correct me on.

[* or possibly in the H and G article in the NRO's journal that they publish declassified extracts of sometimes.]

[LittleBird]

Thanks for th up Hoku. I remember Jim saying that HEXAGON didn't use CMGs, and I thought that I'd read in an NRO source that GAMBIT didn't but I'm now wondering if that's true, especially for the later G3 etc.

no place for them on the Agena

There's a story there that I don't think is in the official records (it may be that I have not seen it), which is that when they started work on the G3, there was concern that the Agena could not provide the fine pointing and stability required for the higher resolution. So somebody did an analysis of that to prove that it could. Maybe that's mentioned in the official histories somewhere.

Am I right in thinking that the key steps from KH7 to KH8 was i)  that Agena stayed attached and ii) that job of fine pointing was taken over by a momentum wheel that was somehow part of the roll joint ?

[Blackstar]

Am I right in thinking that the key steps from KH7 to KH8 was i)  that Agena stayed attached and ii) that job of fine pointing was taken over by a momentum wheel that was somehow part of the roll joint ?

There were a bunch of other things, like a larger mirror and longer focal length. Unless you are only referring to the spacecraft. But there is a separate thread devoted to the G1/G3 (KH-7/KH-8).

[LittleBird]

Am I right in thinking that the key steps from KH7 to KH8 was i)  that Agena stayed attached and ii) that job of fine pointing was taken over by a momentum wheel that was somehow part of the roll joint ?

There were a bunch of other things, like a larger mirror and longer focal length. Unless you are only referring to the spacecraft. But there is a separate thread devoted to the G1/G3 (KH-7/KH-8).

Thanks, my question was indeed quite narrowly focused on the momentum wheel versus CMG aspect, and I see from the 1980 GAMBIT manual declassified in 2016 that the basic design never changed in this respect.

The KH11 relevance is that if KH8 didn't use a CMG, and KH9 didn't either,  then Skylab may have actually been first camera-bearing s/c to fly with CMGs, with KH-11 following it, despite NRO being originator of CMGs if I've undertood their statements correctly ?

I'm also guessing that RHYOLITE and possibly CANYON were first NRO s/c to fly with CMGs, and possibly first usage in space, unless they were tested on R&D spacecraft of some kind. The textbooks on spacecraft control are understandably a bit coy about this sort of thing ... ;-)

[Jim]

I'm also guessing that RHYOLITE and possibly CANYON were first NRO s/c to fly with CMGs, and possibly first usage in space, unless they were tested on R&D spacecraft of some kind. The textbooks on spacecraft control are understandably a bit coy about this sort of thing ... ;-)

GEOsats typically don't used CMGs.

[LittleBird]

I'm also guessing that RHYOLITE and possibly CANYON were first NRO s/c to fly with CMGs, and possibly first usage in space, unless they were tested on R&D spacecraft of some kind. The textbooks on spacecraft control are understandably a bit coy about this sort of thing ... ;-)

GEOsats typically don't used CMGs.

Thanks. I can see why Hughes Gyrostat-derived ones wouldn't (QUASAR, JUMPSEAT etc) and can easily believe that in 1968 CANYON would have used Lockheed's recent experience with momentum wheels. I'd be surprised to learn one day that RHYOLITE [*] didn't use CMGs though ---would seem an almost ideal application for them [Edit: Though I guess it would have added even more technical risk to what must have been an extraordinarily bold project.]


[Edit 2: My reason for making willd unsupported guesses about RH is that we have at least one eyewitness report of it looking "like a French umbrella"-in Richelson's work somewhere iirc, and a declassified doc that mentions a study that calculated dish would need to be ~70 feet diameter-cited in Nautilus Institute compendium.]

[jbenton]

A few months ago, a Maxar satellite imaged the NASA/USGS Landsat 8:

https://landsat.gsfc.nasa.gov/article/satellite-sees-satellite-landsat-8-in-orbit/

On October 7, 2022, Maxar’s WorldView-3 satellite snapped this sequence of images showing Landsat 8 in orbit. The distance between the satellites ranges from between 91.4 to 129.9 km (56.8 to 80.7 miles).
...
The resolution of the Landsat 8 images in this sequence varies from 4.6 to 6.5 cm (SSD stands for Space Sample Distance).

At the time, news of the event was posted in the Landsat 8 tread in this forum. I thought I'd repost it in this thread because this is one of the tasks that the KH-11 KENNEN sats and their successors were designed to do.

The resolution of a picture taken at this distance is certainly impressive, but I imagine that a sat from the Evolved Enhanced CRYSTAL System-series could do even better.

[hoku]

Thanks for th up Hoku. I remember Jim saying that HEXAGON didn't use CMGs, and I thought that I'd read in an NRO source that GAMBIT didn't but I'm now wondering if that's true, especially for the later G3 etc.

There is also an interesting comment from Bob O'Dell's oral history interview on HST:
O'Dell:
(...) We had things that we generally didn't expect, like this business about 2.4 meters being just about the largest size you could package with a low moment of inertia, a point I made in the review panel. That was really the driver, on 2.4 meters. That's what kept the costs down. That was the big break on the costs. The uncertainty of cost in making 3 meter optics was great, but very hard to define, whereas the certainty of the difference in cost between reaction wheels and control moment gyros was clear. That was black and white.
https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4802-1