Comment by VLM | Hacker News Reader

Comment by VLM | Hacker News Reader

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I've never gotten a straight answer on who came first the KH-11 or HST. The mirrors are the same size and they both fit in the bay.

A long time ago I considered writing a "sci fi techno thriller" book plot along the lines of the HST was intentionally mis-built to own the Russians trying to copy the KH-11. There's easier ways to make money LOL.

In the 70s progress was fast and they were blasting new observation sats every couple months and new generations every couple years so it seemed sensible to have a "space truck" to service the rapidly changing technology. Then things settled down and at least declassified nothing is new in quite some time WRT observation sats.

Kind of like rapid changes in the PC industry in the 80s then things slowed down a lot to the point we don't "need" a Radio Shack or CompUSA anymore.

People thought the rapid progress of the 70s in spy sats was going to go on forever, so we need a "space truck" to keep up with rapid changes, and like most things predicted to go on forever, it didn't.

The keyhole satellites. Because of security classification the Hubble design had to be semi-cleanroom reengineered, but the contractors were the same and in fact many of the same engineers worked on both. The keyhole test equipment in Sunnyvale was reused for Hubble.

qq and probably no one would answer but did keyhole have the same mirror defect?

Hubble was fixed by the costar addition. I wonder if there's missions to fix keyhole we don't know about.

Well, there's been a LOT of KH-11 satellites over the years, so unlike with Hubble the NRO has had the opportunity to just put up an updated satellite instead of trying to fix an existing one.

Seriously, Wikipedia lists 5 generations. https://en.wikipedia.org/wiki/KH-11_KENNEN 5+3+4+3+3 total launches.

It is completely depressing that we got one (now two) space telescopes, and… 14 equivalent Earth telescopes.

To be fair, we wouldn't have gotten the space telescopes at all without the Earth telescopes and their predecessors.

That was the entire point of my Sci Fi techothriller I never finished writing where the plot was the HST was a declassified KH-11 and to F the Soviets over we released the declassified HST with an intentional fault so the Soviet clone would be faulty. Its a win-win because the service mission to fix the HST made the right people on our side extra money, but the Soviets didn't have a working-enough space-truck to fix their clones of the HST/KH-11, and we were certainly not going to volunteer to fix their KH-11 clone for them LOL.

It was never going to be a good book plot so I gave up on it. Unrealistic that they'd steal "everything" including the intentional mistake. The idea of a double agent plot where "their guy" was actually "our guy" who made sure they stole the entire lot including the intentional grinding error was, um, cringy. In defense of my bad novel plot, I was young at the time, and I've read worse books.

I always thought that Hubble in fact was a declassified KH-11. And indeed the NRO declassified and donated a couple more obsolete Keyholes to NASA in 2012 [1], one of which is now being used as the chassis (and optics?) of the NGRST [2].

[1] https://en.wikipedia.org/wiki/2012_National_Reconnaissance_O...

[2] https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telesc...

Well, it wasn’t. This is pretty well documented. It has pretty much the same design requirements and even some of the same contractors, but it also differed in key ways. It had a totally different instrumentation board, optical packages, and was built for servicing which KH wasn’t.

The fact that it was the same form factor is not an accident, as Hubble was sized to fit in the shuttle payload bay, which was itself sized based on keyhole.

Hehe, see also: "the Zenith Angle" by Bruce Sterling (he did complete his book).

https://space.stackexchange.com/a/58290 lays out some evidence that Kodak built similar mirrors for the KH-11 spy satellites, while Perkin-Elmer was selected for Hubble (and had built smaller mirrors for other spy satellites).

I can’t speak specifically for keyhole, but I know that Kodak definitely worked on spy satellites. My father worked there and on them.

Early spy satelites even used film; I remember reading about one design that took a film picture, developed, and then used a CCD to scan it and send it back to earth, which is a bit mind boggling to me.

The ones my father worked on used film, too. But I do not think they were developed in space. All I know is a canister was dropped and intercepted (caught) by a passing jet. I don’t see why it would be developed or scanned in space. Just drop the can of exposed film and develop on the ground. Scanners in the 60s? Film chemistry in space? Why?

Maybe I'm misremembering the spy satellites using this (keeping the images secret is harder is you transmit them), but Lunar Orbiter 5 worked this way, so we had the technology in the 60's

[edit]

The lunar Orbiter used an adapted E-1 camera from SAMOS. The E-2 and (canceled) E-3 also used the semi-dry development process and photomultiplier readout method.

It would be interesting to know about the scan out piece here.

The idea makes sense to me, generally, in that film is high res, high speed, can have a fadt shutter. Given where digital computers & imaging were, the idea of turning digitization into a batch slow process decoupled from capture makes all the sense in the world.

> Just drop the can of exposed film and develop on the ground. Scanners in the 60s? Film chemistry in space? Why?

Can't say about recon sats but there are two reasons:

a) you need things fast

b) you can't drop it - you are too far

As sibling points out Lunar Orbiter used this and IMMSMV - some Soviet space probes (Venus?) too.

> Scanners in the 60s?

In the late 60s - just fine. Don't forget, TV existed back then already.

> In the late 60s - just fine. Don't forget, TV existed back then already.

E-1 SAMOS launched in 1960. I was wrong about it using a CCD though, it used a photomultiplier.

https://www.damninteresting.com/faxes-from-the-far-side/

No, that was a manufacturing mistake not a design error. A different contractor was used.

From what I remember, the defect was a manufacturing defect, not a design flaw.

Some chipped paint meant that a critical distance was extended by the thickness of the paint layer.

The defect was a huge deal for a long range telescope because the distortion makes up a larger part of the image the further out you go.

At Earth to spy satellite distances, it's like 1/4" and probably below the resolution of the camera used at the time.

I read somewhere that the mirror defect was specific to Hubble, because it was designed to focus at infinity while the Keyhole mirrors focused at 400 miles or whatever is orbital height. So it had a different curvature but the custom grind rig for that modified curvature was constructed erroneously. There is definitely public discussion of such details if you dig.

From Cliff Stoll's excellent The Cuckoo's Egg:

“With a ninty-four-inch telescope in space, we’ll be able to see phenomenal detail on planets,” I remarked.

“Just think what you could do if you pointed it at the earth,” Greg said.

“Why bother? All the interesting things are in the sky. And anyway, the Space Telescope physically can’t point to the earth. Its sensors will burn out if you try.”

“What if someone made such a telescope and pointed it to the earth. What could you see?”

I fiddled a few numbers in my head. Say, three hundred miles up in orbit, a nintyfour-inch telescope. The wavelength of light is about four hundred nanometers.… “Oh, you could easily see detail of a couple feet across. The limit would be around a couple inches. Not quite good enough to recognize a face.”

Greg smiled and said nothing. It took a while, but it eventually sunk in: the astronomical Space Telescope wasn’t the only big telescope in orbit. Greg was probably talking about some spy satellite. The secret KH-11, most likely.

Great book!

From Wikipedia:

> A NASA history of the Hubble,[24] in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter (94 in) design, states: "In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites".

This, to me, says that KH-11 came first...

>so we need a "space truck" to keep up with rapid changes

Check out Space Truckers, with square pigs, because they pack so tightly!

https://www.youtube.com/watch?v=ReKKdeDpb8A

https://www.youtube.com/watch?v=_zcBjI9N0rI

https://www.youtube.com/watch?v=G8Ifaeff0mA

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