Comments on: Telemetry or Guidance?

By: Ithi

Ithi — Sat, 06 Mar 2010 11:49:46 +0000

As a side note to the start of your article, it is no wonder that Heinlein could theorize at that time so credibly. He was an engineer, after all, with creative patents to his name.

By: bts

bts — Fri, 05 Mar 2010 17:16:39 +0000

I was wondering if this has anything to do with the location of the launch pad which is in north of Iran?

It would be safer to launch from the south, near the sea of Oman, but I guess Iran wouldn’t have much control over the rocket.

A north launch is more daring. Even if the rocket has its own fancy guidance system you still want some control. At least a nice big self-destruct button just incase! Maybe it wasn’t much of an issue with Safir but future rockets will be more massive and a bigger concern.

By: Geoff Forden

Geoff Forden — Thu, 04 Mar 2010 23:15:46 +0000

I don’t think that radiation hardness is an issue for computer guidance during powered flight. After all, computers in space typically experience about one cosmic-ray-induced error per 256 megabytes of RAM per month. That might be important for a satellite, but it doesnt seem to me to be an issue for a booster guidance system that only operates for 5 to 10 minutes.

My impression is that surviving accelerations etc. is a bigger issue for space-qualification of such equipment. But the real issue for Iran, or any country trying to develop guidance systems, especially when they are familiar with SCUD-type guidance, is gaining the experience necessary to utilize a digital computer. Iran—if it is proceeding as I think it is—is making an incremental step in that direction.

By: no_name

no_name — Thu, 04 Mar 2010 19:20:41 +0000

I don’t know much about this field, but I am assuming (and please correct me if I am wrong)that radiation would present a problem with regards to interfering in the circuitry by the induced unwanted noise (whose power’s magnitude I am not sure about).
Is there no way to shield the electronic circuitry (CPU and all other pieces on the boards) by putting the whole circuitry in a shielded compartment rather than necessarily using especially designed components? Is this even a practical approach for space applications?

By: wasd

wasd — Thu, 04 Mar 2010 11:36:18 +0000

Suppose Iran wants more advanced digital control of its missiles, how high would they have to get before they would have to start worrying about radiation hardening, and where would Iran get rad hardened CPU`s and parts?

By: Geoff Forden

Geoff Forden — Wed, 03 Mar 2010 20:41:38 +0000

Andrew, I really appreciate your insightful comments about the circuit board but I want to emphasize that it is an Iraqi pitch programmer and I am only using it as an illustration of how some countries have stayed with analog as opposed to moving to digital controls. That said, I will try to post a larger version. (Though you can find an image of it in the UNMOVIC compendium.)

A slightly larger images is here:
http://www.armscontrolwonk.com/images/1747.jpg

By: Andrew Tubbiolo

Andrew Tubbiolo — Wed, 03 Mar 2010 20:20:22 +0000

The PCB looks very 80’s. The 14 pin plastic DIP next to the large green cap/res looks like an old TI series 74XX series boolean function chip. To the left of that seems to be a UV erasable EPROM chip. Perhaps a digital form of the old cams that used to provide the pitch program. Next to that is a 16 pin DIP with a yellow label on top. 16 pins rules out a byte wise line driver or buffer. Above that lies what looks like a power supply. Something that sources a lot of power. The cans “silver cylinders” are probably the output emitters for various power/signal sources and the To-220 packages along the top are regulators with pots (variable resistors [blue boxes] along the top.). This is not flight hardware. Look at that TO-220 mid picture below the tall metal/ceramic cans. That’s a drop in kludge and is not included in the layout. Not to mention the method of mounting is not consistent with a high g mounting.

Along the ‘cam’ idea this could be a board where addresses come in from offboard to clock out the EPROM to provide the current value for vain position. The power electronics above above might be for an actuator. However I don’t see beefy enough parts to power a jet vain. So maybe they power an actuator that then actuates the real part?

This is interestingly crude. I expected more from a program of national scale. The garage operators from Texas and California, Armadillo and Masten Space Systems are far more advanced than this.

Another question, is that Cyrillic in the lower left hand portion of the BCP? Is there a higher resolution image of this somewhere?

By: Cheryl Rofer

Cheryl Rofer — Tue, 02 Mar 2010 22:03:04 +0000

Back in the days when the SCUDs were first developed, the Soviet Union leaned heavily toward analog computers for pretty much everything. And the US looked at them, too, particularly for applications like process control. There’s a great deal of sense to using inputs like temperature and acceleration directly to give you the conditions you’re looking for.

At the 1959 Soviet exhibition in New York City, some smartass friends and I harassed the poor exhibitors in the computer section about the superiority of digital over analog.

Little did we know…