Friday, October 30, 2009

UAVs vs cruise missiles

I was attending a presentation yesterday and they had a bullet about how using UAVs on a carrier to strike targets would provide cost savings over cruise missiles. My gut said "really?".

So I did some quick analysis about that issue during the presentation.

The assumption is that you wanted 1000lbs of explosive delivered to a target and that you want to maximize the deliveries per dollar spent. Assume you already have a carrier and personnel. Costs are procurement cost for the cruise missile (BGM-109 Tomahawk @ $569,000) or the procurement cost of an F-18E or F-35 ($54,700,000 and $83,000,000 respectively) plus the cost of a bomb (GBU-31 $73100 (MK-84 $3100 + JDAM Tailkit $70,000)) for each use. These costs are from wikipedia and may not be accurate. Feel free to substitute your own numbers. (I for one, do not trust the F-35 data, but I digress) (I used numbers off the top of my head during the presentation, they were fairly close to these numbers)

Assumption: Cost for a carrier UAV will be comparable to a F-18E or F-35. Again, the numbers aren't terribly important, we are just trying to get a feel for how it works

Assumption: ~1000lbs of explosive delivered by a Tomahawk is roughly equivalent to ~1000lbs of explosive delivered by a JDAM. Therefore, we will find the cost for the same # of deliveries.

Assumption: ~80 Aircraft per carrier (could be more or less)

[Cost for Tomahawk option] = [Cost per Tomahawk]*[# of deliveries Tomahawk]
assume: There is enough room for all of the Tomahawks on a carrier (may not be true).

[Cost for UAV option] =
[Cost per aircraft]*[number of aircraft on a carrier] +
[cost per JDAM]*[# of deliveries UAV+JDAM]

Setting the costs equal to each other (so that we can know the "tipping point" where it is better to switch from uav+jdam -> tomahawk or vice vera) and # of deliveries too, we find that that occurs when
[# of deliveries] = [cost per aircraft]*[number of aircraft on carrier]/
([cost per Tomahawk]-[Cost per JDAM])
And [Total Cost] = [#deliveries]*[cost per Tomahawk]

Using the provided numbers,
[# of deliveries low uav cost] = 8825
[# of deliveries high uav cost] = 13390
(note: Original estimate in presentation was 8000-16000 (low-high), so back of the envelope works)

So, going mid-way, about 11,100 deliveries for equal cost. If there are more than 11,100 deliveries wanted per carrier, then we should go with UAV+JDAM. If we envision less than 11,100 deliveries per carrier, then we should go with the Tomahawk. (based on all assumptions, and hand waving away all other things like storage cost, personnel, range, surge sortie rate, etc)

For comparison, if all of the tonnage dropped in Desert Storm was 2000 lb bombs, that would have been 121,248 bombs (not sure I did that right, I considered 1000lb of explosive, but I think it needs to be normalized to tons of TNT?). That would mean about 10.9 carriers of that load.

I don't think that you can fit 11,100 Tomahawks on a carrier, but I think it might be able to handle the weight (not spending time to find out).

Monday, October 26, 2009


In the vein of keeping this blog classy, Mike sent me this image of his captcha that he had when submitting his comment.

Good weekend

I had a good weekend. On Saturday we got some product exploration done (cars) and had some good pizza.

Sunday was reading before lunch, pancakes, groceries, ham & cheese sandwiches.

Then we went running at Cochran Shoals Trail, and hiked a bit in the woods. We saw a lot of wildlife, plenty of chipmunks and squirrels. I found two nuts (walnuts? maybe a type of hickory?), and called a squirrel by rubbing them together. He was pretty excited about it, so I'll have to try that again.

Melted/Poured some lead for a project that I am working on. I also painted the solar heater, we will see how it goes. I figured out why I wasn't figuring out when the sun comes into our windows... its because in the winter, it never does! That might hurt the solar heater's chances...

Pics to follow of the solar heater, I have been saving pictures of the assembly.

Wednesday, October 21, 2009

Waterproof and Wireless keyboard/mouse/screen

I pen a great deal of blog posts in the shower, but promptly forget them as I am drying myself.

Since I already thought about the topic, my brain checks it off as "done".

Thats why you guys don't get any blog posts!

Thursday, October 15, 2009

Dog Scare

I went running with my wife yesterday. As we were cooling down (walking) back to the house, we ran into a mean looking (bit bull + rottweiler mix (just think mean, I don't know the breed) (90lbs?)) dog at a natural choke point [so yes, I got ambushed, smart dog]. To get to our house, we have to go through a 2-car wide section of the road (which was 1 car wide due to a car being parked on the side of the road), which then opens up to a cul-de-sac ish area.

First instinct, pat left hip. No knife. Check pockets. (1) key, (1) music player. A key it is (stab in the eye if attacked?). Dog is acting agressive, all we want to do is get by. I figure that the dog is just scared and does not know what to do next. I ask my wife to back away, putting myself between my wife and the dog. I cautiously try to walk past the dog,

He lunged.

I turn to run, yell "hey hey hey" (very short/loud), and stomped with my right foot(I suppose in preparation for hard core fast running). He stopped, and backed away a bit.

Got my bearings.

A ha! so he was just scared and didn't know what to do with us. I would walk about 2 ft, the dog would get nervous, and be about to growl. I would stomp, yell "hey", and he would back up two feet. We basically repeated that for 30 ft or so until we were past him.

Then, when we were about to get into our house, he runs up and starts barking at a dude trying to get into his car, he dives into his car quickly and makes sure the door is shut.

Anyway, I was fairly mad when I got into the house. First I was like "if I had a P3-AT (Santa, a blued finish would work), I could have used it". Then I thought about that. I don't think I would have wanted to shoot at the dog with the intent to kill it. Next I was like, "well, I could have shot into the berm and scared it". Which I figured was the best option if you were using a gun. Next I thought about well, I could carry a baseball bat/stick (heck, an old lady that runs on our route carries a big axe), but the more I thought about that I realized that I didn't want a dog close enough to me to cause me to be able to use a bat or a stick.

As I was going to sleep, I came upon what I think to be the "best" answer (open to discussion) for that situation. Pepper spray would have been pretty effective, non-lethal, and light. Discharging a firearm like that would not have been very fun to deal with. A stick lets the dog get close, and you better hit it hard. Taser... I have no experience. From the interwebs, some people say pepper spray works, some say it doesn't. I am not going to test it on any dogs I know, so .. hmm. I think it would work on a dog that was just wondering about you but being aggressive. If it was set on biting you, I don't know what you could do to stop it. I had an idea about a good flashlight, but seems that is hit or miss too. The flashlight is something I could test though.

There have been free ranging dogs in the cul-de-sac before, but this was different. There used to be a big white dog, looked like a wolf, but when it came up to you, its tail was wagging. I wouldn't promote random dogs scaring people, but wagging tails is a good thing and can be forgotten. An aggressive dog that blocks free transit in public areas is a problem.

I think I was thinking about this alot because I still don't know what I *would* have done if I had some sort of firearm on me. I also don't know what I *should* have done (they are different).

In retrospect, we should have just gone around the building. Picking a fight with a dog is stupid.

Sunday, October 04, 2009


Yesterday I went on a quick hike at the East Palisades with Curtis and Dane. I met some guys that had a good tip about some off-trail ways to go that had some awesome views. I am going to try it next time.

I baked some bread, to test out this ceramic pot thing that we got.

Pretty tasty, I had it with beans last night (I needed the can for parts for my camping stove), and this morning with some eggs.

I started making the columns for the solar heater, I'll post pics in a separate post when I am done assembling the first panel.