Wednesday, October 24, 2007

Missing Iniki

Me with a months-old Iniki
A grown-up Iniki with our friend Carol.

Iniki was really gentle and had a very soft mouth. She could eat anything out of your hand without bothering you in the slightest. If the kids bothered her she would lick them until they stopped. She was more of a snuggler than Bailey.

When we were out walking, Iniki always greeted other dogs with a bark, a lunge, and her tail held high. Other dog owners didn't always interpret this as friendly, but Iniki certainly meant well.

I remember once hiking downhill from Schilling Lake with the two dogs and Martha. I think we had just Anya with us. Iniki disappeared over the edge of the trail. I looked over the drop and decided there was no way I was going to try that, so she'd have to make it back up on her own. We could hear her crashing around down there, and she wasn't coming back up, so we decided to walk along a bit, calling to her, to see if she could find a way back up.

About five minutes later there was this incredible thrashing sound that just went on and on, and Iniki eventually emerged up through the bushes, legs tearing into the soft ground, hauling the entire back end of a deer up the cliff with her. She looked absolutely as pleased as could be, tail high in the air, as if to say, "Look what I found! I swear, nobody was using it! It was just sitting there!" She dragged that carcass after us for a mile or so before we got her to let go of it.

We travelled to Mammoth when Anya was just learning to walk. One evening while there I went on a short hike with Anya and the dogs. During this hike, we travelled by a frozen lake. Bailey was timid about getting out on the frozen surface, but Iniki just charged right out. On her way back in, she got to some thin ice and fell through.

Her head and shoulders popped back up, and she started padding as best she could... back out into the middle of the ice. I think she knew she was in trouble, and she was trying to retrace her steps. Instead of going through 20 feet of thin ice directly to me, she plowed her way though a couple hundred feet of thick ice. The entire way, she would get her front paws up on the ice sheet, struggle to haul her upper body out of the water, only to crash back through the ice and into the freezing water. It took her 20 minutes or more to chop and grind a passage all the way through the ice back to the shore point where she'd first gotten onto it. Bailey and I waited there for her, me with my heart in my mouth wondering if she was going to freeze or drown. When she got out Bailey barked at her and then tackled her, as if to tell her, "You idiot! You scared the hell out of us!"

Another time, hiking above Schilling Lake, we found a recurring mudslide covering the path. Iniki smelled something in the mud, and pushed her nose into it, then her whole muzzle, and finally her whole head. I don't know what she found in there, but it was pretty funny to see this collar on the ground with a lab's body sprouting from it.

Iniki loved water. When we were out walking around, if she found something even moderately damp, she sat on it or got into it. Here she is enjoying a puddle near Blue Oaks in Portola Valley.

Monday, October 22, 2007

Iniki is dead

On Sunday, I was hiking with the family at Ed Levin Park. Our two black Labradors, Iniki and Bailey, found a rattlesnake in the middle of the path. We called, Bailey came, Iniki didn't, the snake tried to warn her off and after about ten seconds bit her on the muzzle. I'm pretty sure she was dead by the time we got her to the parking lot.

We were probably a mile up the trail, the dogs were in front, off leash, when they found the snake. I had Kathleen on my shoulders and Ava in the pack, probably about 70 pounds all told, on a pretty steep part of the trail. When I saw what the dogs were barking at (a few seconds at most), I got Kathleen on the ground headed back to Martha. Martha heard me yell "snake", and called the dogs. Bailey took off back down the trail, Iniki pointed right at the snake, her muzzle about 5 inches from the thing, barking but not striking. It struck at Iniki repeatedly while I tried to maneuver behind Iniki to go for a grab. I grabbed her by her flanks and yanked. Martha thinks the snake made contact right then.
I should have dropped the backpack with Ava immediately, and then advanced on Iniki. Had I done that, I might have figured out that I could seperate Ava from the pack and then use it as a projectile. With Ava in the pack I was more awkward.

My brother-in-law says the snake's strike range is about 2/3 of their body length, so I was probably in range when I went for the grab -- not very smart. And I screwed around too long setting up the grab. I basically only asserted myself when the snake started striking.

Martha thinks Iniki might have left the snake if I had moved away from it. I don't think so -- 30 minutes earlier she was barking her head off at some dogs on the other side of a fence.
Iniki was a tough if gentle dog. She only whimpered a bit once I had her seperated from the snake. I had her over one shoulder within ten seconds of the bite, and headed back down the trail. At this point I was carrying over 100 pounds on a trail, and I could not run.
Again, I should have dumped Ava with Martha as I passed her. Also, there were several other people within 100 feet. I could have gotten a volunteer to run down the trail with me, trading the load. That would have made a run possible, and also made it possible to check Iniki's airway as she started barfing.
I think the snake bite was very serious. Iniki was barfing and pooping within 2 or 3 minutes, and was unconscious within 5 minutes. This site suggests that death comes from blood loss and then shock "within hours" -- and we just weren't on that schedule.

I made it about halfway down before my arms got seriously wobbly from holding Iniki's weight. Martha caught up, grabbed the dog and kept going. She got 100 feet before she was out of gas. We put Iniki in the baby carrier backpack and I took her the rest of the way down in that. Martha noted when we put her in the pack that her whole rear end was very stiff.
The pack was much easier -- the way to go from the start. I might have been able to run had I started this way. The trouble was I couldn't see Iniki, and I was trying to talk to 911 while walking, and couldn't do that while running either.
Iniki thrashed around a bit about 30 seconds from the parking lot, which I took as a good sign she was still alive. But when I put her hin the car a minute later, I'm pretty sure she was dead.
Later, when we got to the clinic, she doc told us she had aspirated vomit and choked to death. I now think she choked just as she got to the parking lot. I should have dumped the pack and checked her airway when I felt her bucking. I'm feeling seriously bad about this mistake right now.

That said, nobody seems to think she would have made it 25 minutes longer, so I'm not sure my mistake changed the outcome.
We were on an unfamiliar side of the Bay Area. I got someone from the dog park there to drive in front of me and lead me to a vet. Unfortunately, neither she nor the 911 operator I was talking with could find an after-hours weekend vet with anti-venin. It turns out there are only two in the Bay Area, one in San Leandro and one in Campbell. It took at least 25 minutes to drive to the one in Campbell. The doc pronounced her dead when I brought her in.

The biggest question in my mind is, what if it was one of the kids? Iniki was 7 years old, 65 pounds, and unable to control her own airway within 15 minutes. Anya weighs 38 pounds and Kathleen is more like 30. To even have a chance if they had been bitten, we would have had to have an ambulance meet us in the parking lot, maybe with anti-venin, and we would have had to run down the trail. I'm not sure the ambulance folks would have time to pick up anti-venin, and I don't think I could have run all the way down the hill. 911 would have worked better, of course, and there would have been a local hospital with the anti-venin, but it still seems pretty grim.

One big overall mistake here was that I fixed on the idea of getting the dog to emergency aid (and specifically anti-venin) as fast as possible, and neglected everything else. That'll work if aid is minutes away, but if not, it's critical to be able to maintain the basic body functions of the animal (or person!) until help arrives. After reviewing the literature, it seems that anti-venin is not a magic instant cure. Instead, snakebites seem like one more thing where most of what medical science has to offer is basic life support (oxygen, fluids) while one's body fixes the problem on its own.

In this context it is sort of irritating is that the 911 operator couldn't give me basic instructions: check airway, breathing, heartbeat. Perhaps they would have done this eventually; I don't know because I had no cellphone coverage in the parking lot.

I'm feeling sad now.

Tuesday, October 02, 2007

More Lunar Hopper

Here's a specific mission mass budget:

The goal on the lunar surface is to deploy three HDTV cameras with motorized zoom, pan, and tilt. The cameras shoot stills or video, record to flash, and then send their bits to the main transceiver over an 802.11b link. The radio links require line-of-sight and fairly close range, less than 1 km. The camera and radio are powered-down almost all the time, and the onboard battery has enough juice for perhaps five minutes of camera operation and maybe 20 minutes of radio time.

Each camera sits on a little post with three legs and an anchor that secure it to the lunar surface. The anchor is explosively shot a foot or so into the lunar dust, and then a spring-wound mechanism tensions the hold-down string. The hold-down string is to keep the rocket plume from blowing the post over when the lander jumps.

The mission is to land somewhere with a good view of the surrounding terrain, deploy one camera, look around a bit, upload pictures/video, and let mission control find somewhere interesting to hop, then jump there and deploy another camera. Then do that again. Then do a third jump, after which we just use the camera on the jumper. The idea is that the first and later second cameras can get video of the jumper taking off and landing, then send that video back to the jumper, which sends it to Earth.

The camera weight with zoom and pan/tilt sets the mission weight. I don't know anything about spaceflight-qualified hardware, but I've looked at the MSSS web site like many of you. A little Googling around makes it look like pan/tilt heads are pretty heavy, but these are designed for Earth weather and Earth gravity.

HD Video/still camera500 g4 watts
Zoom Lens650 g0.5 watts
pan/tilt head500 g0.5 watts
5 foot post and three legs400 g
explosive anchor and spring reel500 g
battery200 g
radio/computer250 g
total3000 g

Two of these, plus a pan/tilt on the lander are going to be about 8 kg. My guess is that the lander's radio link will be about 4 kg, and the dry mass of the vehicle necessary to land all this will be another 18 kg for a total of 30 kg.

Descent from lunar orbit, landing, and two more hops will take 2000 m/s delta-V. If we're using a N2O4/UDMH hypergolic motor with 2500 m/s exhaust velocity, then we'll need 37 kg of propellant when in lunar orbit.

I think you want to do the earth exit burn, lunar orbit injection burn, and descent and hopping all with the same motor. You do it with drop tanks, which probably get blown off after the first lunar deorbit burn. This gets the mass in low earth orbit to around 400 kg, which is well inside what a Falcon 1 can lift from Omelek.

Monday, October 01, 2007

Lunar hopper?

So, yeah, I work for Google, but I have no specific knowledge of the Lunar X Prize. I just took a look at their home page, saw the brief summary of the rules, but didn't find a complete draft. It looks like they are going to revise the rules a bit after some feedback.

Here's what I've been thinking: if you want to land on the moon, look around, and then get close to something else and take pictures of it, you don't really need wheels, because you've already got a rocket that knows how to land.

In the moon's soft gravity, it takes fairly small amounts of delta-v to jump a long way. In the moon's 1.62 m/s^2 gravity, you can get 50 seconds of flight time with a 82 m/s delta-v. Use some more delta-v to go sideways, and a bit more to manoever for the landing, and you could cover 500 meters with about 100 m/s of delta-v.

Landing from a lunar orbit takes 1600 m/s of delta-v, so adding a few hundred for a few hops is not a huge increase. Yes, it's exponential, but if done with LOX/kerosene or hypergolics, a 2000 m/s total delta-v budget for the lander implies a very reasonable mass ratio.

Why hasn't it been done before? Multiple rocket hops would have been stupid for the manned mission, because the landing was the highest-risk portion of the mission. It's still the highest-risk portion, and the lunar hopper idea stands a very good chance of crashing one of it's landings. But that's okay, because after a few hops the thing will run out of gas and be dead anyway.