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Progeny Mk4 Launch Analysis
After an entire day studying the telemetry data (basic Tlm) and launch video from the first launch of the Progeny Mk4 yesterday, engineers have reached the tentative conclusion that high dynamic pressures caused the tanks in the liquid fuel stage to either collapse or break free of their internal mountings and trigger an explosion when the two propellants mixed. They still have not completely ruled out some sort of malfunction with the engine itself during combustion, or perhaps a combination of these two factors, but they do feel that high levels of dynamic pressure are the main cause. The third stage’s structural integrity was probably compromised during the second stage boost and only held together until separation occurred. This failure however isn’t really a setback, because we purposely threw as much dynamic pressure at the rocket as possible in order to test theoretical stress limits of the rocket’s various components. We are now pretty sure that those theoretical limits have been exceeded in the case of the liquid fuel tanks.
In order to make sure the engine wasn’t an issue during flight, we will be static-firing the second one on the launch pad early next week to ensure that it is performing at the expected levels of thrust under various throttle settings. Since these engines are not designed to be lit off more than once, it will take another two days to refurbish & replace the ignition system before it can be integrated into the stack. We’re aiming to launch NET May 30th.
This next launch isn’t going to make things much better for the rocket either, because now that we know how fast not to go in the lower atmosphere, the question remains how fast can we go in the upper atmosphere? Once the air starts to thin out the rocket can really begin to accelerate and the lack of air to transfer heat away means that thermal build-up is a serious concern that will need to be managed. First though we need to find out where the limits are. We will be switching to a normal launch profile for the second launch, coasting between stages, to ease up on the dynamic pressures early in the flight. The third stage will fire at full thrust for its entire duration and the rocket will either burn itself up or make it through intact and possibly off into space.
First New Civvie Delivered
Although his return was delayed last week by a storm, Jeb was finally able to take delivery of our newest Civvie aircraft and fly it back home, following the same route he took in the Prototype, although he made a small mistake on one leg. When we accept delivery of our third Civvie next week Val will fly the same route yet again but at a higher 4km so that Genesis engineers can do a comparative analysis of both flights to study the performance of the aircraft. The second Civvie was put to work straight-away the following day on a joint mission with KerBalloon and Jeb is very happy with the new cockpit avionics, which are currently being installed in the original Civvie production model that was built here in the HAB.
Record Week for KerBalloon
In a flurry of activity the KerBalloon teams, including Specialists Bill & Bob, carried out a record 4 missions this week, 2 over land led by Bill and 2 out at sea led by Bob.
Bill, being the land-lubber of the two, took charge of the recovery efforts for the latest joint KB/Genesis mission, which went off without any troubles although the balloon only reached a height 2.2km above the contracted altitude at which data collection was to begin, so that wasn’t much of a payout from Bloeting. They then had to turn around the next day and run another mission 44km north on the other side of the bay to launch and recover another high-altitude balloon, this time with a much better ascent to nearly max altitude.
Meanwhile, Bob was out at sea taking care of two high-altitude contracts of his own, the first which was delayed from last week due to the storm at sea & Tongjess’ engine problems. Due to part shortages, after recovering that payload he and his team had to spend several hours removing the control unit and attaching it to their second payload for launch on another mission. Both were successful, with the second payload reaching max altitude of 24.9km.
Everyone is happy but exhausted! Additional KerBalloon units arrived this week but we don’t expect the pace of missions to pick up any more than this. 2 more contracts were signed today, with additional proposals forthcoming.
ATN Database Update
The weekly update for the Asteroid Tracking Network database was posted here. It contains now a total count of 570 asteroids. This past week two Class-C asteroids were discovered to have perikees within Kerbin’s atmosphere, which means they are not on a direct course for impact but will at least graze the planet. It is likely however that upon atmospheric entry they break up and hit the ground if any pieces are still intact. Both events are currently plotted to take place on the opposite side of the planet, so there is no immediate danger. More information will be released after observations have been taken of the asteroids within our SOI on 5/23 and 6/20.
Celestial Snapshot of the Week
Bob is gradually becoming Val’s equal in astrophotography skills and proved it this week with this great capture of Jool while Tylo and Vall are transiting together. Jool is slowly setting lower and lower at sunset, soon it will be out of view for a few days as we pass through conjunction so both Bob & Val have been waiting to get a shot like this before it dropped too low on the horizon.
From the Desk of Drew Kerman
Out of Character Behind the Scenes stuffWritten on 5/10/17
Okay so 8 days of work for 7 days of KSA – I think that’s pretty good considering how much crap I managed to cram into those 7 days. Holy shit what the hell was I thinking?? This is the problem with having such a short lead time, I don’t really take any time to properly plan things out because I feel so rushed to get things done. I have to be extra-extra careful about things too because I don’t have the liberty of realizing I made a mistake three weeks from now and being able to still go back and fix things before they are posted. Now I only have 9 days. But I’m taking things a bit slower these next few weeks so hopefully maybe possibly I can finally start getting ahead again?
Keeping track of parts
Speaking of not planning things, I had to do a leeeetle bit of hand-waving to make those 4 KerBalloon missions actually work with the parts I had in my inventory (see Desk Notes here). Long story short is all the parts were there I just hadn’t deployed them properly so that they could all be used. So for example, this photo is wrong because those two KerBalloons should have had nosecone chutes to free up the two remaining KerBalloon parachutes (that attach direct to the case) to be used by the aircraft drop and UTV carry missions over land. So the missions that were carried out were possible with the parts available, thankfully. I’ve further tweaked the part inventory sheets to help me get better at this.
Mk4 launch clusterfuck
I probably could have had this all wrapped up yesterday had I not screwed up the Mk4 launch so badly in so many ways. First big mistake was that I forgot I had planned to have the launch be slightly delayed, so I flew it launching at the original L-0 time of 12:45 local. Then for that launch I forgot to save the Persistent Trails data so I had to go back and fly it again. After that I finally realized I needed to delay the launch so toss everything out and start over with the new L-0 time of 12:54. Okay, get that launch in the bag but then when breaking down the rocket in the VAB to get deltaV & weight measurements I realize the thrust limiters on the boosters are dialed back. This was from me previously testing TWR settings for future launches but it wasn’t supposed to be dialed back for this launch. CRAP I need to redo the launch again. But wait – I’ve been flying this launch with coasts between stages and OH MY FUCKING GOD I’M SUPPOSED TO BE HOT STAGING THIS LAUNCH – at this point I managed to not pick up and throw things around, but I did “toss” all my launch video & data once again and flew the launch all over for a third time (really fifth or sixth time but third distinctly different launch scenario). Finally I had launch data, video and events I could actually use.
Besides all that I spent some time figuring out how to destroy the rocket with a big boom, because using the Kaboom mod only made things go poof in a bunch of smoke. I had to set the Blast Awesomeness Modifier for the liquid fuel tank to 0.5 to get a nice explosion. Of course, all that time was moot because when I finally realized I needed to hot stage, turns out the rocket comes apart on its own anyways and Ferram Aerospace Research triggers explosions on aerodynamic failures. Son. Ofa. Bitch.
So yea, getting through May 18th was painful.
More photo woes
Do you think this is a great photo? I do. I love how wonderfully detailed the terrain is and how far away the trees go. Buuuut all that comes at a steep price for my PC, which is a decent computer, but good lord does KSP terrain scatter just suck those framerates down a ginormous black hole. Yea so we’re talking a slideshow here, what I actually ended up having to do was just take a photo of the aircraft without any scatter so I could actually move and setup the camera with KerbCam. I tied its position to a static object at the airport so that when I reloaded the game I could snap right back to the same point and take another photo with scatter objects and not have to deal with moving around anything, just click a few buttons and capture the shot. Of course with the scatter objects the godrays feature of Scatterer threw off all kinds of nasty shadows so I had to go back to the main menu, disable those, and reload. It’s good I took images with/without ground scatter anyways since I had to remove some trees and grass from the runway/tarmac. Oh and of course immediately after I captured the second image with ground scatter something flipped the physics out and made the camera view tumble all other the place, so I very nearly had to reset again
But hey, I really like the photo.
Also, even with the flat runway at KGA I still couldn’t get the Civvie to take off properly without slewing off to the side as soon as the rear landing gear comes off the ground. Therefore I suspect the main gear alignment is off, but I haven’t taken the time to look into it yet.
More batch file improvements
Added some more code to my batch scripts that move files out of GameData to slim down my install for various purposes. This code checks to ensure that no other folders are present in the Holding folder I use to temporarily store these files:
for /F %%i in ('dir /b /a "D:\Steam Games\steamapps\common\Kerbal Space Program\GameData - Holding\*"') do (
echo Holding folder is not empty!!
pause
exit /b
)
This will keep me from possibly overwriting stuff I already have there or just adding a bunch of folders atop stuff I don’t want to be putting back into my main GameData with everything else.
Upgrading the static Flight Tracker diagrams
I finally got fed up with having to take time to create the static diagrams in the Flight Tracker, mainly because the script that automates the majority of the process was giving me a lot of fits while running, screwing things up mostly. I don’t know when the new dynamic model will be ready as the author is currently performing an overhaul, but I don’t have the time or willpower to commit anymore to the static diagrams while I wait. So last week was the last time they will be updated until the new system is implemented.
Limited twitter timelines per account
So I just finally bumped up against the limit at which twitter will allow me to create tweet timelines for my KSA account. I was afraid there might be a limit, which sucks but thankfully when I embed timelines into the website you can’t tell what account they are hosted by, and I can use my other twitter accounts (currently have four) to create timelines that contain tweets from KSA. So really I don’t have a limit, I just need to create a new account when an account has run up to its max allowed timelines. Of course, that could eventually get me in trouble with twitter but I’ll cross that bridge when I get to it.
