Mar 29 2019

Operations Summary – Week of 3/25/19

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Ascension LES Test Successful, Next Flight on Schedule

After a full day of analyzing data from the latest Launch Escape System pad abort test held yesterday the Ascension team is happy to announce that everything worked as planned this time around. The LES fired off with a shorter-duration kick motor atop the tower to angle the capsule away from the rocket without flipping it over and thus allowing the push motors at the base to do their jobs properly and lift the capsule high up into the air, almost 400m. This arc carried it away from the pad to a distance of nearly 700m, well outside the 500m blast radius where debris might be a hindrance to recovery crews. This video shows the entire test, with close-up views of the capsule aerodynamically re-orienting itself for a clean chute deploy and jettison of the heat shield. Note the chutes deployed a lot slower this time, which is done when possible to reduce stress on them and the occupants of the capsule, which did not exceed 5Gs.

Now that the LES is proven to work as intended, we can test whether it will still work even if the kick motor atop the tower fails. Under this scenario one of the push motors will fire off first before the rest just enough to angle the capsule off-center. This is important because if the capsule is released mid-flight and doesn’t steer clear of the rocket, an impact could be catastrophic. We’ll be setting up for another test at the end of next week.

The newest Mk1 capsule arrived on schedule today which means the overall schedule for the next launch attempt remains on track as well. We have to do our own quality assurance checks on the capsule to make sure it was built properly and then will be able to begin integration and lock in a launch date for later next month, still no earlier than the 16th.

Genesis Mission Attempt Fails Due to Weather

Thanks to a training accident that damaged the capsule simulator (no injuries to the crew) Jeb & Val had some free time to attempt a Deuce mission that had been in limbo since the C7 fiasco developed late last month. Unfortunately although they tried their best weather got in the way. First when they spotted lots of lighting from a storm over the sea along their route they diverted towards land. After clearing the storm they returned to a southerly course but hit some severe turbulence that forced them around some mountains and to a wide pass where they also experienced wind shear. By now they were well off course and running low on fuel so they had to head back to KSC. Weather over the cape the following day prevented their departure and after that the capsule simulator was fixed and it was back to astronaut training. If they free up again or if the C7 situation is resolved another attempt will be made in the future. Speaking of the future, we look forward to the day we have weather satellites that can tell us when a route to destinations far from KSC isn’t clear to fly!

ATN Database

The latest update for the Asteroid Tracking Network database is available here, containing 3,350 asteroids and 3 updated with new observation data. Here are the 36 asteroids that were discovered this past week:

From the Desk of Drew Kerman

Out of Character Behind the Scenes stuff

Written on 3/26/19

Ok so fell behind a bit once more thanks to another bout with depression over the past weekend but let’s not dwell on that because I’m over it again and shit gone done this week. Let’s dive in:

Alaba radar images

Anyone still around from the original KSA run? I’m guessing it’s not too many so I didn’t feel bad recycling the “radar images” I made back in like 2015 or something. Basically what I did was capture images of an asteroid from several angles and apply some blur and pixelation filters to it along with a noise filter. For reference, here’s a real radar image made by Arecibo. So no, that image is not actually of Alaba, but to be honest even if I did post photos of the real asteroid that represents Alaba I doubt anyone would be able to tell the difference. I’ve got a few more made from back then also I have in the wings waiting to be shared. For some of those, the mod Persistent Rotation added a feature (at my request) that sent all asteroids tumbling a bit, which unfortunately no longer happens in the latest update to make it compatible with recent KSP versions, but swinging the camera around for different angles still works.

Deuce flight

Still had trouble getting myself up for doing all the work needed for an aircraft flight, so still not ready to really get back into aircraft and the C7 saga will continue a while yet. In fact after I spent the 30-40 minutes it takes to just get ready to taxi out to the runway the aircraft was bouncing around on its wheels and I was sure it was going to spin off the runway on takeoff and I would rage quit the fuck out. Thankfully it all went okay. Well, almost.

You may recall a previous desk notes where I talked about how I implement non-rechargeable batteries and how for some reason they weren’t working on the Dhumla but did work fine on the Deuce and Civvie. Well now it seems they are broken on the Deuce as well for some reason? This is only really an issue around takeoff and landing since the engines are throttled back and not enough alternator power is generated. I am recording the screen at that point though so I can see how far the 25EC regular battery (which acts more like a capacitor) on the aircraft is drained and subtract that amount from the total battery capacity of the aircraft, which I keep a log of.

After the mission I needed a photo of the aircraft departing but for some reason I couldn’t get the runway lights I had placed with Kerbal Konstructs to show up anymore. I knew that KK had recently updated its configs for object placement so I though maybe they had gotten updated wrong and tried rolling back a few versions of the mod and the config files (back up yo shit!) but that only seemed to make things worse cause other statics started to not show up. So finally I resigned myself to having to having to take the time to place them again (ugh ugh ugh ugh) but when I went to try to do this I realized I couldn’t find them in the statics list to choose from. WTF?? That’s when it finally hit me  – I had installed Making Less History since I last needed to have the runway lights visible (they don’t turn off during the day so I usually just have their config disabled). This caused the runway lights to fail to load entirely when the game started up since they come from the expansion pack’s desert launch site. Geeeeeeeezzzzz

Also that night shot of the mountains was taken without Scatterer, as for some reason it was putting the horizon haze in front of the terrain so the mountains were not properly backlit by the dawn sky. It’s also a composite shot since when I position the aircraft for the photo it’s not moving, which means if I want to show the speedometer the needle will be at 0. So after taking the shot I just let the aircraft drop and snapped an image when the needle reached the proper speed, then stuck that over the inactive gauge of the original photo. Also took a zoomed-in photo without the dash before dropping in case the composite didn’t turn out well.

LES test

As mentioned after the last test, I had a plan to fix things and the plan was simple – clip small SRB motors into the LES and just use those instead. As it so happens, Internal RCS just recently came out with a new release that has a perfect small SRB model that I was able to use. I was able to make 25% fixed-scale versions of the part through ModuleManager configs for the push motors, and the kick motor was reduced by Tweakscale. This meant the push motors retained their thrust power while the kick motor is less-powerful. Overall the total thrust is only a few kN more than what the actual LES tower motors were putting out, with a similar burn duration as well. The only real issue once I got the motors tweaked to produce the desired separation were the engine plumes. However I replaced them with some custom RealPlume configs to match what the original LES tower motors looked like.

So the added bonus of getting a LES that behaves the way I want it to just by lighting off all the motors is that I also have individual control of all 5 SRBs through kOS. This lets me not only try things like the upcoming LES test that will simulate a kick motor failure but also in some cases just purposely refuse to light the kick motor and only use the push motors instead. For what? That will be revealed during the first capsule launch test…

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