replica LLRV Flying Bedstead, Stock+, Krakentech, Ejectionseat

[DasValdez]

In honor of the 50th anniversary of Neil Armstrong's safe ejection from the Lunar Landing Research Vehicle, I put one together in KSP. 

The LLRV (and subsequent LLTV (Training)), were created to allow Apollo lunar landing pilots a way to practice landings without leaving Earth. The coolest thing (I didn't know) was that the central jet engine wasn't actually controlled by the pilot... it was on a separate mount with massive 20 degree plus gimbal, and automatically controlled to maintain a vertical orientation, even when the main frame was tilted 20+ degrees. This allowed the jet engine to be throttle to provide only 5/6 of the thrust needed to keep the craft aloft... effectively simulating the 1/6 Earth gravity of the moon. 

The remaining 1/6+ thrust had to come from main rocket engines, mounted on the tilting frame, to simulate the actual control and design of the lunar landers. Pilots used RCS to control the attitude (pitch, yaw, and roll) of the frame, and main rockets... the jet engine simply made it "weigh" 5/6 less than it really did. 

Album /a/ttZWDqS will appear when post is submitted

The LLRVs were limited by the available thrust of the central jet engine, and had be be balanced front to back so the craft could VTOL without flipping out.... If you build VTOL craft, you know what I mean. RCS Build Aid is your friend!

Luckily, the designers included an ejection seat in that limited mass. As the LLRV was in no way suited to gliding, if something went wrong, there needed to be a way to get the pilot to safely. Even at 2.5 million bucks a pop, preserving the pilot was far more important than saving the machine. Totally doable in Kerbal, and the same balance rules apply. (There are lots of ejection seat outtakes https://www.twitch.tv/dasvaldez/clips

 

To make all this work in Kerbal, there's a simple krakentech bearing in the middle, which separates the jet engine structure from the rest of the frame. The Jet engine has fuel, a probecore, and plenty of intakes, and is is throttled down to .83 TWR (5/6 G) and set to SAS hold radial out before decoupling. The jet engine continues to fly vertically, holding up 5/6 of the weight of the craft... and the TWR < 1 makes it fall, so the pilot has to control the main frame and use rockets to account for the other 1/6th. 

You can download the craft from KerbalX.. best flown out at the Dessert Airfield if you have it.

https://kerbalx.com/KSpaceAcademy/KSA-X-KLLRV

Entire build is on Twitch, which is half ejection seat shenanigans, if you've got 5-6 hours. 

Enjoy!

 

Edited May 9, 2018 by DasValdez
Imgur Album fix? Maybe?

[Gilbershaft]

Amazing work as always!

[DasValdez]

7 hours ago, Gilbershaft said:

Amazing work as always!

Thanks! Was a really cool build... Crazy Kerbal Contraption IRL! 

[Majorjim!]

This is the second best LLRV replica Iv'e ever seen. Great work matey!

I'm very impressed you got the gimbal-ing central motor man, thats the icing on the cake right there.

Edited May 10, 2018 by Majorjim!

[DasValdez]

On 5/10/2018 at 7:52 AM, Majorjim! said:

This is the second best LLRV replica Iv'e ever seen. Great work matey!

I'm very impressed you got the gimbal-ing central motor man, thats the icing on the cake right there.

Haha, thanks... I'm personally a big fan of the ejection seat too.

[klond]

 I have a question. 

 Say I split a craft that has advanced SAS features turned on, like radial in or out.  When I tab back and forth between the two craft the SAS features don't stick.  Whenever I flip between it's turned back to default SAS (hold position).  The question is - How did you get your advanced SAS feature to stay on a craft you weren't tabbed to?

[fourfa]

@klond in my experience the SAS mode does stick, if the craft's probe core supports it.  Or the Kerbal's skill level (depending on settings)