Ship to ship kinetic energy transfer test report.

[Galane]

When some junior engineers at Alan Aerospace Recycling and Packaging were found goofing around with a couple of old command pods, building escape towers and using parachutes of all things, they were re-tasked to a new project request that had recently been found under a baloney sandwich in the engineering department's In tray. (Our Chief Engineer was especially incensed that the junior engineers' escape tower designs *worked*.)

The paper, headlined "Armed Camp", requested a design with four 'modules' to be propelled at high speed for transferring kinetic energy from one ship to another. The purpose of the energy transfer was stated to be for "High pressure concentrated on a small area for the purpose of rapidly disassembling spacecraft.".

The amount to be paid for the test was enough to fund the build of a kinetic energy transfer module (hereafter KETM) separation test fixture, several sets of four KETMs for testing, one vehicle to receive the energy transfer and one vehicle to deliver the final set of four KETMs to orbit and rendezvous with the receiver vehicle (hereafter RV) - with enough left over for a massive barbecue and luau for the entire staff.

The KETM carrier vehicle (hereafter CV) launch to a 75KM orbit was uneventful, AARP having learned from its previous vehicles how to build a rocket that will stay together.

The first launch of the RV was not uneventful, during SRB separation the Rockomax 64 tank inexplicably exploded. The upper stage was lit and the vehicle very nearly made it to orbit then was allowed to crash into the ocean. A replacement was quickly assembled, with the addition of Sepratrons to pry the boosters away. The luau had to be canceled but the barbeque was still a go for lunch.

Rendezvous was made within 3KM by the RV then closed to 200 meters by the CV.

Targeting was aligned, RCS had to be disabled to avoid a constant wobble from the autopilot tracking. The first KETM was separated and successfully transferred energy, causing the RV to drift farther away. The second and third KETMs also made successful energy transfers as the range extended to 300 meters.

The CV experienced significant excursion in pitch and/or yaw as each KETM was separated and was slow to realign tracking unless RCS was enabled. This increased the duration between KETM separations.

A complete telemetry check of the RV showed zero signs of disassembly or any damage or malfunction. By the time the check was finished, the range had increased to over 400 meters. The fourth KETM made a clean miss.

The RV and CV were both deorbited and destroyed per the details of the "Armed Camp" paper. The anonymous contract stated that no photography or video be made of the test and that upon a successful disassembly completion further contact would be made for delivery of the design documents.

In the event of a disassembly failure the contract stated AARP did not have to return any of the payment and also directed that the design files be placed on a public server for download and that the company would be free to do further R&D towards a successful completion of a test but no further payments would be forthcoming until or if a successful test is made.

All of the staff had a great time at the barbeque.

http://partsbyemc.com/pub/Armed-Camp.zip (All stock parts + MechJeb integrated modules. Armed Guard uses ReStock 5-way RCS. Armed Guard II uses KSPX mini_sas AKA Micro inline reaction wheel.)

AARP would appreciate any input as to why the KETMs failed to disassemble or damage the RV. AARP will also be happy to sell as many apparently indestructible RVs as you may wish to purchase.

Edit: It is important that you do not alter the staging order of the KETMs on the quad mount. The 1-to-4 adapter's stations have a numerical sequence in an X pattern. Move the staging order around and the engines on the KETMs will not activate when decoupled. I assume the 1-to-3 and 1-to-2 adapters work in a similar manner.

Edited December 26, 2013 by Galane

[Galane]

The contract didn't say anything about not posting pics of *further research*, so here's one of Armed Camp II with four Block 2 KETM on the nose. (Double the rockets, double the fun!) The Block 2 has proven much more effective at high speed disassembly though in tests has only had a 50% hit rate.

At the rear, mounted on pylons, are what AARP's engineers are calling "Smart KETM". In three test flights they have completely failed to transfer any kinetic energy to anything but the Kerbin atmosphere.

The decoupler kicks them rather violently sideways, so much so that they end up blasting out at nearly 90 degrees from the CV. They track back towards the target but maneuverability is apparently not good enough. Powered range appears to be at least a kilometer. Another trial with these mounted on the nose will be done to see if they can hit anything smaller than a planet.

[Galane]

Well the result with the V1 S-KETM was just as dismal in the nose mount.

Here's a picture of the V3 S-KETM

The differences from V1 are visually obvious. V2 to V3 changed from stock RCS thrusters to ReStock 5-way and added a pair of small solar panels.

So far the only way hits have been achieved is to first transfer control to the KETM then launch with a zero throttle setting. Smart A.S.S. targeting is NOT inherited from the carrier vehicle (which has the root component) so TGT+ has to be reacquired then RCS enabled prior to going to full throttle.

Even with this "slow launch" method and starting aimed straight at the target, the S-KETM will miss the target when starting from less than 1,000 meters. Failures to hit were made from 500, 400, 300 and 200 meters. One hit was made from 50 meters but without time to accelerate it merely bumped the target (remains of an Armed Camp CV hit during a previous test) apart and did not destroy or damage itself or any components of the target.

The misses were likely aided by the small target size consisting of a Z-4K, RC-L01, FL-R1, four RCS pods and four OX-Stat panels. The test proved that small targets are rather hard to hit.

The 50 meter bump was made with a V3 S-KETM slow launched from the new single carrier, quick response "Armed Guard" rocket. When all you need is one shot, why launch four? Armed Guard benefits from having the root component in the KETM so no control transfers or resetting of targeting have to be made. Deactivate the CV's engine, throttle up, aim, enable RCS then launch.

Clearly what is needed is a component to provide much stronger and more responsive steering control, such as an inline reaction wheel sized to work with the rest of the components used.

There is an upside, the S-KETMs make for some really bright reentry flares!

AARP's marketing department is currently working on a sales packet to promote the V3 Smart Kinetic Energy Transfer Module as a long loiter time spacecraft rapid disassembly tool, capable of staying in orbit indefinitely, ready whenever you need it. "Launch it. Leave it. Love it."

[Galane]

Alan Aerospace Recycling and Packaging announces "Armed Guard II", A Missile With a Mission.

By deleting all RCS equipment and installing a micro sized inline reaction wheel we introduce the Smart Kinetic Energy Transfer Module V4 with Very Enhanced Transfer Potential (VETP). The S-KETM V4 and modifications to its Carrier Vehicle make up the Armed Guard II system.

Fewer parts, lower weight, able to reach higher orbits.

The micro inline reaction wheel provides greatly enhanced control authority, resulting in higher turn rates that enable the S-KETM V4 to turn near hits into actual hits. All previous S-KETM versions are hereby recalled and will be freely exchanged on a one-for-one basis. (Remember, the "R" in AARP stands for Recycling!)

The first S-KETM V4 on reentry after a succesful transfer of kinetic energy. If there were tiny parachutes that would fit on there without causing an imbalance, these would be recoverable most of the time.

Punched right through the RCS tank so fast the rest of this Armed Camp II Carrier Vehicle is barely disturbed. Its systems were so shaken up that remote control telemetry was lost for a while. Immediately after telemetry came back online, some debris hit it and destroyed it, scattering even more debris into orbit.

I've never seen anything like this in KSP before. The RGU is not damaged or destroyed but KSP is apparently temporarily treating it as debris. I didn't close the Smart A.S.S. window, KSP did, same as it does when a rocket crashes. The report claimed it was hit by debris but I bet it was really the Kraken.

An Armed Guard II ready to roll out to the pad.

The download in the first post has been updated with the Armed Camp II, Armed Guard and Armed Guard II. Only Armed Guard II is equipped with the S-KETM V4 but that's easily installed on the other Carrier Vehicles.

The single KETM Armed Guard II simplifies the sequence but only gives you one shot, but it's one much better shot than any of the previous models.

There was still an unused Armed Guard in orbit (thanks to a KSP crash) and I tried several more times to hit things from various ranges but the best it could do was come within a few meters of a hit. Granted, the targets were small but even the old dumb KETM Block 2 could hit them from 100 meters.

Is this the end of AARP's research on Kinetic Energy Transfer Modules? It depends on the next round of tests. After all, one success on the first try isn't much of a test program, even if a 100% success rate sounds really good in the press packet.

Edited October 3, 2013 by Galane

[Dkmdlb]

What kind of delta-v do you get from one of those little things?

[Geschosskopf]

What happens if you put MJ on the missile, tell it to rendezvous with (or fine-tune closest approach to) the target, tell it NOT to match speeds at closest approach, and set the closest approach to 0.1m? Using that, you might be able to achieve fire-and-forget kills over huge distances without eyeballs on the target, assuming MJ will allow it.

[Galane]

Dunno the delta-v of them. They have two Oscar-B tanks and a 48-7S engine. Powered range from (relative) rest is around 2,000 meters. I may try one from 500 meters and see if with the reaction wheel it has enough fuel to come back for a second hit. With the V3's RCS it was lucky to get the first hit, no way it could maneuver for a second. I did let a few of those burnout after a miss from short range but every pass they'd miss by a few meters.

I do have MechJeb 2.0.9 with the mod to integrate it into the control parts.

The only way long range fire and forget would be possible is with the top stage left attached, with just enough fuel so that it'd be staged off right before final approach. Getting the Rendezvous Autopilot to go to "Ramming speed!" ("What to we do now?" "We DIE!" Name that movie.) would be a neat trick.

This is my inspiration for making these. That's why I tried using RCS for steering but the thrusters just aren't strong enough.

Edit: Just finished some more testing. I added three Sepratrons as a first boost stage to the S-KETM V4 and was able to hit the remains of Basic Target 1 dead center. That was a stock large diameter target and I had it held in retrograde orientation. I had to manually trigger the liquid engine since MechJeb wouldn't after the Sepratron burnout. Range was a bit over 2,300 meters. (Was going for 2,500 but MJ gets iffy at longer rendezvous ranges.)

Feeling a bit smug after that, I launched another one with the Sepratrons with a goal of a 3,000 meter hit. FAIL. A near hit but still a woosh fly by and not enough fuel to make a turnaround for a second try. However, the target was only a FL-T800 tank with a LV-909 engine and a FL-A10 adapter with a TR-2V on top of that, an Armed Guard II final stage. Against larger targets, 3,000 meters may be a practical maximum range to at least make contact.

I'd like to see what other people can do with this design, or improvements on it.

Now if the pocket I-beam was replaced with a more frangible piece (how about some rubber rocket buggy bumpers?), some careful aiming could be used to bump fuel-less and powerless things out of orbit. In my original test using only two Sepratrons on a pocket I-beam VS a Basic Target 1, no damage happened but the vehicle was moved around quite a bit - in essence exactly what the mysterious contract writer asked AARP to provide - kinetic energy transfer. The Deorbitizer with a stick-to-anything part on top would be more effective but less fun.

Edited October 4, 2013 by Galane

[Geschosskopf]

Well, I had to give this a try so I made a small MJ-equipped missile and told it to rendezvous with the target at 0.1m final distance, with them starting on opposite sides of Kerbin. The missile was just a probe core, the smallest 1.25m tank, and a 909. And an interesting thing happened. I expected the thing would fly right towards the target and try to stop at the last second, thereby perhaps burning the target with its engine exhaust. But MJ decided the thing didn't have enough fine control for this, so did something totally unexpected. It zig-zagged towards the target, continually passing it going and coming, but each pass inching closer and closer to it. The interesting thing was that it kept passing the target at 5-10m /s and then spinning around at the ends of the passes. Eventually, they just barely scraped paint and MJ said it had accomplished the mission. But this gave me an idea.

So, I built something rather bigger with 8 long girders sticking out radially, with big trusses pointing fore and aft on their outer ends. And I did the same thing with it. What I was hoping for was eventually clubbing the target to death or at least out of orbit, as the big outriggers hit the target on the back-and-forth passes and also when the missile swapped ends each time it wanted to do another pass. And all the while, the outriggers would keep the missile's core from coming within the 0.1m rendezvous distance, thus keeping the party going.

Well, the missile did in fact hammer the target unmercifully, knocking it all over the place. And after sending the target spinning, the missile would go chase it down and start bashing it again. Sadly, it never hit it hard enough to do any damage. Nor did any of these fisticuffs have any noticeable effect on their orbits. Maybe over a LONG time, and purely by chance, the missile might have repeatedly knocked the target lower and lower, but more likely is that it hits the target in a different direction each time, thus all changes canceling out.

So, it seems to me that today's MJ is incapable of a fire-and-forget kinetic kill. However, it's quite capable of fire-and-forget collisions. So, if you could put bombs on the outriggers that would explode on contact......

[Damaske]

The quote is from "the Last Startfighter" when the enemy mother ship get the crap beat outa it from the Gunstar after a Emergency power ramboost, after death blossom.

As for the thread, this is very interesting, I have messed around with kinetic kill vehicles and launches a few multistage ground to space kill vehicles but non ever hit there targets with any sort of repeatable success. This was with using MJ, and was a few updates ago also. Unsure it it was possible to redo now. Might have to download dammed robotics once more and make my launcher vehicle again for testing.

[Galane]

I found the key to hitting the target is in being able to steer quickly, thus the tiny reaction wheel from KSPX. Hitting anything below the large Rockomax diameter was not easy.

I never tried with both the small reaction wheel and the ReStock 5-way RCS thrusters. The official release of MechJeb for KSP .23 has some issues, use the latest development build.