Desdin's Doggie

KSP version 0.19 was released, and it contained rover wheels (but no resource mining as yet), so it was time to design and test a Fido for Desdin, our plucky colonist on Eve. If Desdin ever does decide he wants to return to Kerbin, or if he is successful in extracting enough valuable blutonium from Eve's seas, he is going to have to deliver the payload to the high elevation landing/liftoff site (since my Eve ascent lander can only make orbit from an elevation of around 4,000 meters). The lander site is located 56 km away from Desdin's base...but getting there will involve an even longer trip than that because he will also have to drive around the lake that is between his base and the lander site. My previous RCS-powered Fidos are not up to that task in Eve's heavy gravity, but with the new electrically-powered wheels in version 0.19 this should now be possible.

So the Kerbal Space Center engineers got busy testing rovers around the KSC. Since this Fido was going to be used for long distance travel, it was important that it be able to go fairly fast, but it was also vital that it be safe (it must NOT tip over). Some initial tests using the two-kerbal cabin were disastrous: If your rover uses that cabin, and if it tips over...your kerbals are gonna DIE. So the engineers settled on using the Mk1 aircraft cockpit because of its very high impact tolerance; even if your rover wipes out, you have a good chance of surviving in this cockpit. Plus, it has a great view from inside the cockpit. One of the initial test versions is shown below. It uses the new I-beams and structural panels of version 0.19:

You may wonder what all those landing gear are doing on top of the thing...that is a special Rover Righter mechanism that can be used to flip the Fido over if it ends up inverted. See the picture below of the legs entended. Cycling the legs open and closed several times will right the Fido back onto its wheels. But the engineers decided to NOT use this novel device because NOT having half a ton of lander legs on top of the Fido actually made it resistant to rollovers... and it was hard to attach a lander to the Fido when it had the Righter mounted on top.

The engineers also tested whether or not having an ASAS unit on the Fido was useful. It turned out that with the ASAS unit in place, the Fido could corner safely at speeds 6 m/s faster than without the ASAS on (17 m/s vs. 23 m/s). Below is a test sequence showing the prototype Fido hitting the incline at the edge of the runway at 22 m/s. The Fido wipes out and is seriously damaged (although the pilot survived in the Mk1 cockpit).

The same prototype Fido is shown below hitting the runway WITH the ASAS turned on. It survived undamaged.

Additional tests showed that the prototype Fido would not work well in Eve's high gravity (this was tested by piling extra weight on top of the vehicle) because the frame would flex too much, and the low-slung body would hit the ground. This sagging of the structure is very evident during physical time warping, where the deformation is even greater (for some reason). So the I-beams were replaced with girders that could be braced better (and which KSC engineers have recently learned to make much lighter than before). The girders also gave the Fido an even longer wheelbase for greater stability. It was found during testing that putting some pieces of short I-beam on the bottom of the central structure (under the cockpit and the ASAS & RCS tanks in the rear) would protect those parts from damage when anything hits the vehicle from underneath (since the I-beams are very impact resistant). Also, the number of wheels was increased to eight for better support and ability to operate better if a wheel is damaged. Below we see the final design. It has RCS for use on low-gravity moons (where it will be tested), and parachutes for landing on Eve. The OKTO probe body sticks up rather high, so a second OKTO2 probe body was placed on the right-side structural panel so the Fido could still be driven un-kerballed in case the original OKTO is knocked off in a rollover.

So the Fido KE was born. The "K" stands for "kerballed" since the vehicle can be driven by a kerbal...but it also has probe bodies for un-kerballed control. The "E" stands for both "Electric" (the new power source) and "Eve" (its intended destination). To test the Fido KE, the mission planners first sent one to Minmus where they had the most experience in roving. Below we see the expendable rocket used to send the Fido to Minmus. The side-boosters and central sustainer put the ship into orbit (with fuel to spare, so it was also used to adjust the orbital plane). The X200-16 fuel tank and a Poodle engine are used to transfer the ship to Minmus and brake it into orbit. This stage can also start the descent (and ends up being crashed onto Minmus).

The large plate under the Fido serves as a heat shield...but it's unnecessary on Minmus, of course, since Minmus has no atmosphere. Below we see the heat shield plate has been separated and is falling away as the lander stage begins final braking. The lander stage is rather overpowered with two LV-T45 engines... two LV-909 engines would be fine here, but the LV-T45 engines were used so that the lander stage had enough thrust to be flight-tested at the KSC. The Fido is being landed over 10 km from Minmus Base just to be sure the jettisoned transfer stage and heat shield plate would not cause damage to the base.

The lander stage has four heavy-duty landing legs, and the whole unit soft-lands with the rover. You may also note that the lander stage and Fido are equipped with parachutes, which are also useless on Minmus, but which would be used if the lander was putting the Fido down on a body with an atmosphere. Below we see the ship just before touchdown.

The Fido is attached to the lander stage by Clamp-o-tron Junior ports (and some struts), and the Fido is dropped free by decoupling those ports. The Fido is equipped with RCS, and on a moon with sufficiently low gravity, it can be re-docked with the lander stage if desired (it is driven underneath, and then the RCS is used to jump the Fido up so the docking ports can engage). (NOTE: The mysterious Weird Physics problem I had with docking earlier Fidos like this is apparently the result of using a cubic octagonal strut to attach the port...this causes weird phantom forces when docked. Thank you, Kerbal Forums, for this bit of information. This Fido does NOT use an octagonal strut to attach the docking port, so it does not do the Weird Physics thing.)

It turns out that the rover wheels get very poor traction in Minmus's weak gravity, so the wheels spin and the Fido accelerates only slowly on Minmus. Similarly, the brakes are very slow at decelerating the Fido. The Fido got up to a cruising speed of 23 m/s during the 10 km trip to Minmus Base, and it overshot to base by 600 meters and had to turn around and come back. One of the things that became clear during the drive over: the default key bindings for controlling the rover (WASD) do not work well in low gravity because those keys also casue the Fido to try to pitch and yaw... so the rover control keys were remapped to IJKL and this made controlling the Fido much easier.

Below we see the Fido KE parked next to the older Fidos for comparison, and for a nice family photo of the good doggies. On the left is the original Fido, then comes the Fido Pup, then the Fido KE, and then the old Fido K.

Thus far the Fido KE has been operating in unkerballed mode. Aldner Kerman volunteered to give it a test drive with a kerbal aboard. He immediately found a problem: After the I-beam frame was replaced by the girder frame, nobody bothered to check if a kerbal could still climb into the cockpit...and it turned out the the ladder positioning was a bit too tight, and Aldner could not climb the ladder to get to the cockpit. This didn't stop Aldner, of course, since he just used his rocket pack to get up on top of the cockpit to get inside. But it would have been very embarrassing (and expensive) to have only discovered this once the Fido was sent to Eve (where rocket packs are not an option). This is why we test things, people!

Here is the view Aldner had out of the cockpit windows as he took the Fido out for a test drive up Near Cheek of the Big Butt formation (a standard first test of a Fido after it has been run on the flats).

What Aldner found was a bit disappointing: Because of the very poor traction on Minmus, the Fido KE's electrically-driven wheels could not get the Fido up the steepest part of the slope of Near Cheek. But Aldner found that a blast from the RCS could press the Fido down in better contact with the surface, allowing the wheels to get a grip and make headway. It didn't have to be a long blast...a short blast could get the Fido moving, after which it could go for a ways before slowing back down and needing another blast. The rear-facing nozzles of the RCS quads could also be used push the Fido forward up the slope. Oh...why do you have such BIG RCS ports, Grandma? The Fido has multiple linear RCS thrusters mounted on top and bottom so that it could easily right itself on a low gravity moon using the RCS. And for being pressed down onto the surface, if needed. And for being able to jump up, if needed.

After making it to the top of Near Cheek, Aldner decided to see how fast the Fido could go downhill, with the pedal to the aerospace alloy. He hit a speed of 37 m/s as the Fido hit the sharp transition between the hillside and the flats. Yeee HAH! Alder looks like he's having fun.

Unfortunately, upon hitting the sharp transition at the flats, the Fido wiped out and blew three wheels and went tumbling into the 'air.' Aldner looks a bit concerned now.

But Aldner has nerves of steel. And Minmus has low gravity, giving him plenty of time to react. He took control with the RCS, flipped off the SAS, and righted the Fido for a flat landing facing the right direction.

Aldner managed to splat that puppy down and hold it steady...although he did blow all but one of the remaining wheels, and then he slid along for over a kilometer before coming to a halt. But he looks like he's having LOTS of fun sliding along the surface.

It turned out that the wheels were the only things damaged during the incident. So Aldner hopped out and went around to each wheel where a little right-click magic put them all back into perfect working condition. Then he drove the Fido back to Minmus Base for lunch. The RCS system on board the Fido will probably be no use on Eve, but it can be a real lifesaver on a low-gravity world.

The next Fido KE prototype was tested by sending it to the Mün (another unkerballed mission). The picture below shows the ship still connected to the transfer stage after reaching münar orbit.

Coming in for a landing with a münar arch in the background, 8.6 km away. The marker icon by the arch shows the location of a previous Fido.

The Fido handled better in the Mün's higher gravity, but it was unable to make it up the steepest part of the ridge that the arch sits on without some RCS help (still not enough traction). However, the old Fido that was used here was unable to make it up this slope at all (and had to go back around to try a less-steep path). The new Fido KE could make it up the slope with RCS assist, or if it attacked the slope at at angle to reduce the relative slope.

But then, as the new Fido was about 250 meters away, the old Fido parked by the arch suddenly exploded, throwing pieces off in all directions. What. The. Hell. the last quicksave was just after landing (grr), so I went back to that spot and used the tracking station to check out the status of the old Fido...and it looked fine. Huh. So I drove over to the arch again... and this time the old Fido did not explode violently. Sometimes this game is just freaky.

The new Fido KE arrives at the base of arch where the old Fido sits looking totally innocent ("What? Me explode? You must have been dreaming. Why would I explode?")

So the new Fido KE drove around the arch for a while, occasionally glancing out of the corner of its eye to see if the old Fido looked like it was going to explode again. Which it did NOT. Fine. The markers off in the distance show the landing sites for the lander stages of the two Fidos.

The new Fido parked alongside the old Fido. And so ends this test.

We finally get to the main event: Sending a Fido KE to Eve. For this trip, a transfer stage based on the Mark Twain core was used, and the ship was launched with a standard Mark Twain launcher. This was overkill, but there certainly wouldn't be any fuel problems.

The trans-Eve injection burn required about 1,000 m/s delta V, which took just under 10 minutes for the two nukes. Below we see the ship near the end of the burn. The burn used about 60% of the fuel in the rear tank of the transfer stage.

Below is the plot for the midcourse burn at the ascending node. This burn adjusted the plane of the Fido's orbit and adjusted in the prograde/radial directions to get an encounter with Eve. The burn required 366 m/s of delta V, which burned another 17.5% of the fuel in the rear tank in just over 3 minutes. And here's where I ran into problems again. After the midcourse burn, I was not able to get another maneuver node to show up by clicking on the Fido's orbit. And I needed to make adjustments because the encounter perihelion was way too large. Damn annoying bug. Trying to do the adjustments with RCS was not working because the ASAS was constantly firing the RCS whenever SAS was turned on. Annoying. So I just experimented by pointing the ship prograde, retrograde, and at various right angles and doing test burns with the nukes to see if that was the right direction to lower the periapsis. Eventually I got the periapsis down to 69 km, but I obviously wasn't going to be able to tweak my incoming path easily because I couldn't get any maneuver nodes to show up.

So I waited until I entered Eve's S.O.I. before refining my encounter. I sneaked across the S.O.I. boundary like a thief in the night, traveling at a stealthy 1x time warp, and the 69 km periapsis held...but it turned out that it would be a retrograde orbit, so I had to do some more burns to shift that to a prograde orbit within two degrees of equatorial. That used up another 10% of the fuel in the rear tank, leaving the transfer stage with about 12.5% of its rear tank of fuel.

The aerobraking at 69 km was over the night side of Eve, and you can see the visual entry effects below. Not overly impressive for an aerobraking coming in from interplanetary space... but it wasn't too deep of an aerobraking. The ship was captured into an elliptical orbit with an apoapsis of 7,600 km.

The job of the transfer stage was over now, and it would be left in Eve orbit as a tug/refueling station. But when it separated from the Fido, the transfer stage began to tumble is weird ways. Time warp to freeze it, and it would start tumbling again later. Very odd. I should have put an ASAS on the thing (since it will be used to maneuver and dock with its RCS if it gets used as a tug), but I forgot. Switching to the tracking station and back to the transfer stage did not correct its odd behavior. Huh. Anyway...the Rockomax decoupler at the top of the transfer stage was jettisoned, leaving the docking port on top of the OKTO probe body clear to dock to other ships in its role as tug. When the rest of the fuel in the rear tank gets expended, it too can be jettisoned to reveal another docking port at that end. A short prograde burn by the transfer stage raised its periapsis to 125 km so it would experience no more aerobraking. The rest of the Fido ship continued in the original orbit to plunge back in for more aerobraking. The second aerobraking reduced its apoapsis to 1,600 km, and the third braking reduced the apoapsis to 190 km. A short burn by the lander stage engines raised the periapsis up to 85 km (it had fallen to 56 km) so that the fourth aerobraking (which showed not entry fire effects at all) resulted in an apoapsis of 129 km...and a burn there circularized the orbit.

Now for the entry and landing. The lander stage was designed to be able to put the Fido down on the Mün with fuel to spare, so it is a bit of an overkill just for deorbiting from Eve orbit. The deorbit burn used about 68% of the fuel in the 'tuna can' main tank of the lander stage. Below we see the entry effects of version 0.19 as the Fido falls into Eve's thick atmosphere. Version 0.19 does not actually have heating effects (only visual effects), but seeing the underside of the heat shield get white hot like that makes me glad I included the shield (even though it doesn't actually DO anything at this point in time).

A view of the entry effects from the other side. The 'heating' is concentrated mostly on the lander stage engines since they are not protected by the heat shield (they needed to fire past the heat shield, so gaps were left under them). You can see the markers of the Eve base vehicles at the right by the lake shore. The other marker (to the left of the ship, visible through the entry flames) is the location of the high-elevation lander site.

When all the ionized plasma effects around the ship ceased at about 27 km, the drogue chutes of the lander stage were deployed.

Once the drogue chutes got the ship descending in a mostly vertical direction, the heat shield was jettisoned.

Shortly after the heat shield was jettisoned, the rover was dropped from the lander stage, using an action group key to decouple the docking port connection. The job of the lander stage was now done in this atmospheric entry.

The Fido was unstable as it fell from the lander stage (I should have turned on its SAS before release), but the RCS was used to stabilize it, and then the four chutes were deployed in reefed state. The Fido would tend to nose-down somewhat here, but the RCS was used to level it and the SAS turned on to hold it.

Below, the Fido is about a kilometer up as the jettisoned heat shield smashes into the surface.

At 500 meters AGL, the four parachutes fully deploy, slowing the Fido to a speed that will not damage its wheels upon landing. The Fido touches down 1.2 km from Desdin's original landing site and 3 km from his Eve Base habitat. The headlights can be seen illuminating the ground. After landing I looked around for the lander stage up above (last seen 2 km above the Fido as it was descending), but there was no sign of it (apparently is reached despawn distance).

The Fido KE drove the 3 km over to Desdin's base. It handled quite well in Eve's gravity, and showed no tendency at all to flip even in a tight turn. Below we see Desdin posing with his new toy.

Desdin hopped into the Fido (the repositioned ladder worked fine), and made a quick drive 2.3 kilometers to the Eve Base 2 facility located near the lake shore where he is conduction the blutonium extraction experiments. Wow! This rover will save him lots of time having to trudge back and forth between the base modules on foot!

It was time for the acid test: Would the Fido be able to make the trip to the high-elevation landing site? For this experiment, Desdin got out at his main base ad piloted the Fido by remote control, just in case anything went wrong. The Fido handled perfectly, with a cruising speed of about 20 m/s. Unlike on Minmus or the Mün, you can use physical time warp when driving the Fido on Eve...but I don't recommend using time warp when you are within 2.4 km of any other ship you want to keep intact (I've had time-warping jogging kerbals cause nearby ships to fall over and explode before). The Fido also handles oddly at higher time tends to "slide around" following the gradient of the beware. As on Minmus and the Mün, in full daylight the Fido can cruise along without losing any electrical charge from its batteries (the solar panels and RTGs replace it as fast as the wheels use it). At night, the Fido could probably do several kilometers before it needs to stop and rest a while as the RTGs recharge the batteries.

On the way around the western end of the lake, the Fido came across a landscape anomaly where the pieces of the landscape did not seem to fit together well. Hitting that anomaly at high speed while in time warp caused a wheel to get ripped off of the Fido. Well...that ain't right. So I used a quicksave to undo that, and tried driving slowly over the anomaly. The wheels jerked as if they might get ripped off, but the rover survived intact.

For most of the journey the Fido could maintain a cruising speed of 20 m/s, but on many slopes it could only manage about 10 m/s. But at one point in the trip (see below), the slope was too much for it, so it had to attack that slope at an angle. Oddly, the slopes have a bigger effect when time warping: The Fido may slow almost to a stop trying to go up a slope at high time warp...but the Fido can tackle the same slope at 1x time warp and maintain good speed.

After about 40 minutes (my time) of driving, the Fido reached the lander site at 4,107 meters elevation. You can see Fido checking out the probe body left behind by Adly's lander. The trip took about 1.5 hours of in-game time. This landing site has a slight slope, so it obviously isn't the highest point around. Some scouting with the rover found a couple flatter sites at higher elevations some distance further on (a 4,417 meter site was at -0.912497 N, 151.537881 E, about 4.6 km beyond the original landing site; a 4,485 meter site was at -0.769490 N, 151.557303 E, about 6.1 km beyond the original landing site)... and there appeared to be some even higher sites further north.

For the trip back, the Fido was driven around the east end of the lake. It's a longer route, but with the extra speed of coming back down hill, it was a faster trip. At one point, the Fido hit 44 m/s down hill, which it handled very well even at time warp. The slope may be steeper along this route, so maybe the Fido would have difficulties coming up that way... but there were no landscape anomalies encountered along this route. The trip back tool 1.16 hours of in-game time (and only 22 minutes of time for me, since I spent more of it with reckless abandon at high time warp). The Fido was parked outside Desdin's Eve Base habitat for future use.

Fido KE appears to be up to the challenge of transferring Desdin and any goodies he refines to the lander site. Good Fido! *woof!*

Under the heading of "additional freaky behavior," I noticed in map view that some debris had appeared on Eve at location 0.0 degrees N, 0.0 degrees E (said the coordinates when I pointed at it). What the heck is that? So I took a look, and I found the heat shield sticking out of the sea. Freaky bug. I had this same thing happen to me earlier when one of the nuclear engines from Desdin's landing showed up floating in the sea around the other side of the planet. Sorry for the poor image, but it was nighttime there. I went to look for it again later to get a daylight image, but it was gone by then. Weird things happen on Eve, planet of purple mysteries.