Large Rover Descent and Landing Stage

[schlosrat]

I've posted a previous example of how to build and deploy a small rover with a landing stage to bring it in SkyHook fashion. With that, all the Kerbals that go on the mission *might* return home using their lander and leaving the small single-seat rover behind. Not so with this one...

Here's an example of a large(r) rover built on the TR-3 "Bulldog" frame with 3x RTC "Rottweiler" truck chassis and 6x RoveMax TR-2L wheels.

• I attached a Kelus small ladder under each of the airlock doors on the Bulldog to facilitate climbing in and out.
• I don't trust rover pods as flight controllers for anything other than ground operations as their coordinate frames are optimized for that, so right behind the Bulldog rover cabin there's a Mk2-DC drone core oriented so that it can control the vehicle properly anytime you're in "rocket" mode vs. "rover" mode. To that end I use action groups to force the "Control from Here" setting for these two "pods"Aft of the Mk2-DC there is a Mk2 RFT-400 followed by an RF-AD 400 to carry the fuel needed for descent and landing.
• Aft of the RF-AD 400 I placed a small reaction wheel to augment the torque in the Bulldog command module.
• I mounted a Rottweiler truck chassis with two RoveMax TR-2L wheels under each of the Bulldog, Mk2 RTF-400, and RF-AD 400. To get the Rottweilers to attach nicely I used BZ-52 Radial Attachment Points.
• I attached three SM radial decouplers with an LT-2 "Wombat" leg on each.  Shift these down a bit so they legs don't get hung up on the Rottweiler truck chassis. Also, be careful with which stage the radial decouplers fall in - I put them at the top. Adjust their decouple force to be 0kN for the one that faces the ground when the rover is in "rover" mode, and 5 kN for the other two.
• Aft of the SWR there's a size small engine plate with an LV-909 "Terrier". This will provide more than enough TWR for descent and landing and is reasonably economical in mass and ISP. Adjust the interstage node of the engine mount to be just after the Terrier nozzle.
• Complete the rover part with two SP-XL "Gigantors", a Communotron DTS-M1, and a plethora of lights. In particular, two forward facing spot beams for headlights, two aft facing  wide beams for when you're backing up, some strip lights for on the sides and underneath, and some ordinary light bulbs for on top in strategic locations.
• Below the Terrier is a small decoupler, followed by RS-AD 800 Small to Medium fuel tank, an MRW-250 reaction wheel kit, an X200-16 tank, and an REI5 "Skipper" to handle the transfer, capture, circularization, and at least the first part of the deorbit burn. Basically, a simple transfer stage with some added control authority to aid in pointing.

The craft files can be found here.

A note about fuel capacity: In my test of the system flown I left a 100 km circular Kirbin orbit using only the transfer stage and flying to the Mun. I wasted some gas fine tuning my PE at the Mun which would have been cheaper to do if I'd done it before getting to the Mun's SOI. I then circularized at about a 50km orbit and descended from there. My piloting skills, and particularly my landing skills, may leave something to be desired and I probably waisted some gas on the way down as well. Consequently I ran out of gas at about 600m AGL while traveling around 20 m/s. I needed to switch on the infinite propellant cheat to get down. Flown properly, or if you're headed to Minmus, I'm confident any reasonably skilled pilot can safely land this beast. I typically build my LV stages so that they can handle at least some of the transfer dV too. If I'd done it right, I wouldn't have needed nearly as much of my transfer stage getting to or circularizing at the Mun, and so more of it could have been used and then ditched on the descent. Nevertheless, be forewarned! If you waste a lot of gas you may get into trouble on the way down to the Mun, but there's really no reason to. If you're headed to Minmus then things will be even easier.

Here's the rover after the deorbit burn with the transfer stage gone and the landing legs deployed

Here she is getting closer to the surface. Very easy to control descent with the Terrier at around 1/4 - 1/3 throttle.

Touched down on the Mun.

To get from vertical to horizontal, I recommend retracting the gigantors, then just gently tip her over onto her belly. The SRW in the back plus the torque available in the Bulldog cab are more than enough to both get her tipping and to set her down quite gently.

For decoupling the legs, I set the bottom one to 0kN force and then actuate it by itself. then set the other two to 5kN and fire away!

 Happy roving! Now you just need to plan a rescue mission...

[cfloutier]

excellent, I'll try it to test my auto lander in K2-D2.