Porcupine Rail - Solar System Exploration Vehicle

[Aerol]

A few people in the Welcome forum really liked my high mobility exploration craft and suggested I post it here, I wanted to build something to get around Minmus easier and get more science per trip. Now in revision 4.6 it seems to be in a mature development state. I have variously called it the 'Bobsled' and 'Minmus Rail' but since confirming it could operate places other than Minmus I gave it a new name. So here it is now open for commentary.

Vehicle Name: Porcupine Rail (current version 4.6)

Role: Exo-atmospheric Exploration Science Vehicle

Dry Mass: ~3.74t

Wet Mass: ~10.45t

Total Dv(vac): ~4-5km/s (Depending on Maneuvers and Configuration)

Maximum Thrust: 42kN

TWR(min@Kerbin): 0.41

Docking Ports: 3 'Tiny' (Dorsal, Ventral, Forward)

Unit Cost:apx $95m /w full science suite(x2)

Pre-Thread Feedback:

That's probably the most unusual craft I've seen to date. Looks cool!

Holy crap. I've seen players specialize before, but not to this extent, and with gear bays no less. Head down to the Spacecraft Exchange so more people may view your genius.

Images:

At Minmus, Greater Flats (Ver 4.5 'Minmus Rail')

At the Mun, Midlands (Ver 4.6):

Its Immediate Predecessor(Ver 3, 'The Bobsled'), on return from Minmus:

[tempes156]

What exactly is the purpose of all the gear bays?

[Aerol]

What exactly is the purpose of all the gear bays?

A great question, they are multipurpose really.

Their first and most obvious use is to serve as low friction running rails to move over terrain and control steering. On Minmus once I get up to speed(say 20m/s) I can coast across the entirety of the Greater Flats at its widest point loosing very little speed.

Less obvious is their use as lithobreaks which allow the craft to survive a faster harder landing than would otherwise be possible* regardless of vehicle orientation(IIRC touchdown speed at Kerbin with chutes is still something like 10.2m/s). Lithobreaks are also quite forgiving on landing terrain requirements, for example on my first trip to the Mun with this particular vehicle I undershot my landing zone and ended up landing on 60degree slope which I promptly tumbled down from till I could fishtail slide and come to rest on a 20 degree ridge some 150 meters or so below that.

*water landings not recommended above 7m/s

Third and probably one of the most interesting uses on a low gravity body like Minmus or The Mun is to, in combination with the reaction wheel, allow the pilot to lateral roll the craft turning it into a large spoked wheel to gain speed or travel up hills, all while using no propellents. This can take a bit of practice to get used to navigating precisely but it is quite a useful feature.

Edit: Oh and also lots of headlights I forgot about that...

Edited October 21, 2014 by Aerol

[Slam_Jones]

Nice! I had a similar idea for a rover with wheels sticking out in every direction so it could move regardless of how it lands. Never built it, but I might try now

[r_rolo1]

That reminds me a lot my first "rover" in KSP, when they added the landing gear part. God, that thing was ugly, but indeed it was quite sturdy