HeavyLander, Mun Landing Notes and Pics. [.17 Stock]

[Luuko]

Purchased the game in .16 and amused myself mostly with putting up satellites and making passes around Mun. Landing was out of the question aside from a few tests in and around KSC, which were... lackluster to say the least.

.17 came out and decided to give landing on Mun a shot. Stock parts only.

Several crashes later, 3 crews stranded from botched landings I finally managed to land. There was much rejoicing.

Decided I needed to redesign my landing craft and use large command pods in the process to allow for rescue of those stranded crew. (Extra crew were accidentally 'left' at the launchpad...) Also needed to work on reducing the craft being so dratted top-heavy and tipping over on landing. Another goal was to leave part of the lander on the surface of Mun as a sort of memorial. Further wanted to have a better fuel management system than just stacks of stages, and went with a drop-tank solution. Final goal was to get as much mass and fuel as possible to Mun without too severely adversely impacting performance.

This was the result, HeavyLander-3.

Big craft - for me at least. Central philosophy - fuel goes from the outside, inwards towards the core of each stage, allowing for stages to jettison empty tanks without having extra needless engines and decouplers.

Staging + some pics.

• Loose the large SRB's at about 6000m, with a vertical speed of 680m/s.
  
• Loose the 4 empty external large liquid boosters at about 30000m, vertical speed 934m/s. (These are assisted with the new Sepatron-rockets to ensure they blow away cleanly.)
  
• Rollover and begin gaining transverse velocity once chosen apoapsis is achieved.
  
• Loose the final launch stage. There will be an explosion as the trio of decouplers fail during transition - this is normal. The engines work fine. Usually. 90% of the time.
  
• Continue transverse burn to achieve an orbit. As the first stage of fuel tanks empty, jettison them. (Sepatron assisted to ensure they blow clear.) The LV-909's will engage at this point and also begin drawing fuel from the drop-tanks. This is normal and expected. Didn't engage previously due to prior drop tanks being in the way of the engines.
  
• Achieve Kerbin orbit and begin burn towards moon at right point. (I aimed for about 80* ahead of Mun and got within 50km of the surface no sweat.) This will leave between 1/2 to 1/4 of your fuel in your drop tanks. Plenty for maneuvering and achieving orbit.
  
• Once at Mun's Periapsis Burn till you achieve an orbit. (I didn't care too much about it being circular as I was landing in one cycle.) At Apoapsis, retroburn for a landing approach. As fuel reserves allow (and there is plenty left) choose a landing site.
  
• Enroute, jettison the second set of drop tanks, leaving the core 2 fuel tanks and the main engines. Continue deceleration burn. I usually hit it about 60k up, then about 20k.
  
• Once at about 10k, jettison the engines and empty stage, leaving just the lander. Keep descent below 100m/s.
  
• 5000m, deploy landing struts. Keep burning. About 50 m/s descent. Use your best judgement to slow to below 15m/s depending on terrain.
  
• Land successfully. Celebrate. Do EVA's, etc. Reposition if you want, should have plenty of fuel in the lander for such.
  
• Detach and head home. Limited fuel in the return module so be careful. Use RCS if you have to to get home.
  

All in all, a successful build/launch.

Some thoughts for modifications...

• The lander/return module fuel-tanks probably need to be reversed. Usually end up landing with at least 2/3rds fuel left in the lander as is and seem to be skimping on the return module's fuel. Swapping the small and large tanks around may alleviate this and improve quality. - Fixed in HeavyLander-3a
  
• It is entirely possible to get the entire transfer stage to land on Mun and not eject anything. Bit of a bear to land with all that dead-weight, but the fuel is there for it. Tested it once and got a partial recovery (core stage fell over and a few tanks popped off). May be the basis for building a Munbase.
  
• Separation of the transfer stage from the launch stages proved troublesome - redesigned and reinforced with struts and works much better now.
  
• With this design, I suspect it may be possible to reach Minmus and land/return. May have to try that after I reconfigure the return module/lander as mentioned above.
  
• Swapping the main engines for the transfer stage for the nuclear ones may allow for interplanetary exploration using the heavy lander. Will have to research this.
  
• Weight... will look into saving some, but not sure how much I can successfully cut out. Will have to ping other more experienced KSP members for their thoughts. The parachutes on the initial stage (I like trying to recover as much of that as I can for 'reuse' in my head.) may be a starting point, but certainly open for suggestion.
  

Final Notes: Am looking for feedback and thoughts from more experienced players - Would love to hear about design or approach changes to improve efficiency and such. I've provided the .craft file towards that goal. Also... anyone have a clue how to setup the spoiler tag for this forum so I can clean up this thread a bit?

The Craft: HeavyLander-3a.craft

And the pics:

Edited September 28, 2012 by Luuko
Updated main hanger pic to 3b variant.

[lucavigg]

Don't seem to habe sepMotor1 (Sepatron?) Any ideas?

Looks good though.

[bisto]

My ksp background is similar to yours. Did make it to the mun...but blew up on landing. Today decided to make it there, also upgraded to the 3 man craft. Didn't get any pictures, but i used 3.5 stages. I also used a central extra wide tank with fuel feeding from (6 for me) equally sized extra wide tank boosters to the centre, then lost the boosters (is this asparagus staging?) . Each booster has just the one full sized SRB (the .5 stage). I have to keep an eye on the throttle, for instance keeping it low transitioning between the first and second atmosphere layers and too much does rip the beast apart.

Second stage was just 4.5 of the extra wide fuel tanks with a single big engine- there was a bit of deceleration at first until some fuel burnt away. This got me into orbit and 3/4 of the way to the mun intercept (i'm not the most efficient pilot so a good pilot might make it to the mun and begin the descent with this stage).

My lander originally used a small stack of normal width tanks and 4 of the white engines that protrude out the side. However, it was so top heavy the slightest horizontal velocity made it bail over on landing. I redesigned it with one half lengh, extra width tank below the capsule, and 2 of the same tanks sticking out the side, each with 2 of aforementioned engines (sorry, forgot the name!) and a lot of landing gear. Touched down, quick EVA, and then back home, with enough fuel to spare to change my re-entry path to go pretty close to KSC (well, on the southern tip of the "africa" continent where it is)

Just wanted to share my similar story Not sure what to do next, minmus seems like a whole other ballpark, never mind the planets! Especially considering the size of my vessel, i need to become a more efficient engineer and pilot first! My first attempts with planes didn't go well either, might have a look on youtube for that first.

Edited September 26, 2012 by bisto

[Luuko]

Not sure? Just uploaded version 3b where I fixed the lander/return module fuel configuration. I did notice the old file jumbled the staging a bit... See if it shows up in the new file.

Edited September 26, 2012 by Luuko

[Luuko]

If I'm not mistaken, asparagus staging is when the outer stages fuel the inner ones and peal off as they use up their fuel. Don't hold me to that though.

All my stages do this, though I don't have any rockets on some of them as they're just fuel tanks along for the ride.

Glad to hear others are making progress as well! Let me know when you hit Minmus - I'll be interested to take a look at your design. :3 I think mine can make it there as is, but am going to hold off on that... my rescue mission just crashed-landed next to two of my early Heavy Lander designs (within 100m of the other crash-site). Now I have /3/ crews up there to retrieve. *groans*

I have no problem with a general landing... it's when trying to hop around and hit specific landing zones I have issues.

... Or when I miss my queue with the time-warp. Oops.

Edited September 26, 2012 by Luuko
(just crashed /another/ lander...)