I'm Going To Tylo!

[The Jedi Master]

The Brianna 2, carrying the unmanned transfer ship, was launched... and exploded within a second. I would post a pic, but my machine won't stand for it. Windows, everybody!

[bsalis]

You need an TWR larger than one then landing, and more than 3km/s dV after landing. In short your TWR can be lower than one then you start, It looks a bit hard to me, you probably need an hybrid, say 2 LV-N and some 48-7S you activates for the final braking and turn off then you start gravity turn.

Your TWR will improve and exceed one as the fuel burns up. It's very possible, and to prove it I made a video. Ten long boring minutes (sorry), but you can always skip to the interesting bits.

Edited April 17, 2014 by bsalis

[The Jedi Master]

Quick vote: All in favor of me getting a second Twitter account for the Jedi Space Program?

[The Jedi Master]

Tried to launch the lander today. Things went haywire, and now Jebediah Kerman is stuck in orbit with no parachute. He seems OK with it, though...

[NecroBones]

I'm getting ready to go to Tylo too. I'm favoring a brute-force method for my first attempt at a manned round trip.

TWR, FTW!

http://www.necrobones.net/screenshots/KSP/KSP%202014-04-14%2021-54-57-19.jpg

And on the pad:

http://www.necrobones.net/screenshots/KSP/KSP%202014-04-15%2023-16-13-65.jpg

Tylo landing, and take-off again. Had MechJeb for informational displays, but landing, take-off, and rendezvous in orbit were all manual. I started with the orbiter in something like a 82 x 350 km orbit. The lander proceeded from that, down to the surface, and re-orbited up to an 85km x 95km orbit, with only about 130 m/s dV remaining. So I had the orbiter do the initial rendezvous orbital change, but switch back to the lander again to match velocities. This used up the remaining lander fuel, plus about 10 m/s out of the RCS/monopropellant.

What was amusing (err.. I mean irritating) was that since I rebuilt my computer recently, "sticky keys" was still enabled. Tapping the throttle too many times brought up the sticky-keys pop-up, and I lost control of the lander for a few seconds, right over the surface. I landed hard, but only broke one landing leg, which was easily repaired.

Edited April 18, 2014 by NecroBones

[Jouni]

I also did a Tylo landing yesterday. Four nukes, the big inefficient two-kerbal lander can, and a reusable lander. It was possible (and more efficient) to land on the nukes alone, while the radial engines made a safe landing possible, if the timing of the suicide burn was a bit off.

[NecroBones]

I also did a Tylo landing yesterday. Four nukes, the big inefficient two-kerbal lander can, and a reusable lander. It was possible (and more efficient) to land on the nukes alone, while the radial engines made a safe landing possible, if the timing of the suicide burn was a bit off.

I really like your slim, elegantly efficient design. I went for pure power.

[SkyRender]

I also did a Tylo landing yesterday. Four nukes, the big inefficient two-kerbal lander can, and a reusable lander. It was possible (and more efficient) to land on the nukes alone, while the radial engines made a safe landing possible, if the timing of the suicide burn was a bit off.

That had to have been tough to land. The nukes alone would give you a TWR of maybe 0.85 on Tylo in that configuration and weight profile. Still, entirely doable with some clever timing.

[Jouni]

That had to have been tough to land. The nukes alone would give you a TWR of maybe 0.85 on Tylo in that configuration and weight profile. Still, entirely doable with some clever timing.

Low-TWR landings are pretty much the inverse of an atmospheric ascent. With proper planning tools, they would be easy, but with stock instruments, it takes a while to figure out a good descent path. There are probably more efficient ways to do it, but my approach is to split the landing into three parts. First you kill most of the horizontal speed, while keeping the descent rate within acceptable limits. Then there is a bit of free fall, until you reach the optimal descent rate for your (true) altitude. After that, it's just one big almost vertical suicide burn.

My final descent path from near the apoapsis at a 68x63 km orbit was the following:

1. Burn to 5-10 degrees, until the descent rate reaches 100 m/s.
   
2. Burn to 30 degrees, until the retrograde circle touches the center.
   
3. Burn to 45 degrees, until the retrograde circle touches the center.
   
4. Burn to 60 degrees, until the retrograde circle touches the center.
   
5. Free fall until 25 kilometers. (The free fall started at a bit over 27 kilometers. The altitude of the landing site was probably something like 2 km.)
   
6. Start the suicide burn, while pointing initially to 80 degrees.
   
7. Use the radial engines from 3 km true altitude, until the descent rate reaches 20 m/s.
   

Those steps put me reliably to 100-200 m above the surface, with the descent rate at 20 m/s.