What are your close calls with low fuel?

[KerbonautInTraining]

Here's mine, I also added it to the OP

 

I was trying to do a realistic final approach but underestimated gravity losses I'd encounter during the vertical descent.

Edited March 15, 2016 by KerbonautInTraining

[winged]

Single Stage to Eeloo and back in KSP 0.24.2 I've returned to Kerbin with 50m/s left.

[Kristobal]

My first mission to Moho, I drastically underestimated the delta-V needed. The probe ran out of fuel above the surface, and hit the ground at about 30 m/s, amazingly unharmed. You can imagine how relieved I was 

[Bubbadevlin]

When I was testing my small SSTM (refueling) I went to the Jool system. Me being me I wasted a ton of fuel on a maneuver to aerobreak at lathe, then overheated too much and could not, while I had already quicksaved.  Long story short, I ended up with an encounter with Bop. After a few attempts, I managed to set down with like 4 units of LF left, and in the area I was in did not have enough ore to mine! (using small drills) I then had to rover down the hill, and pray I found a large ore spot before my nuke ran out of fuel. Then when I did, there was no oxidizer for my fuel cells to use, so I had to wait for my 1 RTG to let the converter produce enough oxidizer so the fuel cells could work.... That was fun  

[Kuansenhama]

Landing a 70 ton SSTA on Minimus with ~30 units of Liquid Fuel Left.

[RocketBlam]

My closest calls involve actually running out of fuel and having to use RCS to finish the mission.

[Francois424]

Recently I drove my Rover on Moho, it had 4 twitch engines on the back.  Usually used for generating driving speed as my wheels are the small landing gears and don't have a motor.
I noticed that full of fuel I had a TRW of about 1.35 on Moho... really ?   (Jeb... don't do this Jeb... Jeb??)

And so Jeb put the pedal to the metal on a 30 degree slope and off in the "air" did we go.  Aiming the engines 90 degrees and slowing down to keep altitude and not accelerate, we crossed many a dangerous canyon.
Until Val yelled "Almost out of fuel you [censored]".  But Jeb being Jeb, he managed to land the rover safely, only turning at the land moment to land on the wheels.

Then they both checked remaining fuel...  OX: 0.87 / LF: 0.71 ...  They where more careful after that one.

 

[r4pt0r]

My first manned interplanetary mission was an ike landing. I don't play with any numbers, just stock trial and error, and knew I was rather strapped for fuel. Set up a direct intercept return to kerbin from ike after a successful landing. Hit the atmosphere with less than 2 units of fuel (This was before stock reentry heat). Watching the fuel gauge tick down as the maneuver node got closer to home and not knowing if I'd make it is still one of my favorite moments in ksp. That's also what cemented my view that ksp should never have a stock dv calculator. It would be a shame to remove the suspense from missions like that, to just read a number and know "yep I'm good, I'll make it".

Math is stupid anyway

[Octa]

My Mun lander ran out of fuel during ascent from the mun. I had to circularize with my last monopropellant reserves and the rendevouz was done by my command module. Got all 3 Kerbals back with no LF/O left, the last corrections after the Mun escabe burn for re-entry where made with RCS.

[John FX]

I once failed to pay enough attention to my fuel and was on my way back from Jool. I did a course correction burn and then for some reason my craft would not fire it`s engine and I noticed I ran out of fuel.

Luckily, my path took me into the atmosphere of Kerbin and heating was not implemented at the time. 150 days later I entered a highly elliptical orbit after the first pass then landed on the second.

[Brainlord Mesomorph]

I've had to finish my Kerbin aerobraking insertion burns using retrorockets on more than one occasion.

My nuclear lander (that uses LFO for final decent) ran out of oxidizer about 30 m up. came down hard, broke most of the gear, but survived. Had to drop the payload module and leave one man behind (woman actually) to get the thing to rear up on its hind legs and engage the nuclear drive to get off the ground. She docked with the mother ship tattered and broken, but got home.

The next version of that thing had twice the O2.

[FyunchClick]

Going from Duna to Ike, and misjudging the cost of a mid-course plane correction. I ended up forgoing a circular parking orbit and going straight in for a suicide burn, which nearly became just that with just 5 m/s left in the tanks.

 

[Stewcumber]

Most of my early trips to the Mun involved running out of fuel on the return trip with a Periapsis of about 50k around Kerbin and a Apoapsis in the millions. And that is how I learned about Aerobraking!

 

[Choctofliatrio2.0]

Went on a mission to put comsats in mun orbit for RP reasons. Jeb wasted too much fuel adjusting the orbit for the satellite, and barely got home on fumes.

[IronCretin]

I remember my first Minmus "landing". I was doing an orbit mission, and I'd heard that I could fly a kerbal down to the surface with the EVA pack. So Bob got out of the ship, turned on his jets, and flew down tho the surface. So far, so good. I had a bit of trouble landing, and ended up sliding across the surface for a kilometer or so, but eventually he was able to plant a flag and grab some samples. Satisfied with the mission, I flew him up into orbit, and prepared to rendezvous with the craft. All good, until, wile maneuvering to approach it, I noticed I had 1 unit of fuel left. I ended up having to rendezvous the ship with him, and get it close enough to the hatch that he could get in. Still one of the harder things I've had to do in KSP.

[corvustech]

19 minutes ago, IronCretin said:

I remember my first Minmus "landing". *snip*

I think Minmus is probably the most responsible for my early-to-mid-game hilarious landing fails.  Mun just pulverizes you, but Minmus goes all bounce-house-covered-in-oil.  

[TheMoonRover]

Re-entering and landing a damaged spaceplane with no fuel to run the engines and no electricity to power the reaction wheels.

[Piper]

For me, it was Gilly of all places.  I was using a lander that used only monopropellent, and I had been using the lander over and over again to farm every last bit of science I could, and I wanted to do one last landing and return.  So I transfered all the monopropellent from the mothership to the lander so I would have enough, plus some for a margin of error.  I set the lander down, and realised I used way more then I should have (I got impatient and thrusted towards the surface).  I half expected that I would need my four explorers to jump out and EVA the rest of the way into orbit, but I really didn't want to do that, as I was using TAC Life Support, and I knew I wouldn't have much time for the KSS Discovery to reach them.  I did manage to get the lander into orbit, but I did exhaust the monopropellent.  Once they were in orbit, I redirected the Discovery to pick them up, and even managed to dock with it even though I didn't have any monopropellent left.  Once I was close to the lander, and zero the speed, turned both vessels to face each other, and gently thrusted forward letting Mechjeb keep their docking ports aligned.

I know there's been other times, but I have a hard time thinking of them specifically.  I know I've had landers land on fumes, or just barely return to orbit.  I once had an unmanned Eve lander land with just 6m/s of dV left.

But most of the time I don't, as a general rule I add up my deltaV requirements and then multiply that by 1.25, or 1.5 for precission landings, and that is what I load out my spacecraft with.  So in most cases that means I have tons of fuel left over.

Edited March 16, 2016 by Piper
spelling correction

[Alchemist]

The most hilarious case was in 0.90, when I decided to test if one of my SSTO planes can reach Minmus. Well, in the middle of the landing I've realized that there are just a few units of fuel left. Spending the rest on minimizing vertical velocity just before touchdown... and horizontal Minmus landing at 60 m/s!

Results: lost a canard, had to send a probe to refuel it, barely managed to pull the nose up when landing back on Kerbin (missed KSC a bit... landed near the south pole... at least the terrain was level enough for such landing). It was an automated flight, but the ship could carry 6 Kerbals.

[Motokid600]

Booster landing ran out of fuel a foot off the ground last night. Call that getting my moneys worth.

[HebaruSan]

While trying to lure nieces and nephews away from mobile Minecraft over the 2015 holiday break, I noticed that a pair of Puffs give the Mk1-2 pod a healthy Mun TWR. And it's already got 30 monoprop on board! An experiment begging to be tried, and an excuse for distinct landing/return stages to boot.

Somehow I misread the Δv numbers in KER and ended up with a doomed little craft and a quick quickload. Back to the VAB for some checking, and sure enough, those Puffs are still perfectly capable of taking off even with sufficient fuel. Good to know for future missions, but too late for the one I already sent. Or was it? Time for a rescue!

 

[RocketSquid]

My first ever duna mission, which was an ill-thought-out failure, was originally planned to consist of 3 unmanned presupplies and a manned mission. The first presupply ran on fuel cells, and had too little fuel since I launched it too early. I realized my mistake, and, already rather fed up with the mission, decided to turn infinite fuel on. I assumed that this would hold true for the fuel cells, but it did not. And since this was before infinite electricity was introduced, it was now a dead hulk, floating in space.

[Mjp1050]

I think this is how Imgur works, apologies if it doesn't appear properly.

So I sent a station to Dres, with full monopropellent and fuel. The first picture is of it in Kerbin orbit, the second is it in Dres orbit.

You may notice something is missing...

Edited March 17, 2016 by Mjp1050
Imgur didn't work.

[DowsingSpoon]

I landed on the Mun with a single stage lander while an Apollo-style CSM loitered in low orbit. Now I must have wasted too much fuel on the landing because I just couldn't quite get the lander back into orbit on the return trip.

So, with the lander on a suborbital trajectory, I switched to the CSM and performed a radial burn to intercept the lander. Somehow, I managed to rendezvous and dock with the lander, retrieve the crew and data, and then return to a stable orbit before crashing into the surface.

[kotomikun]

My Tylo landing and re-orbit ended with zero fuel. And I don't mean LiquidFuel...

 

The lander didn't quite make it back to orbit, but EVA fuel was just barely enough. Then I had to burn some more to narrowly avoid hitting a mountain. The mothership did most of the work for the rendezvous, and the last droplets of EVA-prop were just enough to get the kerbal to the door. Good thing surface samples don't have mass.