Jool 5 Challenge - J5 Endeavour report

[purpleivan]

Here is the report for my Jool 5 Challenge mission, level 3 (five landers landed on the fire moons, each by a separate pilot).

The first thing I need to mention is that a few (four or five) of the maneuver burns I made don't have a screen grab to show the delta-v of these. I'd thought that I'd remembered to do this for all maneuvers, but in the earlier parts of the mission, I must have forgetten to hit F12 a few times. I'm hoping that the (rather embarrassingly) large amount of fuel I had spare in the various vehicles at the end out their use will be enough to cover for that.

The second thing that I should make clear, although it is described in the mission report details below, is that the ion powered micro landers, which were used to make the landings on Bop and Pol (by Roley and Gregbert), were earlier made use of by Jeb and Bill after they made their landings on Tylo and Laythe. This was to allows me to transfer these two crew from orbit of their moons, to a rendevouz with the core ship with minimal fuel requirements. Then I switched over the pilots of the micro landers to those that would make the landings on Bop and Pol.

Here is the information about the setup of KSP I used for this mission.

Game version: v0.90.0

Mods used: The only one that wasn't purely aesthetic (e.g. HotRockets, PlanetShine and Chatterer) was Precise Node, which I have to allow me to get around some of KSP's GUI issues (e.g. to adjust maneavour nodes for a rendevouz on a very well balanced orbit, where the closest approach markers were wiggling wildly). So all transfers, rendevouz' and landings done manually (i.e. no Mechjeb).

Ok... now the mission details.

The Pics

I had to break these up into two albums due to Imgur limit of 250 images/album.

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The mission report

Part 1 VAB to Jool

The J5 Endeavour had a launch mass of 2298t and was designed to need no refueling in its return trip to the Jool system. As it turned out the vehicle was significantly over fuelled, a result of

overcompensation for problems with with a previous "all up" test of the vehicle that flew a full rehearsal for the mission.

The total vehicle includes five landers (two propelled by ion drives) plus a core vehicle that acted as accomodation for the crew as well as the return vehicle to Kerbin.

Due to a large difference in the mass of the Tylo and Laythe landers, that were mounted on the vehicle, the Tylo lander was only partially fueled, with fuel being drawn from the core vehicles' drop tanks before separation.

Launch was uneventful, although involved the use of four stages (including asparagus on the base engines).

The initial burn out to Jool wasn't particulary accurate, but a course correction burn put the ship on a trajectory that brought it to about 10,000km from Jool. Further course corrections put the ship on target for a 116km periapsis, that would give it the aerobraking required to put it into orbit around Jool, with an apoapsis between Laythe and Vall. This orbit was then burned to circularise it.

Once in a circular orbit, Jeb and Bill left to safety of the core of the vehicle and ventured to their respective landers (one for Tylo and the other for Layth). Once in their seats, the ship was detached into three separate vehicles.

Core - 3 nuclear engined propelling the habitation modules and the Vall lander

Tylo - 1 nuclear engine propelling the Laythe lander, the Pol lander (used as a transfer vehicle from Laythe back to the core ship

Laythe - 1 nuclear engine propelling the Laythe lander, the Bop lander (used as a transfer vehicle from Laythe back to the core ship

At this stage, Jeb was on the Tylo vehicle, Bill on the Laythe, with Bob, Roley and Gregbert safetly tucked away in the core vehicle.

Part 2 Tylo landing

After making his way to Tylo orbit, the vehicle separated into three parts. The lander, the micro lander and the nuclear engine with its large tank that was still about 40% full. Jeb then burned for descent, taking the lander down towards the surface. On it's way down two pairs of aerospike engines and their fuels tanks were dropped in sequence, to reduce the weight of the vehicle on its way down.

After landing and a quick run around on the surface, Jeb climbed back aboard and headed for orbit, dropping off two pairs of fuels tanks, as each ran dry. Once in orbit he rendevouzed with and transfered to the micro lander, which he would use to transfer to the core vehicle.

Part 3 Laythe landing

Bill took the Laythe vehicle to that watery world, which he passed over (after some course correction) at a periapsis of a little under 27km, which would give him the aerobraking required to put him into a decent orbit.

After some adjustments to make his orbit circular at about 61km , he separated the nuclear transfer vehicle (which still had about 45% o fuel remaining in the tank), the lander and the micro lander.

Once seprated he made a decent burn to bring his lander down towards the island on the equator, with the large crater lake in it. Even with four chutes, the landing speed was going to be a little high, so a small amount of fuel was reserved in the descent/landing stage of the vehicle for a short burn to soften it.

After landing to the south of the crater lake, Bill took a quick look around on the surface, before climbing back on board, through a tight but navigable gap between the ascent vehicle's jet engines. Once aboard he detached the decent/landing stage and fired up the four jets for the ascent.

As it turns out, four jets at full thrust, on a vehicle weighing less than 8 tons, is an awful lot of thrust and Bill soon found that he was getting massive atmospheric heating during the ascent, before detaching the jets and continuing on the single LV-909 to orbit.

Once in orbit Bill rendevouzed with the micro lander and jumped across to it, before pushing out his orbit to 1310km, in order to reduce the impact of Laythe's shadow (a bad thing for ion engines that need to soak in those sunny rays) when he would head off to the core vehicle later.

Part 4 Vall landing

After adjusting its orbital plane to match that of Vall, the core vehicle burned out its orbit to rendevouz with it. After separating the Vall lander, Bob jetted off after it and got himself comfortable in the command seat. A short time later he was burning the single Lv-1 engine, that would serve him both for the descent to and ascent from the surface.

During the descent the pair of rather ungainly looking drop tanks were detached on running dry of fuel, leaving him with only a single FL-T100 tank to fuel the remained of the descent and the return to orbit. Finally Bob made it to the surface with almost half the fuel remaining in the tank for the ascent.

Bob took a quick excursion on the surface of Vall, before climbing back onboard and heading back to orbit and rendevouz with the core vehicle.

Following his return to the core vehicle, it was moved to an orbit between Tylo and Bop, where it would wait for Jeb and Bill to rendevouz with it and to hand their micro landers to Roley and Gregbert, for them to use to make the landings on Bop and Pol.

Part 5 Bop landing

Bill left orbit of Laythe, putting his micro lander, putting it into a 74,800km orbit aroun Jool, from which he made further burns to rendevouz with the core vehicle. On his arrival there, no time was wasted getting him back into a habitation module and Roley into the command seat of the micro lander.

Once sitting comfortable, Roley setup his maneuver to change his orbitla plane to match that of Bop, before a further burn to set him up for rendevouz. On arrival at the mini-moon, he burned into an orbit, which although very eliptical, was only 22km away from its surface at periapsis. From here he burnt for descent to the surface, finally putting it down on a very steep slope.

After a quick run (or more accurately a slow-mo jog) on the surface, Bill got on board the micro lander, unfurled it's solar arrays and headed for orbit.

Part 6 Pol landing

Jeb had been on in orbit of Tylo for some time now and was itching to complete his part of the mission and get back to the core vehicle, so he setup a maneuver to burn out of Tylo orbit, unfortunately the batteries of the micro lander were not sufficient to power burn in a single stretch, so this was broken up into three seprate ones (only the original maneuver is shown in the mission photos), recharging between them.

He then made a series of burns, firstly to circularise his orbit around Jool, then another pair to move it further from that of Tyle (the SOI wouls have caused him difficulty later if not for this) and circularise, then another pair to move it out a little further still. After these further burns were made to rendevouz with the core vehicle, where he gladly gave up his seat on the micro lander (he was getting a stiff back from it by this stage) to Gregbert.

Gregbert, once at the controls, made a plane change burn to match that of the orbit of Pol, followed later by further burns to rendevouz with Bop and enter a 36km orbit of it. From here he made the descent burn towards the surface, giving himself some time to admire the unusual rock formations he could see on his way down.

Once landing had been achieved on a far flatter location that that of the earlier landing on Bop, Gregbert dismounted the micro lander to take a look at the surface. "Hmmm... dirt" was his main comment on it. After this he jumped back aboard the lander and headed for orbit.

Part 7 Return of the micro landers

Bill started this part of the mission when he made a burn out of Bop orbit, followed by others to place his micro lander in a circular orbit of Jool, outside that of Pol and on the same plane as the core vehicle, where he waited for the core ship to come to him.

After some course correction burns, the core vehicle brought itself alongside Bill, who then made his last maneuver by jetting over to the hatch on the Hitchhiker module.

Then it was Gregbert's turn to rendevouz with the core vehicle, which he did, after a mishap burning his plane alignment (0.1 degrees out just isn't good enough with these kind of distances). Once this was corrected, he made the necessary burns to rendevouz with his ticket home to Kerbin, taking time to get some press shots of himself in the micro lander, outside a habitation module window, before joining his fellow crew members on board the core ship.

Part 8 The return

After many years of travelling to and then within the Jool system it was time to head for home. This process began with a long burn to break free of Jools' SOI and to pull their orbit back in towards that of Kerbin.

Following a single course correction, the J5 Endeavour was on course to come 163km from Kerbin at periapsis, this was later burned in to 32.5km to make use of aerobraking to bring the ship into Kerbin orbit.

However an error of judgement meant that a further, long burn on their single nuclear engine was required to acheive orbit as aerobraking at that altitude was not going to be sufficient. Fortunately the ship was fat with fuel at that point, with even the two drop tanks being about 70% full after the burn.

Finally after swinging around the sunny side of Kerbin it was time for landing on its dark side. Separation of the landing module from the engine and fuel tanks was made during the fire of re-entry, followed shortly after by the chutes deploying, much to everyone's relief.

Touchdown was made minutes later at night in the grasslands of equitorial Kerbin. A photo was taken of the crew at the time, but another was made hours later, when lighting conditions were more suitable. However the existence of these two images, plus a joke image taken by the crew, with their ship out of shot, unfortunately led to conspiracy stories about the mission having been faked by the guys at KSC to attract much need funding. Stories that are strongly denied by KSC.

- - - Updated - - -

A quick update of some details I missed in the mission report.

How many Kerbals are on the mission = 5

How many launches was needed to start your mission from Kerbal = 1

Did you needed a refueling mission = No

Did you bring a Living Quarter (Hitch-hiker's Storage) for the guys during the long journey = Yes (1 Hitchhiker can plus 1 Mk1 Lander can)

Did you bring additional stuff like satellites, rovers, etc = No

Share the delta-V informations too, if you tracked it = It's in the pics (sorry)