Kerbal Space Program Mission #8

Munar Lander 5: Double rescue mission

Day 17

Active project: Munar Lander Project

Active missions: Munar Lander 5, 4, and 3
Current mission: Munar Lander 5
Selected vehicle: Lightning 2

Assigned crew: Unmanned

"Are we dead yet?"

While it feels like at least a week since our two astronauts have been left in orbit of Kerbals moon, the game has only let an hour or two pass while I prepare a second unmanned rescue rocket.

The Munar Lander 5 is a re-use of all the hardware previously created for the third mission, which is currently on an intercept course to Josh and Thong.

The mission badge is merely symbolic, nobody will be riding a rocket back to Kerbal.

If Lander 3 is able to meet up with their vessel and bring one home, there's no reason to fiddle with the design to do the same task.

Has space pioneering become that passe in just two weeks that we're skipping the countdown?

The rocket is launched in the same day and without a hitch, it goes without saying.  Sorry to disappoint those of you waiting for some Kaputnik-style launch disasters, but you may have to wait until I develop and begin experimenting with a larger class of rocket parts.

Following an orbital insertion burn, the rocket is set to encounter the Mün in about seven hours. This gives plenty of time to adjust the orbit of the previous unmanned vessel. 

Luckily I included this easy-to-read visualization; my readers would have had NO CLUE how complex orbital maneuvering works!

First of all, I notice a glaring flaw in my previous assessment of Munar Lander 3's interception of the two-man Munar Lander 4: they are orbiting in opposite directions. ML4 took off pointing away from the moon's direction of rotation, putting it in a retrograde orbit; ML3 never landed and is still orbiting pro-grade. It'd be like two trucks passing each other on the highway, but at speeds over 800 meters per second.

I may be cruel enough to make our Kerbals jump through space from one vessel to another parallel craft, but not ones passing in opposite directions.

We sure that's them? That could be anybody in orbit at the dawn of spaceflight.

The first course correction involves reversing direction by thrusting until the same speed in the other direction is met.  From there, a lot relies on the flight path computer to help adjust the orbital path of the ML3 until it passes by Josh and Thong's orbit within a kilometer, and the at that point adjust speed until the it shows the next time we'll pass that spot at the same time.

It's a convoluted process that would require a lot of visual aids to fully depict, so instead I will leave it at that.

You boys look like you could use a lift.

Once both craft come around to that intercept point, the Munar Lander 3 simply needs to adjust relative speed and heading to match the 4th lander to within a few meters per second. Our stranded crew only needs to wait a few more minutes as the rescue ship slowly drifts towards them.

"Let me out, I've been stuck in there for like two whole hours!"

Thong has selflessly volunteered himself to take the first rescue craft. The logic he presented eludes me still, but seeing as no other suggestions were made, I go along with the veteran astronaut's recommendation.

"Sorry Josh."

The vessels pass each other within ten meters at a velocity of less than a meter per second. Not toot my own horn, but that's might precise piloting there, especially as only one ship was maneuverable.

Open the pod bay doors, HAL.

The close encounter makes for a very easy spacewalk to the rescue rocket. One more event for the history book.

Your in-flight entertainment will be listening to the ship's computer make R2-D2 noises for the next 10 hours.

Even with the fuel spent reversing our orbit, the rocket is able to push itself out of the Mün's sphere of influence and back to Kerbin. Three more days and Thong will smack into his home planet's surface.

Well, I mean his flight plan is on course to do so. Thong's craft has its (successfully-tested) parachute and we'll be following his safe descent as the second unmanned rocket makes its approach to Josh still stuck in orbit.

But that's a few hours away and makes for a good break. I have the photos ready to upload for part two, so soon we'll be finishing all active missions with the return of our first moon missions.

Kerbal Space Program Mission #7, part 3

Munar Lander 4, part three: Need a lift?

Day 17

Active project: Munar Lander Project

Active mission: Munar Lander 4
Selected vehicle: Lightning 3

Assigned crew: Thong Kerman

'Sup.

The two moon landing site of Thong and Josh Kerman (no relation?) are separated by a 'mere' three kilometers.

No, that's not a mirage. Fly to it, Josh! Fly to freedom!

While this could be traversed by foot, possibly in under an hour, it would be more efficient for Josh to fire up the rocket pack and boost over there within a couple minutes.

Rocket maaaaaaaaaaaaaaan!

Considering the rocket pack can't even lift a Kerbal off the ground on their home planet, it provides a considerable amount of lift in the Mün's 1/6th gravity.

So close...

Not to mention a hefty amount of fuel built in. Josh could have easily covered two or three times that distance if needed. Something to keep in mind for later missions.

They stare awkwardly for several minutes.

Finally, Josh is brought face-to-face with Thong. Say 'thank you', Josh!

"You don't want to know what my space suit smells like after six days..."

 Or just board the lander, whatever.

"Dang it, Josh..."

At this point the Munar Lander 2 mission is now officially complete, all that's left is to send Munar Lander 4 home.

Pre-flight checklist? Check.

Our crew reviews their collected data, including two rock samples and an extra EVA report (which can be transmitted back to Space Command for its full scientific value). We don't want them to forget to have performed all possible experiments while here, who knows when we'll convince them to come back?

After that has been settled and confirmed, the two kerbals lift off from the barren landscape. I send them on the direction retrograde to the satellite's orbit: this will clear them away from the Mün's gravity well and set the craft on its own orbit around Kerbin. Hopefully there's enough remaining fuel to dip that orbit into the planet's atmosphere for a landing.

Say goodbye to your home for the past week, Josh.

Since there's no air on the Mün the only minimum altitude to be cleared to achieve orbit (or escape velocity in our case) is that of the surrounding hills.

Long story short, they ran out of fuel before they could escape the Mün's gravity.

Whoops!

It was discovered that fuel was running dangerously low well before the Lightning lander would reach escape velocity (over 800 meters per second). I made the call to spend the remainder on circularizing the orbit, rather than watch it smack back into the moonscape.

We have traded one astronaut stranded on Kerbin's moon to two astronauts stuck orbiting it. That's less of a fuel requirement but still a predicament.

There are however two pieces of good news here:

Houston, we're in a bit of a pickle.

First, I noticed that the unmanned Munar Lander 3 rocket has in fact started catching sunlight! Yes this is very helpful, bear with me here.

Number Five is alive! No disassemble!

It had built up enough electric power to allow me to rotate one solar panel into full view and recharge a proper reserve. This rocket still has all the fuel it would have spent on landing.

Need input! IN-PUT!

Since that mission is is no longer relevant, there's plenty of fuel to make orbital course corrections or return home.

Second, by apparent coincidence the craft is already passing relatively close to Thong and Josh's vessel on the next pass. It takes a very minor course correction to ensure it will come within 400 meters, which can be even further refined later in the approach. 

Next time call for a ride home six hours in advance.

It should be possible for one astronaut to use his rocket pack to space walk and match velocity with the Lightning 2 as it passes by. The other could be picked up using another Lightning 2, in as little as a couple hours later depending on how quickly Munar Lander 5 can be launched.

Unless someone has another idea to formulate, I think we have the most expedient plan to see our active missions to completion.

But which Kerbal should be picked up first? On one hand, Josh has been stranded for longer so it's only fair, but taking Thong home first would be funnier. Hrmmm... 

Kerbal Space Program Mission #7, part 2

Munar Lander 4, part two: Let's land it right this time.

Day 17

Active project: Munar Lander Project

Active mission: Munar Lander 4
Selected vehicle: Lightning 3

Assigned crew: Thong Kerman

Finally it is morning in the big far-side Münar crater, bright enough to initiate a landing.

"The Morning is here! / Sunshine is here! / The Sky is Clear! /
Get into gear! / Breakfast is near! / The dark of night has disappeared!"

Thong finally begins to bring the craft down for a landing as close as possible to Josh's site.

We can see Josh from 30km away and even from up here he looks rather peeved.

He might as well take advantage of the broadcasting equipment and send us an in-flight report on the way down.

Imagine a car that goes from zero to 60 in seven seconds, and from 60 to zero in also seven seconds.

When the transfer stage runs dry and has to be finally ditched is when the landing gets tricky. Though not the same way as before, thankfully.

Now imagine that car is stuck on the interstate with a fuel gauge reading 'Empty' and if it doesn't find  a gas station soon it will be stuck going 60MPH forever.

Thong overshoots the site a bit simply for trying to conserve fuel, but this results in a riskier 'slamming on the brakes' maneuver close to the ground.

Well the jokes on you, because Thong is able to pull it off.

The lander's engine proves itself as capable of a quick deceleration and Thong lands the Lightning 3 as the first successful moon landing.

Watch that first step, it's kid of a long drop even in low gravity.

Not to detract from Josh's historical landing of course, but the possibility of returning home is pretty substantial. The vessels are three kilometers from eachother; I was hoping for about a tenth of that to make for an easy journey, but it's still within the achievable travel distance.

Yay!

Having another astronaut on the Mün means the 4th Munar Lander mission can perform more tasks than simply driving Josh home. Thong plants his mission flag for boasting rights and takes a second rock sample. Bringing these two home with their reports and samples will make for a substantial scientific contribution.

But first we have to get both of them off this rock.

Kerbal Space Program Mission #7, part one

Munar Lander 4: OK, let's try this again.

This will be a brief update, but it's mainly due to the sheer volume of screenshots and events in this mission that require splitting it up. I'd like to get the next part published fairly soon, to avoid letting down my handful of readers.

Day 15

Active project: Munar Lander Project

Active mission: Munar Lander 4
Selected vehicle: Lightning 3

Assigned crew: Thong Kerman

After the electrical failure of the previous rocket, a second attempt at a rescue mission has been prepared and launched early the following morning from Kerbal Space Center.

Hurry! We have to save Josh from boredom!

Rather than being left behind as an unused design, the competing lander prototype is now serving as the third model in the program's Lightning series.

Space hasn't changed much since you were last up here.

Thong was the main proponent for using a manned vehicle bearing a spare crew module. Thus on short notice and with no volunteers he has been selected as the one to man it.

I always include a photo of the retro-burn, they make me feel nostalgic.

The launch and orbital transfer stages manage to carry the new, heavier craft into space with a decent amount of fuel left.  At least it's decent from what I can tell at this point. Command does some rough mental math based on the previous designs' fuel usage and concludes that Thong's mission does not need to abort.

What if my head explodes with dark forebodings, too?

However, Josh's landing site is still on the night side; a difficult prospect for a precision landing. We'll let Thong Kerman complete another 5 or 6 orbits until it becomes sunrise at the first Mün landing site. This will push Josh to nearly a full week spent stranded.

We'll come back to the rescue mission once it's ready to land. Stay tuned.