[Pic Heavy] Asteroid Redirect Mission

[CalculusWarrior]

I've always enjoyed building SLS and Orion replicas in KSP (made easier once I discovered this Orion mod), and the news that we were getting SLS-style parts into stock KSP was welcome. I have also been interested in NASA's planned redirect mission, and I resolved to replicate it as soon as 0.23.5 dropped. I have done so, and here are the results of that mission.

For those unaware, NASA's plan to capture an asteroid revolves around locating a good candidate (a small asteroid, kerbals would call it a class A), sending an ion-powered craft to secure it, bring it back to Earth and put it in orbit around the Moon, then send astronauts to study it. This will be the mission the SLS will first be put to use for, and it will likely happen in the early 2020's.

It's a good thing the forums have reactivated the spoiler feature, isn't it? I have split this mission up into three segments, Rendezvous, Capture, and Exploration, for easier viewing.

To begin, I needed a ship. I built an ion-powered ship which would grab onto the asteroid. The final ship utilizes a grand total of eight ion engines, with four Gigantor solar arrays. Since the devs boosted ions' thrust yet lessened their electric power draw rate, this is enough for the ship to run all engines at full power in mostly full sun. I took some design inspiration when building the craft from NASA's preliminary ship:

I originally was planning on using a combination of hinges and structural plates to simulate the 'asteroid bag' which the real mission would fold around the asteroid to secure it. However, Infernal Robotics was broken by the update, so I was unable to put that plan into effect. It's probably a good thing I skipped it, as it may have doubled the mission's weight!

Now that a ship exists to capture the asteroid, I needed to locate a suitable rock. While Class E's are certainly an alluring challenge, I am doing this mission with technology available to NASA at the present day, or at least in the next few years. So no NTRs! As such, I stuck to the planned mission and located a Class A which was bound for Kerbin in around one hundred days. Class A's are still respectable pieces of rock, but they are manageable enough to be maneuvered around by my ion-powered probe.

Finally, it was time to launch. I had to be sure to launch early, so that I would use the least amount of delta-v (and thus have to wait the least amount of time) to shift the rock onto the proper path. The real probe will be launched on one of three launch vehicles, the SLS, Falcon Heavy, or an Atlas V. The Atlas V would be unable to put the ship on an Earth escape trajectory, so it would have to use its own thrusters, coupled with a Lunar gravity assist to get onto a proper interception path. Since I was not in the mood for fiddling around for the exact Mun position and waiting for the ion engines to actually complete a burn, plus there were all these lovely new 3 metre parts to play with, I decided to build something like the SLS's cargo derivative:

I went more for realism, rather than utility for this rocket, and it actually has no upper stage. I mainly based my designs off this chart, which admittedly is a few years old, given by the old clustered SSMEs on the SLS core stage.

As you can see, I tried to make the rocket look like the Block IA cargo variant. Thanks to Procedural Fairings, I feel like I got pretty close!

For the launch, see the spoiler below. It is mostly glamour shots of rockets taking off and reaching orbit, all things you've seen before.

Liftoff! You've got to love these new parts.

The rocket is now flying through the clouds. (I have actual volumetric clouds by the way because I'm trying out the Visual Enhancement mod's new experimental. I strongly urge you to check it out, it makes Kerbin look amazing)

Clouds, glorious clouds.

Just after we began our gravity turn, the SRBs burned out. It is at this moment when I realized I forgot to equip them with Sepatrons. Whoops.

Fortunately, nothing breaks, and we keep flying nominally.

I am in love with this clustered engine. Now if there was only some way to break it apart into its constituent SSMEs...

Fairing separation! I like how Procedural Fairings splits 3 metre fairings into thirds, rather than halves, as it does for the smaller sizes.

Shortly after orbit achievement, the maneuver node which I set up to intercept the asteroid became due. I simply fired up the engine again and shot off into interplanetary space. This sure beats waiting for a Mun gravity assist!

Since the lifter stage is now mostly empty and it takes several years to actually turn it, I elected to dump it now. It will become interplanetary debris, and perhaps one day be mistaken for a Near-Kerbin asteroid, like that Apollo stage a few years back.

I also love the city lights generated by the Visual Enhancements mod; it makes Kerbin really stand out!

We are now on our way to an intercept with the asteroid! I was able to get the rendezvous down to a few thousand kilometres, but even when using RCS, it was too difficult to fine-tune the encounter, especially when turning the ship has as a noticeable effect.

To rendezvous with the asteroid, I burned radially out from Kerbin (thrusting just before the terminator) to ensure my trajectory crosses an asteroid's. I got really lucky, and my very first exploratory maneuver node was mostly in the right position. I have to say, an ion engine really helps out in this situation, as you don't have to worry about overthrusting!

After a thirty-seven-day journey, we finally get to less than fifty kilometres from the asteroid. Unfortunately, I sorely misjudged the acceleration this ship was capable of, and ended up blowing past the rock at over a kilometre per second.

Fortunately, this ship has an insane amount of delta-v; there are more than 10 000 units of xenon on board. This makes catching up again trivial.

Now that we've successfully rendezvoused with the asteroid, we now must determine its parameters. Since our Kerbin-based telescopes are only able to tell us that the asteroid exists and its rough size, the true nature of the rock is mostly unknown to us. The real mission would have to analyze a lot more things about this asteroid, as it would have to deal with spin and other nasty real-life effects. Fortunately, this is KSP, so we don't have to worry about any of that 'real-life' nonsense!

As you can see, the asteroid is not terribly larger than the spacecraft itself. While Class A's are respectable in size, they aren't exactly enormous.

The Claw is armed, and our spacecraft now moves in to grab the asteroid. Tensions rise in Mission Control.

Hard dock! We've done it! I managed to grab the rock very close to the centre of mass, but I would have to do a bit of rotating The Claw's bearing to actually line up my thrust centre with it.

So, now that we've grabbed an asteroid, what do we do with it?

We've got to bring it back to Kerbin, of course! Unfortunately, our acceleration, which was poor before we added several tonnes of rock to the spacecraft, is utterly abysmal now. (Even with the buff, ion engines are still the weakest engines in the game). Aerobraking at Kerbin is out of the question, as it defeats the entire purpose of going to get an asteroid; we want to study one which is unaffected by a tumble through an atmosphere.

As such, we will utilize a Reverse Munar Gravity Assist^TM to decrease our velocity relative to Kerbin, saving on delta-v. This is what the real mission will do as well.

The gritty details of actually capturing the asteroid around the Mun are contained within this following spoiler, as there are an awful lot of glamour shots.

There's Kerbin in the distance! Hello again!

It was around now that I realized that I had included lights on the spacecraft. (For some reason I thought that it would be a lot darker).

The coloured lights were a great addition; it makes the game just that little more customizable.

We now see here the finer details of my delta-v capture burn. Note that it is estimating a burn time of ten minutes. That would be forty minutes, if it wasn't for the buff. Thanks, devs!

Hello, Mun!

Rock, meet Mun. Mun, meet Rock.

And the ten-minute burn begins! In reality, it took much longer than that, as I ran out of power when the Mun blocked my solar panels. Fortunately, I was able to do a bit of last-minute burning and get onto a stable orbit, just in time.

I also discovered the wonderful name asteroids are referred to in the game's code: Potatoroids! (It may be different depending on the size, actually)

But after many minutes of burning I finally find myself on a stable, 1 Gm, prograde orbit. The real asteroid mission would finish with a retrograde orbit, but due to my last-minute burning shenanigans, I accidently switched my orbit direction. I presume when the actual mission is flown, NASA will not repeat my mistake.

Now we have captured our asteroid, it is time to send someone to go investigate it!

At last I was able to build a Block I Space Launch System. No more mucking about with KW Rocketry parts, or trying to attach 1 metre parts to the outside of Orange Tanks to give the illusion of larger parts, we have actual NASA-approved rocket parts! While certainly not an exact replica, I at least tried to get the black stripes right.

Again, the launch of this rocket is hidden away in spoilers, for your viewing convenience. (If they ever take spoilers away again, this post is going to be a right mess).

We have liftoff! Liftoff of the SLS Block I spacecraft! This mission will be the first manned mission in fifty years to travel to the Moon, when it happens.

It appears to be a very cloudy at the KSC today. While no doubt playing havoc with pictures taken from the ground, we have no such limitation, and can take some very pretty shots.

Like this one! We just bursted through the cloud layer! We really should have stock clouds on Kerbin.

The gravity turn has begun, and the SRBs remain attached. I just realized I forgot to include Sepatrons on these too...

Fortunately, nothing terrible happened at separation. The escape tower is now jettisoned, or rather slides off. I had tried to use the integrated separation motors in the Boost Protection Cover bundled with the Orion mod, but the clustered engine was just too powerful! As such, the cover and escape tower slide meekly off after we've shut down the main engine.

With the escape tower out of the way (its real purpose was to look cool, anyway), we can see the front of the Orion. A small docking port now lives in the standard-sized one's spot, as the asteroid ship only possesses a small port. This does free up some space for parachutes and lights, both which look somewhat unsightly on the sides of the command pod.

Now the side fairings are detached. Orion is nearly free of the oppressively heavy lower stage!

I again fell victim to my prevalence towards making things look cool/similar to real life rather than practical. Orion should have a Munar transfer stage bundled with it, but I couldn't find room. Fortunately, the integrated service unit has enough fuel to make the trip. (The fact that we are going to High Munar Orbit also helps)

Solar panels are deployed, in the signature not-quite-45-degrees-from-each-other manner.

Orion burns for the Mun.

Goodbye, Kerbin! The humans aboard the real flight will be the first to see this sight for nearly half a century.

And hello, Mun! I wonder if the Moon will have changed much in fifty years?

We have now arrived at the asteroid. Those signature red lights really give it away. Have I mentioned how much I love the tweakable lights yet?

We're now lining up for docking maneuvers. Both ships do possess onboard RCS supplies, but the capture vessel used it all up when bringing the asteroid home. Turning a multi-tonne rock takes quite a lot of fuel, it turns out.

Steady...steady....

Hard dock! We have connected to the asteroid!

Now, on a real mission, the astronauts would extend a ladder/pole to climb up towards the asteroid. They do not have the luxury of jetpacks which contain several hundred metres per second of delta-v. But ladders are so much more boring (not to mention I forgot to include any on Orion) than jetpacks! Or so Jebediah thinks.

He's really excited about seeing an asteroid close-up. The only thing better for him would be riding one down to the ground on Kerbin in a command seat. In time, Jeb... In time...

For a final spoiler, I've included some images of Bill, Bob, and Jebediah exploring the nooks and crannies of the asteroid.

Jebediah learns that even though he his thrusting down towards the asteroid, this does not provide artificial gravity and allow him to walk like normal (take that, Armageddon!).

Pity you can't plant flags on them. Ah well, there's still plenty to do, and the view is spectacular.

Jeb's face mirrors my own as I was exploring the rock. There's something about reaching out and grabbing a celestial body for yourself that makes it feel special.

Back to the ship for now, Jeb. Bill and Bob want a turn! The real mission would only carry two crew members, as life support in the tiny pod couldn't support three or four for the three-week journey. As I have proven on multiple occasions, however, I am not entirely concerned about perfectly mirroring reality for this mission. (Besides, if a kerbal can survive an interplanetary transfer from Jool, he can put up with a three-man pod for a few days).

TextureReplacer (the mod which I am using to change the skybox) gave Bill and Bob these fantastic mustaches, which I decided to let them keep. I like how such a small thing like facial hair can really distinguish your kerbals from one another.

Bill looks like he's having a good time, but Bob doesn't seem to like being so far away from Kerbin.

Alas, the time comes to return to Kerbin. KSC can confidently label this mission a complete success. Not only did they catch an asteroid from the depths of deep space, they brought it into orbit around the Mun, sent kerbals to it, and (if this was Career mode) gathered important scientific data from it. Hooray!

Resources:

Link to the Asteroid Redirect Mission, as envisioned by NASA itself:

This pdf file was very handy when designing the capture craft, and also for trajectory planning. It provides a lot of great information on the upcoming mission.

[TABLE=width: 1000]

[TR]

[TD]Visual Enhancements[/TD]

[TD]Clouds/City Lights[/TD]

[/TR]

[TR]

[TD]Distant Object Enhancement[/TD]

[TD]Black sky when looking at a bright object, as well as the dots which represent planets/ships[/TD]

[/TR]

[TR]

[TD]TextureReplacer[/TD]

[TD]Custom skybox/kerbals, kerbals take their helmets off on Kerbin[/TD]

[/TR]

[TR]

[TD]Procedural Fairings[/TD]

[TD]Fairings/Nosecones[/TD]

[/TR]

[TR]

[TD]HotRockets[/TD]

[TD]Engine effects.[/TD]

[/TR]

[/TABLE]

Orion screams down towards Kerbin, ready to reenter.

The command pod is separated from the service module, which will presumably burn up on reentry (it actually stayed with us pretty much the whole way down).

Burn, baby, burn! I am almost certain Jebediah is entertaining the possibility of opening the door to roast a marshmallow or two.

The capsule falls towards the cloud layer. Seriously, Visual Enhancements' experimental build. It's fantastic.

Poof! We're through the clouds.

I guess parachutes would help us slow down? I was so distracted by the clouds, I nearly forgot them!

Floating towards ground

Bob breathes a sigh of relief

At last, they are home.

Glamour shot!

Edited April 2, 2014 by CalculusWarrior

[19spacepug]

Awesome job on that mission there.I really like the cloud layer and the great views of the asteroid and kerbin.Great job.

[Cydonian Monk]

Nice! The next question is what do you do with the asteroid once you've caught it? I've not looked into NASA's disposition plan, but I would assume at some point down the road they'd want to either deorbit what they've caught (to prevent Lunar mascons from perturbing its orbit and possibly sending it crashing down to Earth) or sell it to be mined. Kicking up chunks of the Moon by flinging a big rock at it in a controlled fashion and observing the after affects would be a geologists' dream... but if they catch something valuable (say, a rock with mineable nickel), who knows.

[Werwolf]

Really enjoyed this thread. Thanks for the mission report!

[CalculusWarrior]

Nice! The next question is what do you do with the asteroid once you've caught it? I've not looked into NASA's disposition plan, but I would assume at some point down the road they'd want to either deorbit what they've caught (to prevent Lunar mascons from perturbing its orbit and possibly sending it crashing down to Earth) or sell it to be mined. Kicking up chunks of the Moon by flinging a big rock at it in a controlled fashion and observing the after affects would be a geologists' dream... but if they catch something valuable (say, a rock with mineable nickel), who knows.

I think I'll leave the deorbit plan up to Jeb; knowing him it will involve a reentry over KSC. I feel like he's going to want to make poor Gene spill his coffee as he buzzes the tower with a giant rock!

[PeterMueller]

Damn! Wanted to do the same but you were faster! I really love your approach.

Some remarks:

- The SLS is only used to launch the redirect vehicle into a direct lunar gravity assist. For earth orbit insertion an Atlas V is used. (see this NASA PDF page 19)

- I think you missed the upper stage of the second SLS launching the Orion craft! See here for inspiration

Else: Well done!

Here is a shot of my first attempt.

Best

Peter

Edited April 21, 2014 by PeterMueller

[SpaceSphereOfDeath]

Good post, but there's a typo, you say your in a 1Gm orbit around the mun. The highest is 2.2Mm.