Kerbal Space Program Mission #3

Experimental Test Launch 3: Eyeballing the numbers

Day 5

Active project: Experimental Rocket Project

Next mission: Experimental Test Launch #3

Selected vehicle: Thunder Road 3

Assigned crew: David Kerman

The other David quit when he realized this wasn't the sign-up for the raffle.

At Thong's recommendation, Kerbal Space Program has recruited one of its new applicants, David Kerman, for our next mission.

Was told nothing.

I would like to say David has gone through our rigorous training process, but frankly there isn't one. After suiting up he'll be strapped into the Thunder Road 3, which shall be wheeled out to the launch pad. Further instructions will be provided during the flight.




The countdown is set to T-minus 5 seconds as soon as the tranquilizers wear off but before David realizes where he is.

Five... Four... Three... Two... One.

This is clearly not the cab back to the hotel.

Another successful launch brought to us by a trio of SRBs, providing similar performance as on Mission 2.

This time around the boosters are immediately decoupled once exhausted.

Although for some reason the rocket begins to drift pretty bad afterwards (the green circle on the navigation ball is the direction of movement; it should be closer to the direction the ship points on the gold cross-hairs) It may be an issue with available thrust versus weight, or simply poor stage timing.

Fortunately David is able to compensate the lost altitude once the second stage is decoupled. At this point there's plenty of thrust and fuel left to get out of the atmosphere.

Catapulting the Thunder Road way up to 70 kilometers, it will be best for David to wait until reaching apoapsis before applying further thrust. Trust me, I mostly know what I'm doing.

Space ain't the kind of place to raise a kid.

Plotting a course this way allows all acceleration to be applied evenly forward rather than adding extra altitude.

In fact it's cold as hell.

In the meantime, we pop open a goo canister and record its change in properties. For science!

This orbital course leaves the Thunder Road at about one quarter fuel remaining. Turns out this is far better than last mission.

With a stable orbit achieved, there's time to perform the second canister test, this time under the full effects of a vacuum and weightlessness.

Doesn't receive any AM/FM, can sometimes hear KSC's playlist in the background.

David jumps back into the command pod to transmit the EVA report. Unlike this text-only report, the goo canister experiments require further study from the space center and a broadcasted report would only be of partial value. He'll be bringing these back home at the end of the mission.

Maybe tape a penny onto the pod, it might give us free transmissions.

A setback is discovered partway through a second EVA report transmission: not enough electrical power to transmit. The pod only carries so much charge at a time and is only recharged by the rocket engine.

Good enough excuse to perform the orbital transfer test to Kerbin's moon! This is the primary orbital test I wanted performed during ETL3 as it will show whether the current rocket design can perform a fly-by of the moon.

We test the Thunder Road 3's ability to reach the natural satellite's orbit by accelerating using all but the last few units of fuel. This will push its apoapsis as far as possible but leave the lowest point just a few kilometers above the atmosphere.

I'm surprised to say we have a success.  The Thunder Road is now on an extreme elliptical orbit that reaches as far as the moon. What kind of mission can be accomplished next with this kind of range? That I will answer later, as we have about a day before David reaches this ~11 million kilometer distance and then the same amount of time as he slowly fall back to low Kerbin orbit. Sit tight, David.

Kerbal Space Program Mission #2: 2nd orbit and return

Experimental Test Launch 2, part two.

Day 4

Active project: Experimental Rocket Project

Active mission: Experimental Test Launch #2

Selected vehicle: Thunder Road 2

Assigned crew: Thong Kerman

Last time on Kerbal Space Program...

We previously left our active mission in orbit around our planet Kerbin. Now that Thong Kerman has completed one full orbit, he can go ahead and return home.

I must have turned the camera flash off.

It takes around another half-hour for our Thunder Road-series rocket to return to the highest point on its orbit, still on the dark side of Kerbin. As mentioned last time, performing a 'retro-burn' (rotating the rocket around and thrusting in the opposite direction of momentum) at this point allows it to lower its trajectory efficiently.

I'd hate to strand Thong up there without enough fuel to slow down; planning a rescue mission would be a real pain.

Anyway, once the rocket comes back around and dips back into the atmosphere simple friction handles most of the deceleration work.

The fuel is all but gone and the engine has done its job of bringing Thong back home. At this point the final stage is activated and the command pod separates for a landing.

Oh wait, I left my book on that stage.

The Thunder Road 2 comes down over a vast ocean, where the command pod should land safely without issue. We lack the means to properly recover the spent rocket stage and it's left to drift and crash into the sea on its own.

Why is he so happy? Is it the sensation of a warm seat?

The re-entry effect is still quite pronounced here despite the smaller profile presented than last mission's mark 1. The difference being a faster re-entry speed but it's still within temperature limits at this time.

Parachute deploys successfully. You win this time, Thong.

I'm in a pod / I'm in a pod / Everybody look at me / because I'm sailing in a pod.

So that mission accomplished a successful orbit and leaves us with some additional scientific gains, though honestly it's not a huge jump.

Kerbal Space Program's next obvious goal is the moon, but it's going to be a question of building a rocket with enough oomph to get there, and whether the current tech can do it. I'll go into this further in another update, but it's definitely going to be an undertaking

As mission commander and the one playing the game here, I propose one more orbital mission in the Experimental Test project, the objective being a further study of orbital flight to test the feasibility of reaching the moon.

This third mission will use a minor upgrade in the current series, bearing the name Thunder Road 3. Now that we have lateral decouplers, the solid rocket boosters can be chucked after use. Some tail fins should help stabilize flight as well. Stage 1's fuel capacity has been increased with another T-400 tank.

Highly complicated precision equipment.

Finally, the missions so far lacked the ability to send any data back during flight. Not to mention the lack of qualitative experiments to conduct. A broadcast antenna has been added, along with a pair of Mystery Goo™ canisters. These are attached to the command module so they can be used during the entire flight and brought back for material testing.

Day 5

Active project: Experimental Rocket Project

Next mission: Experimental Test Launch #3

Selected vehicle: Thunder Road 3

Assigned crew: ???

Since this mission will involve multiple orbital flight adjustments there is a fair risk of running out of fuel while still left in orbit. However, the first person to nominate a volunteer will receive candy. Yes, I can and will employ bribery.

Kerbal Space Program Mission #2

Experimental Test Launch 2: Electric Boogaloo

Day 4

Active project: Experimental Rocket Project

Next mission: Experimental Test Launch #2

Selected vehicle: Thunder Road 2

Assigned crew: Thong Kerman

Was warned in advance.

I've received a volunteer for this mission. Thanks, Thong!

Now let's get this next rocket launched before he changes his mind!

Countdown in 1.

One. Liftoff!

We should have specified he'd be sitting in a ship whose back end explodes continuously for 4 minutes.

The Thunder Road 2 is off to a fast start thanks to the solid rocket boosters. These start to overheat at T+ 14 seconds but by then the solid fuel is half spent. The boosters extinguish themselves at about 7km, requiring Thong to push stage 1's engine nearly to full throttle to maintain acceleration.

Following the proscribed flight path, Thong begins to pitch the rocket downwards and eastwards into a 'prograde' trajectory (in the direction of planetary spin).

I hope that doesn't land on anyone we know...

Stage 1 empties just before 15km. time to activate the decoupler and release several tons of dead weight.

The rocket continues to pitch down until it levels out in the upper atmosphere. This may be a little short, but there's plenty of fuel left. 

This trajectory has the right altitude now, all it needs now is enough forward speed to make it all the way back around. 

 Almost there...

...And the path makes a full circle. Except this is still technically sub-orbital; dipping back into the atmosphere that far will slow the rocket down enough to not make another pass. For future reference, that lowest point in the orbit is called the 'periapsis', while the highest is the 'apoapsis' (around 400km here).

Luckily, thanks to science and experience I know of a maneuver that will extend the periapsis with far less fuel than if we had the rocket keep thrusting right now. Thong is given the instructions to accelerate forward once he reaches apoapsis, twelve minutes from now.

In the meantime, he's given the OK to perform the first Extra Vehicular Activity spacewalk. 

If you had bothered seeing 'Gravity' you'd be to terrified to perform this experiment.

Logging an EVA report gives us another boost in science. Thong will have to hold onto it until he gets back. Our next rocket really should carry a proper broadcast transmitter.

That's no moon... it's a six-axis control doohickey.

Fuel is a bit scarce at this point and we don't want to waste it on moving into an orbit further than needed. 

Not pictured: proper lighting.

Once at apoapsis on the night side of Kerbin, Thong throttles up and pushes the periapsis up from ~25km to over 77km. This is outside the atmosphere and creates our first successful orbit.

This is a nerdy kind of victory.

More importantly, The Thunder Road has enough fuel to accelerate in the opposite direction once back on the other side of this orbit; that will bring the periapsis down again enough to plunge back into the atmosphere and then fall to the ground.

It will be another 40 minutes or so in space, Thong. How are you holding up?

It's full of stars!

I'll take that as a 'fine'. We'll complete this mission report later. I've got some tech upgrades to think about.

Experimental Rocket #2 Development

It's come to my attention via Kerbal Space Center's R&D department that in order to achieve orbit simply flying straight up isn't going to cut it; gravity is working directly against the vessel's acceleration and will just come straight back down.

Hipster glasses? Check. Hipster mustache? Check.

(Actually I know this from having played the game a lot already. Humor me.)

Instead, we'll be following a curved flight path, angling every 10 kilometers or so until the vessel is out of the lower atmosphere and can reach the speeds needed to sustain a continuous trajectory around Kerbin. Picture the rate you're falling and flying forward being equal to the curvature of the planet. I'd estimate around 2 kilometers per second at an altitude of 70-75km.

Science!

So, two things our next rocket needs to really ensure it can accomplish this speed and distance: more acceleration in the lower atmosphere and less weight later in the flight.  just adding more fuel tanks will hinder both. Our newly-developed components can tackle these issues, particularly solid rocket boosters and decouplers.

First of all, I've upgraded the Experimental Rocket with the new tanks. Same weight and capacity, just less parts.

This design series really needs a name. I'm rather partial to naming spaceships 'Thunder Road', so we'll call this the Thunder Road 1.

Now to refine this into the Thunder Road 2. The only parts to survive landing so far have been the command pod and the empty fuel tanks. It may as well ditch everything but the pod before landing. Placing a decoupling ring between the command pod and the fuel tanks adds an additional stage to the rocket and lets it forcefully separate components when activated.

A third stage can be added to provide more fuel tanks. When the tanks run out they can be discarded and leave less dead weight for the ship to push into space.

Finally, we'll add boosters to that stage to compensate for all that extra weight the first engine has to lift.

Unlike the liquid fuel engines, solid rocket fuel is a dense compound that burns quickly with a high thrust. The reaction is not very efficient however and cannot be stopped once ignited, thus the boosters will help out early on and then become useless. They will be discarded when the first stage decouples. 

I initially considered a pair of SRBs but opted for three of them for more oomph. Placing them away from the main fuselage should also avoid overheating issues. The next mission may reveal which of these need to be tweaked but the current design should work well.

The Thunder Road 2 is ready for launch. I'll just need a volunteer.