Horizontal Space Program

[rcp27]

I know it's been done before, but in light of the space plane parts that came with, what was it, 1.1, I've decided to have a go at a non-vertical-launch space program.  I'm setting myself some basic rules.  The basic philosophy is that what takes off should be like a plane and what comes back should also be like a plane.  I definitely don't want to just launch rockets from the runway, or come up with "workarounds" that let me launch from the runway what I would in another safe launch from the launchpad.  My rules are, to an extent, a work-in-progress, and if anybody has any feedback or comments, I'd be glad to hear them.  My first goal, though, is to make a fun challenge (the fun part is as important as the challenge here).  So the first rule is:

1) if it leaves the ground, it starts on the runway, rolls on wheels and is powered by air breathing engines.

Obviously I want to be able to collect the science from the launch pad, and I don't mind using the launchpad for things like "test landed at Kerbin" type easy-money contracts.  I think this isn't enough, though.  If My craft are going to be like planes rather than horizontal takeoff rockets, they have to do what planes do, and also come back.  I don't think the tech tree is is well suited to SSTOs and SST-far-away if you're playing career mode, and I want to have fun, not grind in this save.  I think therefore it's safe to allow for things like one-way probes, drop tanks, disposable stages (or, if funds allow, like the B52 that carried the X15 up to launch altitude/speed) and missions where I use dedicated non-returnable vehicles for things like transfers or landings (elsewhere). so,

2) If it lands, it has to be capable of a controlled rolling landing on the runway on wheels.  If it doesn't come back, it doesn't matter.

By basic criteria here are that I want to definitely exclude "falling under parachutes but happen to land on the runway" but definitely allow "I messed up my de-orbit burn and don't have the range to actually fly back to the KSC", hence the "to be capable" rather than "lands".  Also, I think drogue chutes are cool.  Parachutes are totally allowed if you deploy them after your main landing gear touches down. Hypothetically, if you can deploy them but maintain or regain controlled flight afterwards, that's OK, so in-flight chutes that you cut away before landing, or early-deployed landing braking type chutes are OK, provided you work within the basic concept that we are dealing with flying things not falling things.  SSTO is not a requirement.  I have no problem with drop tanks, one-way probes, disposable stages etc. I also want to allow the idea of an SSTO spaceplane that gets a refuel in orbit to allow it to fly on to somewhere interesting.  The X15 space plane was dropped from a B52.  I'm playing stock, so if I do something like that, the B52 analogue will be lost.  That's totally OK by my rules.  Equally, you may want a Mun lander or interplanetary ship that has no chance of coming home.  These are all entirely fine by me.  What I specifically want to exclude is cheating with a heat-sheild-and-parachute lander where the crew is rescued by a Kerbin atmospheric plane.  Also, the simple solution of one-way mission is not really in keeping with the idea, so the last rule:

3) No Kerbal left behind.

I've made a start, under 1.2 pre-release, and I'm having a blast.  I want the career play through to be fun, so I've allowed myself two starter-flights of Mk1 pod, Mk16 parachute and Flea booster to unlock enough science to get to the "Aviation" tier that unlocks the basic "toothpick" undercarriage and Juno engine.  I could have build some sort of rolling capsule based science-from-KSC type craft to get there, but that's too much of a grind for me.  So far, I've got some nice planes that can do low altitude observation missions, and built a "SSTsubO" that gets me into space to achieve the "leave the atmosphere" contract.

I've hit a bit of a barrier, though.  I've unlocked the Weasley engines and built an orbit capable craft.  It comprises 3x FL-T 200 fuel tanks, a LV-T45 Swivel first stage engine, a pair of Mk1 liquid fuel tanks radially each with a Weasley and basic circular intake, basic swept wing and a tail on the back, resting on toothpick tricycle undercarriage.  On the front is a TR-18A stack decoupler, LV-909 Terrier, FL-T200 fuel tank, 1.25 m storage bay with science and a Mk1 cockpit.  This will take off on the jets (needs extremely careful handling on the runway as the undercarriage is right at the limit), climb to about 8000 m under jets, light the rocket, the jets flame out at whatever altitude they get to, when the rocket burns out the capsule and terrier can get to orbit at 85 km with plenty of fuel to spare.  I'm totally convinced this can form the basis of more substantial missions.  The problem I'm now having is how to get back within the rules.  I want my rules to allow for the game to still be fun to play.

I have tested this ship by adding a pair of AV-T1 winglets as wings (placement vital to allow stable but controllable gliding) and a simple fin tail and a couple of batteries in the service bay.  This allows the pod to re-enter from orbit, establish controlled gliding flight (using reaction wheels for control) and approach an arbitrary point on the surface nearby at a speed and descent rate that corresponds to a safe wheeled landing at the KSC runway.  I see a couple of decisions I need to take now.  Is it feasible to bring a craft down from orbit with the basic toothpick undercarriage, or will the blow up all the time?  If they aren't viable, I'll work on the assumption that a safe ocean landing (i.e. one that doesn't involve destruction) in the water next to the KSC is as good as a landing on the runway, on the basis that they have a seaplane dock? I'm entirely convinced I could manage a safe splashdown on this craft.  Would it make the challenge better if I required returning craft to not just manage a controlled glide approach but also a powered flight approach?  I'm pretty sure I have the dV on this craft to do it, the question is will that requirement make for a better game?

 

[Curveball Anders]

18 minutes ago, rcp27 said:

I've decided to have a go at a non-vertical-launch space program.

I pity the fool

[Vanamonde]

Looks like this is going to end up being a mission report, and so the thread has been moved to Mission Reports. Carry on. 

[rcp27]

Sorry, wasn't entirely sure the right place to post it, figured a friendly mod type would be along soon enough to put me to rights

[Vanamonde]

Ta-da! 

[katateochi]

11 hours ago, Curveball Anders said:

I pity the fool

Way....WAY back when career mode was first added I did an aircraft only career and it was the most fun I've had with career mode.  First "aircraft" was just a rocket sled so I could get wings unlocked, but then after that everything took off using horizontal thrust and lift. Mostly things did gliding landings but there were a few emergency ejects which resulted in just pods coming back.  @rcp27 id suggest you allow for that in your rules - mostly rolling landings but if you have to eject, you have to eject!  I think I also had some science pods that did parachute landings. 
Of course the scope of KSP has changed a lot since then so it will be quite a different set of missions. Good luck!! 

[rcp27]

I'm aiming here for the fun of a new design challenge, not for some sort of slavish following of arbitrary rules.  The number one rule is that if a rule makes the game not-fun, then the rule gets changed.  Hence, while I want return vehicles to be capable of a runway landing, if my re-entry flight is a bit off, I am happy just to land somewhere convenient and get on with the game.

This is KSP we're dealing with here, and all craft come with small print.  For this particular game the small print reads as follows: Craft are not guaranteed to be able to achieve the full capabilities of the design specification in all flight conditions.  The inclusion of features to allow for the safe recovery of crew members in the event that the flight condition or configuration of the craft deviates from the planned mission profile is at the discretion of the designer.  Any crew member employing such functionality where a board of inquiry finds that the flight condition at the time of deployment did not justify their use shall be subject to severe disciplinary measures including, but not limited to, assignment to experimental flight testing duty, employment as lubrication technician on off-Kerbin ore drilling installations or chief operations officer at the rocket launchpad (currently disused).

[rcp27]

Well progress is slow but positive.  I took my basic orbiter, pared it right to the bone, added as much fuel on the top stage as possible and managed a Mun flyby. With just the Wheasly and 1.25 m parts, putting something together that can get to orbit at all has proven pretty tricky.  The only way to get a useful payload to orbit means using things like jet engines on decouplers as boosters to fly off the runway.  With a capsule at the top that has to be capable of stable controlled flight after re-entry, getting a launcher that can fly straight both with and without jet engine boosters is a real challenge.  I knew I needed to get a good chunk of science quickly, though.  A bit of farming of biomes gave me the first bit step forward: the clampotron Jr.  With this bad boy I can move on to building a craft capable of making LKO and refuelling it with robot tankers.  A nice little craft with a Mk1 cockpit, a 2 man crew compartment (so that I can bring a scientist along to refresh the experiments), a Science Jr and a little cargo bay with batteries, thermometer, barometer and some goo is just the ticket.  Made LKO with fumes in the tank, but help was at hand.  Only problem is, although I have the docking port, I have not yet unlocked RCS.  With a bit of care I managed to mate the tanker, fill the tanks and had enough left in the refuelled to clear up the space junk by sending it to a fiery grave.  With the ship tanked up, and Jeb, Bill and Bob all on board, we made a nice transfer burn to Mun, with a Pe down around 35 km, and established a stable (but pretty highly elliptical) orbit.  That got me the orbit Mun achievement as well as plenty of science both high and low.  One of the problems with the 2-man crew pod, though, is it has no external door.  Every time Bob had to go reset the experiments, I had to get Jeb out, transfer Bob to the cockpit, get him out to do the science work, and them get them all back on board without Jeb drifting away too far.

This was where I met one the big challenges with this set of rules.  No heat shield means carefully nursing the ship through multiple aerobraking passes and hoping to goodness the ship holds together.  That Science Jr certainly has pretty poor thermal performance, and as we came down with flames everywhere and just about every component on the ship with angry red heat bars, I really didn't think I'd make it.  Make it I did, though, and all that science gave the most valuable reward: Supersonic Flight.  Now I have both the Panther engine and the first set of Mk2 components.  A bit of flight testing and I put together a basic but practical SSTO that can get two crew up to LKO and land back on the runway all in one piece.  All those stranded Kerbals waiting for rescue can breath easy, help is now on the way!

So far I've been surprised at how much easier it is than I thought to progress in career with these rules.  In the past I always regarded space planes as something you might consider later in the game, once you had at least the Whiplash engine unlocked.  I always avoided unlocking the aircraft related nodes in the tech tree in favour of getting things like 2.5 m rocket parts. While I have had to leave some nodes to be unlocked later than I would normally like, it's not been too much of a challenge so far, and the solutions to the challenge of getting places under these constraints has resulted in some very "Kerbal" solutions.  The next milestone will be actually landing on Mun.

[Vanamonde]

No pics?

[rcp27]

Sorry, I was a bit busy not crashing. I'll take some of my quality designs out for a spin and do some publicity shots next time