Jump to content

Quick Challenge: Lightest Craft to Orbit [Stock only] New Challenge #5!


Recommended Posts

Without the fairing, you need your re-entry to be shallow, and your Kerbal positioned very carefully behind sufficiently-large parts.  I tried with just a pair of Oscar-Bs for fuel, and that's how I lost Jeb in this save-- they didn't provide him enough of a shadow.

Edit:

Rather than make a new post, I'll just add my update here.  The Ogod-Y Mk.15 has made its flight, and I'm pretty sure I've hit the rock bottom weight for its design lineage at 2.390t unkerballed / 2.484t kerballed (I assume, anyway).  No Mechjeb core on this one, instead relying on Kerbal Flight Data / Kerbal Flight Indicators.  I may only have knocked another 0.054t off the weight of the previous iteration, but that's more than the weight of a Small Inline Reaction Wheel, and gives me more than the tiny hair I had last time on @foamyesque's MicroLaunch Orbiter 1.

Another Edit:  Yes, I lost the battery on landing.  If deemed necessary, I'll take it on another flight, but there was a smidge of fuel still on board, and I really had flubbed the landing several times.  I didn't even notice the broken part until just now, and I really hope that you don't make me try that landing another half-dozen times for this to count, since the rest of the 'pod' did make it.  :P

Nevermind.  It's still there, it's just buried in Hillin's hind end.

Edited by Aetharan
Pseudo Post-Merge
Link to comment
Share on other sites

Okay! time to take 1st place for unmanned and recoverable! I present to you SpeedySat Mk4 wighing in at 2.557 tons, side note: MechJeb was used for delta-v statistics in the VAB but is not present on craft Kerbal Alarm was also installed but not used the parachute and probe core are clipped into the fuel tank I used an engine pre-cooler with the afterburner for the first stage and an flt-100 fuel tank with a spark, that contained the probe core and parachute inside of it as to prevent the probe core from being damaged here's the album -> http://imgur.com/a/8pleU i have no idea how to insert it so just follow the link, my method of ascent was extremely simple and instead of working off the duration of acceleration I used velocity as a marker, typically my first stage was using wet mode for all of its flight and it stopped accelerating anywhere between 17-21 kilometres, the spark had ridiculous efficiency and not only put my craft into orbit, but with an apogee of 98 and a perigee of 77, I was going for a 71 km near circular orbit, it then still had fuel to allow me to de-orbit, the major issue that I had to work against was the fact that the first stage gimbal sent me spinning around often, I could counter it with SAS my second problem was regarding the probe itself, it had no RCS or reaction wheels so when in space it was constantly rotating so when a maneuver was required or I needed to point a certain way I would have to use the engine which made me lose about 1.3 units of fuel, however in the long run it had no effect on the probes overall performance, re-entry was the MOST DIFFICULT part of the entire flight, either I would be entering in sideways, which was bad, with the engine facing down which was good, or the base of the fairing I used to make the craft more aerodynamic during ascent, which wasn't what I wanted but I might've been able to pull off, the craft got ridiculously unstable at 30 k and began spinning, it quickly recovered, I deployed the parachute and it floated to the ground effortlessly, I'm gonna do a manned recoverable now, bye!!

Edited by KSPNewbie
Typo's, added more info
Link to comment
Share on other sites

I'll throw in our first entry for the Manned (but unrecoverable) board: the Strander Mk.1.  Mass is 2.327t in the VAB, 2.421 on the pad with its zombie passenger.  It ultimately achieves a circular orbit at 105 km, and isn't coming back down (lest we suffer a zombie apocalypse!)

 

Edited by Aetharan
Link to comment
Share on other sites

Hello Again!

I hope @foamyesque had his laugh!

http://imgur.com/a/1Fl1y

As seen in my album, I call it the Plankton 29, weighing at 2.355t!

26 minutes ago, Aetharan said:

I'll throw in our first entry for the Manned (but unrecoverable) board: the Strander Mk.1.  Mass is 2.327t in the VAB, 2.421 on the pad with its zombie passenger.  It ultimately achieves a circular orbit at 105 km, and isn't coming back down (lest we suffer a zombie apocalypse!)

 

You posted this right after I finished creating my entry!

Plus, I take no responsibility for copying the Ogod-Y Mk. 15! It took me 8 hours and 29 different models of the Plankton to create a working prototype!

Edit: by the way, when Aetharan released his entry for Manned, I thought he submitted it to Manned and Recoverable! My mistake.

Edited by EliteGuy3
Link to comment
Share on other sites

Well, phoo.  Now I have to find some way to carve another 0.036t off of the Ogod-Y line!

Edit: And done!  The Ogod-Y Mk.15b weighs in at 2.320t unkerballed / 2.414 kerballed, makes an orbit of 70.0 km x 70.4 km, and re-enters for a suicide-burn water landing and recovery.

Another Edit:  We're starting to get down into the real-world weight range for large SUVs, rather than spacecraft, and have been there since roughly @foamyesque's launch.

Edited by Aetharan
Another pseudo post-merge.
Link to comment
Share on other sites

3 hours ago, Aetharan said:

I'll throw in our first entry for the Manned (but unrecoverable) board: the Strander Mk.1.  Mass is 2.327t in the VAB, 2.421 on the pad with its zombie passenger.  It ultimately achieves a circular orbit at 105 km, and isn't coming back down (lest we suffer a zombie apocalypse!)

 

Where exactly is the Kerbal?

Link to comment
Share on other sites

13 minutes ago, Aetharan said:

In the seat.  Look at the sixth screenshot for a good view.

Hey, when will the creator of the challenge put people on the leaderboard, also, I one-upped both of you I'm just working on re-entry details

Link to comment
Share on other sites

9 minutes ago, Aetharan said:

He'll update the leaderboard when he has time, I would assume.  As for the one-upping: If you have, then I'm happy for you.  I'll believe it when I see the gallery.

I'm gonna have to redesign, cannot survive reentry

Link to comment
Share on other sites

Just now, KSPNewbie said:

I'm gonna have to redesign, cannot survive reentry

And there you see one of the reasons that my entries in this thread jumped from the Ogod-Y Mk.2 to the Ogod-Y Mk.14 without showing the intermediate iterations.  The missing eleven were various degrees of "not enough fuel in the upper stage" and "can't survive reentry".

Link to comment
Share on other sites

7 minutes ago, Aetharan said:

And there you see one of the reasons that my entries in this thread jumped from the Ogod-Y Mk.2 to the Ogod-Y Mk.14 without showing the intermediate iterations.  The missing eleven were various degrees of "not enough fuel in the upper stage" and "can't survive reentry".

Yeah, my unmanned recoverable took 4 forms and 10 flights on the perfect design to successfully complete a mission

Link to comment
Share on other sites

Of course, I'm sharing the part-lists and fuel amounts in these craft partly to help those who are competing against me, especially given the convergent evolution of my Ogod-Y and @EliteGuy3's Plankton design.  The Ogod-Y upper stage is currently down to the same amount of fuel that could be held in two Oscar-Bs, and is only still using the ROUND 8 for its broader protection profile on reentry, and I don't really see a way to reduce the weight of the lifter much more, beyond (perhaps) chopping another 4 units of fuel off if it can still make it as high without them.  That Pre-Cooler is pretty light as-is, especially given that it serves a dual-purpose as intake and fuel tank, and I'm using barely over half its capacity.

Link to comment
Share on other sites

Quote

We're starting to get down into the real-world weight range for large SUVs, rather than spacecraft, and have been there since roughly @foamyesque's launch.

I guess so. I it's getting harder and harder to get onto 1st place. 

I've done research as well, and any small craft would result in either in a high drag, low /\v, or simply not enough fuel to return safely.

I think we are hitting the barrier. Just like our computers hitting the berrier. A transistor is the size of 14 nanometers! Any smaller spacecraft would result in Star Wars technology!

We could try to replicate Turbo Pumped's 2.9 ton mission to Gilly by getting rid of access fuel and unnecessary equipment. The payload sent into orbit is under 0.5825t.

Turbo Pumped's 2.9 ton mission to Gilly.                                                                                                                 https://m.youtube.com/watch?v=S3UvNp7Yexk                            

 

Link to comment
Share on other sites

The only methods that I currently see for reducing weight for a manned mission below the mass of the Ogod-Y Mk.15b launch are as follows:

1) Dump the reaction wheel.  This must be done by a pilot more skilled than I am, since all rotation would rely on the engines burning fuel, of which there was precious little left over by the suicide burn.

2) Replace the Spark with 4 or fewer Ants, as I did with the Strander: 4 can make orbit, and come in at 80% the mass of a Spark with a slightly higher ISP.  It reduces the thrust-to-weight ratio of the upper stage dramatically, especially during the suicide-burn where you're going to need the thrust the most.  Of course, that assumes that we don't go for a hatch-based shock absorber like Turbo Pumped did.

This is obviously only my own view, which is limited, and I'm certain that somebody else has the skills necessary to pull it off.  The way I look at it right now is simple: I want second place, and I want the person who beats me to do so only by building and flying something that nobody else can hope to beat.  The narrower the margin between said craft and my own, the happier I'll be.

Edit:  Silly me.  Ants don't have engine gimbals.  You can beat the Spark's ISP and mass by going with a pair of Ants and a pair of Spiders, though.  (290 + 315)/2=302.5.  It's not much, but it's a slight boost in bang for your buck where fuel usage is concerned outside the atmosphere.  Trying to go with only Ants on a ship with no reaction wheel...  well, that's not going to space.

Edited by Aetharan
Link to comment
Share on other sites

@Nefrums how did you survive landing? It doesn't seem possible for an XM-G50 Radial Intake to withstand such a landing.

Edit: Did some experimenting, and it appears that the intake has a relative wing area. I was able to fly with only the intake as a wing!

Edited by EliteGuy3
Link to comment
Share on other sites

31 minutes ago, Nefrums said:

it was a powered landing.  I had plenty of fuel left.

 

oh

Another Edit (I'm lazy to create another post):

I've done sone experimenting with HBSA (Hatch based Shock Absorbers) and they tend to explode when impact on anything beyond 60m/s. Also, If we we're going to apply the HBSA to a space SUV, than that would be an extra 0.1t, and in this challenge that much weight is considered heavy.  I've tried to add a service bay to my Plankton series, but I run into the problem where the craft is either too heavy or is never compliant with aeroforces, plus I can never go slower than 80m/s when in the atmosphere. 

As I've said before, it seems to be getting more difficult to shave off weight from our space SUVs. A couple methods that might do would either be:

Creating a different second-stage: Having a lighter second stage may result in a less demanding first-stage requirement list, thus less weight in the first-stage as well. 

Become a dart: What I mean by this is to become extremely aerodynamic in the air. This would allow a much faster craft in the air.

Different method of landing: Power landings are more efficient (less weight required) but also demands at least 150m/s of /\v. Another method like HBSA or an Absorbent Strut Leg could bring both diversity and different possibilities.

To be honest, I only want to be in the leaderboard for this challenge. This challenge has also chosen to be quite difficult to complete. Hopefully this will be helpful.

Here's were I saw a strut landing:

http://forum.kerbalspaceprogram.com/index.php?/topic/27739-land-on-kerbin-but-without-parachutes-or-engines/

Just look for it.

Edited by EliteGuy3
Link to comment
Share on other sites

52 minutes ago, EliteGuy3 said:

Oh, for those of you who don't know how to convert Kg to Tons, the weight of 2264 Kg is 2.496t.

Hate to say it, but the game is using Metric tons, not the US ton.  2,264 Kg = 2.264t.  He's got the Ogod-Y Mk.15b beat by a solid 0.15t, with the same amount of fuel in a heavier upper stage, but without the fairing for ascent that I've been relying on.  It never occurred to me that the Mk.0 Fuselage plus a Radial Air Intake and an adapter would actually somehow be lighter than the Engine Pre-Cooler, but the trio come to 0.355 for a savings of 0.02t.

The obvious weight-savings in the design difference is clearly the fairing, which makes up 0.157t of the Ogod-Y's bottom-stage mass (between both the shell and the base).  What's blowing my mind is the fact that this accelerates at all.  Just by appearance, it feels like it should be too blunt (with the intake flaring out like that) to work well, but clearly it does.

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...