Kerbal Grasshopper (VTVL)

[Superluminaut]

The Challenge

Build a single stage to orbit rocket that can reenter and land on the launch pad via powered descent.

Leadership Boards

Space Xpert

= Landed on the pad

1. ecat (4.68 payload mass) M
   
2. Superluminaut (4.4 payload mass)
   
3. Climberfx (3.2 payload mass) M
   
4. Hooligan Labs (0.2 payload mass) M
   
5. Climberfx (0.0 payload mass) M
   bsalis (0.0 payload mass)
   

Contract Awarded

≤ 500 meters

1. Uncle Mort (105 meters) M
   
2. Dieselpower (151 meters) M
   
3. Climberfx (416 meters) M
   

Reusable Rocket

≤ 1500 meters

1. Superluminaut (755 meters)
   
2. Superluminaut (1076 meters)
   
3. Climberfx (1366 meters) M
   

Young Grasshopper

≤ 2500 meters

1. Panichio (1900 meters) M
   
2. Giggleplex777 (2200 meters)
   
3. ___ (x meters)
   

Footnote in History

≤ 5000 meters

1. GusTurbo (3700 meters)
   
2. ___ (x meters)
   
3. ___ (x meters)
   

M = Mech Jeb assisted

The Inspiration

The Rules

• Stock (with the exception of mech jeb)
  
• Flight entries with mech jeb must note the use of mech jeb
  
• No parachute/drogue chute use
  
• The rocket may only shed its payload, if it has one (and not before orbit)
  
• The payload does not need to reenter
  
• Orbit = (periapsis ≥ 70 km)
  
• If your strategy involves multiple vehicles, each vehicle must be able to meet the challenge (No stranding lift stages)
  
• Quick load all you like
  
• No clip construction is ok
  
• The rocket may not touch down before it lands on the pad. With exception only to those entries posted before this rule was implemented.
  
• Optional - Please share pictures of your flight showing how you did it
  

Some notes

The Challenge is deliberately open for interpretation.

Note that a payload is not required for completion.

I have reworked the scoring system from its first incarnation. Hopefully this method will make it less of a all or nothing challenge.

Because mech jeb is so popular it will be the only mod allowed. However mech jeb flights will be marked as such for better score comparison with pure stock rockets.

Any ideas for improving the challenge are welcome.

If you are having trouble taking screenshots, try remapping the key.

Edited October 13, 2013 by Superluminaut

[Giggleplex777]

Do I have to post my attempt again? Oh fine, here it is:

Pre-launch.

Dropping off the payload while in orbit.

Re-entry.

Preparing to land.

Landed without chutes 2.2 km from the pad.

The payload weighs 0.1545 tons.

[Giggleplex777]

I must do this challenge with my Falcon 9!

[Superluminaut]

Pics are now optional because in my game I've been having trouble getting them. Once f1 stops working, prtscn, the snipping tool, nothing wants to take my pictures.

I assume others must also experience the problem at some point.

Heres my only descent pic to date (and its dark...). Tons of pre launch and orbit, but nothing when you need evidence the most...

Edited April 21, 2013 by Superluminaut

[Giggleplex777]

Pics are now optional because in my game I've been having trouble getting them. Once f1 stops working, prtscn, the snipping tool, nothing wants to take my pictures.

I assume others must also experience the problem at some point.

Heres my only descent pic to date (and its dark...). Tons of pre launch and orbit, but nothing when you need evidence the most...

You can remap the screenshot key. I remapped mine to 1 and remapped action group 1 to f1.

[GusTurbo]

This was a fun challenge! Hard to get close for me, because I had to take a shallow reentry path so I'd have enough fuel to land. Do I get any bonus for making a huge rocket?

[Superluminaut]

This was a fun challenge! Hard to get close for me, because I had to take a shallow reentry path so I'd have enough fuel to land. Do I get any bonus for making a huge rocket?

To get closer here is what works for me.

Always use the same deorbiting burn. I use a 100m/s burn. Remember the geographic location at which point your projected orbit meets the surface. If you fall short of the space center, next time make the orbit meet the surface a bit past that geographic location. Eventually you will find a sweet spot you can use as a target.

Zero your inclination with the mun. Then adjust not according to the ascending/descending degree value, its not accurately enough, but according to the change in velocity required. For example in my last attempt a 6m/s ascending burn lined me up perfect.

Until maneuver nodes can calculate atmospheric affects, these "simulations" is how I have been doing it.

Maybe its time to try calculating it.

[GusTurbo]

I've started from scratch on a new design for a second entry. Thanks for the helpful advice, I'll try to use it to get closer.

[Superluminaut]

Remaping screen capture worked!

This is the SpaceFrog, my falcon look alike. The 9 engine cluster actually works very well, although it does cause vibrations that I have yet to fix.

Orbit and dropping payload.

Powered descent.

And I missed, again. 755 meters

This rocket actually has the equivalent of 4 orange tanks, but I clipped to make it pretty. It also has a nose cone clipped into the top for extra drag, or it can only nosedive.

[Panichio]

http://imgur.com/a/oHPVn#0

Here's my entry, which was assisted by MechJeb. 1.9km from the launchpad. Could have got closer, but whatever.

Also, for a VTOL rocket challenge, I think this needs a lot more categories and chances to get points. There are so many different ways to judge how good one is, and how close to the launchpad it can land is not the most indicative. What are your thoughts?

[GusTurbo]

Remaping screen capture worked!

This is the SpaceFrog, my falcon look alike. The 9 engine cluster actually works very well, although it does cause vibrations that I have yet to fix.

Orbit and dropping payload.

Powered descent.

And I missed, again. 755 meters

This rocket actually has the equivalent of 4 orange tanks, but I clipped to make it pretty. It also has a nose cone clipped into the top for extra drag, or it can only nosedive.

Can you elaborate a little about the nosecone? I also encountered the nose-dive issue with the first design I tried (which also featured the 9-engine cluster), but how does having a nosecone clipped inside the top help alleviate that?

Also, would it be within the spirit of this challenge to have the multiple stages from the video that each land at the pad? Or would you want to save that for a later challenge thread? As a proof of concept, this thread seems to show the viability of the SpaceX concept in KSP.

Edited April 21, 2013 by GusTurbo

[Superluminaut]

http://imgur.com/a/oHPVn#0

Here's my entry, which was assisted by MechJeb. 1.9km from the launchpad. Could have got closer, but whatever.

Also, for a VTOL rocket challenge, I think this needs a lot more categories and chances to get points. There are so many different ways to judge how good one is, and how close to the launchpad it can land is not the most indicative. What are your thoughts?

The spirit of the challenge is meant more along the lines of "rapid reusability". But what did you have in mind.

[GusTurbo]

So the SpaceX video features a rocket with 3 stages, each of which makes a powered landing at the launch site. This challenge is about making a SSTO rocket that can land on the pad, which makes up the first stage of the SpaceX rocket, but would you accept entries that replicate the entire thing? Basically, it would be like launching a payload once in orbit, but instead of just leaving it there, we would separate that payload into two parts and land each one as close to the launch pad as possible.

What do you think? Doable within the constraints of the challenge, or do you think that would warrant its own thread after this one has run its course?

[Superluminaut]

Can you elaborate a little about the nosecone? I also encountered the nose-dive issue with the first design I tried (which also featured the 9-engine cluster), but how does having a nosecone clipped inside the top help alleviate that?

Also, would it be within the spirit of this challenge to have the multiple stages from the video that each land at the pad? Or would you want to save that for a later challenge thread? As a proof of concept, this thread seems to show the viability of the SpaceX concept in KSP.

The game calculates drag including (mass * drag coefficient). When using engine clusters it adds up and you need to add more mass and drag to the other end. I tried the cone because it has a drag coefficient of .3, and it works better than anything else I tried.

[Superluminaut]

So the SpaceX video features a rocket with 3 stages, each of which makes a powered landing at the launch site. This challenge is about making a SSTO rocket that can land on the pad, which makes up the first stage of the SpaceX rocket, but would you accept entries that replicate the entire thing? Basically, it would be like launching a payload once in orbit, but instead of just leaving it there, we would separate that payload into two parts and land each one as close to the launch pad as possible.

What do you think? Doable within the constraints of the challenge, or do you think that would warrant its own thread after this one has run its course?

A single stage that breaks up in orbit sounds good to me. As long as only the payload stays up.

[duncan1297]

Heres my kerbalcon 5 which uses mechjeb only for the smart A.S.S

it kind of barely has enough fuel to land which causes landing leg and engine smashing.

Edited February 2, 2014 by duncan1297

[GusTurbo]

Take the lower-case 's' off of each of the file names. If those are still sitting there and you haven't hit "end flight," you should get another craft on the pad so you can measure the distance. That is amazingly close.

Heres my kerbalcon 5 which uses mechjeb only for the smart A.S.S

it kind of barely has enough fuel to land which causes landing leg and engine smashing.

also if anyone knows how to make the pictures bigger please tell me.

[Panichio]

The spirit of the challenge is meant more along the lines of "rapid reusability". But what did you have in mind.

Yes, and that's one good way of measuring how good one SSTO rocket is, but I was thinking of things like capabilities. Things like maximum payload weight, or if the rocket can actually get to Mun or Minmus, or even another planet. Maybe how many crew members it can transport, or if it can dock to a space station as well, and then return again. Oh, and if the aim of the challenge is "rapid reusability", then another thing to add would be fastest time to orbit and back.

But if you do, just pray Scott Manley doesn't come along with his rocket.

[GusTurbo]

I'm going to revisit this challenge with a closer approximation to the real thing. Should be fun.

Edited April 22, 2013 by GusTurbo

[AD-Edge]

Heh, cool challenge to see pop up.

Ive built one already (100% stock), had it working back in January and Im in the process right now of putting together a video of it in action.

Works exactly like the reusable SpaceX-like rocket in the video does... Took a lot of work and balancing....

Edited April 23, 2013 by AD-Edge

[Superluminaut]

Yes, and that's one good way of measuring how good one SSTO rocket is, but I was thinking of things like capabilities. Things like maximum payload weight, or if the rocket can actually get to Mun or Minmus, or even another planet. Maybe how many crew members it can transport, or if it can dock to a space station as well, and then return again. Oh, and if the aim of the challenge is "rapid reusability", then another thing to add would be fastest time to orbit and back.

But if you do, just pray Scott Manley doesn't come along with his rocket.

If you can land on the pad, then rockets will be ranked by payload mass. The first goal of the challenge is the reusable element. After that I think the only measure for any launch system is payload mass. If the payload is a 1,000 stage interstellar space penis or a sputnik, payload functionality is irrelevant to this challenge, we just have to get it into space, and then get the rocket back to refuel.

[Hooligan Labs]

I've been doing a video of this, this is how close I have gotten thus far...

Close but doesn't count (explosion followed soon after)

Full album! http://imgur.com/a/wZVgc

Edited April 24, 2013 by Hooligan Labs

[bsalis]

Finally I did it. A stock VTOL SSTO Spaceplane. Yeah I know it has a mechJeb radial on it, but I have flown without it.

Here we go...

Couple of jets under the wings keeping us aloft.

Ascent

Pe 100Km. MechJeb tells me I have 833 m/s dV.

Does not look bad either...

Landing. Mostly vertical descent... didn't want to risk a straight down landing on this flight.

Ta da. Sorry about the nightness.

[Superluminaut]

Yo peeps, cool stuff, but please measure out the distance you landed from the launch pad to receive your fame and glory. Thanks.

[Hooligan Labs]

Very nice SSTO VTOL, bsalis! I'm so bad at air-breathing flight that I completely gave up on it. Maybe one day when there is a one-button Mechjeb spaceplane to orbit.

Anyway, here is my video! I landed squarely on the pad. Takeoff weight, 54.42 tons.