Pan-Kerbal Super Sonic Transportation Challenge!!!

[Archangel Lucifer]

The 5 min deadline has helped slightly but Jet engines just don't cut it for this challenge. The only real option is to go for an aerospike rocket build but as always finding the right balance of fuel, lift and thrust is tricky - especially considering the fuel consumption of aerospike rockets.

Sure the fuel bug is there but even so, I challenge anyone to make a craft capable of completing this task while staying below the upper limit of 30km (and no higher than 30,100m imo). This is by far the hardest challenge I have attempted thus far, which was unexpected to say the least!

Here is my best attempt to date

<a href="http://s1170.photobucket.com/albums/r540/ArchangeLucifer/?action=view&current=aa9c62a0.png" target="_blank"><img src="http://i1170.photobucket.com/albums/r540/ArchangeLucifer/aa9c62a0.png" border="0" alt="Best Pan-Kerbal Time 1"></a>

With this as my current best design

<a href="http://s1170.photobucket.com/albums/r540/ArchangeLucifer/?action=view&current=4d2e4b6a.png" target="_blank"><img src="http://i1170.photobucket.com/albums/r540/ArchangeLucifer/4d2e4b6a.png" border="0" alt="Stingray Supercruiser Revamp"></a>

It has 6 aerospike rockets mounted into pods in the wings (the long Mk3 fuselage parts in the wings) and a main body 8 Mk3 parts long plus tail and cockpit and 16 400L liquid fuel tanks underneath in drop pods but this is still not quite enough. Although with some tweaking of my take-off trajectory I may be able to get it with no further modifications. Rather than add heaps of extra lift at the front to counter the weight of the drop tanks I opted for a rocket assisted takeoff using solid boosters as the rules don't say that that isn't allowed.

So the challenge is out there - Surely someone can accomplish this fuel bug or not!

[Archangel Lucifer]

Finally I can claim success!

After a slight fin modification and adding 4 more LFT's I had more than enough fuel to make the Pan Kerbal journey back to KSC. The amunt of fuel rerquired is staggering - I used a total of 58 fuel tanks with only the drop tanks being LFT's. Unfortunately I forgot the cruise speed screenshot at MET 5:00 but this ship easily gets to 600 - 700m/s by that time. All the relevant photos are in this album but there are a few other Kerbal related ones too.

http://s1170.photobucket.com/albums/r540/ArchangeLucifer/

Aircraft Name : Stingray Supercruiser

Total Time Elapsed : 58:00

Comments : Powered by 6 Aerospike rockets and carrying massive amounts of fuel, the Stingray Supercruiser is able to attain Hyperspeeds up to heights of 30km but as of yet is untested at higher altitudes.

With a range of 4000-5000km this ship is capable of reaching >700m/s after 5 mins of flight time and Hyperspeed within 30 mins.

A Pan Kerbal flight in less than 60 mins makes this the aircraft of choice for all your Supersonic and Hypersonic transport needs (Kerbals cite a lack of competitors as the main reason).

In my excitement I also forgot to take a screenshot of the mission results screen and when I went back to the flight from the tracking center the stats for the flight had reset so I'll have to do another run and take a screenshot of it then.

[ssTALONps]

Finally I can claim success!

After a slight fin modification and adding 4 more LFT's I had more than enough fuel to make the Pan Kerbal journey back to KSC. The amunt of fuel rerquired is staggering - I used a total of 58 fuel tanks with only the drop tanks being LFT's. Unfortunately I forgot the cruise speed screenshot at MET 5:00 but this ship easily gets to 600 - 700m/s by that time. All the relevant photos are in this album but there are a few other Kerbal related ones too.

http://s1170.photobucket.com/albums/r540/ArchangeLucifer/

Aircraft Name : Stingray Supercruiser

Total Time Elapsed : 58:00

Comments : Powered by 6 Aerospike rockets and carrying massive amounts of fuel, the Stingray Supercruiser is able to attain Hyperspeeds up to heights of 30km but as of yet is untested at higher altitudes.

With a range of 4000-5000km this ship is capable of reaching >700m/s after 5 mins of flight time and Hyperspeed within 30 mins.

A Pan Kerbal flight in less than 60 mins makes this the aircraft of choice for all your Supersonic and Hypersonic transport needs (Kerbals cite a lack of competitors as the main reason).

In my excitement I also forgot to take a screenshot of the mission results screen and when I went back to the flight from the tracking center the stats for the flight had reset so I'll have to do another run and take a screenshot of it then.

LOL finally!!! that monster managed to circumnavigate!!!

and since your highest altitude is 30km, your behemoth is qualified as successful PK-SST design!!!

Edited August 29, 2012 by ssTALONps

[halocon720]

Darn... I just posted a challenge just like this. Of course, mine says you can use NovaPunch and it has part limits, no deadline to the 500 meter per second speed, etc.

[JackAz]

Wow, really like the design.

[JackAz]

Finally I can claim success!

After a slight fin modification and adding 4 more LFT's I had more than enough fuel to make the Pan Kerbal journey back to KSC. The amunt of fuel rerquired is staggering - I used a total of 58 fuel tanks with only the drop tanks being LFT's. Unfortunately I forgot the cruise speed screenshot at MET 5:00 but this ship easily gets to 600 - 700m/s by that time. All the relevant photos are in this album but there are a few other Kerbal related ones too.

http://s1170.photobucket.com/albums/r540/ArchangeLucifer/

Aircraft Name : Stingray Supercruiser

Total Time Elapsed : 58:00

Comments : Powered by 6 Aerospike rockets and carrying massive amounts of fuel, the Stingray Supercruiser is able to attain Hyperspeeds up to heights of 30km but as of yet is untested at higher altitudes.

With a range of 4000-5000km this ship is capable of reaching >700m/s after 5 mins of flight time and Hyperspeed within 30 mins.

A Pan Kerbal flight in less than 60 mins makes this the aircraft of choice for all your Supersonic and Hypersonic transport needs (Kerbals cite a lack of competitors as the main reason).

In my excitement I also forgot to take a screenshot of the mission results screen and when I went back to the flight from the tracking center the stats for the flight had reset so I'll have to do another run and take a screenshot of it then.

Was the landing difficult ?

[Archangel Lucifer]

The landing was rather easy, if I knew how to upload my ships I'd put it up for download so you can try for yourself.

Thanks for appreciating the effort I put into it. If I could change one thing about the ship I'd set the engine pods in line with the main fuselage instead of a bit below it as then it could go to the Mun. Atm if I go much above 30km it starts to push the nose up even at minimum throttle.

I'm working on another contender for this challenge that uses less fuel and can most definitely reach the Mun too.

[Archangel Lucifer]

Figured it out, here is the ship.

[a7i20ci7y]

What kind of frame rate did you manage with that thing?

[Archangel Lucifer]

On takeoff - not very many, but after the drop tanks are done then the framerate is fine on my pc. I also set persistent debris to off to speed things up, other than that I play with maxed out graphics and its quite playable. As soon as it gets off the runway switch the camera view so the planet isn't visible, that should help too. Again once the drop tanks are jettisoned then you can look at the planet fine.

I've also successfully circumnavigted Kerbin with a second craft that uses just 2 aerospike rockets. I only used 37 fuel tanks in this build and it's way more stable at higher altitudes than the Stingray - so stable that I have taken it to the Mun and also Minmus. I didn't design it for this challenge but I thought I'd see how far around the planet it could go at a height of 30km and with a bit of modification it went the whole way. Due to the weight of the drop tanks this one also uses a solid booster for a rocket assisted takeoff.

Introducing the Hunchback Type 2a...

In the hanger.

The drop tanks.

At MET 5:00.

Approaching KSC after Pan Kerbal flight.

Safely landed and mission results.

Also, just to back up my Mun and Minmus claims here it is at the Mun.

And Minmus.

Aircraft name : Hunchback Type 2a

Total time elapsed : 1:02:46

Comments : Concerned by the success of KSC and their Stingray Supercruiser and the lack of competition for Pan Kerbal flights, the researchers at KSC2 unexpectedly came up with this abomination after building a ship designed merely to traverse to KSC and back. The one man Hunchback prototype turned into the three man Hunchback Type 2 that, after successful high altitude and orbital tests, was capable of reaching the Mun. At this point the scientists realised the potential for a rival to KSC's Stingray Supercruiser and set to work achieving this goal, culminating in the Hunchback Type 2a Pan Kerbal variant.

The unique twin aerospike rocket design ensures fuel consumption is kept to a minimum while still providing rapid speeds of +1400m/s at 30,000m, circumnavigating Kerbin in just over an hour. At this height a maximum range of 4500km can be expected although the Hunchback can also make the journey to the Mun or Minmus if needed, opening up a whole new range of Ker-tourism oppurtunities.

And finally the craft file.

[djnekkid]

Is this actually possible with jet engines alone? I've tried to crunch some numbers, and here goes:

600 radius

15 km altitude

615 total radius

3862,2 length of the circle

0,6 assumed average speed in km/s

6437 seconds needed to curcumvent in 0.6km/s

0,4 fuelburnrate on the turbojet per second

6 number of engines

150 max thrust per engine in Newtons

900 Total thrust

2,4 fuelburnrate on all engines per second

15449 Time * burnrate = number of fuelunits needed (5 large tanks is 16k units)

200 number of fuelunits per 'ton'

77,2 tons' of fuel

1,1651390399 Thrust/weight ratio on pure thrust and pure fuel

Adding more weight

77,2 fuel

1 mk3 cockpit

7,2 engines

0,42 6 deltawings

0,5 10 wingsections

0,5 10 struts

0,2 4 fuel lines

0,6 2 tri-couplers

10 5 empty large tanks

97,7 tons

0,922 Final TWR

With that TWR, i highly doubt the thing would actually lift off. When we start looking at normal commercial jets, say a boeing 777-300, it have a MTOW of 300tons, and a thrust of about 420kN (depending on manufacturer). This gives about 1,3 TWR.

If we could actually acheeve this TWR, i doubt the 1,8km runway is sufficient. The mentioned plane needs nearly double that, namely 3380meters. (Ref: http://en.wikipedia.org/wiki/Boeing_777#Specifications)

However, if either thrust is increased by about 50%, or fuelconsumption is reduced to 0.25, then we get a TWR of about 1.4, and we should be able to do this.

*run and 'hack' a .part file, and see*

(for the calculations, take a look at this file)

[EndlessWaves]

Wings are force multipliers in KSP so with sufficient wings you can take off at very low speeds and lift immense weights. I've done 100 tons on 100 thrust using 200 wings. 9 TWR is easily doable, it just means you can't head straight up (which requires over 9.81). I suspect the speed of 600m/s might be the more difficult element to achieve.

EDIT: A brief test:

Topped out at 275m/[email protected] after the initial climb finished. I don't know where the point of diminishing returns is but I'd suspect the lack of engine power above that altitude means you can't push it far enough.

EDIT2: Unless you had less tilt on the wings but more wings, that might beat the barrier.

Edited September 9, 2012 by EndlessWaves