0 to Mach 10 in 10?

[stickman939]

Who here thinks they can create a replica of the

Sprint Missile that is as close to the real thing as possible?

Specs of the Sprint:

Height: 27 ft (8.23 m)

Max diameter: 4.5 ft (1.37 m)

Weight: 7,600 lb (3,477 kg)

First stage: 650,000 lb (29,484 kg) thrust for 1.8 sec.

Second stage: 150,000 lb (68,039 kg) thrust for 2 sec.

Acceleration: 1st stage - 130 G, 2nd stage - 90 G, Maneuvers - 60 G

Max velocity: 10,200 ft/s (3,109 m/s)

Warhead: W66 thermonuclear warhead (a low kiloton range neutron bomb) (totally optional xD)

Rules are as follows:

No Debug Menu

No Hyper Edit

Not much more to say other than "good luck"... Oh, and post pictures of your creations!

[SpaceplaneAddict]

10 what?

[stickman939]

And before you try to eat me over "Nothing in KSP can get that fast without exploding"

I know.

KSP is about a fourth of the real world, unless I'm mistaken. Plus, I said "As close to the real thing as possible"

- - - Updated - - -

10 what?

Seconds.

[Wild Cobra]

Well...

"The Sprint accelerated at 100 g, reaching a speed of Mach 10 in 5 seconds."

In the wiki link.

I don't think five to ten seconds is possible without editing the parts.

[stickman939]

Yes I acknowledged that in the previous and original post, noting that KSP is about 1/4 real world size, and complete accuracy is not a requirement.

I was merely giving data on the Sprint for those who may have wanted to know a bit about it, and if they wanted dimensions to convert to a KSP equivalent.

Apologies for my miscommunication.

[Wild Cobra]

The missile was also already moving before the first stage was ignited:

Sprint was 'popped' from its launch silo by a powder gas generator which propelled a piston on which the missile rested. The missile was pushed through a membrane at the top of the cell, while the piston is stopped at the mouth of the silo. Once clear of the cell, the first stage was ignited and the missile tilted over in the direction of the incoming target. Aiming the missile so early in the trajectory reduced the forces involved in moving the missile's trajectory and allowed a very fast interception to take place. Some reports indicate that the missile was supersonic by the time it left the cell.

http://www.nuclearabms.info/Sprint.html

[mythbusters844]

Since the rules permit it, I changed the decoupling force of a separator to a few million and got to several times the speed of light within a fraction of a second.

Pics:

Edited October 9, 2015 by mythbusters844
edited for rule 2.2.d

[n.b.z.]

So I did something that I think is in the spirit of this challenge. However, it's nowhere near the specs of the real thing.

Since we don't have tanks with ablative heat shields, I first experimented with the concept of using an "ablative nosecone", and would have declared the evaporation of that nosecone to be intentional. But this left me with a blunt top end of the vehicle, which slowed it down too much in the upper atmosphere.

Instead, my vehicle now sheds no other parts than the first stage, and is designed to ascend as rapidly as possible without turning itself into plasma.

My "requirements":

• Conforming to challenge rules: No debug menu, no Hyperedit
  
• Stock, no part modding or cheats, no engine or tank clipping
  
• Since there are no incoming warheads in KSP, my objective is simply to reach space (suborbital, above 70km)
  
• 2 stages, because Sprint
  
• Most ridiculous low-altitude speed I can manage without exploding
  

Named not exactly creatively, I present the "Sprinter".

1st stage: liquid fueled, burns for 9 seconds

2nd stage: solid fueled, also burns for 9 seconds

Some data of the second test flight (the one in the album below):

TIME        ALTITUDE    VELOCITY       REMARKS
T+0:0        87m (pad)     0.0m/s        Clamp release and ignition
T+0:5        1148m       481.5m/s        11g acceleration
T+0:8        3024m       816.0m/s        12.5g acceleration
T+0:9        4256m       904.2m/s        STAGING, <3g acceleration - so that's a sustainer stage only
T+0:18      12518m      1262.3m/s        MAX. TEMP (temp display bar almost maxed out), 2nd stage CUTOFF
T+0:30      25393m       994.6m/s        Half a minute is over. Two more minutes until apoapsis.
T+2:31      80675m       221.1m/s        APOAPSIS
T+5:14          0m       152.2m/s        Impact in ocean

I did not manage to perfectly time the T+0:18 MAX TEMP screenshot. That temp display goes to 1 or 2 pixels below the maximum before cutoff happens. (In case the nose cone decides to change its state of matter, it will expose a heat shield that saves the remaining vehicle from destruction.)

Album:

Javascript is disabled. View full album

[FungusForge]

Since the rules permit it, I changed the decoupling force of a separator to a few million and got to several times the speed of light within a fraction of a second.

Oh god I can't breath.

Also your acceleration was apparently too insane for the poor G-meter to catch anything.

[n.b.z.]

I also found his G-meter reading very entertaining. My guess is that the value was to large for the data type that KSP uses for this value.

[Gaarst]

I made a small rocket that peaks at 94g acceleration, and reaches 600km when launched straight up. It is made of mostly modded parts though.

I will get screenshots whenever I remember to.

[stickman939]

So I did something that I think is in the spirit of this challenge. However, it's nowhere near the specs of the real thing.

Since we don't have tanks with ablative heat shields, I first experimented with the concept of using an "ablative nosecone", and would have declared the evaporation of that nosecone to be intentional. But this left me with a blunt top end of the vehicle, which slowed it down too much in the upper atmosphere.

Instead, my vehicle now sheds no other parts than the first stage, and is designed to ascend as rapidly as possible without turning itself into plasma.

My "requirements":

• Conforming to challenge rules: No debug menu, no Hyperedit
  
• Stock, no part modding or cheats, no engine or tank clipping
  
• Since there are no incoming warheads in KSP, my objective is simply to reach space (suborbital, above 70km)
  
• 2 stages, because Sprint
  
• Most ridiculous low-altitude speed I can manage without exploding
  

Named not exactly creatively, I present the "Sprinter".

1st stage: liquid fueled, burns for 9 seconds

2nd stage: solid fueled, also burns for 9 seconds

Some data of the second test flight (the one in the album below):

TIME        ALTITUDE    VELOCITY       REMARKS
T+0:0        87m (pad)     0.0m/s        Clamp release and ignition
T+0:5        1148m       481.5m/s        11g acceleration
T+0:8        3024m       816.0m/s        12.5g acceleration
T+0:9        4256m       904.2m/s        STAGING, <3g acceleration - so that's a sustainer stage only
T+0:18      12518m      1262.3m/s        MAX. TEMP (temp display bar almost maxed out), 2nd stage CUTOFF
T+0:30      25393m       994.6m/s        Half a minute is over. Two more minutes until apoapsis.
T+2:31      80675m       221.1m/s        APOAPSIS
T+5:14          0m       152.2m/s        Impact in ocean

I did not manage to perfectly time the T+0:18 MAX TEMP screenshot. That temp display goes to 1 or 2 pixels below the maximum before cutoff happens. (In case the nose cone decides to change its state of matter, it will expose a heat shield that saves the remaining vehicle from destruction.)

Album:

http://imgur.com/a/wNmCm

Impressive! And an ingenious use of that tail part too!

- - - Updated - - -

I made a small rocket that peaks at 94g acceleration, and reaches 600km when launched straight up. It is made of mostly modded parts though.

I will get screenshots whenever I remember to.

I look forward to seeing it.

[Gaarst]

There it is !

8.9t at launch, two stages.

First stage is liquid powered, has 900kN thrust and burns for 6.8s. TWR at launch: 9.60 asl.

Second stage is solid powered, has 1080kN thrust and burns for 8.3s. TWR at activation: 28. According to KER, max TWR is 195 !

Top speed was ~3700 m/s, max G was 91.2g and apoapsis at 391 km.

Max temp percentage was ~90%, but got as high as 95% on some flights. Didn't blew up anything during flight !

It uses parts from: Ven's Revamp (1st stage engine and structural bits), SpaceY (2nd stage boosters) and Procedural Fairings. I also used RSS and Real Fuels.

Javascript is disabled. View full album

EDIT: I am actually going to try hitting Mach 10 in 10 secs, 5 secs if I feel like it.

EDIT2: Working on a version topping at 180g and Mach 20 after 16.5 secs of burn, reached >2000km apo. It leans to one side for some reason and often ends up flipping, trying to fix this.

Edited October 18, 2015 by Gaarst

[Gaarst]

0 to Mach 20.2 in 16.6 secs !

I guess we can say "good enough" !

[Gaarst]

There you are: Sprint Missile v2

Javascript is disabled. View full album

One half of the top fairing always blow up for some reason, but overall, the craft survived !

- - - Updated - - -

Nailed it !

Edited October 20, 2015 by Gaarst

[stickman939]

I'd say that's a perfect replica right there, Gaarst! lol

[BlueCanary]

So I'm trying with stock parts:

Other than the Launch Escape System, which would be very impractical to use, the highest TWR's are from the Sepratron and the Mammoth, so they'll have to be the engine's of choice. The sepratron would be much more practical size wise and has a much higher potential TWR (when it's empty it's like 7 times as high as the mammoth. so it'll probably work best. But discounting air resistance, the 100G acceleration is theoretically possible for a near empty sepratron (empty TWR of 146), so this might actually be possible.

My first test (pictured below) exploded at 1200m/s from heat, but maybe there'll be a way to improve that.

EDIT: Nothing to see here, just a stick of explosive spaghetti crashing my computer:

Edited October 30, 2015 by BlueCanary

[MatterBeam]

I think you should do this with Precedural SRBs....

[ihtoit]

somewhere around I have a test video of a shot with a KWRocketry 5m engine (that sounds like a Death Star laser when you fire it) with about three second's worth of fuel for 11MN thrust and a 0.5t capsule snuggled under a standard nosecone.

Several THOUSAND G later, and somewhere going off in a straight line out of the Kerbolar system, Bob is wondering who dropped a fart bomb into his snack box.