Orbital Sciences Antares/ Cygnus/Cygnus Enhanced

[Keenan Smith]

Hey Guys,

Keenan here

im new to the modding scene but im pretty nifty with Sketchup (which can apparently be imported into Unity )

so i'm going to try my hand at replicating to the best of my abilities the Orbital Systems Antares/Cygnus

Wish me luck as this will be my first mod

I am Working alongSide Nutt to model Orbital launch vehicles and payloads

First i will start with Fairings and Payload base..

will post some updates soon ...

Keenan

p.s this is my first time making a mod so go easy on me...

i think i have covered it all so here we go...

Edited June 4, 2013 by Keenan Smith

[Netris]

I was waiting for it big time

[Keenan Smith]

i hope not to Disappoint

[Read have Read]

Hmm, the first stage looks exactly like the satellite lifters I make with KW rocketry, even with the Vesta 6D twin nozzle. However I am curious to see how that second stage and cargo payload will turn out.

[Kerbal01]

There is already a great Cygnus mod out there by Nutt you should just make the rockets

[Greys]

Competition benefits the consumers, make it all!

[Guest]

Since Nutt is already working on Cygnus, how about you cooperate with each other? You'll make the Antares and he'll do Cygnus.

[Kerbal01]

Do you have any indev pics yet?

[bigdad84]

Yes. I agree with almost everyone else. See if you can talk to Nutt and cooperate with the pack

[Keenan Smith]

Updating Sketchup and beginning

i'll Contact Nutt, If not i'll Make a Cygnus anyway's...

i'm Still Deciding on size... 2.5m or 3.5m?

+ i need some Decent reference pics of the Antares

Will post some In-Dev Pics ASA i Get Started

Keenan

[lpam]

i'm Still Deciding on size... 2.5m or 3.5m?

The real thing is 3.9m in diameter, the 64% rule says that it should be 2.496m (aka bang on 2.5m)

[Keenan Smith]

ite 2.5 it is... + by sizing it that way it fit nicely with the ISS mod

im just thinking what size orbit shoud it be capable of .. im thinking of having it have the 1st stage set the Apoapse at 75-80Km and then the SRB Circularizing (about 1250m/s Delta V on the Second Stage? and then the remaining 3800m/s Delta V in the 1st stage ? )

now that just leaves me short of some reference Drawings....

[lpam]

Googled around for some images with dimensions etc and the best I could find were on Orbitals website itself.

http://www.orbital.com/Antares-Cygnus/

Look at the various fact sheets on the right hand side, they show some pictures with basic dimensions.

[Keenan Smith]

i found that During Launch the have to Run the Engines at 108% for 10 Secs Just to get it off the Pad (it has a launch TWR of around 1.2:1)

The initial thrust-to-weight ratio of the vehicle is about 1.2:1, so even though it will consume close to a ton of propellants every second after lift-off, the early acceleration will be surprisingly slow. When the engines first ignite, the rocket will not lift off from the pad for two full seconds. At 10 seconds after Stage 1 engine ignition (or about 8 seconds after lift-off), the vehicle will have accelerated to about 40 mph and climbed to 230 feet altitude. At 20 seconds after ignition, it will be traveling at 100 mph at be about 1,250 feet above the pad. Even after 60 seconds, the vehicle will still be subsonic (about 460 mph) at just over 3 miles in altitude.

Antares achieves Mach 1 about 75 seconds after lift-off, when it will be at about 30,000 feet in altitude. From that point, things happen quickly: at Stage 1 engine shutdown, about 3 minutes 50 seconds after lift-off, it will be traveling at nearly 10,000 mph at over 70 miles altitude. After another 4-plus minutes, it will be in orbit at 155 miles in altitude and moving at 17,000 mphFor those accustomed to the rapid acceleration of Orbital's solid-fueled launch vehicles following lift-off, today's Antares launch will be very different, especially during the early phase of its trajectory.

The initial thrust-to-weight ratio of the vehicle is about 1.2:1, so even though it will consume close to a ton of propellants every second after lift-off, the early acceleration will be surprisingly slow. When the engines first ignite, the rocket will not lift off from the pad for two full seconds. At 10 seconds after Stage 1 engine ignition (or about 8 seconds after lift-off), the vehicle will have accelerated to about 40 mph and climbed to 230 feet altitude. At 20 seconds after ignition, it will be traveling at 100 mph at be about 1,250 feet above the pad. Even after 60 seconds, the vehicle will still be subsonic (about 460 mph) at just over 3 miles in altitude.

Antares achieves Mach 1 about 75 seconds after lift-off, when it will be at about 30,000 feet in altitude. From that point, things happen quickly: at Stage 1 engine shutdown, about 3 minutes 50 seconds after lift-off, it will be traveling at nearly 10,000 mph at over 70 miles altitude. After another 4-plus minutes, it will be in orbit at 155 miles in altitude and moving at 17,000 mph

so i figure in order to Replicate that slow acceleration i'm thinking, Make the Fuel Real Heavy(lots of it), make the Engines Just powerful enough to get it off the pad (with cygnus atop) and then make the Engines Real thirsty (low ISP)

Also it Appears that there is a Fairing over the top half of the Engines... but i can't for the life of me find any good pics

if you look on the 2nd Page Diagram you'll See What i mean http://www.orbital.com/NewsInfo/Publications/Antares_Fact.pdf

[Keenan Smith]

Ohh One last Thing... Does anybody know how tall (Minus the Interstage fairing) is Antares' First Stage?

[lpam]

Your plan to keep acceleration low sounds good.

Also it Appears that there is a Fairing over the top half of the Engines...

If i were you I would model the engines with the covers as one part, that way you wouldn't have to model the complex plumbing and also it requires one less part.

I agree with you about the lack of pictures too, Cygnus doesn't get much love!

[Keenan Smith]

Ohh One last Thing... Does anybody know how tall (Minus the Interstage fairing) is Antares' First Stage?

Nevermind...

Total Rocket height (including Fairinngs) when scaled Down to 64% is 25.92m (well call it 26 ... )

i managed to find out from page 5 of this PDF that the Payload fairing is 9.9m Tall (in Real Life) So that Leaves me slightly less clueless... if i can find out the first stage dimensions then i could get busy withe the 3D model (since i know the length of the Fairings which is 4.6m when scaled to 64%)

here's the first Taurus II Stage 1 core leaving the Yuzhmash plant in Dniepropetrovsk headed for Wallops via the Port of Wilmington

and Apparently on the Taurus II (which is what the Antares was named Previously apparently has a 1st Stage length of 27.6 m (90.6 ft) long According to the manual (of which i don't have access to ) so that scales to a 10m 1st Stage and a 4.6m fairing.. (which leaves me 11.4m of rocket to guess ?)

That Just Leaves the Interstage Dimensions and the 2nd Stage Dimensions...

I'm Gonna go get started on the Fairings and Maybe the First Stage.. (minus engines as they will be done as a Separate part.. )

BTW does anybody know how big the interstage fairing is ?

[Keenan Smith]

Your plan to keep acceleration low sounds good.

If i were you I would model the engines with the covers as one part, that way you wouldn't have to model the complex plumbing and also it requires one less part.

I agree with you about the lack of pictures too, Cygnus doesn't get much love!

Sounds Like a Plan! Just the Fairing and Engine Bell? for the Engines..

yeah Space X Provide lotsa info on there rockets... Orbital! Y U NO GIMME MORE REF PICS (and info)

[Keenan Smith]

Got Started on the First Stage Tank (No-where near Done, Yet.... )

Heres a Fairing Ref pic i found

K

[cesarparent]

Nice project !

I had a try at modelling the Antares a month ago, but I don't have the time, nor the knowledge to finish it. I could send you my sketch up files, however, if it can be of any use

Anyway, keep on the good work !

[Keenan Smith]

Yeah Sure Send em along...

every little helps, though i will probably Re-do you First Stage

i PM'ed you my Email Address

P.s is that at 1.1 scale and would i have to scale it down..

[Blaylock1988]

Interesting, my best friend's name is Keenan Smith...But I'mt pretty sure you are not him. lol

[Keenan Smith]

Interesting, my best friend's name is Keenan Smith...But I'mt pretty sure you are not him. lol

A. are you in the UK...?

if so

B. Whats your first name?

[Blaylock1988]

Haha, no, I am in California. He would have recognized my username anyways

I do love the UK because they invented Drum & Bass!

[lpam]

I do love the UK because they invented Drum & Bass!

Hahahaah that made me laugh, Drum & Base, UK's finest export.