[Stock] [1.0.5] Nova II - 229 tons to LKO

[Temstar]

 

Edit: an updated version of this launcher, the Nova IIB UHLLV has been released. This version is now considered obsolete.

Tired of launch vehicles that barely register as a blip next to the monster rockets built by aliens from the Sol system? No longer!

Presenting: Nova II Ultra Heavy Lift Launch Vehicle
Craft file: http://www./download/92j7fo82d2ecfj1/Nova_2_UHLLV.craft
(Craft file contains proofing payload)

Specifications:

• dry weight: 181 tons
• wet weight: 849 tons
• cost: √234,004
• part count: 181
• payload: 229 tons to 75km x 75km orbit
• payload fraction: 21.25%

Cost per ton to LKO:

• without RHEUS recovery: √1022
• 80% average RHEUS recovery rate: √824
• 50% average RHEUS recovery rate: √898

Features of Nova II:

• usability focused design targeting a balance between payload fraction, cost per ton to orbit and part count
• asparagus staging with fine tuned stage separation and TWR
• reusable upper stage for precision orbit insertion, space loitering capability, clean space act compliance and reduced launch cost

Typical mission profile

Spoiler

 

Turn on SAS, throttle up to max and stage. Once the booster has reached altitude of 500m, tilt over 5 degrees to east, toggle SAS to prograde and wait for separation of first booster pair at T+ 32 seconds.


Keep following the prograde and leave the throttle on full power for the entire boost phase. Second booster pair separation should happen around T+ 1 minute 14 seconds, and the last pair at T+ 2 minutes 17 seconds. You want the Time to Apoapsis to hang around 30-60 seconds during the core stage burn. Don't be alarmed by engine overheat warning - the extremely long burn utilised by asparagus staging causes this and its well within the engine's capability to withstand.


Core stage burnout will happen around T+ 4 minutes 8 seconds. Nova II utilises hot staging technique for stage separation between core stage and the upper stage to ensure positive separation so don't be alarmed by the rather loud staging sequence. Payload fairing is also jettisoned at this point.

The Reusable High Energy Upper Stage coasting with the payload after boosting the apoapsis to near 75km. The RHEUS has powerful flywheels and a built in RCS system to help pointing the giant payload in prograde direction. You may want to disable payload monopropellant drain while RHEUS is still attached. At 30 seconds before AP, drop out of time warp and switch SAS to prograde and turn on RCS and RHEUS will point the payload in prograde for the circularisation burn.


Payload release. Note the extremely small inclination and eccentricity demonstrating RHEUS' capability for high precision orbital inserting of oversized payloads.


After payload release one could simply deorbit the RHEUS, which results in a cost of √1022 per ton to LKO. However Nova II was specifically designed to break through the √1000 per ton barrier for expandable launch vehicle and to achieve this the RHEUS is equipped with recovery capability. Either fire the main engine or the four auxiliary monopropellant thrusts to begin the deorbit burn and aim for LZ near KSC.


Being an empty rocket stage the RHEUS returns more or less ballistically without cross range capability. It is however equipped with four drag fins which can be deployed to adjust if you which to reduce downrange travel. Being an empty rocket stage however gives the RHEUS one advantage over reentrying spaceplanes - the ballistic coefficient is so low (with airbrakes deployed it falls through the atmosphere much like a giant shuttlecock) that even reentry from very shallow angles without airbrake deployment results in mild heating that causes little heat management problem.

Once it safe to do so, deploy the recover parachutes and RHEUS will float down at around 7m/s. The safe landing speed of the engine is also 7m/s so for safety I recommend setting the engine thrust limiter on 10% thrust and throttle up slightly as you near the surface to reduce speed below 7m/s. If you are out of bipropellent the auxiliary monopropellant engines can also be used for landing cushioning.

Safe landing, 8.9km from KSC.


Here's another safe landing - a splashdown again several km from KSC. At this sort of distance from KSC you will get more than 90% of the value of the RHEUS back.

 

Edited January 31, 2016 by Temstar

[SheVa Nine]

Awesome! I´ve been looking for a launch vehicle for my 55.9 ton DSEV, but there´s no kill like overkill (especially since the DSEV wants to be in HKO)

[Paranoid Shark]

Works perfectly, I am still exclusively using your zenith launcher family that you designed ages ago. Do you plan on re-designing any of the others?

[Temstar]

I did originally have some vague plans to redesign the others but I'm not sure if it's all that relevant in this day and age. Back in those 0.20-ish days the only metric to measure how good a rocket is designed was payload fraction and part count per ton. Zenith LVs were pretty good in payload fraction but were never that good in parts per ton.

Nowadays the picture is more complicated. Cost per ton is obviously very important now and that sort of work against asparagus design since you're throwing away a lot of engines. Similarly one of the original impetus for making Zenith was that LV-T30 and LV-T45 has better ISP than the 2.5m engines and cheaper per unit of thrust to boot, so it made sense to cluster them for core stage of an asparagus. These days 1.25m engines are worse than 2.5m engines so the main reason for clustering is gone. I did try to make a clustered core stage using a few Swivel and lots of aerospike but aerospikes are really expensive for the amount of thrust they give so it wasn't really worth it.

That said I'm not setting around either. The current plan is to make a new group of launch vehicles focused on low cost per ton to orbit. It won't be a rocket family as such since partially/fully reusable launch vehicles of different size need different methods of approaching that problem. For example the smallest one:

Is a SSTO rocket booster with jet engines to allow atmospheric flight to land back at KSC.

The next biggest one can put 45 tons into LKO, it uses all solid first stage (7 kickbacks! It's pretty exciting to look at when launching) with a stretched RHEUS as upper stage.

Currently working on this guy:

Which is three winged boosters pushing an engine-less fuel tank and payload. Still having trouble to get those boosters to fly straight though as they are extremely ass heavy.

Once the whole set is ready I'll release them as a pack and do a tutorial to talk about reusability.

[PointySideUp]

The Nova II is great, I've used it to launch some huge interplanetary mining ships with relative ease.  This is my go to booster when I want to fly a heavy load and don't feel like coming up with a launcher.