[0.23] Tangent Rockets - Second Generation - 18% Payload fraction lifters

[mhoram]

Version 1.0 2014-01-25 for Kerbal Space Program V 0.23.

Lifter Family with 18% Payloadfraction and tug engines that

participate in the liftoff.

Download on Spaceport http://kerbalspaceprogram.com/tangent-rockets

Download on Dropbox https://www.dropbox.com/sh/573rc6a1jtnmkow/jM_6Pq1X8f

This is the second generation of the Tangent rocket lifter family.

For infos about the first generation see this forum thread.

This lifter family provides

• High payload fractions of over 18% to a LKO of 75km
  
• Payload capacities of 20, 30, 60, 120 and 180 ton
  
• Tug engines (LV-N) that stay optionally with the payload
  
• Enough RCS fuel to deorbit the final stage of the propellant for a debris free orbit
  
• Flat surface on top of the nuclear engines for building the payload
  
• Support payload that provides no own rotational control
  
• Stock parts only
  
• MechJeb tested and verified
  

ROCKETS

Currently this set consists of the Tangent 2, 3, 6, 12 and 18. The

download contains .craft files with predefined payloads and

subassemblies.

The rockets were tested with differently formed payloads. The folder

'example-payloads' in the package contains payloads that were

successfully brought to orbit manually and with MechJeb.

Here are the specifications:

USAGE

The ascent trajectory differs from the first generation greatly.

While the rockets of the first generation were quite easy to handle in

manual ascent, the second generation requires more skill and practice

to get into orbit.

To get a feeling how to perform the gravity turn, try MechJeb.

ADDONS

If you use MechJeb 2.1.1, the following settings were tested

successfully with all rockets.

- orbit: 75km

- inclination: 0°

- Turn start altitude: 10km

- Turn end altitude: 70km

- Final flight path angle: 4°

- Turn shape: 40%

The only difference to the first generation rockets, is the

final flight path angle changes from 0° to 4°

KNOWN ISSUES

The margin for steering errors is quite small, so keep a steady hand

during the gravity turn and don't overshoot the 75km LKO too much.

(Actually this is not an issue but a feature)

Tangent 12 is a little bit squishy, so do not take much time until

liftoff.

CHANGES

0.1 - Initial Release

0.2 - Added Tangent 12 with a payload fraction of 16.70%

0.3 - Updated all rockets to KSP 0.22:

- the payload fraction dropped a bit

- Reworked Tangent 3 and 6 to be handled by MechJeb without

problems

1.0 - Second generation - complete redesign

- Start Nuclear Engines at liftoff (Thanks to Rune for the hint)

- Tested and verified with MechJeb 2.1.1

- Update to KSP 0.23

- Increase Payload fraction from 16% to 18%

FUTURE

Tangent 1 forces a very difficult design because the nuclear engine

must be placed in the center for symmetry reasons. Only made it work

during initial tests with a payload fraction < 15% which I am not

happy with. So don't expect many rockets with an odd roman numeral in

the Tangent series - actually Tangent 3 will stay most likely the only

odd numbered rocket in this series.

Tangent 48 will probably never be finished because the part count

exceeds 500 without the first propellant stage and struts. Lag is no

fun!

Edited January 25, 2014 by mhoram