Zenith Rocket Family

The Zenith Rockets are a series of 3rd Generation Heavy lift rockets built by Roskosmos, with Superheavy capabilities. The Zenith Rocket overall capability is similar to the KASA Mercury Rocket Family. However, the actual use of the Zenith is very comparable to the Explorer-Class Shuttle for LKO payloads.

The Zenith's use a central rocket, with 4 powerful boosters. The Zenith is not a stack design, instead the payload is strapped to the side.

History and Design:
After the successful KASA launch of the Challenger shuttle, work began on a Roskosmos version. Roskosmos saw a threat from the Explorer, giving KASA the ability to launch and recover Roskosmos satellites.

However, Roskosmos wanted to increase the capability of their shuttle and expand from the lessons learned through proxy of the Explorer.

The Explorer was not nearly as reusable as originally planned, so to avoid costly refurbishment costs, it was decided that the Zvezeda-Class Shuttle would ride on the side of a disposable Rocket.

This would also allow for further usability for non-Kerbin-return missions such as rovers and probes.

For these non return missions, payloads are launched on the disposable vehicles.

Zenith I:
The Zenith I history is as the prototype for the later Zenith II rocket. The Zenith I was never intended to launch any meaningful payload. The Zenith II and the Zvezeda-Class Shuttle was to launch any payload that the Zenith I would've been capable of carrying anyway.

The Zenith I main S2 center rocket was powered by a bootleg version of 1 Kerbodyne KS-25 "Vector" engine, called the KD-55. The surrounding boosters of the Zenith I were heavily modified Lyra II boosters, powered by the RK-7 "Kodiak" engines.

After being originally retired, the Zenith I was recommissioned as the launch vehicle for the KiG-2101 Shuttle.

Zenith II:
The Zenith II is the production full size Zenith rocket, and one of the most powerful rockets ever built. The Zenith II is the launch vehicle for the Zvezeda-Class Shuttle.

The Zenith II central rocket is powered by the Kerbodyne KS-25x4 'Mammoth', a commercial engine sold by Kerbodyne using 4 heavily modified KS-25 "Vectors". This was the first application of the Mammoth. The Zenith II also had 4 boosters, powered by a modified version of the same center stack of the Zenith I.

On a later version of the Zenith II, Roskosmos worked with C7 Aerospace to make these boosters completely reusable.

Zenith III
The Zenith III was a verticle stack variant of the Zenith II designed for interplanetary exploration to the Mun. It was the direct successor to the Herkules Rocket that had first landed Roskosmos on the Mun.

The Zenith III uses 8 Zenith I rockets as boosters, aswell as a modified Zenith II-M as a second stage.

Zenith II-M