Sarnus INT-21-HOW
by gc1ceo
uploaded 2017-07-18
(updated 2018-06-03)
mod station
#sarnus #saturn #hokulani #skylab


  • Type: VAB
  • Class: station
  • Part Count: 63
  • Mods: 3


  • Bluedog DB
  • Squad (stock)
  • TweakableEverything

The success of the early Apollo program was followed up with the Apollo Applications Program meant to use existing Apollo technology for a variety of additional projects with the potential to further lunar exploration and colonization. One of the major elements of the program was to develop space stations, both in earth and lunar orbit, as well as habitation modules for long voyages using the S-IVB stage of the Saturn V. However starting in 1969 following the success of Apollo 11 there were a number of huge budget cutbacks for NASA which eliminated many of the plans for the AAP.

The concept of using a S-IVB as the basis for a space station was scaled down and combined with a number of other AAP projects such as the Apollo Telescope. The result was the first American space station, Skylab, which was launched in 1973. It had a troubled start as its maiden voyage saw the loss of one of its two solar panel wings as well as damage to its shielding. However the first Skylab mission saw partial repairs which allowed it to be used for several successful missions starting with a 28 day stay and ranging up to a 90 day stay. There were a number of plans to further support the Skylab and boost its decaying orbits to allow for more stays. There was also an initial early plan in the Space Shuttle’s development to dock it with Skylab. However budget constraints, focus on the Space Shuttle’s development, and aging technology cut all these plans and it finally splashed down in 1979.

The Hokulani Orbital Workshop (HOW) is Bluedog Bureau’s build of the original Skylab complete with docking space for two spacecraft and a radio telescope mount. It is designed for up to six crew, presumably from two different 3-man Kane CSM, but in a crunch it can also temporarily house two additional crew in the airlock module. This could also be visited by the extended 5-man Kane CSM variant as it can support its entire crew compliment.

The Hokulani is launched on-board a modified Sarnus V, designated the INT-21, with the telescope mount initially mounted on top of the stack. The INT-21 variant of the Sarnus V can be a bit easier to control with the first stage bringing the payload into the upper atmosphere and the second stage handling the rest of the ascent and orbital process. There should be enough fuel to place the HOW into any LKO (Low Kerbit Orbit) you deem necessary for your mission parameters. I recommend an orbit between 100-350km to make docking operations more feasible and if you wish to approximate the real Skylab then an orbit around 310km is suggested.

The real Skylab’s telescope mount was attached to the station through a system of motorizing arms which moved it from the top of the stack to its final place on the zenith side of the docking module. However the Hokulani’s telescope mount works a bit differently and is initially docked at the forward docking port. The normal procedure is to undock the unit where in it becomes a small remote controlled probe and then move it around to re-dock on the zenith docking adapter. The zenith docking adapter and the mount’s docking port both use the CADS (Common Androgynous Docking System) ports so that they aren’t interchangeable with the Kane docking adapters used for the forward and nadir docking ports. The position of the two CADS ports should prevent the telescope mount from being connected at the wrong orientation but there’s always the possibility you may have re-dock and rotate the mount so that the mount’s solar panels at 45 degree angles from the docking module. I highly recommend that you avoid opening the mount’s four solar panels until you are satisfied with its docked position on the station.

Unlike other space stations the HOW lacks an on-board engine but has a decent set of RCS thrusters for lateral and rotational control. There are thrusters located both on the station’s body and the telescope mount as both sections need to be operated independently as the mount is moved and re-docked in its final place. The radiator system being technically unnecessary also acts as a sizable monopropellent tank negating the need to refuel the space station for most operations. The station gets its power from large solar wings on the sides of the station body and four additional extendable solar panels on the telescope mount. However it should be noted that none of these solar panels can track the sun but are built in such a manner that at least one of the panels will be facing the sun. This also provides for a bit of redundancy in case something catastrophic to one of the solar panels as happened to the real-life Skylab.

Built in the VAB in KSP version 1.4.3.

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