KerbalX

Description

I took the Ion-Powered Space Probe stock craft, and accepted the challenge of building something to get it into orbit (as well as somewhat enhancing the Probe itself). Not, perhaps, in the simplest or most efficient way possible, but, hey, it does the job.

There’re five different engine stages in the thing:

• A liquid-fuelled first stage, powered by a single Swivel engine (this stage contains most of the powerful flight controls, in the form of the Swivel’s gimballing and a reaction-wheel assembly at the upper end of the stage - by the time this stage is ditched, we’re already out of the lower atmosphere and the aerodynamic forces should be low enough for the reaction wheels on the upper stages and the probe itself to handle comfortably);
• A small but high-thrust solid-fuelled Flea motor, which provides a decent kick as well as serving as the mounting point for the vehicle’s aerodynamic payload fairing;
• A low-thrust but long-burn-duration Mite solid-fuelled sustainer motor, which keeps the craft up to speed as it leaves the atmosphere and boosts its apoapsis high enough to give it sufficient time to accelerate into a stable orbit;
• A pair of Puff monopropellant engines, which drain first from two drop tanks (one after the other), and then from the tank on which the Puffs themselves are mounted;
• And, finally, the Dawn ion engine on the probe itself, which has exceptional vacuum Isp (and, thus, Δv), but very low thrust, and requires electrical power to produce thrust. As a result, the vehicle has to be launched in a very high, lofted trajectory in order to give the probe the time it needs to accelerate into a stable orbit with the meagre thrust from the Dawn, and can only be launched during the times of Kerbin’s day when it will be able to get sunlight to allow its solar panels to keep the probe’s batteries charged for the entire time it’s thrusting.

Improvements in the probe itself:

• As the name indicates, it now has three relay antennae (a top-mounted RA-2, plus two smaller HG-5 deployable antennae on the sides), replacing the stock probe’s Communotron 88-88, which, although powerful, was direct-communications-only, not being useable for relay duty;
• The grossly-inadequate PB-NUK RTGs of the stock probe have been replaced by a set of six OX-4L solar arrays, which provide enough power to run the Dawn engine continuously at full thrust;
• The twin Z-100 battery packs found on the stock probe have been moved upwards (to make room for the HG-5 antennae below them) and augmented with a Z-200 battery bank, nearly doubling the probe’s battery capacity and considerably increasing the margin of safety if some of the solar arrays occlude each other or the Sun is temporarily eclipsed by the Mun during orbital insertion;
• Finally, the probe’s OKTO probe core, which provides only basic SAS capability (limited to attitude hold), has been augmented by a nose-mounted OKTO2 core, with its considerably-more-advanced SAS (providing prograde/retrograde, radial out/in, and normal/antinormal hold in addition to simple attitude hold) allowing more precise flight control.

A stock rocket called Ion-Powered Relay. Built with 36 of the finest parts, its root part is probeCoreOcto.v2.

Built in the VAB in KSP version 1.9.0.

Details

• Type: VAB
• Class: satellite
• Part Count: 36
• Pure Stock
• KSP: 1.9.0