Launched on December 20 1974, Helios was part of a partnetship between NASA and Germany and was designed to study the sun. A twin of the first satellite was launched 13 months later.
In recreating this satellite I did a little trick that allowed me to have a dish on both sides. (The dish was not a high gain radio antenna, the part I used here, but a structure designed to protect delicate instrumentation from direct sunlight). I built the satellite on the Probodobodine OCTO core, set the antenna on top, and then picked it up and rotated it so that the antenna rested inside the booster.
Sometimes when you have parts too close to one another, game mechanics treats them as if they are attached, sometimes causing decouplers to not decouple. In this case, they separated just fine.
I tried to get the satellite into a scale orbit. Mercury has a semimajor axis of .387 AU and the satellite has a periapsis of .29 AU. Using the same proportions as Moho's orbit, I would need to have set the satellite's periapsis at a little under 4 million km. The booster I chose, and a poorly executed orbital transfer, meant I was short of fuel to the tune of 600,000 kilometers.