KerbalX

Details

• Type: VAB
• Class: probe
• Part Count: 23
• Mods: 3
• KSP: 1.12.5

Mods

• Bluedog DB
• Squad (stock)
• TweakableEverything

One of the first steps in paving the way to manned lunar missions would be to simply prove the feasibility of reaching the Moon. This set the course of the first Pioneer probe whose mission was to be the first payload launched beyond simply orbiting the Earth, orbit the Moon, and prove basic but valuable data. Unfortunately three separate attempts carrying the original and two copies of the probe carried by the Thor-Able were failures although the second and third attempts did provide some useful data on radiation fields with the second attempt reaching the highest altitude of any man-made object to that date.

The Thor rocket began life as America’s first intermediate ballistic missile, which while having only a relatively short deployment, was the beginning of an entire rocket family using the Thor rocket as the first stage which eventually evolved into the Delta rocket family which is still used today such as the Delta IV Heavy which is used for heavy classified payloads.

The Able rocket began life as part of the USN’s Project Vanguard where it served as the second stage of the Vanguard rocket before being re-purposed and modified as one of the few liquid-fueled upper stages. It served as a reliable upper stage, along side the Agena, for several years before being retired but its engine would serve as the basis for a long-line of engines used for both upper stages and even the Apollo’s service module.

The Altair solid rocket also began life as part of the USN’s Project Vanguard where it served as the third stage of the Vanguard rocket before it began its own family of upper stages initially used in a number of Thor-Able flights such as the ones launching the first Pioneer probe attempts. While the stage was historically reliable problems with it are what led to the failures in two of the attempts.

The Alpha is an approximation of the original Able rocket stage and is a highly efficient liquid-fueled upper stage that allows for precise control over the payload’s orbital parameters. It is most efficient, by more than 400%, in a vacuum, so is designed for use once you have reached space.

The Staara-20 in the X-248 configuration approximates the Altair and is a vacuum-efficient solid rocket that provides the final boost for the payload. It will provide approximately 700 m/s dV which can be fine-tuned by reducing its fuel.

The P1 Ramo is an approximation of the original three Pioneer problems, and as such, it has two small engines meant for course correction and orbital insertion. The smaller one only gives approximately 15 m/s dV, while the other provides around 400 m/s dV, which is better suited for the orbital insertion burn.

The actual historical missions failed to achieve lunar orbit which you can simulate by simply not making an orbital insertion burn or overshooting your ascent stages. The first stage gets you out of the atmosphere and into space while the second stage should get you to the Mun. The third stage will likely be unnecessary under stock settings; in this case, you can either deplete it before launch or omit firing it and simply decouple the probe.

The ascent profile is incredibly simple with a direct mun ascent, which means you set the mun as a target and launch straight up when the target is about 45 degrees, it doesn’t have to be precise under stock settings.

Once the probe is decoupled, I recommend putting it in hibernation so it has enough power to turn and fire engines. The small engine is good for averting a munar impact, and the larger one for the orbital insertion burn.

Built in the VAB in KSP version 1.12.5.