KerbalX

AS-3A Skystreak - Tier 3 R&D Not Required

Aero/Spacecraft - 3A

The AS-3A Skystreak is a Tier 2 R&D SSTO. It also does not require the High Altitude Flight node.

It has 3 sets of engines: quad Panthers for atmospheric flight, twin Thuds for orbital insertion and maneuvering, and twin Puffs for additional orbital maneuvering.

Ascent profile has very little error margin. Wheels up at 80m/s. Pitch up to 45 degrees on dry mode. Switch to wet mode at 3500m-4000m, pitch up to 60 degrees. Pitch down begins at 7000m, smoothly pitch down until around 9000m. If done correctly, Panthers will continue increasing in thrust up to a maximum of 130kN at 11000-12000m. Pitch up again to 45 degrees around 13000m to utilize remaining and dropping Panther thrust to increase vertical speed. Activate Thuds before 16000m. Maintain between 30-45 degrees pitch until apoapse is above 70000m. Circularize using combination of Thuds and Puffs to retain liquid fuel for atmospheric flight on de-orbit.

Some trial and error required.

Ignore the album below, there is a corrected ascent profile, and it is much simpler.

Takeoff as normal. Continue on dry mode at 25-30 degrees pitch. Switch to wet mode around 3000m, pitch up slightly to 35-40 degrees. Continue until about 7000-7500m, when pitch down begins. Pitch should be at 5-10 degrees by 9000m. Continue until 750-800m/s. Pitch up to 40-45 degrees around 13000m. Activate Thuds and RCS by 16000m. Maintain 40 degrees pitch until about 25000m, from then a gradual pitch down towards prograde. Orbit should be achieved solely on Thuds with around 300m/s combined dV between Thuds and Puffs.

With an optimal ascent profile, there should be enough dV to perform low-orbit part retrieval missions. However, this is done unconventionally, by physically capturing the part in the cargo bay. This means orbital time warp is not easily possible. Once physics warp returns upon de-orbit, the part should remain in the cargo bay (if bouncing around loosely). Upon landing at KSC, the part does not count as ‘retrieved’, so that part of the contract will not be completed. Have a rover waiting with a Claw to complete that part of the contract before Recovering the part.

Built in the SPH in KSP version 1.3.1.

Details

• Type: SPH
• Class: spaceplane
• Part Count: 88
• Pure Stock