*** This craft has been taken out of service as per 1.1, and it's role has been taken over by the S5 Arrow, which has lower costs for the same performance. This craft is suited for 1.05 with the only exception that the droptanks don't line up properly and will need to be manually adjusted. The fuel ducts can be removed as well if you enable fuel crossfeed on the hardpoints. ***
Welcome to the S4 Apollo, the bigger, more beefed up brother of the S2 Athena. It is a medium sized SSTO capable of 400 km return trips to kerbin and is as such ideally suited for carrying kerbals into or out of space. Refueling in orbit gives it a further 2000 m/s of dV to burn. This SSTO is ideal for transferring Kerbals into or out of Kerbin orbit or to bring small equipment and utilities to space stations (using seat inventories), should KAS be installed.
It comes equiped with liquid fuel droptanks for the early stage of flight and two take-off boosters. Those are at all unnecessary but do make the craft take off really, really fast.
Maneuverability of the spacecraft is good and flight characteristics are generally forgiving, meaning that even an utter idiot can fly this thing and come home in one piece.
Take-off is simple:
- Accelerate down the runway, when 80 m/s is reached pitch the nose up by about 7-10 degrees.
- Take off when 110 m/s is reached.
- Accelerate at 10 degrees pitch until 300 m/s is reached, then pitch up towards 15-18 degrees. Due to the curvature of Kerbin, nose up attitude will adjust upwards automatically. When done correctly, a speed of about 1100 m/s will be reached @ 20 km.
- Switch to closed cycle by closing the air-intakes by pressing the custom 2 key.
- Continue ascend, adjust as desired.
Descending and landing is simple as well: Place your periapsis between 5 and 20 km, depending on how fast your re-entry is. Landing speed lies at about 90-100 m/s.
A hot and fast entry is survivable, should you fear to overshoot KSP. However, I claim no responsibility for fried kerbals.
Other craft in the S-series
S4 Apollo (taken out of service as per 1.1, it's superseded by the S5 Arrow)
S6 Axe (due to come online later)
S9 Beluga (due to come online later)