KerbalX

Details

• Type: SPH
• Class: spaceplane
• Part Count: 368
• Pure Stock

Hearts Chevron 96 is a rapier space plane that can carry a lot of cargo. Hearts Chevron is named by the shape of the engine blocks. In flight it forms this unique contrail pattern.

This is the 2375MC version which stands for 2 x 3.75 meter center referring to the attachment setup. The weight is default fuel mass and you can place something else. However, while having no rear fairing attachment points it is most useful to haul anything else that doesn’t require a fairing.

The default cargo consists out of.

*16 x Kerbodyne S3-14400
*2x Kerbodyne S3-7200
*4x Kerbodyne ADTP-2-3
*4x Rocket protective nosecone Mk7

It thereby carries 1.445 Tons of the maximum 1450 tons to orbit with a payload fraction of 52.5%

It should be able to reach ~1600m/s during the jet phase and at MTOW the rapiers can easily break past 400m/s while it’s carried by one rapier per 28.5 tons of weight.

Using physical timewarp is possible, in fact, it is advised even

1. Use 3x physical timewarp on runway (1 during takeoff)
2. Use 2x physical timewarp near sea level.
3. Use 3x physical timewarp when holding SAS after achieving 400m/s above the sea.
4. Use 4x physical timewarp above 13km.
5. May want to revert to 3 or 2x if pitching is unbalanced (use engine modes to realign center of thrust)

1: Use existing cargo or put something custom on the decoupler under the belly. Use move:tool to drag the cargo so that the COM is under the COL Distribute weight on both sides evenly. If that isn’t possible use extra weight on one side. Put draggy parts in fairings and use a symmetrical cargo type with a centered weight or use the other types of this vessel found on my craft page.
2:Accelerate to the 2 blocks at the end of the runway and pull up to 5-8°.
3:Keep pushing the nose down to stay near sea level and accelerate up to 400m/s and then gently pull up (tap the S key) Don’t pull up to hastily or you might face RUD.
Best is to use Mechjeb Surface mode and hold 5°
4: Lower nose to 0-4° when climbing past 10km. The nose would have naturally risen to or past 10°. If the nose wants to rise use action group 7 to deploy front spoilers to stabilize. Keep accelerating at this angle until 20+km
5:Using most payloads you will reach 1600m/s at 20-23km altitude. Use Action group 7 to deactivate spoilers and action group 1 to toggle to closed cycle and stay at 10° until vertical climb rate is above 250m/s and then hold prograde until Apoapsis is just above 70km.
If necessary use action group 4 to toggle on/off the lower engines if the nose wants to rise nearing orbital velocity.
6: Circularize at Apoapsis and stage to detach payload. If the payload stays in place use timewarp and let the payload pass through the vessel and then exit timewarp.
7: Do a roll over and a retro burn. You may need to use action group 2 through 6 to deactivate the lower engines for stability.
8:You can do the re-entry various ways. The vessel is very heat resistant. You can do a retro burn with a Pe to 30km and keep diving to prograde and then force the nose up to do a quik decceleration. Or you can hold a pitch angle of 90° to 50° depending on atmospheric height. Due to high placed CoL the nose will not be able to dive down holding W alone during aerobraking. Instead push down first using W then pull up using S until the nose is at or past 90° and then force the nose down again with W to get it to prograde. If you don’t you will be in a irrecoverable flat body stall until below 250m/s.
Make sure you get the nose back to prograde with a max 20 degree difference at or above 1000m/s to avoid this.
9:Activating the brake action groups extends spoilers on all control surfaces while maintaining stability. It’s handy to get rid of the last one hundred or so m/s when coming in to fast at the runway. Empty it can also land anywhere including in the
water.

IMPORTANT Use action groups 2 through 6 to toggle engines on/off on the engine blocks. Several dozen combinations are possible for realigning center of thrust.
This is necessary if the payload is unbalanced.