Version 0.23.5 was released on April 1st 2014. This made many users speculate on whether it was an April Fool's prank. Officially this version is called Asteroid Redirect Mission and the version number is largely only for housekeeping. In the FAQ article by HarvesteR the version was advertised as 0.23.10 but eventually changed to 0.23.5. Originally the version after the prior version (0.23) should be 0.24, but because of the complexity and the announcement that NASA was working with Squad the release of the Asteroid Redirect Mission was separated into this version.
- KSP: Asteroid Redirect Mission is Officially Released!, in the official forum
- Steam community announcement
The original release version number is 0.23.5.459 and after a second update the number is bumped to 0.23.5.464.
New SLS-styled parts
Because this version was developed in cooperation with NASA, there are several parts which are similar to the Space Launch System currently being developed by NASA. It also contains the first safety launch escape system and is one safety feature which is usually absent from updates.
- Extra large liquid fuel tanks, in full (Kerbodyne S3-14400 Tank), half (7200) and quarter-height (3600) variants. All of them carry also oxidizer.
- S3 KS-25x4 Engine Cluster, the single most powerful piece of rocketry ever added to KSP.
- Kerbodyne KR-2L Advanced Engine, for when immense amounts of thrust is required.
- LFB KR-1x2, the first liquid fuel booster: A new way to boost spacecraft, the LFB is a single part featuring twin engines, plus a very respectable amount of fuel. What more, more liquid fuel tanks can be stacked on top of it.
- The Launch Escape System: Modeled after the Apollo LES, this new escape tower can save the crew if the rocket does not behave as expected.
- The S1 SRB-KD25k: A SRB that is designed in the style of the SRBs used on the space shuttle and the SLS.
New part joints
- Large parts feature a new system that allows them to attach much more rigidly to other parts, eliminating many cases where spamming struts was required.
- Increased PhysX's global max angular velocity settings to improve joint stability.
- Angular inertia values for parts now properly scale with mass. Some ships may feel heavier to fly now, but handling feels much more realistic overall. This also improves joint stability a lot.
- Re-did the Strut Connector joints as well, to use the new joints system instead of their old ones. This dramatically improved their reliability and significantly reduced the number of occurrences where ships spontaneously disassemble themselves on the launchpad.
- Added filters in the map view to filter unknown and space objects.
- Focusing vessels on the Tracking Station or targeting them in map view will now display their patched conics trajectory, taking encounters with other celestial bodies into account.
- Added time warp controls to the Tracking Station and Space Center scenes.
- The clock can now show the universal time (UT). A button beside the clock allows switching between mission elapsed time (MET) and UT.
- Maneuver nodes are now persistent.
- Targeted objects are now persistent.
- Added buttons to discard/accept maneuvers on the delta-v gauge by the navball.
- Added buttons to add/remove an orbit to the date of a maneuver node, allowing nodes to be planned for several orbits ahead.
- Maneuver handles can now be fine-tweaked with the mousewheel when hovering over them.
- Monopropellant and xenon gas containers on earlier stages are now drained before containers on later stages.
- Celestial bodies now show a 'Focus View' button on their context menus in map view.
- Added named quicksave and quickload with Mod+F5 and Mod+F9. (unannounced)
Bug fixes and tweaks
- The part of orbits in other sphere of influences will be shown in local mode when they are focused on the map view or Tracking Station.
- Switching between linear and rotation controls in docking UI mode no longer toggles SAS.
- Fixed a bug where patched conics on extremely eccentric orbits could break the simulation at very high warp speeds.
- Fixed incorrect rendering of ascending and descending nodes when targeting a non-closed orbit.
- Fixed a bug where targeting an object on a hyperbolic orbit wouldn't display rendezvous information on the map.
- Tweaked the thrust and Isp values of the PB-ION Electric Propulsion System, LV-1 Liquid Fuel Engine and LV-1R Liquid Fuel Engine. All were severely underpowered to be of any practical use.
- The mass of the Inline Clamp-O-Tron was increased from 0.125 tons to 1 ton.
- Quicksaving is now allowed at all times. In unstable situations, an autosave won't be created at the same time.
- Greatly improved the accuracy of the physics to rails transition, eliminating drift on nearby vessels when warping during a rendezvous situation, especially high-velocity ones.
- The map filtering buttons now toggle independently on left click, and toggle single/all on right click.
- Fixed several cases where Kerbals on EVA would glitch out in very painful ways, mostly when the game changed reference frames while they were in ragdoll state.
- Intersection nodes between orbits no longer 'skip' the closest intersection when placing a maneuver node near the player's position.
- The courage displayed in the Tracking Station and map view are inverted to the value displayed in the Astronaut Complex.
Originally the 0.23.5 update had a bug which could reset the science progress when an old save was used but is fixed in 0.23.5.464. Loading a save from before 0.23.5 and entering the Research and Development facility would reset the progress which can't be fixed by loading the save in the new version. Instead a quicksave created before the issue appeared can recover this by loading it with the fixed version.
Asteroid Redirect Mission
Unlike previous versions of the game, this version is officially called Asteroid Redirect Mission. It was usually announced as a mod pack or expansion pack, but in the end it contained so many ground breaking changes that it is considered a usual version update. The redirect mission consists of approaching an asteroid and either capturing in Kerbin's orbit or simply preventing the asteroid from hitting Kerbin by altering its orbit.
- “Kerbal Space Program: Asteroid Redirect Mission - The FAQ” released by Rowsdower on March 15th
- The version number in the FAQ was changed so there is no direct evidence for the version number 0.23.10 but there are comments like the one by Majiir which mention the other version number.
- “To the Mun and back: Kerbal Space Program” by Charlie Hall published on January 27, 2014
- “Devnote Tuesdays: The "Almost Forgot to Title This Post" Edition” on the forum released on January 28th
- “Devnote Tuesdays: The “Work on ALL the Things” Edition” on the dev blog released on February 18th