Search the Community

So, how do you land your SSTO (space plane, with wings) in 1.0.5 (stock, no dynamics mods, no high-tech stuff) ? This is a question. I offer my answer. I very welcome YOUR answers and YOUR corrections! Its very useful to learn this, by going into sandbox mode, putting your plane in 120k Orbit, named quicksaving ([mod key]+F5) and learning to land safely. Edit: I think I found all the reasons to make descend 100% reliable and predictable. 1. Know-how Assume, the planet is Kerbin. 1.1 The number one factor is - angle/trajectory. The steeper you go down, the more heat will you absorb. The higher your speed, the better is to aim at near flat trajectory. For example, Jool with thick atmosphere will destroy any spacecraft aimed too steep. Airbraking trick via Jool to save fuel instead of retrograde burn is pretty known. As such, if your speed is more than 2100m/s in high Kerbin orbit (70k), you might consider air-braking loops around planet. a) If your angle is too steep, burn anti-radial. 1.2 The number two factor is - speed. Higher speeds at same altitude cause atmosphere to heat more and cool less. At 55k, your speed should be less than 2000 m/s. If your speed is higher than 2000m/s - you are at risk. Ways to disengage speed: a) if you have fuel, burn retrograde between 70k and 50k. b) if you have substantial surface amount (wings), position yourself as a cobra: nose pointing at angle between anti-radial and prograde, and carefully try to maintain this position as long as possible. There is some risk your plane flips, so be careful. This approach makes, basically, "AIRBREAKS" from your whole spacecraft. c) if you have nothing, the most efficient way is to position yourself normal/anti-normal, engage SAS on stability and hold rotation key (Q or E) permanently down. This is similar to cobra, but more stable - and rotation causes equal heat distribution. Parts with less than 2k Tmax may explode! 2. Methods 2.1 Blackbird - direct descend from high-orbit at high speed (pictures) Note: because of high speed, you will only stabilize at around 10k. 2.1.1 Target almost shallow trajectory to surface, preferably not mountains. Correct for about place you want to descend. 2.1.2 Plasma heat starts around at 55k. Set your course to prograde (currently - vector of descend) and lock it. If you can only stabilize - stabilize at prograde and over time carefully push down to be within prograde vector. From observation - any attempt to deviate against prograde at this altitude will result in more heating and shorter descend (more heating at lower trajectory). 2.1.3 Between 55k and 33k, any part with less Tmax than 2400 will overheat and explode. 2.1.4 Around 35k it is possible to shorten the descend by - switching autopilot to stabilize for some time, then switching back to prograde. Trying to do this manually can induce too sharp angles and cause flip, immediate overheat+explosion. 2.1.5 Around 15k, it is encouraged to do breaking maneuver as in (5) above. At this altitude atmosphere is actually capable to cool the SSTO more, than drag can heat it. 2.1.6 Stable trajectory is possible at 10k or continue descend + landing as a regular plane. Congratulations, you survived! 2.2 Shallow cobra (community contributed) Note: this method will only work, if you dropped speed below 2100m/s at 55k. Any higher, go more shallow. At certain speed limit, it does not help anymore. "I don't know about FAR but stock aero from Kerbin orbit, cobra reentry is the way to go. Set your periapse to 30 km, point the nose at the zenith and nothing gets very hot. " Outcome 1: descend from 200km Apo (stock method). My outcome - explosion. Proof: http://imgur.com/a/3TpBY Outcome 2: descend from 60km Apo (as in author image). My outcome - explosion. Proof: http://imgur.com/a/U1Cx9 Outcome 3: Additional test using more traditional (flat, with more wings) type of SSTO. My outcome - flip and explosion if nose at "zenith", yet SURVIVED if nose is between 45 and 0(variates depending on heat and stability). Proof: http://imgur.com/a/1Kpz4 The bottom line: deviations from prograde (descending vector) in 55-35km are deadly. 22km-12km - helpful. 2.3 Rotating apporoach (community contributed) Note: this method is superb, if you lack any wing area. Its very useful for orbital worker bots or re-usable rocket stages. "a reentry technique with as much chaotic movement as possible. The angle doesn't matter as your chaotic rotation will keep the heat evenly distributed and let parts cool off while they are occluded." "A demonstration with FAR, no damage due to aerodynamic stresses, craft is kept cold, works in 100% of cases with no part loss" "The actual rotation speed was about 1 rotation per 1-2 seconds. " Outcome 1: descend from 200km Apo. My outcome - explosion. Retested 4 times to be sure, same situation in the end, same outcome. Proof: http://imgur.com/a/15ffD Outcome 2: descend from 60km Apo. My outcome - SURVIVED. Retested 3 times, every time - survived. Proof: http://imgur.com/a/KcFa8 The bottom line: rotating helps a lot to distribute the heat equally.