Ballistic Reentries

[CodeFantastic]

 So i started a new career mode and I've started to escape the atmosphere. The problem is though, since I don't have enough deltav to get into a full orbit, my orbits tend to be sub-orbital and semi ballistic. The Apo. tends to be ~80km, and yet when I re enter the pod is going to fast for me to deploy the parachutes in time. I'm getting frustrated and am wondering if this is suppose to happen.

[Wemb]

This will happen if you go straight up and then straight down again - or anything remotely close to it.  

When you re-enter from orbit, remember, your mostly going sideways - so you get to spend a long time in the atmosphere to loose speed.  Sub-orbitally, the horizontal component to your velocity will be much less - which means you'll have less time in to the atmostphere to slow down.

There are a few approaches to this - you can try and give your re-entry body improved lift characteristics so that you glide back rather than falling like a rock - which will prolong the time in the atmosphere. Alternatively you can researcha and use drogue chutes which aren't enough to land with but can slow you down enough to deploy the main chute.

But, early on, your best bet is to simply do less steep sub-orbital missions.  Burn sideways more - you'll limit your potential Ap, but at this stage all you're trying to do is hit >70km before coming back - so use any excess thrust to get sideways velocity which will protect you on the way back down.

Good luck

Wemb

Edited March 31, 2016 by Wemb

[FullMetalMachinist]

This is a really common problem with newer players. Basically you're going so fast that the air just can't give you enough drag before hitting the ground. 

There are usually two answers, either redesign your craft to be more draggy, or use a gentler ballistic arc (have more horizontal speed, so that you spend more time in the air before you lose too much altitude). 

In order to know which of those to suggest, it would be helpful to see a couple screenshots. One of your craft, and one in map view showing what you trajectory looks like when you start reentry. 

[CodeFantastic]

4 hours ago, FullMetalMachinist said:

This is a really common problem with newer players. Basically you're going so fast that the air just can't give you enough drag before hitting the ground. 

There are usually two answers, either redesign your craft to be more draggy, or use a gentler ballistic arc (have more horizontal speed, so that you spend more time in the air before you lose too much altitude). 

In order to know which of those to suggest, it would be helpful to see a couple screenshots. One of your craft, and one in map view showing what you trajectory looks like when you start reentry. 

I'm not new at all and I understand that ballistic trajectories are bad but I guess the new aeromodel makes things a lot more different since I haven't played career since .90. Plus Im not used to the whole "ya gotta wait for the parachutes to be safe to deploy thing, just used to winging it.

[FullMetalMachinist]

13 minutes ago, CodeFantastic said:

I'm not new at all and I understand that ballistic trajectories are bad

Apologies for the assumption, didn't mean to talk down to you or anything. 

However my last paragraph still stands. If you really want specific advise to your particular situation, we'll need to see some screenshots. 

[steuben]

The other option I've found is to not worry about making it very draggy. That usually gives you trouble on the launch, especially in early game. You've got add more thrust and dv to get up. But if you add a lot of control to it either with control surfaces or gyros you can execute a series of controlled maneuvers (or tumble wildly) between 20 and 2 km up to scrub off speed down to 250 m/s.

[Madscientist16180]

À little trick that can really help in my opinion is to turn the capsule sideway as soon as heat generation drop enough. In the very first sub-orbital flight, the aerobreaking effet given by pointing the "heat shield side" prograde can indeed by insuficient. I normally simply tilt the capsule, pointing more surface area prograde, and thus slowing much more. 

Doing this sometimes make such à difference that i can open the chute at around 4/5000m instead of not slowing enough to actually open them at all. Just gotta be careful not to blow a radial chute or battery when you start doing it.

I never really noted at what altitude i start to do it unfortunatly. And anything bigger than a 1.25m pod will definitly never need me to do this.