Landing Class A Asteroid on Kerbin.

[jbdenney]

I have a contract to land a Class A asteroid on Kerbin. From what I can tell it does need to be attached to my grabber pod to get credit.

I minded out all of the resources to lighten the rock. I have gotten it into a 100KM orbit. I have tried stopping the orbit relative to the surface  and just dropping into the atmosphere. I also tried a standard reentry with the PE at 40KM. I also tried as shallow a reentry as I could get ( started with a 60KM PE and it made a few orbits dropping the PE and AP a little  at a time. In all three cases the speed of the rock never dropped to the point of even trying ot deploy the radial  Mk2-R Parachutes. In every case I do not get down to 1000m/s until I get to an altitude of 1000m which means every thing goes splat.

I have looked online but I have not found any help that does me any good. Can any one give me ideas to park the rock on the ground in one piece with the attached pod(and Jebediah) intact.

I have noticed something odd.

When I first attach to the rock I show a total mass of 11.318t for the reentry pod and the rock (all engines dropped). But when I break it down  the Rock shows a mass of 8.59148t and the reentry pod/grabber is 2.727t...

BUT...

When I have mined out the rock it show as a total mass of 10.518t which is more than the total mass before mining. The rock shows a mass of 0.51549t and the re-entry pod has a mass of 1.927t. The retrieved ore was carried off by a different ship so it is not included.

The only difference between the two different times I measured mass was the first was done BEFORE the asteroid was mined and the second was after the mining was completed and the ore hauled off. In both cases the orbit was the same at 37Mn.

Before mining the vessel mass and Rock mass adds up correctly. But after mining the rock the sum of the two parts is 2.44249t but the total mass shows 10.518t. Where did the extra 8.07551t come from?

Just prior to de-orbit at an orbit of 100Km the numbers are  total mass of 11.318t with the reentry pod being  2.727t and the rock is still 0.51549t. The total mass went up a bit in the closer orbit but the difference between the sum of the parts and the listed total mass is still 8.07551t which is the same difference at the higher orbit.

Is this the reason I cannot get the rock down? The game thinks that the total mass is too high?

I have thought about attaching bigger parachutes but I never slow down enough to be able to safely deploy.

 

Thanks in advance

 

[AHHans]

I guess it is a bug.

[...]

Could be bug #25730 on the bug-tracker.

16 minutes ago, jbdenney said:

I have thought about attaching bigger parachutes but I never slow down enough to be able to safely deploy.

Have you tried drogue chutes?

[jimmymcgoochie]

What you need is drag, lots of drag. Inflatable heat shields are great for that, they’re very big and also very heat resistant; stick a few of those on your asteroid grabber and position them so they’ll inflate into the airflow and add drag. Drogue chutes are another option as they can open earlier than main parachutes and slow you down a bit until the mains can open.

[king of nowhere]

19 hours ago, jbdenney said:

 I have tried stopping the orbit relative to the surface  and just dropping into the atmosphere.

this means you have over 2000 m/s of deltaV. but this approach is not good. you stop the orbit, then the asteroid is in free fall, and it has a lot of time to pick up speed. If you make a normal 40 km reentry, and then you start burning the rockets to slow down, you should be able to slow it enough to open the parachutes. without need to send more stuff in orbit.

[AlpacaMall]

If the other methods don't work, the worst case scenario is that you use engines to brake in the atmosphere once you're down at parachute altitude. At 1000m/s, that's about 250m/s you need to shave off for the drogue chutes to open.