How to locate a landed asteroid?

[Ethen Sun]

So I poked around in the Tracking Station, and saw not one but TWO Kerbin-intercepting asteroids. I was thinking of watching them come down, but since Kerbin was rotating I had no idea where it would come down. Anyway, I overdid the time warp and they both impacted and disappeared off the radar, without me seeing where they landed. All I know is that it's somewhere around 50 degrees north. Is there any way I can locate them? Would my orbiting survey scanner be of any use? Would I see a dot of ore concentration? It has a short band, surface scanner, everything.

[Ultimate Steve]

When you are not within a certain distance of any craft, it is considered "On-Rails" by the game. This means that no physics are simulated other than the object following its orbital path. If it hits a planet, or gets too deep in the atmosphere, it is considered destroyed by the game. Unfortunately, your asteroids are gone.

[HvP]

Hello @Ethen Sun and welcome to the KSP forums.

As Ultimate Steve said, if you aren't focused on the asteroid the game will consider it destroyed as soon as it enters the atmosphere. However, if you want a challenge, it is possible to grab an asteroid in space and land it on Kerbin with a ship designed to safely recover it.

I've never attempted such a feat, but I know there are others here who can give you pointers on what it takes to land one.

[Ethen Sun]

1 minute ago, HvP said:

Hello @Ethen Sun and welcome to the KSP forums.

As Ultimate Steve said, if you aren't focused on the asteroid the game will consider it destroyed as soon as it enters the atmosphere. However, if you want a challenge, it is possible to grab an asteroid in space and land it on Kerbin with a ship designed to safely recover it.

I've never attempted such a feat, but I know there are others here who can give you pointers on what it takes to land one.

Thanks for the welcome and the answer. I'm horrible at rendezvous, and i would probably struggle very much to land a 1000 ton mass. If i use an expendable ship that is destroyed on impacting Kerbin, I will have the asteroid, right? Since a ship is with it while it impacts? If I switch away after landing, will it still be there?

[HvP]

33 minutes ago, Ethen Sun said:

i would probably struggle very much to land a 1000 ton mass.

I admit that I'm not very good (or patient enough) to rendezvous with asteroids, but on the upside if you bring mining equipment with you the asteroid will lose mass as you convert its ore to fuel.

33 minutes ago, Ethen Sun said:

If i use an expendable ship that is destroyed on impacting Kerbin, I will have the asteroid, right? Since a ship is with it while it impacts? If I switch away after landing, will it still be there?

Based on previous threads I believe that asteroids stay persistent once they are safely on the ground, but I have no first-hand experience to confirm this. I would be very careful about letting your ship explode during the landing process however. If your probe core explodes while the asteroid is moving through the atmosphere (even for a little bounce) and there are no other ships within physics range, then the game might delete it.

Edited July 10, 2017 by HvP

[Ethen Sun]

By the way, what are the chances of this happening? In about 40 days of game time, i now have two asteroids orbiting Kerbin, and two that have impacted. (Without any intervention)

[Dafni]

3 hours ago, Ethen Sun said:

By the way, what are the chances of this happening? In about 40 days of game time, i now have two asteroids orbiting Kerbin, and two that have impacted. (Without any intervention)

I would say that sounds perfectly fine, for Kerbin standards. I never counted, but yes, they are pretty abundant.

[Cpt Kerbalkrunch]

While landing an asteroid is certainly possible (even a class E), for an asteroid that "impacts" Kerbin, you didn't miss anything. I once had the brilliant idea of using an asteroid as a heatshield when entering Kerbin, and I'm sure I'm not alone. Plenty of people have probably tried it, cuz it sounds like a great idea. Except it's not. The asteroid simply overheated and blew up. And not even an entertaining explosion. It just went "poof", and was gone. So I would guess that without help to slow down, or at least soften their approach angle, your asteroids probably never reached the surface at all.

[Snark]

15 hours ago, Ethen Sun said:

i would probably struggle very much to land a 1000 ton mass.

It may not be as hard as you think.  As long as you manage not to have it overheat and explode in the atmosphere on the way down, I expect you could do this by spamming a bunch of airbrakes, followed by a bunch of drogue chutes, followed by a bunch of regular chutes.  I think asteroids have a reasonably high impact tolerance (a few dozen meters per second, IIRC), and parachutes' air resistance goes up with the square of the speed, so they could probably do the job.

Actually, perhaps your best bet would be to have some of the inflatable 10m heat shields attached on, and inflated so they're facing directly retrograde.  Those things are great-- they're like hypervelocity flame-resistant parachutes.  I played one career where I wanted to send a big fuel tanker from Minmus back to Kerbin with load of fuel it had mined on Minmus.  The ship was on the order of 400 tons when it hits Kerbin's atmosphere at 3000 m/s.  It had two of the 10m heat shields (one on the front, one on the back), and was able to brake into LKO with just a single aerobraking pass, shedding around 1000 m/s of speed and tipping down to a Pe of 28 km.  So, a few of those would probably do a great job of slowing down an asteroid like that.  Your 1000-ton rock is bigger than my 400-ton tanker, but not hugely bigger.

Just make sure that all of your airbraking and parachuting hardware is all on the side of the asteroid as it's plowing through atmosphere, so that they're shielded from the heat.  Airbrakes, in particular, melt pretty easily (1200K), but as long as you keep them in the lee of the stone, they'll be fine.  The good news is that as long as they all start out on the back side, they'll stay there, because it'll be aerodynamically stable that way.

15 hours ago, Ethen Sun said:

If i use an expendable ship that is destroyed on impacting Kerbin, I will have the asteroid, right? Since a ship is with it while it impacts?

As long as the asteroid itself is not destroyed on impact, then you're fine.  Once it lands, it lands and will be persistent.

15 hours ago, Ethen Sun said:

If I switch away after landing, will it still be there?

Yes.