Jump to content
  • 0

Complicated Minmus Rescue


Question

I'm in the rather unpleasant situation of having a Kerbal, his craft and a truckload of data stuck on Minmus. I have pretty much zero monoprop left in the ship - just enough for a 100m jump upwards.

I guess that situation's not exactly uncommon, but the problem here is that in order to recover not only the astronaut but also the science, I'll have to dock with the stuck craft (Docking Port Jr. on top, Docking Port below) to transfer the science from the Storage Unit and back to Kerbin, unless there's a way for a Kerbal to transfer 7 experiments (multiple surface samples and EVA reports) into the new ship without docking. The lander in question ran out of fuel for the way home despite refueling in LKO and I'm not sure if refueling twice (at 130km and 19,000km) will help or cost more fuel than I'll gain (both stations have a capacity of 2 FL-T400 tanks each).

Attached is a screenshot of my science tree progress to give you an idea of what I'm working with. I'm playing in Science Mode, so KSC upgrades or craft cost don't matter.

Vb6SztY.png

Link to post
Share on other sites

6 answers to this question

Recommended Posts

  • 2

Yep, Kerbals can transfer an infinite number of experiments in their pockets. You only have to land a rescue ship within a dozen km of this stranded ship, have the kerbal get out, get close to the Storage Unit, click the "take data" button on the context menu, fly over to the rescue ship, and go home. And it will only take you about 250 m/s of deltaV to get home, so you certainly don't need to do any refueling.

In fact, the Kerbal could get out, grab the data, and then fly most of the way back to Kerbin himself. You'd want to save a little EVA fuel so he can board a rescue vessel -- but he can probably get back to an 80 x 2500km orbit at Kerbin all by himself.

 

Edited by bewing
Link to post
Share on other sites
  • 2
On 6/9/2018 at 11:42 AM, HashtagMC said:

I'm in the rather unpleasant situation of having a Kerbal, his craft and a truckload of data stuck on Minmus. I have pretty much zero monoprop left in the ship - just enough for a 100m jump upwards.

Good thing that kerbals have ~600 m/s of dV in their EVA packs, huh?  :)

On 6/9/2018 at 12:02 PM, bewing said:

You only have to land a rescue ship within a dozen km of this stranded ship, have the kerbal get out, get close to the Storage Unit, click the "take data" button on the context menu, fly over to the rescue ship, and go home.

^ What bewing said.  But actually it's even easier than that:  you don't even need to land the rescue ship.  Your "stranded" kerbal can easily fly himself to Minmus orbit on EVA thrusters; then all your rescue ship needs to do is an orbital rendezvous to pick him up.

In fact, a kerbal standing on the surface of Minmus easily has enough dV to go all the way home to Kerbin with EVA alone.  Used to be you could actually do that, i.e. fly from surface of Minmus to surface of Kerbin without a ship.  A while back, though, they made reentry heating more intense, so if you try to do that now, I expect your unprotected kerbal will fry on reentry.

But if you wanted to, you could have the kerbal escape from Minmus on EVA and go into an orbit that puts his Pe just above Kerbin's atmosphere, and then snatch him with a rescue ship there.  Would be a bit less dV than sending a rescue ship to Minmus orbit, but a harder rendezvous to do (i.e. more of a navigational challenge), so it's probably easier just to take the kerbal up to Minmus orbit and pick him up there.

 

Note:  this approach works on the Mun, too... but just barely.  A kerbal on the Mun's surface can barely make it to low Mun orbit-- and by "barely", I mean to a really low orbit, as in "under 10 km, and you have to fly an efficient ascent path".  But it's doable, I've done it.

Link to post
Share on other sites
  • 0
On 6/9/2018 at 8:42 PM, HashtagMC said:

I'm not sure if refueling twice (at 130km and 19,000km) will help or cost more fuel than I'll gain (both stations have a capacity of 2 FL-T400 tanks each).

Snark and Bewing nailed down the rescue part. For your future endeavours though, I'm going to adress the "refuel twice" bit. Yes it would likely cost you more fuel than you'd gain. Not only a station in a 19,000km circular orbit is not actually on your path to Minmus/other planets, because you'd go there with an eliptical path, but due to the Oberth_effect, you want to burn as close to Kerbin as possible, for as long as possible. As unintuitive as it sounds, the efficient path from Minmus to Jool involves lowering your PE near Kerbin.

Link to post
Share on other sites
  • 0
21 hours ago, Kesa said:

Snark and Bewing nailed down the rescue part. For your future endeavours though, I'm going to adress the "refuel twice" bit. Yes it would likely cost you more fuel than you'd gain. Not only a station in a 19,000km circular orbit is not actually on your path to Minmus/other planets, because you'd go there with an eliptical path, but due to the Oberth_effect, you want to burn as close to Kerbin as possible, for as long as possible. As unintuitive as it sounds, the efficient path from Minmus to Jool involves lowering your PE near Kerbin.

Unless your rescue ship is Way Too Heavy, it won't take 1600 units of Lf/O to change orbit from LKO to 19,000 km.  With a Mk. 1-3 pod, powered by a Poodle under a 2.5 m tank, you can transfer from LKO to Munar orbit, capture there, and return to Kerbin reentry on less than that.  I used to send Mk. 1 size spaceplanes, powered by a Swivel, to Munar orbit and aerobrake return with four tourists and a pilot, on 800 units from LKO.  Minmus is only a couple hundred m/s more dV (though I surely wouldn't attempt to aerobrake with a Mk. 1 Cockpit from Minmus -- it was all I could do to get it done from the Mun).

I completely agree, Snark and Bewing have it nailed -- just have the Kerbal grab all the science data and fly into Minmus orbit, and pick them up there; you should be able to do that easily on a single 1600 unit refuel from LKO, and most likely have almost half that Lf/O left.

Link to post
Share on other sites
  • 0
11 hours ago, Zeiss Ikon said:

snip

Good point, refuelling (or staging) should not even be needed for a single non landing mission in Kerbin SOI, save maybe once in LKO if you launch empty ships.

Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...