Kerbin Re-Entry Velocity Challenge

[medicdude]

All kerbals agree that going fast is a lot of fun. Kerbal scientists need you to find out exactly how much fun they can have by going really, REALLY fast around Kerbin.

The challenge; push an 8.025ton (or more) payload through the atmosphere of Kerbin, and survive, using only intra-kerbin system maneuvering (mun and minmus flybys/bounces only).

The details: Your final payload must include an MPL Mobile Processing Lab, Cupola Module, 2.5m service bay, full 2.5m heatshield, and an additional 1.1250 tons (or more) of discretionary mass (full FL-T200 tank for reference). Stock engines and fuel tanks only. Starting orbit around Kerbin is 80km apoapsis maximum, 70km periapsis minimum (ideally 75km circular if using orbit editing). All flight assistance mods are allowed, and any non-thrusting mod parts may be added to the payload. (EDIT: Because a 2.5m heatshield just doesn't cover enough, you will probably need at least a 3.75m heatshield)

A 'bonus' refuel while landed on minmus is allowed, if desired, an independent refuel rover is allowed to dock and disconnect to starting craft. You could edit to landed on minmus if you really want, but that takes all the fun out.

You may submit entries with a starting mass of 25, 51, and 100 tons (or less), payload included.

The reference entry is simply the default payload plus Kerbodyne S3-7200 tank plus Poodle engine (50.275 tons), a good design should be able to squeeze more delta v than this.

The ultimate goal of the challenge is re-enter kerbin OR skim kerbin's atmosphere with the fastest velocity, and survive (lower is faster, but also hotter).

Any scoring or design recommendations are welcome.

 

Edited November 9, 2017 by medicdude
periapsis fix, some design changes to accomodate re-entry

[Joseph Kerman]

"""The ultimate goal of the challenge is the fastest speed at apoapsis of kerbin, and survive (lower is faster, but also hotter)."""

*periapsis

[medicdude]

So my first attempt has ended in glorious explosions at 56km going 4835 meters/sec, this is apparently far too low for the single heatshield; I will try again at a much higher periapsis of 62km.

[medicdude]

Second attempt ended in explosion at 64km, I will instead go for a 69km grazing with the next approach.

Finally a success, going 5768 m/sec past kerbin, with a periapsis of a measly 69,380, resulting in a beautiful kerbin escape velocity of 5011 m/sec, enough to break the conic limit around the sun, for a kerbol eccentricity of 1.315, wooo-e!

Edited November 9, 2017 by medicdude
more details on kerbin escape velocity.

[medicdude]

A new survival at 5544 m/sec has been achieved, with significant slowing from the atmospheric entry.  I did not realize the slowdown would be so significant XD. I will try bringing up a large heatshield with the next craft and place the survival modules behind the service module.

I will have to add separate challenge categories for fastest 70km velocity and greatest atmospheric break performed based on initial and final velocity at 70km.

Imgur screenshot of -0.1 sec to periapsis: https://imgur.com/a/wKcmS

(Err, how do I embed the imgur picture so it actually displays inside the post?)

Edited November 9, 2017 by medicdude
added screenshot

[Rocket In My Pocket]

13 hours ago, medicdude said:

(Err, how do I embed the imgur picture so it actually displays inside the post?)

Button on the bottom right, says "Insert other media", click it, then select "Insert image from URL"

Paste your link there; like this. (In the case of imgur, you have to right click the preview image and open the actual image link.)

^Your pic.

Edited November 9, 2017 by Rocket In My Pocket

[medicdude]

Thanks for the feedback Joseph Kerman and Rocket In My Pocket,

I have another very successful aero-capture entry at 5786m/sec with a 20km apoapsis  This is without a mun boost, just burning a poodle with a full kerbodyne 7200. I tried out some wings on this design, they burned up pretty fast. There was some aerodynamic instability after the wings burned off, I managed to stabilize without burning up by opening the cargo bay doors, I might have to try some smaller fins that can fit behind the heatshield.

Anyways, pics:

https://imgur.com/dGSo5T7

and

https://imgur.com/C40TyI7

(Insert other media still won't work for me, maybe its blocked for newbie accounts?)

 

[Rocket In My Pocket]

3 hours ago, medicdude said:

(Insert other media still won't work for me, maybe its blocked for newbie accounts?)

My fault, I didn't explain that well.

The standard imgur link doesn't work because it needs to be the actual image link. What you tried to link is the "image page" with the preview image embedded in it; the forum doesn't know what to do with that because it's not actually an image but a webpage.

You can get this by right clicking the image, opening it in a window. Now copy-paste that "link" from your address bar into the field.

So the links you wanted in this case were:

https://i.imgur.com/dGSo5T7.jpg

https://i.imgur.com/C40TyI7.jpg

See the difference in the links? This is one of the reasons I hate using imgur! Lol.

Edited November 9, 2017 by Rocket In My Pocket