Kerb-X Eve Messenger Probe - [Partial Success] [VERY pic heavy!!]

[Werwolf]

Mission Objectives

Land a probe on the surface of Eve via unpowered parachute descent. Probe is equipped with a Poodle engine and enough fuel for about 30 seconds of flight. After sufficient data and pictures have been taken, the probe is to attempt to lift off and fly as high as it can at terminal velocity in order to gain more understanding about what sort of conditions are experienced during Eve ascent attempts. When engine burnout occurs, deploy a second stage of parachutes and land back onto the surface of Eve, providing a permanent observation outpost and marker for a possible future landing.

Launches

1st launch: Fuel tank assembly.

2nd launch: Probe Payload docked to fuel tank assembly

3rd launch: Nuclear engine module attached to fuel tank/probe assembly, forming the craft to transit to Eve. Empty tanks are jettisoned from the fully configurable fuel tank assembly.

Eve craft has been fully assembled. From the left to right is the Nuclear Engine Module, the Payload Transfer Package containing the probe, and the fuel tank assembly.

Empty fuel tank and mostly full Monopropellant tanks are decoupled and left in orbit for future reuse. Burning for the Mun gravity slingshot maneuver...

The Mun slingshots usually entail very close calls to achieve the speed required to leave the Kerbin system without extra fuel use...

Passing the Mun at very close range, outbound to the Sun's SOI..

Eve arrival! Circularization burn in progress.

One of the two tanks I brought is now empty after getting us all the way here, so it is parked in a 100X200km orbit for use by future missions, possibly as part of a space station. All of the individual tanks have docking ports on either side so they can be used in many ways..

With the empty tank gone, it's time to reconfigure the spacecraft to facilitate the payload separation, leaving the extra fuel in orbit with the Nuclear Engine Module.

Successful spacecraft reconfiguration!

Now it's time for the Payload Transfer Package to decouple and begin the de-orbit burn with RCS..

De-orbit burn via RCS

When the deorbit burn is complete, ensuring ground contact for any debris, the Payload Transfer Package is decoupled off of the probe. The PTP debris will impact the surface of Eve, leaving no trash in orbit.

Feelin the burn...

It is at this point that the mission suffered a severe failure. The drogue chutes were deployed at 10km altitude. However, when the chutes fully deployed at around 4km altitude, the resulting force snapped the main fuel tank/engine/lander assembly off of the probe body, which remained attached to the parachute assembly. The battery was ripped off of the probe, so the electrical charge drained faster than I could deploy the solar panels, which were left intact on the parachute assembly. The probe was dead before it hit the ground.

Probe impacts the surface of Eve, dead as a doornail and upside down.

Conclusion:

Even strong and thorough use of struts throughout the probe body did not keep the craft from separating. The main chutes never had a chance to deploy, with the drogue chutes seeming more than capable of slowing the craft down. Probe failure due to high G forces experienced during drogue chute deployment. Future probe bodies must be more robustly constructed.

Edited June 16, 2013 by Werwolf

[suzin.felipe]

Maybe you should have killed some speed with the engines before opening the chutes. I did that in Duna and it worked as I had the same problem with my landing ship.

[astropapi1]

Did you quicksave on Eve orbit?

[[email protected]]

this is a problem with the remote control units, they are 'weak' and they snap off at the nodes easily..

[Werwolf]

Maybe you should have killed some speed with the engines before opening the chutes. I did that in Duna and it worked as I had the same problem with my landing ship.

I had thought about doing this, but was below 100m/s and the chutes had not yet opened so I saved the fuel. I wanted to save as much as possible anyways for my test.

[Werwolf]

Did you quicksave on Eve orbit?

I did, but it was a legitimate failure. I don't use quicksaves unless the game really glitched out on me.

[Werwolf]

this is a problem with the remote control units, they are 'weak' and they snap off at the nodes easily..

what surprised me was that i had a 4x heavy strut around connecting everything to everything above and below it, and yet it still broke off... sigh.