It's been a while. Part II

[NewtSoup]

Having Realised that the KSC is up and running again, Kerbin's most infamous Billionaire, Bezoar Kerman has commissioned his own vessel to take him to Duna.  Under his kreative guidance the KSC has produced a vessel to his specifications.

The Blue Oaxaca!

The pilot of this vessel will be Valentina Kerman.  Once in orbit the BO will be refuelled and a Duna Lander vessel attached to the bell on the end.  

Blue Oaxaca has space for six Kerbals aboard although only five seats will be filled.  The remaining space will be filled with snacks and video tapes.  Given that if only one cassette were sent it would probably be worn out part way through the mission it has been decided by the KSC that 10 copies of "The Invisible Kerbal" should be sufficient at an average of three viewings per day.

[NewtSoup]

Launch Day!
Blue Oaxaca blasts off with Valentina and Bezoar aboard.  Currently Mission Tourist Bezoar has the hitch hiker container to himself although Valentina may have got the internal comms stuck on "I'm a Barbie Kerman" by mistake.,



And the BO settles into a 100km parking Orbit.  It may be more than a year to the transfer window but it's widely considered that it would amuse everyone on kerbin be better for the mission that Bezoar should "train" in orbit in a real environment.   In other news the KSC has announced that all orbital communication is to be shut down for maintenance.

[NewtSoup]

Suddenly, a wild re-fueller appears!

Re-fuel rocket.
Blasts off into the dark night,
Also it has snacks



The re-fueller provided The Blue Oaxaca with the needed snacks and fuel to make the interplanetary journey to Duna.  Originally the BO had been designed to have a swappable engine cluster such that the Mainsail Lifter engine could be replaced with a Poodle for the higher efficiency.  However, it was found out that even with the Duna Lander attached to the nose the BO would have more than enough dV to do the job.  The engine swapping  plan was therefore re-directed to /dev/null for secure storage.

One more re-fueller would be needed to complete the job and that would stay attached to a side docking port until the the Duna Lander had been launched and made rendezvous with the BO.

[NewtSoup]

It's launch day for the Duna Lander.  Just a few hundred days before the Duna Transfer Window!

By the way I am using Alex Moon's Launch Window Planner online since Kerbal Alarm Clock and Transfer Window Planner are out of date.  It seems to be quite a nice tool.  I'm not sure how to read the graph exactly as it's a 3D graph of Flight Time vs Departure Date ( from epoch) vs dV needed.    But it automatically works out the least dV needed for your transfer anyway.  I think you could in fact use it to plan any transfer from any orbit.

The Duna Lander (DL) sits atop it's lifter inside the fairing. 

At launch the boosters and the twin boar engines lit fine.  At around  2000m the lifter rolled left 90 degrees to facilitate booster separation.   A the boosters burned out it was discovered that a mistake in staging lit the second stage Cheetah engine in addition to jettisoning the boosters.  This burned out the actual stage separator leaving it's shroud intact.  This was not a huge disaster as there was plenty of fuel on board the lander which could rendezvous with the BO under it's own power rather than being delivered by it's own lifter.


 

So the DL separated and circularised on its own.  Summer then began working on the manoeuvre to intercept the BO.

 

Finally docked.  The Lander and the Oaxaca were topped up with fuel from the re-fueller.

Edited August 23, 2021 by NewtSoup

[Maria Sirona]

Absolutely love this! Small correction: it's means it is. "Belongs to it" would be its, without the '.

[NewtSoup]

9 minutes ago, Maria Sirona said:

Absolutely love this! Small correction: it's means it is. "Belongs to it" would be its, without the '.

Dyslexic brain can never properly remember that.  I mostly only spell correctly because of the wiggly red line :D.

I do like to get it right though, so thank you.  Corrected it.

 

All I have to do now is the actual transfer.  I was going to do it right away but I've been distracted because on a whim I applied to do a 3 year degree in acting.  I passed the audition  so I've suddenly had to deal with preparing to be a student again at 50 years old 

Edited August 23, 2021 by NewtSoup

[NewtSoup]

I have a question on orbital mechanics for those that might be reading this:

The transfer window planner has given me the following information:
 

Departure		Year 18, day 281 at 4:48:00
Arrival			Year 19, day 115 at 3:07:12
Time of flight		259 days 4:19:12
Phase angle		33.80°
Ejection angle		160° to prograde
Ejection inclination	3.87°
Ejection Δv		1,066 m/s 
Transfer periapsis	13,328 Mm
Transfer apoapsis	20,408 Mm
Transfer inclination	0.18°
Transfer angle		160°
Insertion inclination	-1.42°
Insertion Δv		607 m/s
Total Δv		1,673 m/s

 

Most of it seems fairly explanatory.  What I'm not clear on is Ejection Angle.
Can anyone explain what it means by 160 degrees to prograde?

My plan was to wait until an hour or so before transfer departure date and time and then just mess around with a manoeuvre node until I saw an encounter with Duna.  But if I wanted to do it as accurately as possible how do I read the information I've been given?

Linky to the entire page showing what I see when I ask for a transfer window.

 

Edited August 23, 2021 by NewtSoup

[Free Trader Beowulf]

As I understand it an ejection angle of 160 degrees to prograde is the angle between your craft's position and the prograde vector of the planet you are orbiting, rather than your ship's prograde vector. So, for example, if it was 90 degrees to prograde, you would burn a quarter orbit before crossing the planet's prograde vector. Does that make sense?

Messing with the manoeuvre node until it works might be just as good though :-)

[NewtSoup]

8 hours ago, Free Trader Beowulf said:

As I understand it an ejection angle of 160 degrees to prograde is the angle between your craft's position and the prograde vector of the planet you are orbiting, rather than your ship's prograde vector. So, for example, if it was 90 degrees to prograde, you would burn a quarter orbit before crossing the planet's prograde vector. Does that make sense?

Messing with the manoeuvre node until it works might be just as good though :-)

Oh I think I get it now. It's one of those things that "must be".  If I've managed to plot a manoeuvre that gets me to Duna's SOI then the ejection angle will be 160 because it can't be anything else.   There's probably ways to finesse it but I'm sure the manoeuvre node will be close enough.

[Maria Sirona]

For me eyeballing the launch window based on what at what degrees is the target ahead/behind and then just playing with the node till i get an ecounter is the best and most fun way

[NewtSoup]

It's time.
Time to burn!

A roughly 1050m/s burn got the Blue Oaxaca to a Duna encounter with a periapsis of about 16,000 km. Not too bad.  A course correction or two along the way will fine tune it.  


In other news Valentine, Summer, Siglorf and Vertrey have all taken up residence in the Hitchiker Storage container and Bezoar is "Piloting" from the Duna Lander for the  duration of the mission.    Vertrey (Mission Engineer) has disconnected all controls in the DL so that Bezoar can practice to his heart's content.
 

[NewtSoup]

A suitable time mid-journey was randomly selected for Valentina to fine tune the Duna encounter.  With a little jiggling she managed to get the encounter to a more-or-less equatorial PE of just 89km above the surface. 

As the Mission Scientist.  Siglorf decided she should show imitative and actually do some science while in a Solar orbit.  A space walk was required to safely retrieve the data gathered and store it in the Lander.  She took a moment to stare directly into Kerbol's gaze.  As the light bored into her brain she realised that her next mission would have to be to ... her mind went blank!  Where would the next mission be to?  Answers on a stamped and addressed Edam to:

Siglorf Kerman
C/O The Astronaut Complex
Kerbal Space Centre
KS1AC

Edited August 24, 2021 by NewtSoup

[NewtSoup]

Duna eventually hove into view.  The excitement aboard the BO was palpable.  

Bezoar announced that he would be first to make footfall onto Duna's surface.  The crew had different ideas however.  Vertrey and Summer joined him in the crew section of the lander and sang Christmas Carols to him until he left for the hitchiker container to join Siglorf.  Siglorf however chose to EVA and joined the others in the Lander at which point they closed the access to the docking ports.

Valentina performed a capture burn into Low Duna Orbit and parked the vessel 65/70km cicularish orbit.  Close enough.


 

 

[NewtSoup]

With a dull thunk and a soft hiss, Summer undocked the Lander from the BO.  The docking port itself made no sound at all as it detached.

She then slung the lander into a J-Turn to end up facing the other way and began a de-orbit burn.

The next few shots show the descent of the lander through Duna's atmosphere.  Nothing exciting happened.  There absolutely didn't need to be several reloads to randomly find a spot that wasn't so steep the lander fell over and exploded.  That never happened.  Not once.

 

 

The lander touched down. Rather precariously, but stayed upright!

And Siglorf got out to make footfall and pose, staring off into the distance.  She was the very first Kerbal on Duna ( at least in this universe ).

Science was done and experiments were run ( on the Kerbals who were still alive ) and so Summer and Vertrey joined Siglorf on the surface.  Vertrey, the Mission Engineer decided to take a look at the parachutes for Kerbin re-entry later.  It was her job after all and the sole reason she'd been selected.  However it turned out that maybe she shouldn't have faked her resume.  She knew nothing about parachutes and was unable to re-pack them.  She hoped that this wouldn't come back to bite her later.  After casually stuffing them into their storage she joined the others on the surface for snacks and a photo opportunity.


 

Edited August 24, 2021 by NewtSoup

[NewtSoup]

Due to Vertrey's monumental screw up with the parachutes it was realised soon that the lander, or rather just the re-entry pod would not be making it back to the surface alone.  Thankfully the BO has a huge amount of fuel left and so the plan has changed.  Ascend to orbit.  Catch the next transfer window back to Kerbin ( 3 years 198d, 4h ),  Capture into a highly eliptical Kerbin Orbit.  Aerobrake down.   Perform a powered landing on Kebin as close to the KSC as possible.  Or just onto the surface.  We have no idea if this will work.  Atmospheric drag should provide most of the braking forces need.  Should everything to pear shaped then all five Kerbals will EVA and parachute to safety. And Siglorf has to retreive the science data too.  This is not a good plan.

To maximise DV the lander was emptied and dumped onto the surface of duna leaving only the Pompegranate re-entry module attached to the BO.

 

Bye Bye Lander.  Rest In Pieces.

[NewtSoup]

The Final Adventure.  This will be the last post for this thread.  At least the last one with mission pictures.

 

	It's departure day.  Summer and Crew wave bye bye to Duna.  It's a short burn to get back to Kerbin's SOI just 660m/s. The initial burn got the BO within a few hundred thousand Km of Kerbin.  A mid course correction got that down to around15,000km
	A 460m/s capture burn at PE then put the Oaxaca into an elliptical orbit to the edge of Kerbin's SOI.  From here a series of aerobraking manoeuvres were done until it was possible to decend to the surface. Much use was made of the monopropellant on board which had hardly been used to save as much liquid fuel as possible for the final burn that would land the craft gently on the surface of Kerbin
	The final approach.  From here on in it was do or die!
	<insert re-entry noises here>
	Just a few hundred meters from crashing, Summer "Suicide" Kerman took control of the BO She had more experience of suicide burns than Valentina.   Valentina was not useless though, her job was to keep her foot jammed firmly into the RCS controls to slow the descent as much as possible.
Spoiler	<REDACTED>
	Success!  Summer Suicide Safely Secures Spacecraft! The plucky little Kerbal has once again earned her nickname.  She touched down in the Ocean east of the KSC with 0dV Remaining in the tanks. The engines flamed out an instant before they touched the water. The crowds went wild when the entire craft gently bobbed back to the surface fully intact.

A low amount of science to be sure.  But not bad for only their third science gathering mission.

Nuts the image links dont' work properly because I used affixes to get smaller versions.  Oh well

 

Edited August 24, 2021 by NewtSoup

[NewtSoup]

I don't like the format of that last post.  It was an experiment.  I won't do it again.

A wish to the forum managers / developers - I wish it were possible to edit tables after creation - change borders, change alignment, add / remove rows or columns.

Edited August 24, 2021 by NewtSoup