KGSS: Recording solar flares

[togfox]

The Kerbin Geographic and Science Society (KGSS) is a casual and open society of volunteers that like to inject a little bit of real life science into the Kerbal Space Program. Exploding rockets and designing bizarre planes is fun but once you learn basic rocket design and orbital mechanics you may feel the urge to do something more purposeful. For those looking for a mission with a reason, or a reason to do a mission, the KGSS invites you to attempt the below hypothetical mission:

Insert a satellite in Kerbol orbit to record solar flares in real time

The KGSS is offering a grant to any scientist that can insert a satellite in Kerbol orbit (the sun) so solar flares can be captured in real time. The sensitive instruments mean the orbit must be at 7,000,000km in a circular orbit. It is hoped this orbit can be maintained for 7 orbits after which, the satellite is to return to Kerbin safely so the results and images can be processed. Your mission is to:

- design and launch a satellite that can insert into a Kerbol orbit of 7,000,000km and return to Kerbin safely.

- to measure solar flares for seven orbits for later analysis (hypothetical)

Mods: Any

Restrictions: Kerbol orbit must be 7,000,000km.

Restrictions: The satellite (command module) with data must return to Kerbin safely

Rewards: Fun

Tips: You will need to understand orbital maneuvors and exercise patience in achieving a return trip. 7,000,000km is about halfway between the sun and Kerbin.

The KGSS tries to inject real (or hypothetical) science into your space missions. If you decide to attempt this mission then please share your findings in SPOILER tags so the rest of us can enjoy the same fun you had in discover the result. More information on the KGSS can be found here: http://kerbalspaceprogram.com/forum/index.php?topic=11388.0

[Felix]

Getting out of a kerbol orbit is super hard. I want to see someone try this without heavily modding the game.

[SunJumper]

You do realise that a satellite orbiting Kerbol would not need to return to Kerbin for the scientists to recieve their data. It can simply transmit the data via radio waves.

[ggPeti]

That depends. The Kerbal scientists in this case seemed to have decided on not installing a telecommunication antenna and the solar panels powering it, but getting it back to the planet. Maybe they\'re also analyzing some stellar material collected by the probe

[SunJumper]

I would tell the engineers that they could earn 30 times more money if they glue a comm unit to it, and stellar wind can be found much past Kerbin\'s altitude...

[Zephram Kerman]

Er, it\'s... um... because of the incredibly large amount of data being recorded, we decided the best way to transmit is by sneaker net. So the research craft is loaded with shoes terabyte drives, which will be uploaded to the cloud afterwards.

[PakledHostage]

Getting out of a kerbol orbit is super hard. I want to see someone try this without heavily modding the game.

Check out BoolyBooly\'s Shoot for the Sun! challenge.

[Alchemist]

Getting out of a kerbol orbit is super hard. I want to see someone try this without heavily modding the game.

With the current it\'s rather easy to intercept the planet. Just remember the relative position when you got to the target orbit.

[ggPeti]

Felix, does MechJeb count as heavily modding the game? Because with the orbital transfer function and a bit of hand correcting it\'s really easy.

[Alchemist]

This takes forever.

More than 300 days is too much even for 10000x warp.

And with that ion engine I took for this mission the burns are longer than 1 hour. 2x warp doesn\'t help much

[Felix]

Check out BoolyBooly\'s Shoot for the Sun! challenge.

Thanks for showing me this! Should be fun.

With the current it\'s rather easy to intercept the planet. Just remember the relative position when you got to the target orbit.

True, but you have to get in reasonable close to he sun 7,000,000km, waste a lot of fuel creating a circular orbit, and then Wait for the suns position to line up... Its all really tedious.

Felix, does MechJeb count as heavily modding the game? Because with the orbital transfer function and a bit of hand correcting it\'s really easy.

Depends on your opinion! I don\'t like the idea of an orbital transfer button, But hey, I don\'t make the rules!

[Jarnis]

Fairly trivial with MechJeb and no need for exotic modding or ion engines or any of that junk. Just plain old Liquid Fuel Tanks and engines.

I gave it a shot with my generic satellite deployment rocket (minus the satellite that usually sits on top with Mk2 chute) and managed to do it on the first try with about 10% fuel left at the last stage tank. Looked tad hairy when burning back to Kerbin and the automatic Trans system got confused by math inaccuracies but I managed to manually adjust the trajectory for a *perfect* Kerbin encounter at '0km periapsis'. Had I had more fuel left over, I might have tried very low level aerobraking and settling back to Kerbin orbit but decided not to risk it considering I had roughly nothing left.

See attached image for the rocket used. Mission total time 118d 14h and no, I didn\'t wait for the hyphotetical 7 orbits around Kerbol.

Didn\'t take screenshots along the way because I honestly didn\'t expect to succeed on first try. If needed, I guess I can re-fly this tomorrow

* First Stage: four radially mounted 3xLFT + LFE boosters + 4x SRB radially mounted for initial kick off the pad. Takes everything to ~60km apogee, just shy of 75km orbit insertion.

* Second (core) stage: 4xLFT + steerable LFE finalizes the orbit and does Kerbin escape burn. with about 1 tank left over. Kerbin escape was done with good old 'eyeball mk1' burn with MechJeb holding prograde heading. Leftover of this stage is used for initial braking towards 7M km periapsis around Kerbol and the core stage is then ditched.

* Third (upper) stage: 1xLFT + small LFE finalizes the transit to Kerbol orbit at 7M km. In my run it ran dry about 50m/s before circular 7M km orbit.

* Fourth (return) stage: 1xhalf-sized LFT + small LFE does the final adjustments for the required orbit and then the burn back to Kerbin.

Atmosphere and parachute handle the braking. About 12.3G peak on re-entry, Jeb didn\'t even flinch... Only non-standard parts are the pod decoupler and some cosmetic solar panels. Oh, and MechJeb, of course. All hail MechJeb for super accurate burns and required instrumentation.

[MaverickSawyer]

See below...

[VincentMcConnell]

I plan to take a more scientific approach and record solar flares while on the Mun. It is believed that radiation activity can be as intense as 110MeV of radiation particles on the Mun\'s daylight side.

[khyron42]

I would try this, but I\'ve had previous bouts of fighting the kraken. Those two previous flights prove that it can be done with stock only, though.

[togfox]

I tried this for hours yesterday and came up with bizarre navigation anomolies just as I left Kerbin SOI. I found it impossible to navigate (and hold) a retrograde course. I put this down to the Kraken though I was only doing 8000 m/s. Surely that is not fast astronomically speaking.

I did reach an orbit of 7M km once but I had no return fuel so I shall try again in the name of the KGSS. Those solar flares must not remain a mystery!

[PakledHostage]

I completed this challenge because I think it is a good demonstration that it is already possible to put together an inter-planetary mission with the game in its current state. I didn\'t encounter the Kraken or any other navigational anomalies during my flight. I flew it using only stock components, patched conics and some good old-fashioned ded reckoning. I didn\'t have to resort to using MechJeb.

To be fair, I have encountered the Kraken in the past but it seems to prey mostly on more complex ships. I haven\'t encountered it when using simple spacecraft without ASAS or SAS. For what it is worth, it seems to me that the Kraken causes control reversals in one hemisphere of the navball while leaving the other half unaffected. The SAS and ASAS can\'t handle that and cause the ship to spin out of control. On the one occasion where I encountered it, I was able to stop the spinning by hand through a combination of really concentrating on applying the correct control input (which required some luck to get it right) and turning off the SAS. Ever since that time, I\'ve tried to minimise my manoevering while outside Kerbin\'s SOI.

Back on topic, the Kerbal scientists have recovered the Kerbolar Solar Flare Experiment package from my mission\'s capsule and are analysing the samples as of this writing. The results of the mission\'s second objective are already available. The second objective of the mission was to verify Kerbol\'s mass and radius. My Kerbals had previously determined that Kerbol has:

Mass: 1.757 x 10^28 kg

Radius: 65400 km

These values were confirmed during this most recent mission by recording certain key parameters during the transfer down to 7000000 km, during the seven orbits at 7000000 km altitude, and again on the transfer back to Kerbin\'s orbital altitude. The length of Kerbin\'s year was also confirmed as 106 days, 12 hours, 32 minutes long.

Below are my screen shots:

Edit: Clarified paragraph about my experience with the Kraken

[khyron42]

Amazingly well done!

I don\'t think I\'ve done much deep space flying since the smaller engine was added, I\'d forgotten that more efficient deep space flights were now possible since we\'re carrying less engine weight. I\'ll have to give this a try myself to see how hard it was.

I\'m guessing Kerbin escape slightly past the dawn line to exit its SoI retrograde, additional adjustments as needed based on the patched conics could be made even during the initial burn... and eyeball the rough angle between sun, kerbin, and 7 million km periapsis to know the rough angle to use for timing your return burn?

[VincentMcConnell]

Finding the Kerbin year is easy. Basically just calculating Kerbin\'s orbital period. Excuse me while I calculate the length of a month on Kerbin.

OFF TOPIC:

If my calculations are correct, a month on Kerbin is: 38.612800340434050698059694445 hours.

[Jarnis]

Amazingly well done!

I don\'t think I\'ve done much deep space flying since the smaller engine was added, I\'d forgotten that more efficient deep space flights were now possible since we\'re carrying less engine weight. I\'ll have to give this a try myself to see how hard it was.

I\'m guessing Kerbin escape slightly past the dawn line to exit its SoI retrograde, additional adjustments as needed based on the patched conics could be made even during the initial burn... and eyeball the rough angle between sun, kerbin, and 7 million km periapsis to know the rough angle to use for timing your return burn?

The fact that you can do this with fairly small rockets is all about the efficient 'vacuum engine' (small LFE). You do not need massive thrust for anything once you are in orbit. Heck, a single small LFE could push any kind of mega-stack of fuel - burns would take long, but it doesn\'t really matter.

[togfox]

I got into a 7M orbit, collected the data and raised my AP to that roughly of Kerbin. Unfortunately, it will take a lifetime in real time to wait for an intersect at maximum warp.

Shame. I have 169kg of gas left and I\'m keen to see if that is enough to get me into a Kerbin orbit and then de-orbit ...

[PakledHostage]

I\'m guessing Kerbin escape slightly past the dawn line to exit its SoI retrograde, additional adjustments as needed based on the patched conics could be made even during the initial burn... and eyeball the rough angle between sun, kerbin, and 7 million km periapsis to know the rough angle to use for timing your return burn?

I started my burn 6 minutes and 57 seconds after Kerbol first crested the horizon, as viewed from my 150 km high parking orbit. I burned for 3 minutes and 8 seconds to place my spacecraft into a hyperbolic trajectory with eccentricity 1.539 and periapsis of 158.1 km. My objective was to cross Kerbin\'s SOI at 1607 m/s, retrograde to Kerbin\'s orbit about Kerbol. My actual burn put me into a 13.533 million km by 7.070 million km orbit about Kerbol, which I easily trimmed into a 13.533 million km by 7.000 million km orbit. The only tricky part about planning all of this was that the angular position of the hyperbolic periapsis moves by 14 degrees during the burn, and this has to be accounted for.

As for the return to Kerbin, I calculated the timing of the burn by ded-reckoning. I added up the orbital periods of the 2 transfers and the 7 orbits at 7 million km and then worked out what fraction of an additional orbit at 7 million km I\'d have to wait before starting my burn to return home.

Finding the Kerbin year is easy. Basically just calculating Kerbin\'s orbital period. Excuse me while I calculate the length of a month on Kerbin.

OFF TOPIC:

If my calculations are correct, a month on Kerbin is: 38.612800340434050698059694445 hours.

I\'m glad you brought this up. It is 'easy' if you know Kerbol\'s mass and radius but what if you don\'t know either value? How would you know what they are? The orbital altitude shown in the game is the altitude above Kerbol\'s surface, not the distance to Kerbol\'s centre of mass. The distance to Kerbol’s centre of mass is dependent on Kerbol\'s radius and Kerbol is big enough that its size matters.

In the case of your calculation above, you only know the Mun\'s orbital period because someone else has calculated Kerbin\'s mass for you before hand. What if they were wrong? What if the radius you’re using is wrong? Why not try, as I suggested in your Ideas for experiments while in orbit thread, to calculate both the mass and radius simultaneously? In the case of Kerbol, solving for both simultaneously is the only thing you can do and you need both to figure out the length of Kerbin\'s year.

[TerLoki]

Well shoot, I think I already have a rocket that can do this, and it\'s mostly stock too. Guess I\'ll go ahead and give it a shot, wish me luck!

[Cesium137]

Now that I\'ve seen this I have to try it. This is just the thing to take up a few hours

[TerLoki]

Well, I\'ve made three attempts so far, and it looks like all of them are going to be failures. Ran out of fuel on the first one when trying to break away from Kerbol, ran out of fuel on the second one while trying to brake into Kerbin orbit, and even though I\'m using an ion drive now so I can\'t run out of fuel I can\'t seem to get the orbit right to rendezvous with Kerbin.