Interplanetary Nuclear-Solar Powered Ion Thrust Expedition

[i dont know how to forum]

Spoiler

Introducing the Kerbal Space Agency's newest line of heavy lift rockets, the Kerbin Launch and Acceleration System for Spacecraft. Despite a rocky development and many, many failures, the KLASS-I is now fully ready for flight. With its twin-Mammoth-II core stage, two Clydesdale solid rocket motors, sleek design, and traditional black and white color scheme, this is a launch vehicle with some class.

The Kerbal Space Agency's latest project will require three launches. Launch 1: Transfer vehicle.

Launch 2: Lander.

Launch 3: Crew. The KLASS-Y is the crew-rated configuration of the KLASS rocket, SRBs removed and topped with a Launch Escape System to guarantee the safety of all kerbals on board. Hopefully.

Crew module Korion uncouples from the KLASS Upper Stage to prepare for docking.

With crew on board, the transfer vehicle docks with the lander and extends solar panels to prepare for departure.

This is INSPITE, the Interplanetary Nuclear-Solar Powered Ion Thrust Expedition. Recent developments in nuclear fission reactors and upscaled solar arrays have finally made ion engines viable for long range crewed vessels. This experimental craft will carry a crew of five to Duna for a surface landing before returning to Kerbin. Unfortunately it seems nobody at the KSC understands the concept of launching during transfer windows, and the crew will be required to wait in a parking orbit for a full year and a half before departing.

Prepare for burn. Bringing reactors online, balancing reactor conversion rate for stable engine output. Burn duration: sixteen minutes. Delta-v: 539 m/s

Burn complete. Next burn in approximately 10 days. Burn duration: [data lost]. Delta-v: 641 m/s 

The crew is visited by the Menu Spirit. It is said that this kerbal wanders the skies searching for their long lost ship. A visitation from this mysterious spirit is meant to bring voyagers good luck.

Goodbye, friend!

Sadly it seems that mission control's estimate of the transfer window was somewhat imprecise. A rather large correction burn will be necessary for an intercept. Next burn will begin shortly. Burn duration: thirty minutes. Delta-v: 1,113 m/s

Burn complete. We are on course for Duna! The Menu Spirit has graced the crew with their presence once more to wish them luck on their journey.

The INSPITE crew:

From left to right:

Patwise Kerman, flight engineer

German Kerman, surface specialist

Valentina Kerman, mission commander

Tim C Kerman, pilot

Orman Kerman, ion drive technician

0 days until next adventure.

Bonus:

Spoiler

Kerbals like to stick their mag boots to each other. A lot. Setting up this group photo was a pain, but worth it.

INSPITE blueprints:

Drew these before the Early Access launch once we had the full parts list. Initial idea was to rush something out quickly to test some of the new features on day one, but this did not happen for many reasons.

Mission objective is to land on and return from Duna.

In spite of awful performance on my below-spec laptop.

In spite of the many bugs, glitches, and broken features.

In spite of my rockets initially flipping over, wobbling, and exploding.

In spite of the camera bug causing my upper stage to become unusable during my initial attempts.

In spite of struts disappearing half the time I try to launch and having to replace them all manually.

In spite of certain radial parts drifting away from my craft during time warp, which irritates me to no end (you may notice floating RCS thrusters in some shots).

In spite of my game suddenly deciding not to create save files when saving at one point.

In spite of the undocking bug I keep hearing about and am dreading for when I need to undock my lander.

In spite of everything, I am having a ton of fun with the game, and I can't wait to see where it goes from here.

[lemon cup]

6 hours ago, i dont know how to forum said:

0 days until next adventure.

EXCELLENT craft design and excellent photography! Please keep it up, can’t wait to see the rest of the mission.

Also kudos for getting this all in place despite all the bugs - no small feat. 

[i dont know how to forum]

After some additional minor correction burns, the INSPITE crew prepares for Duna capture.

Spoiler

Duna periapsis has been lowered to 85km, with the intent of utilizing the Oberth effect for orbital insertion.

As the vessel enters Duna's SOI, a strange transmission is detected. The signal is barely readable, and somehow, it seems to be coming from the planet's surface. Patwise attempts to clean up the message...

"This is Jebediah Kerman. I have completed the mission objective in honor of our great agency. I will be waiting for your response. Transmission over."

A kerbal? On the surface of Duna? How did they get there? This was not part of the mission briefing. The crew is shocked, all except Valentina. She knows Jeb, and this sounds like exactly the kind of thing he would do. He must not have even told anybody he was going.

In any case, it seems the mission parameters have changed; this is now a rescue mission. Tim C will have to be ready for a precision landing.

First, however, there's still the matter of orbital insertion. Unfortunately, it seems this will prove more difficult than anticipated. Low thrust maneuvers are weird, and nobody at the Kerbal Space Agency quite understands how to manage them yet. Perhaps entering with such a low periapsis was not the best idea.

Still, mission control manages to put together a maneuver plan for orbital capture. This obit will take the vessel out to the very edge of Duna's SOI, where it can easily change its periapsis and inclination.

Starting insertion burn, ion drive online. Expected burn time 42 minutes, delta-v 1,537 m/s

And... oh dear.

It seems the solar arrays simply don't provide enough power this far out from Kerbol. Patwise is pushing the reactors to their limit, but they just aren't giving enough juice to keep the drive running forever.

Nine minutes into the burn, the batteries run dry.

The engines continue to burn.

Patwise and Orman double check the math. Six SP-XXL solar arrays at about 15 EC/s each, two SP-XL arrays at about 5 EC/s each, and two KR4-P3 reactors at 50 EC/s each. Twenty-four IX-6315 ion engines, each running nominal at 2kN/s, each consuming 10 EC/s. That's ~200 EC/s generated, 240 EC/s consumed, and a dead battery.

Where's the extra 40 EC/s coming from? Did the engineers miscalculate the power usage? Are the engines powered by dark magic? Is it a blessing from the Menu Spirit?

Orman can't explain it. They seem almost disappointed. The engines are supposed to reduce their thrust automatically if they're not receiving sufficient power. Instead, they seem to be chugging along at full thrust as though nothing had happened.

Meanwhile, as Duna approaches, Tim C struggles with holding the maneuver while not letting their periapsis get too low. He doesn't fully trust mission control's maneuver plan, and this vessel is not rated for aerocapture.

He activates RCS for better control. Long dormant thrusters suddenly spring to life.

Spoiler

Yeah, I got nothing here. Those floating struts and RCS thusters are ugly. Really hate this part drift bug, especially since it's not game breaking and is therefore probably a low priority.

Lights within the crew cabin turn off. Back on, then off again, flickering as power fluctuates in the ship. As the dark side of the planet grows closer, things are tense among the crew. Will they make orbit in time? Nobody expects whatever miracle is keeping the engines running to continue once the solar arrays have shut down. 

Darkness. For a brief moment, the drive continues to burn...

It doesn't last. The engines stutter and turn off. INSPITE has failed to make orbit.

Valentina steps up. The mission isn't over yet. As soon as they're back in sunlight, they'll resume the burn. They will make orbit. They will land on Duna. They will rescue Jeb, and they will make it home.

Patwise keeps the reactors hot to recharge the batteries. They'll need everything they can get.

As soon as the solar arrays have been properly reoriented, the drive is reactivated. No longer caring where their periapsis ends up, Tim C points retrograde and sets the throttle to max.

Success! We have Duna capture!

The crew celebrates, but the hard part isn't over yet. Next step: preparations for landing and rescue.

 

[i dont know how to forum]

11 hours ago, Intercept Games said:

• Re-tuned electrical systems, including adjustments to xenon engine electrical draw, xenon engine thrust, reactor fuel burn rate, and RTG lifetime 

...oh dear.

Orman, what did you do?

Edited March 17, 2023 by i dont know how to forum

[Speeding Mullet]

Ah yes, the classic year and a half on orbit before departure to Duna! Very nice craft design, the Klass-1 is a well-proportioned launch vehicle.  I'm looking forward to more complex mission reports coming out of the woodwork post patch 1, so I'll be following this one.  Keep it up!

SM

[i dont know how to forum]

Things are, uh...

Spoiler

This one... this one doesn't count.

Things are happening. Update soon, I hope.

[Maria Sirona]

What a lovely mission report this is! Really looking forwards to future updates. Love the story. Followed!

On 3/12/2023 at 2:58 PM, i dont know how to forum said:

before departing.

Also, having a blocked docking port is a questionable design choice 

Edited April 1, 2023 by Maria Sirona

[Soda Popinski]

Nice!  I've got a much less ambitious nuclear/solar ion craft heading to Eve (no lander, just want to take a look).  I didn't realize that was reduced to 0.2 kN, so I thought my 6 engine craft would be ok with a 45 minute burn.  Turned it to be a 450 minute burn.  

[i dont know how to forum]

 Update, finally! Sorry for the wait.

Spoiler

After a successful Duna capture, Orman inspects the ion drive and makes a startling discovery. It seems the engines, originally rated for 2kN of thrust each, will now burn only 0.2kN each. Orman speculates that whatever had kept their engines going under insufficient power previously must have had a permanent effect on them.

This isn't enough to dissuade the crew, however. Preparations for precision landing are already underway. At the very edge of Duna's SOI, INSPITE burns for polar orbit.

Unfortunately, periapsis is still on the dark side of Duna. Circularization will require multiple passes.

Thrust is cut to 80% to allow constant power to the engines while in direct sunlight.

The sun disappears, the battery runs dry, and the engines cut off.

Next pass. Engines up to 80% again.

The vessel again passes into darkness. The drive flickers...

...and refuses to die.

Tim C tries to shut it down, to no effect. A realization is soon reached: the engines are eating all reactor power, leaving none for the onboard computer. With no computer control, the engines can't be deactivated.

Patwise prepares a manual reactor shutdown, but Valentina suggests they should just let it run. As long as the ship continues to point retrograde, the engines can only help them, so why not let them? As soon as they're back in sunlight, they can turn them off normally.

On the third pass, the crew takes advantage of this idea more directly. Thrust is set to 80% in sunlight, 40% in darkness.

Valentina is starting to get impatient with these low-thrust circularization passes, however. With periapsis at 100k and apoapsis at 380k, the orbit isn't quite circular, but she decides that's close enough. INSPITE is go for landing!

Valentina, Tim C, and German board the Solomon and prepare to undock. Patwise and Orman are left to watch over the transfer vehicle in orbit.

Drogues are deployed early to slow down for precision landing.

Touchdown! The Solomon has landed safely on Duna, 11km from Jebediah Kerman and the Arizona Cowboy! Not bad as far as precision landings go.

Surface specialist German Kerman inspects a fascinating nearby rock. Unfortunately it seems this landing site is rather flat and uninteresting, German's skills are a bit wasted here.

Meanwhile, Jeb says his goodbyes before heading off.

The jetpack is nice while it lasts, but halfway there it runs dry and Jeb is forced to run the remaining distance.

Rescue! At last!

Bonus:

Spoiler

You have no idea how many attempts this landing took. Not sure if I can get back up to orbit either.

 

[Dunas Only Moon]

Jesus

On 4/4/2023 at 12:57 AM, i dont know how to forum said:

 Update, finally! Sorry for the wait.

  Hide contents

After a successful Duna capture, Orman inspects the ion drive and makes a startling discovery. It seems the engines, originally rated for 2kN of thrust each, will now burn only 0.2kN each. Orman speculates that whatever had kept their engines going under insufficient power previously must have had a permanent effect on them.

This isn't enough to dissuade the crew, however. Preparations for precision landing are already underway. At the very edge of Duna's SOI, INSPITE burns for polar orbit.

Unfortunately, periapsis is still on the dark side of Duna. Circularization will require multiple passes.

Thrust is cut to 80% to allow constant power to the engines while in direct sunlight.

The sun disappears, the battery runs dry, and the engines cut off.

Next pass. Engines up to 80% again.

The vessel again passes into darkness. The drive flickers...

...and refuses to die.

Tim C tries to shut it down, to no effect. A realization is soon reached: the engines are eating all reactor power, leaving none for the onboard computer. With no computer control, the engines can't be deactivated.

Patwise prepares a manual reactor shutdown, but Valentina suggests they should just let it run. As long as the ship continues to point retrograde, the engines can only help them, so why not let them? As soon as they're back in sunlight, they can turn them off normally.

On the third pass, the crew takes advantage of this idea more directly. Thrust is set to 80% in sunlight, 40% in darkness.

Valentina is starting to get impatient with these low-thrust circularization passes, however. With periapsis at 100k and apoapsis at 380k, the orbit isn't quite circular, but she decides that's close enough. INSPITE is go for landing!

Valentina, Tim C, and German board the Solomon and prepare to undock. Patwise and Orman are left to watch over the transfer vehicle in orbit.

Drogues are deployed early to slow down for precision landing.

Touchdown! The Solomon has landed safely on Duna, 11km from Jebediah Kerman and the Arizona Cowboy! Not bad as far as precision landings go.

Surface specialist German Kerman inspects a fascinating nearby rock. Unfortunately it seems this landing site is rather flat and uninteresting, German's skills are a bit wasted here.

Meanwhile, Jeb says his goodbyes before heading off.

The jetpack is nice while it lasts, but halfway there it runs dry and Jeb is forced to run the remaining distance.

Rescue! At last!

Bonus:

  Hide contents

You have no idea how many attempts this landing took. Not sure if I can get back up to orbit either.

 

Looks hard... You need much more respect man, good job

[TheBlackJackal]

Thoroughly impressed!  I've never really explored the ion engines.  I know they're useful in long range missions.  But maybe someone could explain if they are more useful than standard engines? 

[i dont know how to forum]

3 hours ago, TheBlackJackal said:

Thoroughly impressed!  I've never really explored the ion engines.  I know they're useful in long range missions.  But maybe someone could explain if they are more useful than standard engines? 

The main advantage of the ion engine is its incredibly high ISP. Nothing else even comes close. You can build small ships with insanely high delta-v and go anywhere you want.

The main disadvantage of the ion engine is its incredibly low thrust. Nothing else even comes close. After patch 1, even the RCS thrusters have higher thrust than the ion engine.

KSP2's acceleration under time warp makes extremely long burns viable, and the new reactors are able to provide constant electrical power to the engines even without direct sunlight. This makes ion engines far more useful, but I still wouldn't recommend using them for more complex missions such as this one. Being unable to rotate while under time warp makes long burns more difficult. Long burns are also less useful in the limited space of a planet's SOI due to the curvature of the orbit. My current predicament is that I have to rendezvous two craft in very different orbits entirely using ion engines, and I'm struggling to come up with a reasonable solution.

Something I'd like to try in the future though is building ships that are able to switch between ion and chemical/nuclear thrust. Ion engines could be used for interplanetary transfers, while chemical engines could be used for short high-thrust burns within a planet's SOI. See here: http://www.projectrho.com/public_html/rocket/engines.php#shiftgears

[TheBlackJackal]

6 hours ago, i dont know how to forum said:

The main advantage of the ion engine is its incredibly high ISP. Nothing else even comes close. You can build small ships with insanely high delta-v and go anywhere you want.

The main disadvantage of the ion engine is its incredibly low thrust. Nothing else even comes close. After patch 1, even the RCS thrusters have higher thrust than the ion engine.

KSP2's acceleration under time warp makes extremely long burns viable, and the new reactors are able to provide constant electrical power to the engines even without direct sunlight. This makes ion engines far more useful, but I still wouldn't recommend using them for more complex missions such as this one. Being unable to rotate while under time warp makes long burns more difficult. Long burns are also less useful in the limited space of a planet's SOI due to the curvature of the orbit. My current predicament is that I have to rendezvous two craft in very different orbits entirely using ion engines, and I'm struggling to come up with a reasonable solution.

Something I'd like to try in the future though is building ships that are able to switch between ion and chemical/nuclear thrust. Ion engines could be used for interplanetary transfers, while chemical engines could be used for short high-thrust burns within a planet's SOI. See here: http://www.projectrho.com/public_html/rocket/engines.php#shiftgears

I will definitely be testing these out tonight then! Thank you for the tip!