Chapman Challenge

[Piper]

Since I work the night-shift, I often spend a lot of time challenging myself in Orbiter going to different places, usually using one of my [ame="http://www.orbithangar.com/searchid.php?ID=789"]Chapman probes[/ame]. Since these probes only have so much DeltaV, it can be quite challenging finding ways to get places, and I'd like to share some these journeys by challenging people to make the same ones.

So, I present the 1st ever "Chapman Challenge." I don't know if I will do this every couple of weeks, or every month, or longer, it depends on peoples interest in this idea. For all the missions, you have to be able to make your own scenarios (although for the first two, you can get the scenarios from the default Chapman addon). For missions to asteroids, or where you can pick the destination, you will need the [ame="http://www.orbithangar.com/searchid.php?ID=1436"]MPC Database Viewer/Exporter[/ame]. For the first one, I've started with 3 levels or difficulty (beginner, intermediate, and advanced), and after this one I will narrow it down to 2 (regular, and advanced):

Beginner: Launch a Chapman-1 probe from Baikonor to the moon. Launch date: July 1st, 2010
Intermediate: Launch a Chapman-2 probe to 90 Antiope (Bonus, try and pass between the two bodies). Launch date: Anytime after January 1st 2011
Advanced: Launch a Chapman-Outer probe to orbit a Jupiter Trojan asteroid (I used 2001 DZ3, but you can pick any one). Launch date: Anytime after January 1st 2011

 

[Kaito]

I'd love to do it...if I knew how to use rockets...I think I'll start messing around with Atlantis before I take this on..but sounds fun

 

[HiPotOk1978]

Piper are we able to use any in production/out of production launch vehicle?

Are you going to provide us with a scn? This sounds interesting and I would like to take part in it. Give me some limitations/details and I will be happy to see how far I can carry your challenge

May I also susgest sending a Chapman to Venus? Don't ask me why but I like Venus

Also what are the weights of these probes, ISP etc

 

[Piper]

Piper are we able to use any in production/out of production launch vehicle?

You can use any rocket that is currently in use (Soyuz, Atlas V, Ariane V, etc.), or in use in the near future (Falcon 9, etc). You can't use out of production models though (ie, Saturn V, Atlas II, etc). And of course, in case it isn't obvious, you have to start from launch each mission, from an existing launch center (Baikonur, Cape Canaveral, Kourou, etc.), you can not start in orbit.

Are you going to provide us with a scn?

Yes and no. Included in the download for Chapman v2.0 are 4 default scenario files (all of which are set on July 1st 2010, the same day as the beginner challange), plus 4 mission scenarios (one of which is for 90 Antiope, which happens to be the intermediate mission). You can also use any of these as starting points for making your own scenario file.

Since there is no set target for the advance mission, other then having to be a Jupiter trojan, no set date, and no set launcher, there isn't much point in making a scenario file for it. Besides, if you have the skill to complete this one (remember, you have to actually get into orbit of it, and not just do a fly-by), then you probably know how to make a scenario file by then.

For future mission, I may or may not make actual scenario files, it depends on the challenge. Regular missions I will usually provide one, however the advanced missions will always need you to make the scenario yourself (this is part of the challenge for this level).

Also, for those who complete the missions, I'm going to make a page on my IOSS site for the missions, and list everybody who can complete them. Post a screenshot of when you have arrived at the destination (or in orbit), a brief synopsis of what you did to get there (ie, flightplan, launchdate, any fly-by's, tricks, etc), and I will add it to the list. Feel free to make your "mission report" as simple, or as detailed as you wish. You can even make a "photo diary" or something along the lines of what I did for my Eris Explorer if you wish.

Along with the list, I will post the rules (in a more uniform format), and any other relevant information for the Chapman Challenge.

And please, NO CHEATING. Don't go and and use "unlimited fuel" or create a scenario with you already in orbit of the destination, or add fuel if you accidentally run-out early, and then say you completed the challenge. Other then bragging rights, and the satisfaction that you where able complete a difficult task, there are no prizes or awards for completing the missions. There is no limit on how many tries it takes you do complete a mission, you are just as successful if you complete it on your hundredths attempt as if it was your first. So if you cheat, the only person you are really cheating is yourself.

At the moment, the close date for this Chapman Challenge is set for the end of December. Depending on how popular this is, and how long it takes people to complete the missions, I will make future challenges either shorter or longer (although I can't imagine it taking longer then 1 month). Also for reference here are the MJD dates for the three levels:

Beginner: July 1st, 2010 - 55378.0000 to 55378.9999
Intermediate and Advanced: Anytime after January 1st 2011 - 55562.0000 and up

 

[Piper]

Ok, I've updated my IOSS website with a page for the Chapman challenge. It includes scenario files for both the Beginner and the Intermediate missions. If you need any help with the missions, I'll be glad to give advice and help.

I'm eager to here some success stories, so get started, and GOOD LUCK!

 

[tblaxland]

I'm eager to here some success stories, so get started, and GOOD LUCK!

I'm looking forward to trying this, hopefully over my Christmas holidays. Finish by Dec 31st? I'll see how I go...

Nice probe, BTW :speakcool:


-----Post Added-----


As nice as Mustard/BrianJ's Baikonur and Mustard/No Matter's Soyuz are, they have brought my ageing hardware to its knees. I'm getting 7fps sitting on the launch pad! I'll take out my hires Earth/Moon textures and go back to the stock ones and see how I go. Perhaps its time for a hardware upgrade, especially since our Govt is asking us to spend, spend, spend...

Notwithstanding, I've decided on a launch time for the Beginners challenge, in consideration of my next attempt.

 

[tblaxland]

I sorted out my frame rate issues by starting with a clean install and launched at the planned time. I used LaunchMFD and the Soyuz auto-pilot to get to a LEO parking orbit that was not quite what I wanted, but not too bad considering it was the first time I had launched a Soyuz from Baikonur. I'll try again in a couple of days, but I have to congratulate Mustard/BrianJ/No Matter on their great work with the Soyuz and Baikonur - very nice :speakcool:

 

[Piper]

I sorted out my frame rate issues by starting with a clean install and launched at the planned time. I used LaunchMFD and the Soyuz auto-pilot to get to a LEO parking orbit that was not quite what I wanted, but not too bad considering it was the first time I had launched a Soyuz from Baikonur. I'll try again in a couple of days, but I have to congratulate Mustard/BrianJ/No Matter on their great work with the Soyuz and Baikonur - very nice :speakcool:

Keep trying! Feel free to use a different Soyuz launcher if you wish, there's a nice CVEL one on Orbit Hangar that I used to use all the time.

As for the beginner mission, I actually have an old tutorial already on my site (http://www.ioss.ca/OffPlaneTutorial/index.html) that shows how to do exactly that mission (although the tutorial uses the previous Chapman probe, but exact same concepts and steps). Feel free to use that in aiding you in completing the mission.

As the missions progress, I will add on more tutorials (that will conveniently match regular missions) that will explain other topics like slingshots and how to launch into the right LEO to go to another planet.

 

[tblaxland]

Keep trying! Feel free to use a different Soyuz launcher if you wish, there's a nice CVEL one on Orbit Hangar that I used to use all the time.

I wouldn't normally have any trouble getting to the Moon but I was trying to be a bit of a perfectionist with my delta-v and that just takes a bit of getting used to a new launcher's flight profile. I actually found the guidance included (otto.txt) to be not the most efficient so I ended up with a compromise - I used the autopilot until booster sep, and then used LaunchMFD's PEG to get to a 220 x 250 parking orbit. The Fregat was not even needed for orbital insertion and it had plenty of gas left in the tank after TLI.

As for the beginner mission, I actually have an old tutorial already on my site (http://www.ioss.ca/OffPlaneTutorial/index.html) that shows how to do exactly that mission (although the tutorial uses the previous Chapman probe, but exact same concepts and steps). Feel free to use that in aiding you in completing the mission.

Interesting read. I used IMFD for my navigation and I was once again impressed by its accuracy. I had three MCCs totalling only 3.3m/s to put me at a pericynthion of 105km. Overall, I think the only thing I would do different would be to choose my parking orbit LAN a little better to reduce my waiting time in LEO.

As the missions progress, I will add on more tutorials (that will conveniently match regular missions) that will explain other topics like slingshots and how to launch into the right LEO to go to another planet.

Great! In all my time playing with Orbiter, I have never attempted a slingshot. One mission that I have found very interesting is Cassini's, especially the way it dropped down to Venus for two flybys. It seems counter productive to lower your orbit before raising it again.

 

[tblaxland]

An update on my progress with the Intermediate Challenge. I tried to get the Atlas V working but I was getting some multistage.dll errors that I couldn't resolve. Anyways, I thought I'd try Well & No Matter's Ariane 5 which worked very nice for me. Using the ECA configuration I had about 4.5km/s dV plus the Chapman's ~3km/s. Not quite enough for a direct flight to 90 Antiope, I thought, so I went for a Mars flyby. I had some trouble planning the flight with IMFD and ended up failing miserably. I'm off to learn TransX, I think its "stages" will help me but I have never used it in earnest before...

EDIT: I also tried Francisdrake's Delta IV Heavy Versatile but had quite a bit a trouble getting an accurate launch with it, especially rolling to the correct heading at lift off. The docs mentioned an autopilot but I couldn't see how to activate it. I tried using the launch compass in Launch MFD but the roll performance made it quite difficult to fly accurately. If anyone has any tips or can suggest an alternative Delta IV Heavy, I would be most interested.

I like Mustard/No Matter's Soyuz and Well/No Matter's Ariane 5 because they use the Multistage autopilot. I usually use that guidance until booster sep and then fly to the PEG pitch given by Launch MFD.

 

[Piper]

An update on my progress with the Intermediate Challenge. I tried to get the Atlas V working but I was getting some multistage.dll errors that I couldn't resolve. Anyways, I thought I'd try Well & No Matter's Ariane 5 which worked very nice for me. Using the ECA configuration I had about 4.5km/s dV plus the Chapman's ~3km/s. Not quite enough for a direct flight to 90 Antiope, I thought, so I went for a Mars flyby. I had some trouble planning the flight with IMFD and ended up failing miserably. I'm off to learn TransX, I think its "stages" will help me but I have never used it in earnest before...

You're on the right track! Using a slingshot by Mars is exactly the way I did it (after launching aboard an Atlas V 422). An Atlas V 552 could have got me there in one shot, but I figured I would use a smaller rocket, and just get the extra deltaV from Mars.

 

[Piper]

Only 10 days left till the challenge is over! So far only one person (tblaxland) has said they have completed the beginner challenge. I'd like to think that there's more people out there that can get to the moon

 

[tblaxland]

Success with the Intermediate Challenge! I managed to scrape together enough dV for a direct flight. Here's the stats:

Launch Date: 2011 May 30 (about 10pm UTC, IIRC)
Launch Vehicle: Ariane 5 ECA
Launch Site: Centre Spatial Guyanais, Kourou, French Guiana, 5.06°N/52.56°W
Launch Azimuth: 83.0°
Parking Orbit: approx 240km x 290km (2 orbits)

Arrival Date: 2013 Jan 28 (approx 10:30 UTC)
Closest Approach: approx 40km

Eject dV: approx 5300m/s
MCC's: approx 100m/s for flyby (<1000km) and approx 100m/s for setting up "fly between".

Image diary:

Final orbital sunrise after ejection manoeuvre:

Approach to 90 Antiope and S/2000 (90) 1 (note position of velocity vector between the asteroids):

Mission success:

Thanks for the challenge. I may attempt the Advanced at some stage, but not before Dec 31

 

[astrosammy]

I would like to fly the Intermediate, but always when I try to export Antiope to Orbiter the exporter crashes:

EDIT: In English the error message is
"Run-time error '6': Overflow"

 

[Piper]

I would like to fly the Intermediate, but always when I try to export Antiope to Orbiter the exporter crashes:

EDIT: In English the error message is
"Run-time error '6': Overflow"

You can download 90 Antiope from Orbit Hangar at [ame="http://www.orbithangar.com/searchid.php?ID=3621"]90 Antiope (Binary Asteroid)[/ame]. As for the overflow message, I have a feeling that it is because German uses a comma for its decimal point, instead of a period like English, and the program is getting confused. Temporarily, change the "Regional and Language Options" in your control panel to English, and the program should work. I'll try in the future to make it a little more "language-friendly."


-----Post Added-----

Success with the Intermediate Challenge!

.......

I may attempt the Advanced at some stage, but not before Dec 31

Congratulations! Don't worry if you can't get the advanced stage just yet, I'm going to do that one again on a later date since no one tried it.

 

[astrosammy]

You can download 90 Antiope from Orbit Hangar at http://www.orbithangar.com/searchid.php?ID=3621. As for the overflow message, I have a feeling that it is because German uses a comma for its decimal point, instead of a period like English, and the program is getting confused. Temporarily, change the "Regional and Language Options" in your control panel to English, and the program should work. I'll try in the future to make it a little more "language-friendly."

Ok, I've downloaded that from OH, and the probe is on it's way now(launched by a Falcon 9 heavy).

Changing the Regional and Language Options worked, I succesfully exported Apophis to Orbiter.

 

[Woo482]

I think I will have a go at the beginner challenge

 

[tblaxland]

Congratulations! Don't worry if you can't get the advanced stage just yet, I'm going to do that one again on a later date since no one tried it.

OK, I'll have a go when I get the chance. The first thing I'll need is more practice at getting an accurate (hence dV conserving) parking orbit insertion with the Delta IV Heavy. The other thing that I've been considering is that I'll need multiple flybys somewhere so that the probe has enough dV for orbital insertion. Orbiting makes it quite a bit tougher than a flyby.

One thing I forgot to say last night because I was too tired: Nice work on 90 Antiope. Flying between those two rocks was very impressive. :speakcool:

 

[astrosammy]

I've finished the Intermediate.
Launch vehice: Delta IV Heavy
Launch site: Cape Canaveral Air Force Station
Launch date: 19. May 2011
Arrival: 18. August 2012 (Very strange, some months earlier than tblaxland but the same Eject dv)

After the launch into a ~100km x ~1000km Orbit the first stage had 1% fuel left so I made the first part of the eject with it. One orbit later the second stage made the last part of the burn. After leaving Earth's SOI I made a final burn with it before seperating the payload. In the middle of the flight I used the Orbital period of S2000 90 1 to find a good arrival time and make the targeting burn. After the flyby I had enough fuel left to make a burn to fly to Earth. (Maybe I crash it, or if possible I make a slingshot back to Antiope).

Launch

Ejection burn

Spacecraft seperation

Flyby

 

[astrosammy]

After the flyby

Earth ejection burn (for Moon flyby)