Chapman Challenge - Page 6 - Orbiter-Forum

**Piper** · 01-11-2009, 03:00 PM

Quote:

Originally Posted by atuhalpa

Piper, I have been experimenting with almost all the launch rigs and I have a problem with D4HV EDS. After my initial burn out of LEO I leave the earths SOI and even though I have 24.1 % fuel left Rotation doesn't respond only translation. Any thoughts?

Atuhalpa

The fuel in the DIVH upper stage is cryogenic, which means in reality that it boils away if not kept actively cooled. The DIVH in orbiter simulates this by cutting out your thrusters and engine after a certain length of time (I'm not sure how long that is, but it's not very long).

atuhalpa · 01-12-2009, 03:26 PM

Piper, I have finally after many trials with many launch engines achieved a highly eliptical (Pea 29.38M, Apa 405.5M) orbit of venus by aerobraking at 104.5 k altitude. I don't know if the aero dynamic effects of the solar panels and antenna boom are modeled but it seemed that the probe was much more stable when they were retracted. Unfortunately I have NO Dv left at all whatsoever as I used the last of it attempting to circularize my orbit as much as possible. My question is (if it is not asking too much) In your experience with this scenario, What is a reasonable amount of Dv to have in reserve after achieving orbit around Venus? I used Soyuz with fregat and I launched from Kourou.

Atuhalpa.

( I found out I don't know as much about Orbiter as I thought I did!)

**Piper** · 01-12-2009, 03:45 PM

Quote:

Originally Posted by atuhalpa

Piper, I have finally after many trials with many launch engines achieved a highly eliptical (Pea 29.38M, Apa 405.5M) orbit of venus by aerobraking at 104.5 k altitude. I don't know if the aero dynamic effects of the solar panels and antenna boom are modeled but it seemed that the probe was much more stable when they were retracted. Unfortunately I have NO Dv left at all whatsoever as I used the last of it attempting to circularize my orbit as much as possible. My question is (if it is not asking too much) In your experience with this scenario, What is a reasonable amount of Dv to have in reserve after achieving orbit around Venus? I used Soyuz with fregat and I launched from Kourou.

Atuhalpa.

( I found out I don't know as much about Orbiter as I thought I did!)

I find its best to use just enough to get yourself into orbit (and a little bit more), and then let aerobraking do the rest.

**astrosammy** · 01-13-2009, 09:21 PM

I've completed the Venus challenge, see my blog for informations.
http://orbiter-forum.com/blog.php?u=...ogcategoryid=7

T.Neo · 01-13-2009, 09:35 PM

Wow, astrosammy, you used a space shuttle to launch, I would have used any old launcher.

Did you reenter and land the shuttle?

**astrosammy** · 01-13-2009, 09:45 PM

Yes, I reentered and landed. I always wanted to use a shuttle with IUS, after seeing some cool pictures of IUS deployments:

T.Neo · 01-13-2009, 10:35 PM

**Piper** · 01-13-2009, 10:44 PM

Wonderful job Astrosammy, those pics look fantastic!

atuhalpa · 01-15-2009, 08:21 PM

Atuhalpa's Chapman challenge report:

Launch vehicle: Atlas 551
Launch Date: 55993.1069
Location: Kourou
IMFD: Surface launch
Transx: Ejection and subsequent course corrections

LEO: 84% fuel 2nd stage
Post eject: 8.9% fuel 2nd stage
1st mid course @ 56027.5807 7.7% fuel 2nd stage
2 additional minor course corrections to maintain PeA @100kms~

Aerobrake positioning @ 56085.0291 7.3% fuel 2nd stage
1st aerobrake pass @ PeA 85.72kms; ApA 7.215Mms
2nd aerobrake pass @ PeA 82.88kms; ApA 1.958Mms
Orbit circularization@ .0001 Ecc; ApA 562.5kms 2.7% fuel 2nd stage
Mission complete @ 56085.3879

atuhalpa · 01-15-2009, 08:29 PM

I can't thank Piper and the rest of you dedicated people enough for the wonderful gift that Orbiter is. I used to fly online combat flight sims and play RTS games rabidly. Now I educate myself and delve into Orbiter rabidly. I had a great time piloting Deepstar, Vespucci, and even the Millenium Falcon, but attempting realistic and challenging scenarios such as the Chapman challenge has taught me and stimulated my pleasure and reward centers way more than the futuristic scenarios ever did. As we used to do in IL2 Strumovik: <S!> (Salute) to all who make Orbiter the international phenomena that it is.

Sincerely, Atuhalpa.

**Zachstar** · 01-16-2009, 10:41 PM

Just a note here.

The Centaur push stage uses fuel that boils away over time in space. It will be a dead hulk by the time it gets to venus much less have any fuel to do anything.

With serious modifications it may keep most of its remaining fuel to make it to the moon but no way outside of that!

mjanicki · 01-17-2009, 12:19 AM

Quote:

Originally Posted by Zachstar

The Centaur push stage uses fuel that boils away over time in space. It will be a dead hulk by the time it gets to venus much less have any fuel to do anything.

I knew there was a reason I shouldn't have carried the Centaur with me. Thank you for this information. It will help when planning future challenges and other voyages.

atuhalpa · 01-17-2009, 06:34 AM

When I try to export anything into orbiter I get a run time error 76. Any thoughts?

Atuhalpa.

**astrosammy** · 01-17-2009, 08:52 AM

Maybe running this in the background helps:

Format converter

.

atuhalpa · 01-17-2009, 05:53 PM

Thanks sammy. I fixed the problem by turning on some stuff I had turned off in "startup"

01-12-2009, 03:26 PM	#77
atuhalpa Orbinaut	Challenge Questions Piper, I have finally after many trials with many launch engines achieved a highly eliptical (Pea 29.38M, Apa 405.5M) orbit of venus by aerobraking at 104.5 k altitude. I don't know if the aero dynamic effects of the solar panels and antenna boom are modeled but it seemed that the probe was much more stable when they were retracted. Unfortunately I have NO Dv left at all whatsoever as I used the last of it attempting to circularize my orbit as much as possible. My question is (if it is not asking too much) In your experience with this scenario, What is a reasonable amount of Dv to have in reserve after achieving orbit around Venus? I used Soyuz with fregat and I launched from Kourou. Atuhalpa. ( I found out I don't know as much about Orbiter as I thought I did!)

01-15-2009, 08:21 PM	#84
atuhalpa Orbinaut	Chapman challenge basic Atuhalpa's Chapman challenge report: Launch vehicle: Atlas 551 Launch Date: 55993.1069 Location: Kourou IMFD: Surface launch Transx: Ejection and subsequent course corrections LEO: 84% fuel 2nd stage Post eject: 8.9% fuel 2nd stage 1st mid course @ 56027.5807 7.7% fuel 2nd stage 2 additional minor course corrections to maintain PeA @100kms~ Aerobrake positioning @ 56085.0291 7.3% fuel 2nd stage 1st aerobrake pass @ PeA 85.72kms; ApA 7.215Mms 2nd aerobrake pass @ PeA 82.88kms; ApA 1.958Mms Orbit circularization@ .0001 Ecc; ApA 562.5kms 2.7% fuel 2nd stage Mission complete @ 56085.3879 Attached Thumbnails

01-17-2009, 06:34 AM	#88
atuhalpa Orbinaut	MPCORB viewer problems When I try to export anything into orbiter I get a run time error 76. Any thoughts? Atuhalpa.

01-17-2009, 08:52 AM	#89
astrosammy Dash!	Maybe running this in the background helps: Format converter Format converter .

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01-11-2009, 03:00 PM	#76
Piper Orbiting Space Addict	Quote: Originally Posted by atuhalpa Piper, I have been experimenting with almost all the launch rigs and I have a problem with D4HV EDS. After my initial burn out of LEO I leave the earths SOI and even though I have 24.1 % fuel left Rotation doesn't respond only translation. Any thoughts? Atuhalpa The fuel in the DIVH upper stage is cryogenic, which means in reality that it boils away if not kept actively cooled. The DIVH in orbiter simulates this by cutting out your thrusters and engine after a certain length of time (I'm not sure how long that is, but it's not very long).

01-12-2009, 03:45 PM	#78
Piper Orbiting Space Addict	Quote: Originally Posted by atuhalpa Piper, I have finally after many trials with many launch engines achieved a highly eliptical (Pea 29.38M, Apa 405.5M) orbit of venus by aerobraking at 104.5 k altitude. I don't know if the aero dynamic effects of the solar panels and antenna boom are modeled but it seemed that the probe was much more stable when they were retracted. Unfortunately I have NO Dv left at all whatsoever as I used the last of it attempting to circularize my orbit as much as possible. My question is (if it is not asking too much) In your experience with this scenario, What is a reasonable amount of Dv to have in reserve after achieving orbit around Venus? I used Soyuz with fregat and I launched from Kourou. Atuhalpa. ( I found out I don't know as much about Orbiter as I thought I did!) I find its best to use just enough to get yourself into orbit (and a little bit more), and then let aerobraking do the rest.

01-13-2009, 09:21 PM	#79
astrosammy Dash!	I've completed the Venus challenge, see my blog for informations. http://orbiter-forum.com/blog.php?u=...ogcategoryid=7

01-13-2009, 09:35 PM	#80
T.Neo SA 2010 Soccermaniac	Wow, astrosammy, you used a space shuttle to launch, I would have used any old launcher. Did you reenter and land the shuttle?

01-13-2009, 09:45 PM	#81
astrosammy Dash!	Yes, I reentered and landed. I always wanted to use a shuttle with IUS, after seeing some cool pictures of IUS deployments:

01-13-2009, 10:44 PM	#83
Piper Orbiting Space Addict	Wonderful job Astrosammy, those pics look fantastic!

01-15-2009, 08:29 PM	#85
atuhalpa Orbinaut	I can't thank Piper and the rest of you dedicated people enough for the wonderful gift that Orbiter is. I used to fly online combat flight sims and play RTS games rabidly. Now I educate myself and delve into Orbiter rabidly. I had a great time piloting Deepstar, Vespucci, and even the Millenium Falcon, but attempting realistic and challenging scenarios such as the Chapman challenge has taught me and stimulated my pleasure and reward centers way more than the futuristic scenarios ever did. As we used to do in IL2 Strumovik: <S!> (Salute) to all who make Orbiter the international phenomena that it is. Sincerely, Atuhalpa.

01-16-2009, 10:41 PM	#86
Zachstar Donator	Just a note here. The Centaur push stage uses fuel that boils away over time in space. It will be a dead hulk by the time it gets to venus much less have any fuel to do anything. With serious modifications it may keep most of its remaining fuel to make it to the moon but no way outside of that!

01-17-2009, 12:19 AM	#87
mjanicki Addon Developer	Quote: Originally Posted by Zachstar The Centaur push stage uses fuel that boils away over time in space. It will be a dead hulk by the time it gets to venus much less have any fuel to do anything. I knew there was a reason I shouldn't have carried the Centaur with me. Thank you for this information. It will help when planning future challenges and other voyages.

01-17-2009, 05:53 PM	#90
atuhalpa Orbinaut	Thanks sammy. I fixed the problem by turning on some stuff I had turned off in "startup"