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Old 08-05-2008, 11:57 PM   #1
pete.dakota
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Default Sub-orbital 'hops' in a DGIV.

Hello all. I'm trying to find a semi-decent, potentially realistic flight plan for a sub-orbital jaunt to Habana from KSC in a DGIV.

So far, all of my trusty test pilots and passengers have had to experience around 7-9g on re-entry. This is due to the rapid thickening of the atmosphere bought about by a ballistic flight path. The hull doesn't get too hot, but the G forces would be unsatisfactory for a 'commercial' service.

I'm using the Mark IV engine, with the fuel set to 'realistic'. I vent the fuel down to 40% and the RCS down to 30%. I take off from runway 15, turn to a heading of around 195 degress, climb at 20deg pitch up until about 5km, go full throttle, hit the turbo pump and pitch up to about 65 degrees. I wait, holding 65, and then pitch accordingly to keep the PeA at 80-100km. I shut down with a slight, ballistic (MapMFD- no atmosphere) overshoot of Habana and set the entry AP for a 45 degree AoA. A short time after this, all of my passengers eyeballs are pushed to somewhere down near their shins and everyone winds up a few mm's shorter than they were when they boarded.

Is there any reasonable flight plan for hop of this type? One that would only perhaps encounter 3gs max? Without using the hover engines (cheating ), I doubt it. But I thought I'd ask anyway.

Cheers,
Pete.
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Old 08-06-2008, 01:48 AM   #2
Nickmick95
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There is a sub-orbital autopilot at Dan Stephs website. Here it is: http://orbiter.dansteph.com/index.ph...IVMore&DId=168
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Old 08-06-2008, 02:56 AM   #3
eveningsky339
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The only thing I suggest for lightening up the G's would be a much more shallow trajectory. But that would entail a pretty distant landing site...
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Old 08-06-2008, 03:00 AM   #4
Eagle
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Quote:
Originally Posted by eveningsky339 View Post
 The only thing I suggest for lightening up the G's would be a much more shallow trajectory. But that would entail a pretty distant landing site...
Or reduce your apogee. This will cut down on your 'freefall' time and may potentially take more time and fuel to complete a hop. Not to mention, short trips turn you into just another rocket powered airplane.
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Old 08-06-2008, 02:46 PM   #5
Jarvitš
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Or, you could just make a powered atmospheric flight at 30km and mach 7, it would take around the same time and you would likely spend even less fuel, seeing as how you won't need to vent it.
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Old 08-06-2008, 03:01 PM   #6
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 Or, you could just make a powered atmospheric flight at 30km and mach 7, it would take around the same time and you would likely spend even less fuel, seeing as how you won't need to vent it.
But do you get to catch floating M&M's in your mouth? Ah, there's the rub...
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Old 08-06-2008, 03:04 PM   #7
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I could change my Suborbital Autopilot for flights to Habana.
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Old 08-06-2008, 03:16 PM   #8
pete.dakota
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Yes, I would like to have a flight plan that gets over 100km. For the sake of actually getting the passengers into space.

I'm starting to think that the DG wont be able to make a comfortable, commercially acceptable suborbital flight without a SS1esque 'feathered' configuration. Or perhaps something similar. Even straight up and down I can't keep the Gs below 4.


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Quote:
Originally Posted by astrosammy View Post
 I could change my Suborbital Autopilot for flights to Habana.
I have flown your AP, astrosammy. It only does what I would do if going straight up - straight down. I still experience over 6gs coming back in. How might you change it for flights to Habana without excess G forces?
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Old 08-06-2008, 03:24 PM   #9
astrosammy
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Quote:
Originally Posted by pete.dakota View Post
 I have flown your AP, astrosammy. It only does what I would do if going straight up - straight down. I still experience over 6gs coming back in. How might you change it for flights to Habana without excess G forces?
I'll have to try around with different AOAs, and with different fuel levels.
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Old 08-06-2008, 03:26 PM   #10
ar81
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What I do is to raise apoapsis right below 45 km. Then I fly like a plane and use AerobrakeMFD to put impact point right on target base.
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Old 08-06-2008, 03:31 PM   #11
Jarvitš
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Originally Posted by eveningsky339 View Post
 But do you get to catch floating M&M's in your mouth? Ah, there's the rub...
There's always the option of an unpowered parabolic 0g descent from 30km if you want freefall.
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Old 10-13-2019, 11:07 PM   #12
Ballisto
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Default Sub-orbital autpilot?

Quote:
Originally Posted by Nickmick95 View Post
 There is a sub-orbital autopilot at Dan Stephs website. Here it is: http://orbiter.dansteph.com/index.ph...IVMore&DId=168
Link is dead. I have been looking everywhere for this autopilot for DGIV.

Anyone have it somewhere? It looks like Dan no longer hosts it.

Thanks.
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Old 10-17-2019, 04:11 PM   #13
Ballisto
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Originally Posted by Ballisto View Post
 Link is dead. I have been looking everywhere for this autopilot for DGIV.

Anyone have it somewhere? It looks like Dan no longer hosts it.

Thanks.
BUMP

If anyone has the above mentioned Dan Steph addon "Suborbital Autopilot" installed I would be most grateful if you could share a copy of it.

The problem is that since Dan had to do a server migration a lot of content was lost for the DG. Also it seems Dan is no longer active.

Many thanks in advance.

Ballisto.
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Old 10-17-2019, 06:07 PM   #14
Marijn
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What about SuborbMFD?
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Old 10-17-2019, 08:46 PM   #15
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Quote:
Originally Posted by Marijn View Post
 What about SuborbMFD?
Its for version 060929, and, is intended for airless planets/moons. It may work on Mars. Pursuit MFD can handle Mars, but you have to keep a close eye on it.
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