Red Dragon Discussion Thread (1)

[Elmar Moelzer]

Well if my trig is correct, to get down to that sort of loss you need the thrusters to be firing at 20-25deg from vertical.
If they are actually at 45deg, which the artists' impressions suggest, the losses are about 29%.

The display of the Dragon in the artwork is outdated. As has been stated by several sources before and can be seen in some mockups shown by SpaceX. The actual setup of the superdracos on the updated dragon will be slightly different. The superdracos will be in a kind of nose that protrudes from the capsule and because of that will be angled more downwards.

[Garrett]

The pad abort test for Dragon v2 is supposed to be in Q2 next year, so presumably before then.

I was hoping it would be before the parachute drop test, which should be very soon. But that Dragon might only be a very basic boilerplate.

[aero]

Well if my trig is correct, to get down to that sort of loss you need the thrusters to be firing at 20-25deg from vertical.
If they are actually at 45deg, which the artists' impressions suggest, the losses are about 29%.

The display of the Dragon in the artwork is outdated. As has been stated by several sources before and can be seen in some mockups shown by SpaceX. The actual setup of the superdracos on the updated dragon will be slightly different. The superdracos will be in a kind of nose that protrudes from the capsule and because of that will angled more downwards.

My solid geometry is weak but couldn't the Dracos be angled sideways to shoot "around the corner" so to speak and thrust more downward from wherever they protrude? Never vertically but relatively more so.

[Elmar Moelzer]

Here is a picture of the mockup. It might not be exactly what the crewed dragon will look like. People seem to have different opinions on that depending on how you interpret various statements by Musk and SpaceX, but it clearly shows the superdracos at a more vertical angle.
http://communicatescience.com/zoonomian/wp-content/uploads/2012/08/IMG_7024_dragon.jpg

[Jason1701]

The pad abort test for Dragon v2 is supposed to be in Q2 next year, so presumably before then.

I was hoping it would be before the parachute drop test, which should be very soon. But that Dragon might only be a very basic boilerplate.

The parachute drop test is a boilerplate modified from the cargo drop test vehicle that does not have the new complete OML.

[Garrett]

The pad abort test for Dragon v2 is supposed to be in Q2 next year, so presumably before then.

I was hoping it would be before the parachute drop test, which should be very soon. But that Dragon might only be a very basic boilerplate.

The parachute drop test is a boilerplate modified from the cargo drop test vehicle that does not have the new complete OML.

thanks for that info!

[cambrianera]

To everyone searching for the SD angle from vertical.
This is a sketch I did some time ago. Dimensions of superdracos derived from old pictures in this post: http://forum.nasaspaceflight.com/index.php?topic=30455.msg992694#msg992694
The pic was retrieved and posted by Lars_J in another thread (after my sketch).
Likely SD angle will be similar or slightly bigger than Dragon's wall angle.

[Kaputnik]

Hard to calculate an angle from that sketch as it lacks the exact information required. But it does look pretty close to vertical, I admit- less than 20deg. Would the proximity of the sidewall and the heatshield lip have some sort of effect on the effective thrust angle?

What are the panel's thoughts on the likely mass of each super-Draco?

[go4mars]

Another thing Red Dragon could do at relatively low additional expense is collect and transmit magnetotelluric data. 

[Chris Bergin]

Now moved on to thread 2.

This one into the 100,000+ archive.