SpaceX Falcon 9/Dragon CRS-2 SpX-2 MISSION GENERAL DISCUSSION

[Zed_Noir]

I hear Elon has an idea to upgrade the recovery ship with a hydrofoil, to get back to port more quickly.

He's going to call it the hypersloop. 

No, he'd call it the Hyper-X!

  Afraid not. Name is already taken and trademark by Kingston Technology for various RAM memory modules and solid state hard drives.

[krytek]

Could it be the result of some sort of electric current running between Dragon structure and the ISS? They do have separate solar panels... how is the "earth" generated in space?

They hook up more than one wire, that's how.

(But actually, it is possible to discharge to the diffuse plasma of space.)

IIRC snow white (the coating) is conductive for exactly that reason.
I wanna see some post recovery pics...

[Kasponaut]

Hello everyone.

I have been wandering about this for a long time and it begins to irritate me now, so I have to post this question:

Why is SpaceX so secretive and so badly informative or is it me?
There a next to no pictures of this latest Dragon after the return to earth or the recovery of it?
The same was the case the last time 
Why?? This is 2013 with lots of digital cameras!!!

Or is there a good reason?

Cheers,
Kasper

[Lar]

Hello everyone.

I have been wandering about this for a long time and it begins to irritate me now, so I have to post this question:

Why is SpaceX so secretive and so badly informative or is it me?
There a next to no pictures of this latest Dragon after the return to earth or the recovery of it?
The same was the case the last time 
Why?? This is 2013 with lots of digital cameras!!!

Or is there a good reason?

Cheers,
Kasper

They have to get the aliens out safely first.

More seriously, because they're a private company and they don't have to. They're managing their PR just fine, I think... (be glad they aren't as secretive as Blue Origin !!!)

[Lars_J]

Hello everyone.

I have been wandering about this for a long time and it begins to irritate me now, so I have to post this question:

Why is SpaceX so secretive and so badly informative or is it me?
There a next to no pictures of this latest Dragon after the return to earth or the recovery of it?
The same was the case the last time 
Why?? This is 2013 with lots of digital cameras!!!

Or is there a good reason?

Cheers,
Kasper

This video was just posted in the updates thread, some great footage of the moving of the Dragon from the boat to the truck.

[mjv.theory]

Musk's comment about Dragon Version 2 (not DragonRider) having larger windows was interesting. I remember some discussions on the forum about whether the new vehicle would have docking windows. I wonder if it will.

I sincerely hope that there is no intention of allowing humans any meaningful control of spaceships. Let computers do the jobs they do best and refrain from designing human error into the system.

Welcome to the forums! Also it is likely it will be dual controllable. The automated systems will be the primary system, but there will be a manual backup if the crew wants to take control. For example with the most recent flight the crew could have cycled the thruster pods themselves rather than having to have the ground scramble to get communication and code new software on the fly in order make the valves cycle to release them.

That's a good point. It is also important to have manual controls as a backup if the goal is to get to Mars where real time adjustments from Earth will not be possible.

In fact, manual controls as a backup is a requirement. The suitable windows for docking are also a requirement (though arguably a suitable substitute system could be accepted by NASA, ala a periscope).

The thruster "fix" was performed by the computer via a software update - is it really likely that passengers would have a similar level of competence. That said, my original comment was with regard to navigating/steering Dragon, or indeed any future spacecraft. Just because Apollo and the Space Shuttle had manual control, it does not make it a good idea. If fully autonomous flight is possible, surely it is vastly preferable. It does seem quite odd to me that berthing of Dragon involves the skill of station astronauts to capture using the robotic arm. Surely a docking port could provide incoming spacecraft with guidance signals, allowing a docking spacecraft to guide itself in with sub-millimetre accuracy. NASA needs to relieve themselves of the legacy of human flight control and let machines do the mundane grunt work of steering spacecraft.
Perhaps if there is a complete power failure during re-entry, the a manual chute deployment might be a reasonable redundancy, but the thought of humans versus computers when it comes to powered landings (and powered flight) seems to me like a easy win for the computers. Time to move on and file human flight controls along with the horse and cart -  that's the way we used to do things when there were no better alternatives.

[Space Pete]

Surely a docking port could provide incoming spacecraft with guidance signals, allowing a docking spacecraft to guide itself in with sub-millimetre accuracy. NASA needs to relieve themselves of the legacy of human flight control and let machines do the mundane grunt work of steering spacecraft.

I've honestly lost count of how many times this has been covered before, but Dragon berths, not docks - and it is simply, flat-out, not possible for a spacecraft to berth under its own guidance and control, as there is no capture mechanism on the berthing port. Thus, they have to be captured by the arm first.

[woods170]

Surely a docking port could provide incoming spacecraft with guidance signals, allowing a docking spacecraft to guide itself in with sub-millimetre accuracy. NASA needs to relieve themselves of the legacy of human flight control and let machines do the mundane grunt work of steering spacecraft.

I've honestly lost count of how many times this has been covered before, but Dragon berths, not docks - and it is simply, flat-out, not possible for a spacecraft to berth under its own guidance and control, as there is no capture mechanism on the berthing port. Thus, they have to be captured by the arm first.

I don't think that a newbie member with only two posts under his/her belt has taken the effort to read every thread on this forum, before posting. So, uninformed posters alike will keep appearing from time to time.

[Chris Bergin]

Given CRS-2 is very much in post-flight, we now have a CRS-3 (SpX-3) GENERAL DISCUSSION thread:
http://forum.nasaspaceflight.com/index.php?topic=31513.0

[Andy USA]

This thread was dragged off topic. I removed and saved the 14 posts, so someone PM me and give me a thread title (robotbeat suggested it on the thread but failed to report to mod, which is the wrong way around).

[sittingduck]

It was noted earlier by several NSF users that there appeared to be some type of residual movement of the first stage, several seconds after the second stage moved away and its thrust could no longer impinge upon the first stage. Some speculated that this was an attempt at active control and others dismissed this idea.

I made a very rough 3D animation of the first and second stage separation, using the available footage to track the relative movement of the stages and Earth to get a rough idea of when and how the first stage moves.

http://www.youtube.com/watch?feature=player_detailpage&v=NH2L6BlKo0I

Staging occurs around 0:04 and the movement begins around 0:23.  The video ends roughly where the feed is cut off from the first stage.  It appears to me that there is a relatively deliberate sudden motion and not a gradual change.  What does everyone think given this visualization?

Note: Some of the details on the model may not correspond with their orientation in reality.

[Lars_J]

You need to provide a side-by-side comparison of the real footage with your "simulation" from the same angle, otherwise it means nothing.

[Comga]

I was one of those "several NSF users" who commented on this after more than one Falcon 9 launch.  While Lars_J has a good suggestion of putting the footage beside the animation for comparison, as it is this is very much what I thought I saw.   If we did have them side-by-side we could see that the second stage plume impinges much earlier than the start of the rotation.

[mlindner]

I was one of those "several NSF users" who commented on this after more than one Falcon 9 launch.  While Lars_J has a good suggestion of putting the footage beside the animation for comparison, as it is this is very much what I thought I saw.   If we did have them side-by-side we could see that the second stage plume impinges much earlier than the start of the rotation.

Regardless of what we saw or think we saw the reasoning for why it would be done doesn't work.

If SpaceX wanted to test their cold gas thruster they already have vacuum chambers capable of testing small engines. If they wanted to test guided entry, why did they rotate horizontal? They want to be engines first.

More so why would they make a modification to the Falcon 9 when they already have v1.1 coming online? More so again, where did this thrust come from? We have pictures of the rocket on the ground. Has anyone seen a hole for the thrust?

Let's try possible causes: venting from residuals in the engines or elsewhere, atmospheric turbulence, turbines spinning down causing a torque, other things I haven't thought of.

Question on your video, did you grab the images frame by frame and measure or did you use the initial impulse and then interpolate?

[sittingduck]

Question on your video, did you grab the images frame by frame and measure or did you use the initial impulse and then interpolate?

There are two good points of reference that can be seen from the first stage: the second stage which has traveled far enough away by the time of movement that it appears as a fixed object far away and then the Earth as it rotates into view.  With a single 'tween' it is possible to make the footage align almost perfectly frame per frame, but in reality there is a slight wobble.

The view from the second stage does not show a sudden change in orientation of that stage at the moment that it begins to traverse the field of view from the first stage camera. This seems to imply that it really is a sudden movement of the first stage.  The moment the second stage is out of view the Earth's horizon can be seen and it is clear that the movement was real and continuous. 

I will try to make another video which shows the camera view inside the first stage with the second stage visible as it departs.  Would be nice to have some data on its speed relative to the first stage for these 40 seconds or so.  In the mean time here are still images which demonstrate the same.  Just wanted to add that while I believe the stage does spontaneously begin to rotate I do not know about which point it is rotating or why it is rotating, nor do I care to speculate.

[sittingduck]

You need to provide a side-by-side comparison of the real footage with your "simulation" from the same angle, otherwise it means nothing.

In this video the 3D 'simulation' has been layered above the actual footage.  It matches up pretty closely.

[Lars_J]

Nice, that overlay view seems to be pretty conclusive.

[sittingduck]

Sorry for spamming this thread but here is a final view which shows the position (but not scale) of Earth with a slightly tighter accuracy. Notice that the first stage is imparted with a slight rotation after s2 ignites and this motion is later reversed.

Edit: For clarity I mean to say that the very slight movement visible at 0:14 is later reversed by the movement that begins at 0:19.

http://www.youtube.com/watch?v=ddJijvD-Bac&feature=youtu.be

[bubbagret]

You need to provide a side-by-side comparison of the real footage with your "simulation" from the same angle, otherwise it means nothing.

In this video the 3D 'simulation' has been layered above the actual footage.  It matches up pretty closely.

While watching the video in full screen, at 11 seconds there is an obvious change in motion in the cable swaying at roughly the 10 o'clock position to a short impulse of some kind. Which also happens to coincide with the beginning of the stage rotation.

The cable goes from a side to side swaying motion to more of a "bounce" in line with the direction of rotation.

edit: spelling

[sittingduck]

My one observation you said "this motion is later reversed." I assume you base this on the appearance, at the end of the tumbling portion of the video, of the view forward to the clouds, when the clouds appear to freeze motion for a second or two before the camera view cuts away.

Sorry to not have made this clear enough, I meant that the (almost imperceptible) motion of s1 caused by s2 engine ignition at 0:14 is reversed by the tumble that happens later for unknown reasons at  0:19.