SpaceX Dragon to the ISS

So, the second SpaceX Dragon mission is coming up on April 30th, this time an attempt to deliver some cargo to the ISS. But will it work? Ladies and gentlemen, place your bets!

Lol, thanks for putting a smile on my face!

Ok, serious: I'm not really sure how things will work out. If I remember correctly, I was right in predicting the success of COTS1. But this time there is so much new electronics stuff on board of dragon that could cause problems. As a software engineer myself I know that if software can go wrong, it almost always will go wrong

Most of the like 6 months or so of delays of COTS2/3 are supposedly because of extensive software in the loop testing, so I guess SpaceX did do their homework well, but it still is a complex system that is not yet flight proven (in the complete constellation with trunk, computers, solar arrays, etc..).

So my guess is a ~60% to 70% chance of complete success and I think that problems would most likely occur after launch in the "early operations phase" while checking out the dragon. If dragon works as intended, then I'm highly confident, that approach and berthing will go (almost) as planned.

I really don't know how much of the in orbit testing was done on the last Dragon flight, so difficult to judge. Did they test manoeuvring? What other tests required for this flight was already done on the previous flight?

Makes the vote difficult to judge. But I've gone with fails to berth. If it does succeed to berth, then I reckon everything else will go to plan.

I think they are going to make it, perhaps some minor glitches, but I think they will complete the mission.

They seem to be getting better and better and really learning from their previous launches, so I think the odds are in their favor. However this is actually rocket science and they are still the new people and even the experienced guys makes mistakes, so I guess we will have to wait and see if they actually pull it off, I'm planning on watching the launch with a few friends over the net, does anyone know where to stream it from? The more sources, the better.

I guess it will be broadcasted live on nasa tv but I don't know if there is any alternative source.

Spaceflightnow will probably have a restream of nasatv, and I suppose SpaceX will also have something on their site.

I went with full success option, with 'Launch successful, some issue during checkout prevents Dragon from attempting to berth with ISS' as my second (though a lot less preferable) choice.

Basically if anything looks fishy during the COTS2 programme, NASA will give a 'no go' to proceeed with COTS3 activities... and that's it. One more flight needed to start hauling cargo to ISS.

JamesHughes: yes, some manouvering was performed on previous flight, although probably very basic. They had to reorient the capsule for reentry after all (they did some more apart from that).

[edit]

Oh... and Rogue Dragon scenario sounds at least as plausible as any of the failure scenarios

I've extended the poll deadline to May 3rd now, and will keep extending it as the launch date slips. Re-voting is now also enabled, so you can change your opinion if you're losing or gaining faith.

I have just seen that may the 7th is now the target launch date.

I say that they're gonna make it.

Hi all. Back again after a bit of a hiatus.

Vote for complete mission success. Going out on a limb as software has proven to be the achillies heel for many ventures not just space, but, SpaceX have delayed quite a bit for this aspect of the mission and Elon has said they won't fly until ready. Presumably May 7th is 'ready' at this point.

I've shortened the voting window by a day (can't do it any more specifically) so that it ends before launch. So, if you want to put in your vote, or change it, do it soon!

Awwww. No go! Well, that's what that hold-down feature is for I suppose. We've seen on previous launches that it can be somewhat finicky and conservative, but that's probably a good thing. Wonder what they'll find that triggered it...

Elon Musk via twitter:

https://twitter.com/#!/elonmusk/status/ ... 8222678016

Better safe than sorry I suppose.

Another tweet from Elon Musk (via SpaceflightNow.com)

"Engine pressure anomaly traced to turbopump valve. Replacing on engine 5 and verifying no common mode."