SpaceX: Falcon 9 Hotfire Attempt 2 Updates

[Robotbeat]

Maybe they should call it a suborbital test flight with a slight possibility of launching a Dragon test article into orbit.

They have a decent probability of recovering the first stage, even if the upper stage fails. It's a kind of hedging their bets.

It also makes me wonder if DragonLab flights later on may actually be fitted with the abort system, since the abort fuel can be used to increase delta-V capability and also to save the capsule and pressurized payload in case of a launch vehicle problem. I mean, might as well standardize on one configuration if you can and it's not too expensive.

[ugordan]

It also makes me wonder if DragonLab flights later on may actually be fitted with the abort system, since the abort fuel can be used to increase delta-V capability

AIUI the abort system would tap into the existing RCS tanks so it would provide no delta-V gain. Having abort engines would actually provide a slight delta-V penalty due to increased dry mass, but the idea of fitting DragonLabs with abort motors is interesting, especially if those are reused crew Dragons. Not sure how the payloads inside would cope with 10+ Gs of acceleration in case of abort, though.

[Jim]

The individual systems all seem to be working.  Where SpaceX suffers from immaturity is overall systems engineering.  Not surprising, considering that their chief systems engineer is just learning how to do the job.

With some more maturity under their (His) belt, I hope for good things from SpaceX.

Bingo

[edkyle99]

... Not one Spacex vehicle has ever exploded. ...

Except for that first Falcon 1, when it impacted the surface at high speed with a largely unburned propellant load.  That one exploded.

 - Ed Kyle

[ugordan]

Except for that first Falcon 1, when it impacted the surface at high speed with a largely unburned propellant load.  That one exploded.

Sure, ram a car fast enough into a wall and it might explode as well. An explosion wasn't the failure mechanism is what he's saying.

[stockman]

Moderators - Now that the Firing is done and documented maybe this thread should be locked - Good conversation going on here but maybe better suited to the spacex discussion threads...

[edkyle99]

Except for that first Falcon 1, when it impacted the surface at high speed with a largely unburned propellant load.  That one exploded.

Sure, ram a car fast enough into a wall and it might explode as well. An explosion wasn't the failure mechanism is what he's saying.

I'm trying to remember a launch vehicle that failed *because* it exploded.

 - Ed Kyle

[ugordan]

I'm trying to remember a launch vehicle that failed *because* it exploded.

One of SRB-related failures would be a start. Liquid rockets, not so much.

[mmeijeri]

I'm trying to remember a launch vehicle that failed *because* it exploded.

Er, Challenger?

[Ben the Space Brit]

Except for that first Falcon 1, when it impacted the surface at high speed with a largely unburned propellant load.  That one exploded.

Sure, ram a car fast enough into a wall and it might explode as well. An explosion wasn't the failure mechanism is what he's saying.

I'm trying to remember a launch vehicle that failed *because* it exploded.

I've seen lots of newsreel footage of early Atlas and Titan-Is blowing up.  Or were those range safety destructs?

[JMS]

Explosion wasn't the failure mechanism with Challenger either.

[ugordan]

Titan 34D-9, Delta II GPS 2R.

[mmeijeri]

Explosion wasn't the failure mechanism with Challenger either.

Because it was just a deflagration? Or because it was one of the SRBs that broke off? It did "explode" in flight in the ordinary sense of that word. The Falcon exploded on impact. Seems like an important distinction. An explosion in flight could blow up the crew, an engine failure would still allow them to get away safely. It wouldn't matter to them if the vehicle did explode on impact.

[Art LeBrun]

Titan 34D-9, Delta II GPS 2R.

Since 34D-9 is IDed by number then Delta 241 was the 1-17-1997 failure......

[mr. mark]

Anyone else notice that in one of the pics that the rocket appears to be bending to the right. I'm thinking it must be a camera affect but, I noticed someone here mentioned it as well. I don't see the bending in any of the other pics or in the videos.

[ugordan]

Explosion wasn't the failure mechanism with Challenger either.

Because it was just a deflagration? Or because it was one of the SRBs that broke off? It did "explode" in flight in the ordinary sense of that word.

So did many other vehicles, either due to range safety or ISDS action. Doesn't meant the explosion was the primary failure mechanism.

[Chris Bergin]

Moderators - Now that the Firing is done and documented maybe this thread should be locked - Good conversation going on here but maybe better suited to the spacex discussion threads...

Agreed, and sorry for not noticing sooner.