SpaceX COTS Demo 2 Updates

[ugordan]

If they do a two burn trajectory to inject Dragon into its rendezvous course for the ISS, it might require a total of four burns to then get the second stage into a circular 775 km orbit.  That does not sound possible.

The injection orbit for C2 was posted somewhere already, it's pretty close to circular, direct insertion profile. Dragon separates and the 2nd stage performs a restart to an elliptical orbit with 780-ish km apogee. Two MVac burns total. The Orbcomms circularize themselves.

[Comga]

NASA has the luxury of taking the approval process very slow. It's not at all on the critical path. Whether NASA approved the combined mission last January or this October makes no difference -- SpaceX won't fly until November at the earliest.

Not my point. 

Musk says "SpaceX will have FH at the launch site by the end of next year."  (random but definitive pseudo-quote)

Suffradini says "The other part that we had to look at was the assessment of [...] the last flight of the Falcon 9 that we have worked with SpaceX, and we didn't see anything of large concern there.  So we're having some final discussions about the actual flight itself that would occur ... we'll call it the combined flight ... but the next flight - and there's some secondary payloads on there, or a secondary payload on there that they'd like to fly, so that's a factor so we're having those discussions now."   (actual but indefinite quote)

Let's hear some steely-eyed missle-man talk from NASA!  Make decisions.  Move out. 

[ugordan]

I'm kind of wondering why it seems they're concentrating on the launch vehicle at this stage in the game, shouldn't the primary consideration be Dragon's safety to ISS?

[Lurker Steve]

NASA has the luxury of taking the approval process very slow. It's not at all on the critical path. Whether NASA approved the combined mission last January or this October makes no difference -- SpaceX won't fly until November at the earliest.

Not my point. 

Musk says "SpaceX will have FH at the launch site by the end of next year."  (random but definitive pseudo-quote)

Suffradini says "The other part that we had to look at was the assessment of [...] the last flight of the Falcon 9 that we have worked with SpaceX, and we didn't see anything of large concern there.  So we're having some final discussions about the actual flight itself that would occur ... we'll call it the combined flight ... but the next flight - and there's some secondary payloads on there, or a secondary payload on there that they'd like to fly, so that's a factor so we're having those discussions now."   (actual but indefinite quote)

Let's hear some steely-eyed missle-man talk from NASA!  Make decisions.  Move out. 

You want steely-eyed missle-man talk, try this.

SpaceX is mucking up the COTS testing process by flying secondary payloads. If the secondary payloads are an issue, they get them off this flight. Those secondary payloads only make the flight software more difficult to develop and test anyway.

Fly the Orbcomm satelites on their own launcher. Give the commerical community some confidence that you still remember how to launch their payloads. Perhaps a successful commerical launch might even bring in some additional business.

In the meanwhile, trying to fly secondary payloads on the COTS missions is delaying the flights, and delaying the start of the CRS contract. All of these schedule delays mean delayed payments from NASA. Getting the last of the COTS milestone payments and starting the CRS payments earlier should help cover any additional costs of launching these secondary payloads on a separate launcher.

[ugordan]

In the meanwhile, trying to fly secondary payloads on the COTS missions is delaying the flights, and delaying the start of the CRS contract.

Says who?

[renclod]

The question of the combined COTS 2/3 came up (once more) during today's STS-135 post MMT briefing, and was answered by Mike Suffredini (ISS Program Manager).  This is my transcript:

Mike Suffredini:
"...
But the planning is all assuming that we're flying the next flight to ISS - that's what we'll be doing, so we're not losing any time with regard to being prepared for that flight. ..."
 
Now what does that mean ?!
Is SpaceX looking at the next flight as *not to ISS* ?
Do they want to launch another payload before flying C2/C3 ?

 

[ugordan]

It means they're going ahead with preparing as if COTS-2 *will* berth to station so they're not really losing any useful time over the indecision so far in that respect.

[mr. mark]

Let's not get into what if's. It's been explained by Elon Musk and Spacex many times over. Cots 2 will fly 2 Orbcomm sats along with the Dragon capsule. NASA is just being careful with making sure all payloads meet THEIR mission requirements.

[docmordrid]

Aviation Week....

>
Agency and company officials reached agreement on planning dates of Nov. 30 for the launch and  Dec. 7 for the rendezvous and berthing of the Dragon cargo spacecraft with the station during a July 15 meeting.

The plan depends on how SpaceX intends to manage the deployment of two small satellites during the flight that could pose an impact hazard to the station. “I think we will find a way to sort that out,” Suffredini says.
>

[mr. mark]

Ok, it looks like the plan is for Spacex to go for a combined mission with a November 30th launch and a December 7th berthing date (hopefully a date that will not live in infamy for Spacex)

[ugordan]

Color me skeptical, but I don't see where it's officially combined in there. All I see is a tentative timeline they're working towards *should* the mission be combined, just as Suffredini said.

[corrodedNut]

Aviation Week....

>
Agency and company officials reached agreement on planning dates of Nov. 30 for the launch and  Dec. 7 for the rendezvous and berthing of the Dragon cargo spacecraft with the station during a July 15 meeting.

The plan depends on how SpaceX intends to manage the deployment of two small satellites during the flight that could pose an impact hazard to the station. “I think we will find a way to sort that out,” Suffredini says.
>

Could someone explain how exactly the orbcomm sats "could pose an impact hazard to the station"?

[baldusi]

Aviation Week....

>
Agency and company officials reached agreement on planning dates of Nov. 30 for the launch and  Dec. 7 for the rendezvous and berthing of the Dragon cargo spacecraft with the station during a July 15 meeting.

The plan depends on how SpaceX intends to manage the deployment of two small satellites during the flight that could pose an impact hazard to the station. “I think we will find a way to sort that out,” Suffredini says.
>

Could someone explain how exactly the orbcomm sats "could pose an impact hazard to the station"?

When it comes to security, you have to demonstrate that it doesn't. I'm not saying it's a danger, only that it does require a lot of analysis for contingencies. In other words, obviously that if everything works nominal they would pose no danger. The issue is to analyze all the possible contingencies.

[yinzer]

Aviation Week....

>
Agency and company officials reached agreement on planning dates of Nov. 30 for the launch and  Dec. 7 for the rendezvous and berthing of the Dragon cargo spacecraft with the station during a July 15 meeting.

The plan depends on how SpaceX intends to manage the deployment of two small satellites during the flight that could pose an impact hazard to the station. “I think we will find a way to sort that out,” Suffredini says.
>

Could someone explain how exactly the orbcomm sats "could pose an impact hazard to the station"?

If the Dragon gets inserted into an orbit "close" to that of ISS, deploys the Orbcomm sats, which then fail to work as planned.  Or if they accidentally deploy while near to or while docked to the ISS.

[corrodedNut]

Forgive my ignorance of orbital mechanics, but wouldn't that mean the 2nd stage (a presumably malfunctioning one) would pose an impact hazard as well?

[Prober]

Ok, it looks like the plan is for Spacex to go for a combined mission with a November 30th launch and a December 7th berthing date (hopefully a date that will not live in infamy for Spacex)

Now your talking.......I would even be happy with just another Dragon launch and return.

[cuddihy]

Forgive my ignorance of orbital mechanics, but wouldn't that mean the 2nd stage (a presumably malfunctioning one) would pose an impact hazard as well?

No, IIRC F9 relies on the Dragon to do circularization. Since the satellites are supposed to be in the trunk, they would separate after the Dragon itself is on an intercept orbit. So they are actually by design an impact hazard unless Dragon does some more complex orbital manuevers prior to  its visit to the ISS.

I wonder if that would hurt the margin for doing ISS separation and abort.

[tigerade]

So does Nov 30th look solid enough to ask for the day off? 

[robertross]

So does Nov 30th look solid enough to ask for the day off? 

WAY too early to be thinking about that. 

[ugordan]

No, IIRC F9 relies on the Dragon to do circularization. Since the satellites are supposed to be in the trunk, they would separate after the Dragon itself is on an intercept orbit. So they are actually by design an impact hazard unless Dragon does some more complex orbital manuevers prior to  its visit to the ISS.

So, you're saying the F9 boosts a heavy Dragon to a high apogee orbit which is required for Orbcomm disposal, then Dragon drops them off and *lowers* the orbit back down using precious propellant it's supposed to save for rendezvous ops.

Or...

F9 boosts Dragon directly into a phasing orbit for chasing ISS, separates and then uses the remaining performance margin to boost itself + Orbcomms (attached to the 2nd stage as already illustrated) into an elliptic orbit with a high apogee.

Which is more likely?