SpaceX COTS Demo 2/3 Updates (THREAD 2)

[Orbiter]

"SpaceX’s launch of it's Falcon 9 rocket and Dragon capsule to the Space Station now is targeted for Monday, April 30, 2012 at 12:22 p.m. ET."

http://twitter.com/#!/NASA/status/180358568720072706

Only off by two hours, not bad  . I was judging by the Heavens-Above predicted in-plane times.

Orbiter.

[Jim]

Whether or not a rocket *can* do yaw steering to get back in plane is a function of the flight computer and software.  Didn't Delta II have instantaneous windows for planetary shots and A-train missions?

Whether or not a mission *does* yaw steering is a function of performance margin.  Shuttle could've been constrained to instantaneous windows had G&C used the margin elsewhere.

They have said in the past that they can support windows longer than instantaneous.

[yg1968]

Or maybe they thought about it some more and realized that it makes sense to keep as much prop on board Dragon as they can in case they have to abort an on-orbit test and want to be able to fix the problem and try again.  Having a massively constrained launch window is probably still cheaper than having to launch another Dragon-Falcon stack.  Having tridaily launch attempts actually keeps the ops folks happier since one doesn't have to amp up for attempts on multiple days in a row.  As far as usability once operational, I would think that the Demo will establish an initial prop margin for the Dracos, one that's conservative and can be partially retired with more data points.  At least that's how the experienced folks do it.

Now, if the operational windows are this bad, then it's time to worry.

Jim,

I meant the explanation above hasn't been refuted and it seems as good an explanation as any other.

[Rocket Guy]

As noted before, they have talked about increasing window length on later missions. And as someone else pointed out, that may have to do with phasing and manuevers on this one.

[ChefPat]

Doesn't this mission have to do an approach & abort maneuver before it can berth to the ISS? Once it's proven it can do that doesn't it have to be able to do it again for real if necessary?

[robertross]

Doesn't this mission have to do an approach & abort maneuver before it can berth to the ISS? Once it's proven it can do that doesn't it have to be able to do it again for real if necessary?

Yes and yes

[Comga]

Our freind anik has posted April 30 on his schedule.   

2012
March 23 - ATV-3 "Edoardo Amaldi" launch
March 28 - ATV-3 "Edoardo Amaldi" docking (to Zvezda)
March 31 - ISS orbit's test raising by ATV-3 engines
April 5 - ISS orbit's raising by ATV-3 engines
April 19 - Progress M-14M undocking (from Pirs)
April 20 - Progress M-15M launch
April 22 - Progress M-15M docking (to Pirs)
April 25 - ISS orbit's raising by ATV-3 engines
April - Progress M-14M deorbit
April 30 - Soyuz TMA-22 undocking (from Poisk) and landing [Shkaplerov, Ivanishin, Burbank]
April 30 - Dragon (SpX-D) launch
May 3 - Dragon (SpX-D) capture and berthing (to Harmony nadir) by SSRMS
May 15 - Soyuz TMA-04M launch [Padalka, Revin, Acaba]
May 17 - Soyuz TMA-04M docking (to Poisk)
May 21 - Dragon (SpX-D) unberthing (from Harmony nadir), release by SSRMS and landing

Plus lots more details and a link to a cbsnews article.

Now we know it's real!   

[Robotbeat]

Not real until FRR, IMHO. And could always have an abort that causes them to miss the flight window and have to delay a few days (how many times did they abort last time?). Won't be long, though.

[Garrett]

Not real until FRR, IMHO. And could always have an abort that causes them to miss the flight window and have to delay a few days (how many times did they abort last time?). Won't be long, though.

I think it was OV-106 who pointed out that the FRR is a formality. If the FRR is going ahead, then the flight is going ahead. Maybe somebody could clarify that?
Also, having to scrub the launch because of a last minute (or second) fault doesn't make it less "real". A scrub on the launch pad means that it already is "real".
This is as real as it gets.

[ChefPat]

Doesn't this mission have to do an approach & abort maneuver before it can berth to the ISS? Once it's proven it can do that doesn't it have to be able to do it again for real if necessary?

Yes and yes

Just how much margin will this eat up?

[Antares]

FRR's are not convened unless expected to be successful.  Once in a while someone asks a hard question that has not been considered, or one group decides to be obstructionist, or a briefer gives a weak response.  In that case, a date won't be settled.  With these guys, I won't consider the date as real until FRR is less than a week away.

[Kabloona]

Let's keep in mind Elon's statement that the Dragon software revisons are the long pole in the tent, and NASA is going to want to see all the V&V done before FRR. SpaceX may be on track with the software to support an April 30 launch, or they may not. AFAIK we haven't heard anything about the software status since the early Feb report that deficiencies had been found.

Edit: And speaking of software and FRR's, I see that Pegasus/NuStar has been postponed due to concerns that the (presumably heritage) software had not been sufficiently verified with the new flight computer. So it's never too late for software to wreak havoc with a launch schedule.

[Lars_J]

New Dragon/F9 pic from the SpaceX twitter feed:

[majormajor42]

So with exception to the usual suspects that delay aircraft launches, such as weather or the unforseen mechanical issues, when can we start getting hopeful that 4/30 will be the first attempt of launching? After this 4/16 FRR? I would think that by a week before that, such as 4/9, we would know if the software and everything else is on pace. Others might say that we can start counting down now, that 4/30 looks like it will be the day.

[robertross]

So with exception to the usual suspects that delay aircraft launches, such as weather or the unforseen mechanical issues, when can we start getting hopeful that 4/30 will be the first attempt of launching? After this 4/16 FRR? I would think that by a week before that, such as 4/9, we would know if the software and everything else is on pace. Others might say that we can start counting down now, that 4/30 looks like it will be the day.

I think Antares answered this well enough just 3 posts up.

[mr. mark]

It seems that the solar panel covers turned out to be not as wide as I thought. Looks like they are more flush with the trunk. I would love to get an open view of the trunk compartment.

[Comga]

The ISS Flight Program Working Group document  linked in the ISS section has the COTS2/3 Dragon arriving May 3rd and staying 17 days berthed at the Node 3 Nadir.

It also has the CRS-1 Dragon arriving August 20 and staying 30 days, and CRS-2 arriving before the end of the year and staying into January of 2013.  I guess the FPWG would vote for three flights in the 2012 launch poll. 

It also has the Orbital COTS flight arriving September 6.  Is that reasonable?  (I haven't been watching Orbital as closely.)

[Avron]

Next fight? is SpX-1

"Sensor: ISS SERVIR Environmental Research and
Visualization System, internal (WORF).
Manifested on SpaceX flight, 2012"

[Comga]

Next fight? is SpX-1

"Sensor: ISS SERVIR Environmental Research and
Visualization System, internal (WORF).
Manifested on SpaceX flight, 2012"

On the FPWG PDF the next flight is SpX-D, which I assume stands for SpaceX Demo i.e. COTS.  SpX-1 is CRS-1 shown docking 8/20.

Where are you seeing that "Sensor: ISS SERVIR ..." detail?

PS The more I look at the FPWG schedule, the more I appreciate its density.  Edwin Tufte would appreciate it, even if it was done in a PowerPoint. 

[AnalogMan]

Here's a slide giving some information about the C2/C3 demo flight requirements (click to enlarge).