SpaceX COTS Demo 2/3 Updates (THREAD 2)

[butters]

One ISS crew member at the RWS running the arm, one ISS crew member at the CUCU running the Dragon?

It seems like progress is being made, but maybe that's for the sake of appearances. Last time, it was an oddly-belated realization that maybe nobody thought to analyze thruster pluming of the solar arrays. This time, we have an oddly-belated request that maybe Dragon (and all future VVs?) should follow the same rendezvous profile as ATV and HTV. Maybe next time it will be some other objection that really should have been voiced at a much earlier point in the mission planning process.

It's a weird situation, because it's almost equally plausible to speculate about a certain institutional reluctance from one or more interested parties as it is to speculate that all parties have had difficulty organizing and coordinating the mission planning under this new commercially-oriented management structure. All we see is an uncharacteristic series of ball-dropping going on really late in the game.

I mean, how did we manage to get this far down the road toward commercial cargo transport to the ISS without clearly defining the rendezvous profile requirements? That's even more inconceivable than last-minute concerns about pluming.

[Chris Bergin]

Thanks MS. I'm useless at dramatics anyway

Another question:
"approval for the combination of the C2/C3 (D2/D3) missions – which would result in Dragon arriving at the orbital outpost – is still pending official approval from NASA and the ISS partners."
This is obviously not your fault, but nowhere in the entire article is the most obvious question of WHY the decision is "still pending" answered. Seriously, what's the deal? Such a lack of explanation for something like that invites speculation.

It allows those who are wont to blame NASA to blame NASA, those who are wont to blame SpaceX to blame SpaceX, and those who are wont to blame Russia blame Russia (your article hints in that direction, but doesn't outright say it... was it intentional to slightly hint that the reason for the continual delay in approval for combining the flights lies with Russia?).

Thanks again.

Well there's no way to avoid approval being pending, as that's the situation. But the problem is, I can't - and thus won't - guess who's the "blame" just to avoid people speculating, given nothing I write would stop that from happening, heh!

If I was to "blame" anyone, I'd blame due diligence, safety and doing it right. This is - after all - a new commercial spacecraft heading to a $100 billion Space Station and if I was an ISS partner, I'd want to have any doubt removed before I'd let Dragon or any new vehicle anywhere near it....as was the case with HTV and ATV with the checkpoints (which is why I added that HTV graphic to the article)

One can't "blame" them for that, so no blame is required.

[Prober]

Tough crowd on here! .....so into the lion's den, with:

SpaceX Dragon ISS flight to slip further, pending combined mission approval:

http://www.nasaspaceflight.com/2011/12/spacex-dragon-flight-slipping-further-combined-approval/

thanks for the update Chris.

[Space Pete]

One ISS crew member at the RWS running the arm, one ISS crew member at the CUCU running the Dragon?

The CUCU doesn't require any crewmember interaction during rendezvous, rather it just enables the ISS to talk to Dragon.

Both crewmembers will be operating the RWS in the Cupola - one will fly the SSRMS and do the capture, the other will check that all procedures are being followed, work the laptop displays, handle radio comms, etc.

[Robotbeat]

One ISS crew member at the RWS running the arm, one ISS crew member at the CUCU running the Dragon?

The CUCU doesn't require any crewmember interaction during rendezvous, rather it just enables the ISS to talk to Dragon.

Both crewmembers will be operating the RWS in the Cupola - one will fly the SSRMS and do the capture, the other will check that all procedures are being followed, work the laptop displays, handle radio comms, etc.

Ah, thank you! Good explanation.

[Ben the Space Brit]

Both crewmembers will be operating the RWS in the Cupola - one will fly the SSRMS and do the capture, the other will check that all procedures are being followed, work the laptop displays, handle radio comms, etc.

I seem to recall that this is pretty much SOP.  One guy does the work, the other holds the Flight Plan and makes sure he is doing it right.

Of course, having two crew members able to perform the manoeuvre also means that it can proceed if one crew member is 'incapacitated'; not critical in this case but the sort of thing that is nice to have, just in case.

[Space Pete]

If anybody wants a good example of how two crewmembers work together during free-flyer capture operations, then have a watch of this video, shot inside the Cupola during the HTV-2 capture in January this year.

As you'll see/hear, one crewmember flies the arm, and the other handles everything else that might otherwise be a distraction during critical phases.

[Chris Bergin]

Tough crowd on here! .....so into the lion's den, with:

SpaceX Dragon ISS flight to slip further, pending combined mission approval:

http://www.nasaspaceflight.com/2011/12/spacex-dragon-flight-slipping-further-combined-approval/

thanks for the update Chris.

Thanks Mr P

That's a great video from Pete. HTV just hanging there, great angles.

[Jorge]

One ISS crew member at the RWS running the arm, one ISS crew member at the CUCU running the Dragon?

The CUCU doesn't require any crewmember interaction during rendezvous, rather it just enables the ISS to talk to Dragon.

I think he's confusing the CUCU with the CCP. The CCP does require crewmember interaction during rendezvous. The CCP talks to Dragon through the CUCU.

[Norm38]

It is currently understood that two ORBCOMM satellites will ride uphill with Falcon 9 during the C2/C3 flight, which caused ISS managers some interest from the standpoint of a potential collision risk with the ISS. As such, NASA noted the use of their experienced Monte Carlo analysis methods to clear this concern. No further information has been noted since.

There see, that wasn't so hard was it?  A few quick orbital simulations and poof, the risks are well understood.  Of course the orbits of these satellites need to be well mapped and analyzed for risk.  But that shouldn't take 6 months to verify, and there was never basis for the claims the Orbcomms were a mission-derailing risk.  Handling them was always just a matter of routine trafic control.  And if it isn't yet routine, then it needs to be.  Something to work on.

[Space Pete]

There see, that wasn't so hard was it?  A few quick orbital simulations and poof, the risks are well understood.  Of course the orbits of these satellites need to be well mapped and analyzed for risk.  But that shouldn't take 6 months to verify, and there was never basis for the claims the Orbcomms were a mission-derailing risk.  Handling them was always just a matter of routine trafic control.  And if it isn't yet routine, then it needs to be.  Something to work on.

Yes, I'm sure NASA just sat on their hands for 5.9 months, then ran a quick simulation and poof, problem solved.

[iamlucky13]

It is currently understood that two ORBCOMM satellites will ride uphill with Falcon 9 during the C2/C3 flight, which caused ISS managers some interest from the standpoint of a potential collision risk with the ISS. As such, NASA noted the use of their experienced Monte Carlo analysis methods to clear this concern. No further information has been noted since.

There see, that wasn't so hard was it?  A few quick orbital simulations and poof, the risks are well understood.  Of course the orbits of these satellites need to be well mapped and analyzed for risk.  But that shouldn't take 6 months to verify, and there was never basis for the claims the Orbcomms were a mission-derailing risk.  Handling them was always just a matter of routine trafic control.  And if it isn't yet routine, then it needs to be.  Something to work on.

Did it take six months, or has clearing the Orbcomm payloads been merely one of a great many preparatory tasks that have been identified and addressed as resources on both sides allow over that time?

Has SpaceX actually been delayed by this, or is it largely coincidental to their own launch preparations?

We have yet to see an update that there's a Falcon 9 sitting on the pad waiting for a piece of paper with a signature on it. Nor do we hear Musk talking about how ready he is to dock with the station as soon as he has an ok.

[tigerade]

Don't worry folks, SpaceX will fly again soon enough.  I believe the last shuttle flight supplied the space station enough for the end of 2012 correct?  Well unless the other suppliers (Soyuz, HTV, ATV, etc) can somehow compensate for commercial cargo not getting off the ground (and I'm assuming Taurus/Cygnus will move farther to the right as well), then there will come a point where NASA will need those CRS flights from SpaceX.  And that is when I'm predicting that the flight rate will actually increase.

[robertross]

There see, that wasn't so hard was it?  A few quick orbital simulations and poof, the risks are well understood.  Of course the orbits of these satellites need to be well mapped and analyzed for risk.  But that shouldn't take 6 months to verify, and there was never basis for the claims the Orbcomms were a mission-derailing risk.  Handling them was always just a matter of routine trafic control.  And if it isn't yet routine, then it needs to be.  Something to work on.

Yes, I'm sure NASA just sat on their hands for 5.9 months, then ran a quick simulation and poof, problem solved.

Yeah, and 'quick simulation' (wrt/ Monte Carlo) is a wide open interpretation. If seen all sorts of timeframes depending on complexity.

[go4mars]

Dragon requires two trained crewmembers to berth it. Dan Burbank is the only crewmember currently aboard ISS who has completed the training, so Dragon C3 cannot proceed until the next Soyuz arrives with Don Pettit or his backup. At that time, ISS will have a crew of six. So the requirement is not that ISS have a crew of six, but the real requirement (two trained crewmembers aboard) will not be satisfied until there is a crew of six.

Time for ISS to order a big, automated Goff Stickyboom.  It would be useful for avoiding these kinds of pickles.  Call it "The Dragon Licker"? 

[Antares]

And if it isn't yet routine, then it needs to be.  Something to work on.

Yes, I'm sure NASA just sat on their hands for 5.9 months, then ran a quick simulation and poof, problem solved.

Yeah, and 'quick simulation' (wrt/ Monte Carlo) is a wide open interpretation. If seen all sorts of timeframes depending on complexity.

And input data.  Norm38's assumption is multifariously naive.  New systems (in anything, not just space) have more unknowns and larger error bars than ones that have been operated many times.  Then, this is trying to do something new from other free-flyers.  Shuttle missions to Station dropped off secondaries after dropping below the Station orbit.  Presumably Orbcomm wants their satellites to last a while, so they aren't paying for a ride to a lower altitude.  So this is new analysis that hasn't been done before.  Last, one hasn't experienced the true joys of regulation (or government mission assurance in this case) until one has sat on both sides of the table trying to figure out what the risk of something is and coming to an agreement between the government and the private sector on how to analyze that risk.  Add those 3 up, while people are trying to do everything else in getting a spacecraft to go to Station for the first time (SpaceX/NASA) and/or operate and protect the Station (NASA) in their day jobs... it's easy to see how it could take a while.  Space is still hard.  Hand-wavers need not apply.

[psloss]

And input data.  Norm38's assumption is multifariously naive.  New systems (in anything, not just space) have more unknowns and larger error bars than ones that have been operated many times.  Then, this is trying to do something new from other free-flyers.  Shuttle missions to Station dropped off secondaries after dropping below the Station orbit.  Presumably Orbcomm wants their satellites to last a while, so they aren't paying for a ride to a lower altitude.  So this is new analysis that hasn't been done before.  Last, one hasn't experienced the true joys of regulation (or government mission assurance in this case) until one has sat on both sides of the table trying to figure out what the risk of something is and coming to an agreement between the government and the private sector on how to analyze that risk.  Add those 3 up, while people are trying to do everything else in getting a spacecraft to go to Station for the first time (SpaceX/NASA) and/or operate and protect the Station (NASA) in their day jobs... it's easy to see how it could take a while.  Space is still hard.  Hand-wavers need not apply.

Buzzkill

[Comga]

(snip)
Presumably Orbcomm wants their satellites to last a while, so they aren't paying for a ride to a lower altitude. 
(snip)

Correct
From Spaceref:
The planned Falcon 9 launch will place ORBCOMM's first two OG2 satellites into a 52* inclined 350 by 750 km insertion orbit. The satellites' onboard propulsion systems will then be used to circulize the orbit at 750 km.

So they will start out in orbits that cross the ~390 km altitude of the ISS and boost themselves above it.

[Ben the Space Brit]

(snip)
Presumably Orbcomm wants their satellites to last a while, so they aren't paying for a ride to a lower altitude. 
(snip)

Correct
From Spaceref:
The planned Falcon 9 launch will place ORBCOMM's first two OG2 satellites into a 52* inclined 350 by 750 km insertion orbit. The satellites' onboard propulsion systems will then be used to circulize the orbit at 750 km.

So they will start out in orbits that cross the ~390 km altitude of the ISS and boost themselves above it.

I wonder how they'll achieve that initial orbit; long-life upper stage that waits until Dragon-C2 is well clear and then does a second MPS burn?

[Robotbeat]

(snip)
Presumably Orbcomm wants their satellites to last a while, so they aren't paying for a ride to a lower altitude. 
(snip)

Correct
From Spaceref:
The planned Falcon 9 launch will place ORBCOMM's first two OG2 satellites into a 52* inclined 350 by 750 km insertion orbit. The satellites' onboard propulsion systems will then be used to circulize the orbit at 750 km.

So they will start out in orbits that cross the ~390 km altitude of the ISS and boost themselves above it.

I wonder how they'll achieve that initial orbit; long-life upper stage that waits until Dragon-C2 is well clear and then does a second MPS burn?

That was already demonstrated on COTS demo 1.