SpaceX Falcon 9 / Dragon 2 : SpX-DM1 : March 2, 2019 : DISCUSSION

[vaporcobra]

NASA's preferences for redundancy are well documented.  That their original program design and management plan intended to have the 2 IDA installed before manned flights occurred is a fact.  That it is important to them is an assumption on my part.  It could be that NASA only cares because they want to park two visiting vehicles simultaneously eventually.

Found this in a NASA OIG document released today:

The most significant item lost during the SPX-7 mishap was a Docking Adapter necessary to support
upcoming commercial crew missions. Although NASA had planned to have two adapters installed on the
Station before the first “crewed” commercial crew demonstration mission scheduled for June 2018, it is
now likely there will be only one installed in time for this mission. Having only one adapter means that a
commercial crew vehicle will not be able to dock with the ISS if technical issues arise with the single
available docking port. ISS Program officials told us they plan to have the second adapter installed
before regular commercial crew rotations begin in late 2018.

That sounds like the second adapter should still be flown up around CRS-16.

(Those dates for the test mission and first crew rotation obviously aren't going to happen.)

Nice catch. I wonder if NASA is willing to conduct DM-1 with just one adapter. It seems that the need for docking redundancy is more related to financial risk than crew risk, given that mission abort is inherently always a possibility and any Demo mission is unlikely to include anything mission-critical for the ISS and crew.

[deruch]

NASA's preferences for redundancy are well documented.  That their original program design and management plan intended to have the 2 IDA installed before manned flights occurred is a fact.  That it is important to them is an assumption on my part.  It could be that NASA only cares because they want to park two visiting vehicles simultaneously eventually.

Found this in a NASA OIG document released today:

The most significant item lost during the SPX-7 mishap was a Docking Adapter necessary to support
upcoming commercial crew missions. Although NASA had planned to have two adapters installed on the
Station before the first “crewed” commercial crew demonstration mission scheduled for June 2018, it is
now likely there will be only one installed in time for this mission. Having only one adapter means that a
commercial crew vehicle will not be able to dock with the ISS if technical issues arise with the single
available docking port. ISS Program officials told us they plan to have the second adapter installed
before regular commercial crew rotations begin in late 2018.

That sounds like the second adapter should still be flown up around CRS-16.

(Those dates for the test mission and first crew rotation obviously aren't going to happen.)

Nice catch. I wonder if NASA is willing to conduct DM-1 with just one adapter. It seems that the need for docking redundancy is more related to financial risk than crew risk, given that mission abort is inherently always a possibility and any Demo mission is unlikely to include anything mission-critical for the ISS and crew.

From the quote, NASA sounds willing to conduct DM-2 (the one with crew) with just one adapter, so they obviously would be okay with it for just DM-1.  To me, the more interesting question is what happens in the event of docking failure on DM-1 due to a problem with the only IDA?  Would there be a requirement to fly a second DM-1 mission (DM-1B) that achieves successful docking prior to a crewed test mission?  I assume so because much of the DM-1 testing is related to performance while docked to station.  Hopefully, there won't be any issues for either company.

[Norm38]

I assume so because much of the DM-1 testing is related to performance while docked to station.

Performance while docked?  Can you elaborate?  While docked isn't the D2 mostly passive?

[guckyfan]

I assume so because much of the DM-1 testing is related to performance while docked to station.

Performance while docked?  Can you elaborate?  While docked isn't the D2 mostly passive?

I seem to remember that initially docking of DM-1 was not even the plan. It was added later. Do I remember wrong?

[envy887]

I assume so because much of the DM-1 testing is related to performance while docked to station.

Performance while docked?  Can you elaborate?  While docked isn't the D2 mostly passive?

Have to make sure it can properly not do anything.

[the_other_Doug]

I assume so because much of the DM-1 testing is related to performance while docked to station.

Performance while docked?  Can you elaborate?  While docked isn't the D2 mostly passive?

Have to make sure it can properly not do anything.

No, I recall, that, too -- the DM-1 flight originally was to demonstrate rendezvous and stationkeeping within 100 meters of ISS, and then demonstrate successful entry and landing.  It wasn't supposed to attempt an unmanned docking.

AFAIK, there haven't been any demonstrations of unmanned U.S. docking maneuvers, have there?  I know the Russian system has been successfully used for years, by both Russian and European vehicles, and the Chinese are using s imilar system.  But all American dockings have either been crew-managed, or not really dockings, but SSRM-handled berthings, right?

So, will DM-1 be America's first completely automated docking of an unmanned vehicle to any other vehicle?

[nacnud]

Well Orbital Express did some automated dockings.

[the_other_Doug]

Well Orbital Express did some automated dockings.

Thanks for that.  I guess more recent updates have failed to "save" to my long-term memory.  My best recollection was of a DoD test back in the '80s, where spacecraft launched separately were supposed to perform automated rendezvous and docking tests, during which one or both of the spacecraft ran out of fuel before they achieved a successful docking.

Good to see DARPA figured it out...

Still, this automated docking is not something that's been done a whole lot by American spacecraft, and certainly not something done by the U.S. in support of ISS operations up to now.  So, still rather impressive...

[Comga]

Well Orbital Express did some automated dockings.

Thanks for that.  I guess more recent updates have failed to "save" to my long-term memory.  My best recollection was of a DoD test back in the '80s, where spacecraft launched separately were supposed to perform automated rendezvous and docking tests, during which one or both of the spacecraft ran out of fuel before they achieved a successful docking.

Good to see DARPA figured it out...

Still, this automated docking is not something that's been done a whole lot by American spacecraft, and certainly not something done by the U.S. in support of ISS operations up to now.  So, still rather impressive...

DARPA didn't figure out anything except funding.
Boeing and Ball Aerospace built Orbital Express.  As it should be.

Technology is almost here to do autonomous driving of cars and trucks with all the human and environmental variability involved in crowded conditions.  Compared to this, autonomous orbital rendezvous is simple.

[cwr]

I assume so because much of the DM-1 testing is related to performance while docked to station.

Performance while docked?  Can you elaborate?  While docked isn't the D2 mostly passive?

Have to make sure it can properly not do anything.

No, I recall, that, too -- the DM-1 flight originally was to demonstrate rendezvous and stationkeeping within 100 meters of ISS, and then demonstrate successful entry and landing.  It wasn't supposed to attempt an unmanned docking.

AFAIK, there haven't been any demonstrations of unmanned U.S. docking maneuvers, have there?  I know the Russian system has been successfully used for years, by both Russian and European vehicles, and the Chinese are using s imilar system.  But all American dockings have either been crew-managed, or not really dockings, but SSRM-handled berthings, right?

So, will DM-1 be America's first completely automated docking of an unmanned vehicle to any other vehicle?

It seems to me that you are describing the original Dragon 1 demonstration plan which involved 3 flights.
The 1st Dragon 1 COTS demo was launched on 2010/12/08 and just demonstrated orbital operations,
re-entry and recovery.
At that time, 2 more COTS Demos were planned fro Dragon 1.
However after Orbital announced their 1st Demo would berth, SpaceX asked to merge their 2nd and 3rd Demos into one flight [I'm guessing that the orbital plan triggered SpaceX to change, it could just as easily have been schedule crunch or cost]. That merged demo was executed via launch on 2012/05/21.

I could be wrong but I've only heard of 2 orbital demo launches [demo1 unmanned docking and demo2 manned docking] for commercial crew with both SpaceX and Boeing submitting similar plans.
Nor do I recollect an FPIP that showed anything different.

Carl

[biosehnsucht]

Well Orbital Express did some automated dockings.

Reading the wiki page, sounds like it used a robotic arm to manage the dockings, not doing it how Dragon will (and the Russian and Chinese systems have)?

[FutureSpaceTourist]

Brooks asks if its correct SpaceX got waiver to not fly functioning life support system on first, uncrewed Crew Dragon launch.
Lightfoot: don’t know, but we will have safety policies in place when we do fly crew.

https://twitter.com/jeff_foust/status/971409824780079104

SpaceX says it has not applied for a waiver, plans to fly life support on Demo 1.

https://twitter.com/flatoday_jdean/status/971506957277376512

[AncientU]

Brooks asks if its correct SpaceX got waiver to not fly functioning life support system on first, uncrewed Crew Dragon launch.
Lightfoot: don’t know, but we will have safety policies in place when we do fly crew.

https://twitter.com/jeff_foust/status/971409824780079104

SpaceX says it has not applied for a waiver, plans to fly life support on Demo 1.

https://twitter.com/flatoday_jdean/status/971506957277376512

That was EM-1 that got the waiver...

Wait, they don't need a 'waiver' -- they're making up the rules.

[The Phantom]

I spend just about zero time in the SX public forums, so maybe you’re already aware of this. I saw this object on the back of one of the GO boats in Port Canaveral today. Practice for Dragon recovery?

[Kansan52]

Consensus is yes.

[vaporcobra]

I spend just about zero time in the SX public forums, so maybe you’re already aware of this. I saw this object on the back of one of the GO boats in Port Canaveral today. Practice for Dragon recovery?

As Kansan52 mentions, very likely yes. Go Searcher has been out and about with that specific article for a couple weeks at this point.

Regardless, thank you for sharing! We more or less unilaterally appreciate any new photos of SpaceX hardware we can get.

[jpo234]

I spend just about zero time in the SX public forums, so maybe you’re already aware of this. I saw this object on the back of one of the GO boats in Port Canaveral today. Practice for Dragon recovery?

Probably that one:


Source NASA

[jimvela]

I saw something similar back on March 2nd (was out to view the launch of GOES-S).

We (humorously) speculated about the uses of the little black room to the right...

[vaporcobra]

I spend just about zero time in the SX public forums, so maybe you’re already aware of this. I saw this object on the back of one of the GO boats in Port Canaveral today. Practice for Dragon recovery?

Probably that one:


Source NASA

Had the same thought, but the article on Go Searcher appears to more identically match the shape of a real Crew Dragon - note the SuperDraco alcoves actually protrude visibly, whereas the article used for crew recovery testing appears to be a smooth, generic capsule. I think it's more likely a boilerplate mass and drag simulator or even the mockup capsule SpaceX often shows off at certain events, though I doubt that version is an accurate mass representation.

[Jakusb]

Core 1051 reserved for this mission:
https://twitter.com/SciGuySpace/status/978335789309407232