COTS Q&A

[Orbiter]

Q: I believe this goes in the COTS thread as I can't find a better thread to ask it in.. what exactly will the 2nd flight of the Falcon 9 do? And flights afterword?

Orbiter

[Antares]

2 complete orbits plus ascent and descent, less than 5 hours IIRC.  Just check out all of the Dragon systems that are flying.

COTS Demo 2 will establish RF interface with the Station and test those rendezvous systems.

COTS Demo 3 will actually rendezvous with Station and physically berth and open the hatch.

[Danderman]

For the SpaceX COTS Demo 2, presumably there will be cheese or water in the Dragon for delivery to ISS. So, what is the possibility that, if there is a launch abort mid-flight, that Elon can get his cheese back? With no launch escape system, how does the Dragon survive an abort?

[pathfinder_01]

For the SpaceX COTS Demo 2, presumably there will be cheese or water in the Dragon for delivery to ISS. So, what is the possibility that, if there is a launch abort mid-flight, that Elon can get his cheese back? With no launch escape system, how does the Dragon survive an abort?

For cargo this is an non-issuse. I mean would you pay the price of a recovery team to recover mostly food, water, clothes, ect.... Even ISS parts in theory could be replaced and flown on the next cargo flight. It is not like human life is at stake.

[Danderman]

For the SpaceX COTS Demo 2, presumably there will be cheese or water in the Dragon for delivery to ISS. So, what is the possibility that, if there is a launch abort mid-flight, that Elon can get his cheese back? With no launch escape system, how does the Dragon survive an abort?

For cargo this is an non-issuse. I mean would you pay the price of a recovery team to recover mostly food, water, clothes, ect.... Even ISS parts in theory could be replaced and flown on the next cargo flight. It is not like human life is at stake.

Are you saying that there is no abort capability for Dragon, or rather that there shouldn't be?

[manboy]

For the SpaceX COTS Demo 2, presumably there will be cheese or water in the Dragon for delivery to ISS. So, what is the possibility that, if there is a launch abort mid-flight, that Elon can get his cheese back? With no launch escape system, how does the Dragon survive an abort?

For cargo this is an non-issuse. I mean would you pay the price of a recovery team to recover mostly food, water, clothes, ect.... Even ISS parts in theory could be replaced and flown on the next cargo flight. It is not like human life is at stake.

Are you saying that there is no abort capability for Dragon, or rather that there shouldn't be?

There isn't for the cargo variant. Why would there be?

[Danderman]

For the SpaceX COTS Demo 2, presumably there will be cheese or water in the Dragon for delivery to ISS. So, what is the possibility that, if there is a launch abort mid-flight, that Elon can get his cheese back? With no launch escape system, how does the Dragon survive an abort?

For cargo this is an non-issuse. I mean would you pay the price of a recovery team to recover mostly food, water, clothes, ect.... Even ISS parts in theory could be replaced and flown on the next cargo flight. It is not like human life is at stake.

Are you saying that there is no abort capability for Dragon, or rather that there shouldn't be?

There isn't for the cargo variant. Why would there be?

You need to remember that "abort capability" and "Launch Escape System" are not necessarily the same thing.  LES is a subset of abort systems.

Let's say you are appointed head of the COTS program.  The next day, a Falcon 9 launches with a cargo Dragon as payload. One second before orbital insertion, the Falcon 9 second engine stops burning.

If there is no abort capability, the Dragon never reaches orbit, and lands somewhere where it cannot be recovered. You get fired. Well, not really.

On the other hand, if you are clever, upon getting hired as COTS manager, you insist that the Dragon mission have some sort of abort capability, so it could at least get off the stack safely during the later phases of the mission, or use its engines to attain orbit, if abort-to-orbit is feasible. In all cases, you examine the most plausible off-nominal conditions to determine if there are cost-effective means of mitigation.

I would imagine that development of abort capability, where feasible, for COTS missions would be of some interest to COTS management for Dragon missions.

[Antares]

That's not handled by COTS requirements.  It's handled by FAA regulations.  The FAA has decided the risk is low enough, which means either it's good just as it is due to the specific trajectory it launches on or Dragon can steer to avoid population centers on its way back down.  It might break up aerodynamically if it's ejected from the Falcon in an uncontrolled fashion.  Since Dragon would nominally attach to Station, it can't have ordnance in it for a command destruct or automatic, inadvertent separation destruct.

[Danderman]

That's not handled by COTS requirements.  It's handled by FAA regulations.  The FAA has decided the risk is low enough, which means either it's good just as it is due to the specific trajectory it launches on or Dragon can steer to avoid population centers on its way back down.  It might break up aerodynamically if it's ejected from the Falcon in an uncontrolled fashion.  Since Dragon would nominally attach to Station, it can't have ordnance in it for a command destruct or automatic, inadvertent separation destruct.

I am not confusing an auto destruct system with an abort capability. I am simply asking if the Dragons used for COTS will have any capability of dealing with off-nominal situations during launch that would either save the mission or save the capsule.

[ugordan]

I am simply asking if the Dragons used for COTS will have any capability of dealing with off-nominal situations during launch that would either save the mission or save the capsule.

While it's conceivable a Dragon could be made to separate from a shutdown upperstage, this most likely requires further software development to implement the logic. Given that one of the primary drivers of C2 delays right now is software, I think they have bigger things to think about in the software department than implementing abort modes.

[tigerade]

Can anyone tell me the similarities/differences between the Japanese HTV and Orbital's Cygnus?

[Space Pete]

Can anyone tell me the similarities/differences between the Japanese HTV and Orbital's Cygnus?

Very few similarities in terms of cargo capability - HTV can carry rack-level cargo, Cygnus cannot (due to both its internal cargo carrying structure and its smaller CBM hatch). Also, HTV can carry external cargo, whereas Cygnus cannot.

In terms of payload masses, HTV can carry ~6000kg, whereas Cygnus can only carry 2000kg.

[thydusk666]

Speaking of Cygnus, do we know what is the cost/kg compared to Dragon?

[tigerade]

Can anyone tell me the similarities/differences between the Japanese HTV and Orbital's Cygnus?

Very few similarities in terms of cargo capability - HTV can carry rack-level cargo, Cygnus cannot (due to both its internal cargo carrying structure and its smaller CBM hatch). Also, HTV can carry external cargo, whereas Cygnus cannot.

In terms of payload masses, HTV can carry ~6000kg, whereas Cygnus can only carry 2000kg.

Thanks for the reply.  As far as Cygnus's actual berthing procedure for the ISS, I read that was very similar to HTV.  Is that the case?

[Space Pete]

Thanks for the reply.  As far as Cygnus's actual berthing procedure for the ISS, I read that was very similar to HTV.  Is that the case?

Yes, the berthing procedure for HTV, Cygnus and Dragon is practically identical.

[Antares]

http://www.orbital.com/cargoresupplyservices/

According to Orbital's web site, Cygnus uses the JAXA Proximity Link System, so even the hardware is similar if not identical.