Pros and Cons, Dragon V2, CST-100 and Dream Chaser

[Rocket Science]

As stated by M Sirangelo the DC has no blackzones, meaning it can abort anywhere in the launch and either land at a runway or achieve orbit. In the case of the capsules both will most likely end up in the sea if they abort, this could be 100s km into the atlantic. During every launch Navy rescue ships will have to be on station just in case.

I'm still skeptical about this claim... Although I admit it is more of a gut feeling than based on calculations. But if you follow the ISS launch track northeast from CCAFS, yes it does go close to the east coast. But after that there is a large area of the Atlantic before Europe is reached.

EDIT: I added an approximate ISS launch path from CCAFS, as annotated in Google Earth.

Mark replied to a question about trans-Atlantic aborts beginning about 35 minutes in this video.



For aircraft ferry flights across the ocean here are typical routes with landing fields such as the Azores in the mid-Atlantic and factor in DC's 1000 mile crossrange as well.

http://220kts.com/ferry-flights/atlantic-ferry-routes.html

[Lars_J]

Thanks for the video link.

For aircraft ferry flights across the ocean here are typical routes with landing fields such as the Azores in the mid-Atlantic and factor in DC's 1000 mile crossrange as well.

http://220kts.com/ferry-flights/atlantic-ferry-routes.html

DC will be going to an ISS orbit from CCAFS, so it cannot follow those ferry routes exactly. The one that matches the launch track the best has indeed no stop between Newfoundland and Europe.

But if they do indeed have 1000 mile cross-range from a direct abort (not with a long re-entry), then my gut reaction is clearly wrong.

[Rocket Science]

Thanks for the video link.

For aircraft ferry flights across the ocean here are typical routes with landing fields such as the Azores in the mid-Atlantic and factor in DC's 1000 mile crossrange as well.

http://220kts.com/ferry-flights/atlantic-ferry-routes.html

DC will be going to an ISS orbit from CCAFS, so it cannot follow those ferry routes exactly. The one that matches the launch track the best has indeed no stop between Newfoundland and Europe.

But if they do indeed have 1000 mile cross-range from a direct abort (not with a long re-entry), then my gut reaction is clearly wrong.

The ferry routes were only there to show landing fields...  For DC its all a matter of height, velocity thus energy available... So I guess we'll have to wait for SNC to disclose the arranged sites...

[sghill]

What? No barge landings for DC?

[Lar]

What? No barge landings for DC?

It would have to be a very LONG barge.  

More seriously, I expect even an aircraft carrier might not work, not enough rollout length. And I expect DC gear would not do well being arrested, plus you'd need a tailhook to also drop out... Could be wrong though.

[joncz]

Compare that to the flare and float of the shuttle, DC, etc.  The weight penalty for the required landing gear would be egregious.

[Rocket Science]

What? No barge landings for DC?

It would have to be a very LONG barge.  

More seriously, I expect even an aircraft carrier might not work, not enough rollout length. And I expect DC gear would not do well being arrested, plus you'd need a tailhook to also drop out... Could be wrong though.

Ideally a 7000' barge for margin.... Sounds like a project for a Chinese shipyard!

[Oli]

Somebody has to pay for these rescue ships. For ISS launches the navy will most likely provide the service for free. What happens for private launches to a commercial station or a tourist flight.

Couldn't you just alert to coast guard? I mean that's what you'd do if your ship sinks and you end up in a lifeboat.

[rcoppola]

There was a discussion beginning on the SNC Dream Chaser discussion thread about a new Dragon being used for each NASA Crew mission because it's too complex to re-certify a previously flown one. So I'm picking it up here:

What is it about re-certification that makes it so complex that it becomes more efficient to build a new Dragon-V2 every time as opposed to a few and recycling them. Now they may as well have NASA pay for, let's say 6 capsules and then re-use them for other clients. They'd have a whole fleet by the 2020s.

But I'm curious what drives that decision specifically, not just that it's too complex. What makes it so complex? Is it:

1. NASA requirements that by the time you took it all apart and re-certified you may as well just build a new one?
2. Is it any design decisions from the start that make it difficult to re-certify on behalf of NASA?
3. Is it  timing where it's more efficient  to set up the production line to produce in volume first?

Will this "Complexity" effect DC and CST re-use desires?

[Lars_J]

It's just a question (IMO) of cost... SpaceX seems to think that they can be cost-competitive without re-use. (It simplifies some things, and they can still re-use them later for other purposes) Whereas DC seems to be built with the assumption of many re-uses. In other words, DC has a higher cost per unit.

[abaddon]

What is it about re-certification that makes it so complex that it becomes more efficient to build a new Dragon-V2 every time as opposed to a few and recycling them.

SpaceX and NASA are, if SpaceX is selected, going to have to come up with a certification process for a new Dragon V2.  Same as the other possible providers.  Just developing that process itself (not talking about executing on it) is going to be a complicated and lengthy endeavor.  To be able to include a reusable Dragon V2 as part of the CCtCAP proposal, a separate re-certification process would need to be included as a part of that proposal, or a modified version of the new capsule certification process.  Either would introduce substantial additional complexity in the CCtCAP timeline.

Commercial Crew is already underfunded and late.  I don't think SpaceX or NASA wants to slow anything down by insisting on adding re-certification of a reused capsule to their required milestones for CCtCAP.  Later on, sure.

[yg1968]

I suppose that it depends on the number of NASA flights that are involved. If NASA decides to keep two commercial crew providers until 2024, we are talking about 7 flights total for SpaceX. Re-use for only 7 flights likely doesn't make sense. SpaceX might decide to build 7 new capsules for NASA and reuse some of them for Bigelow flights.

But I will be interesting to see what happens on that front. There has been discussions between NASA and the FAA to impose certification requirements for non-NASA flights. Because of the moratorium, the FAA is currently unable to impose certification requirements for non-NASA flights but it's unclear when the moratorium will end.

I am guessing that SpaceX will also forego certifying reused first stages because of the added complexity. So commercial crew will only get new first stages.

[rcoppola]

So does this extend out to say Dream Chaser? If they get 7 flights, will they be building 7 DCs? And if not, why?

Is the cost to build a DC so much higher then Dragon that the added complexity of re-certification is a mandatory from a business case no matter how complex or time consuming it is to execute against?

I would think there will be specifics of re-cert tailored to a vehicle but overall there would need to be  guidelines that cover re-use in general, even if only one vehicle intends to do it.

[abaddon]

We're all guessing here.  My guess is that yes, DC will need reuse to close the business case with a price-competitive bid, and yes, this will impact the timeline for their proposal relative to Dragon V2.

I think the guidelines for reuse are simple; the vehicle must be certified for reflight.  Certification would be vehicle specific.  Not sure what other guidelines would be required?

[docmordrid]

@TheLurioReport
Confirmed info, no CCtCap announcement thru Friday. Ref here 26Aug.:"Contractors will get 2 day warning..." Waiting for Sept. date.

[yg1968]

@TheLurioReport
Confirmed info, no CCtCap announcement thru Friday. Ref here 26Aug.:"Contractors will get 2 day warning..." Waiting for Sept. date.

Chris reported the same in his SpaceX article.

With an announcement now expected in September, a likely scenario would see two spacecraft winning through to the CCtCAP stage.

[Robotbeat]

SNC isn't vertically integrated for one. Costs them a lot to build a new Dreamchaser for that reason.

[rayleighscatter]

Is the cost to build a DC so much higher then Dragon that the added complexity of re-certification is a mandatory from a business case no matter how complex or time consuming it is to execute against?

It's also possible that re-certification for DC could be cheaper than Dragon, especially considering the lesser reentry forces, and stresses, DC faces compared to Dragon.

And the 7 flight number people are throwing around is low. Keeping up the current flight rate between 2018-2024 is 24 flights, divided by 2 if we have two providers.

[Avron]

Is the cost to build a DC so much higher then Dragon that the added complexity of re-certification is a mandatory from a business case no matter how complex or time consuming it is to execute against?

It's also possible that re-certification for DC could be cheaper than Dragon, especially considering the lesser reentry forces, and stresses, DC faces compared to Dragon.

And the 7 flight number people are throwing around is low. Keeping up the current flight rate between 2018-2024 is 24 flights, divided by 2 if we have two providers.

They said that of STS.. then they had to change that to rebuild every flight..

[dglow]

They said that of STS.. then they had to change that to rebuild every flight..

Thank goodness DC isn't STS!