LAS for non human payloads.

[Adaptation]

I don't know how much insurance for launches is these days but I can't imagine it would be cheap.  SpaceX is already getting super draco for dragon rider, could the same tech be applied to non dragon payloads in a cost effective way?  How would this affect upmass, im sure you would want an axially aligned third stage vacuum expanded draco to use the fuel so it's not wasted mass. 

I could be mistaken but isn't the fairing already airtight, some cargo requires inert atmosphere.  Would the fairing survive a splashdown without leaking.  What are the g load requirements for normal for payloads would building payload to survive a LAS event be an unreasonable expense.

What do you think the cost would be and how big of an impact would this have on insurance rates?   

Not saying this would be standard hardware but an option a customer or their insurance provider could purchase.

[Jim]

I don't know how much insurance for launches is these days but I can't imagine it would be cheap.  SpaceX is already getting super draco for dragon rider, could the same tech be applied to non dragon payloads in a cost effective way?  How would this affect upmass, im sure you would want an axially aligned third stage vacuum expanded draco to use the fuel so it's not wasted mass. 

I could be mistaken but isn't the fairing already airtight, some cargo requires inert atmosphere.  Would the fairing survive a splashdown without leaking.  What are the g load requirements for normal for payloads would building payload to survive a LAS event be an unreasonable expense.

What do you think the cost would be and how big of an impact would this have on insurance rates?   

This has been discussed before.  It is not viable
A.  The fairing is not airtight and in fact, has vents to allow the conditioned air to vent on the pad and for the air to vent out during ascent
2.  The g loads during abort would be too high
3.  Splash down is not a load that payloads are designed for
4. There is the issue of the ocean environment
5.  Also, status of the payload with hazardous fluids and it might be autonomously operating and outside of RF links.
6.  Most fairings don't handle spacecraft loads, they are shells and only handle aeroloads.  So they are relatively fragile.
7.  The performance impact to negate all these issues.

[Dudely]

Sattelite insurance covers three risks:

1 Relaunching the satellite if the launch operation fails.
2 Replacing the satellite if it is destroyed, positioned in an improper orbit, or fails in orbit.
3 Liability for damage to third parties caused by the satellite or the launch vehicle.

A Launch Abort System would only cover risks 2, and only covers total destruction due to failure of the launch system. You would still need insurance for the other two, and for the other ways in which you might need to replace the satellite (ex. earthquake hits and the whole thing blows up).

In addition, insurance differs in these three areas as well. For example, you might have insurance against the sattelite getting destroyed up to the point the rocket engines ignite, and different insurance covering the same loss, but only after the engines turn on.


I'll let other people explain why adding engines where there exists no plumbing for the fuel is a bad idea .

[Robotbeat]

It would be useful for pressurized cargo flights to ISS using Dragon if SpaceX ends up consolidating the manned and unmanned versions. But its value would be somewhat limited, since usually the pressurized cargo is less valuable than a typical commsat.

[Elmar Moelzer]

It would be useful for pressurized cargo flights to ISS using Dragon if SpaceX ends up consolidating the manned and unmanned versions. But its value would be somewhat limited, since usually the pressurized cargo is less valuable than a typical commsat.

I think it would be quite useful. Don't forget the value of the Dragon capsule in addition to the value of the cargo.

[Adaptation]

>A.  The fairing is not airtight and in fact, has vents to allow the conditioned air to vent on the pad and for the air to vent out during ascent
Vents are a little different than not being air tight, they are obviously necessary for pressure reasons but is it air tight without considering the vents.  The things got to withstand supersonic flight can't imagine leaks would be a good thing. 

>2.  The g loads during abort would be too high
What are the g load design requirements for a typical payload.  Isn't a typical LAS is dialed in to get people out as fast as they can without the force of escape killing them.  You could probably tone down the LAS a little for cargo.

>3.  Splash down is not a load that payloads are designed for
I would immagine splashdown from a parachute would be a rather soft compared with the rocket ride. 

>4. There is the issue of the ocean environment
Yes the ocean environment does seem to be a little issue.   

>5.  Also, status of the payload with hazardous fluids and it might be autonomously operating and outside of RF links.
There has always been the possibility of hazardous fluids outside of RF links in spaceflight. 

>6.  Most fairings don't handle spacecraft loads, they are shells and only handle aeroloads.  So they are relatively fragile.
Obviously it would need to be implemented as additional stage not into the fairing itself with a base to mount hardware, I see it as moving the las onto a truncated dragon trunk which the fering gets mounted to. 

>7.  The performance impact to negate all these issues.
I wonder what the performance impact would be.  Yes you're adding mass but you also get another stage.

[Jim]

1.  Vents are a little different than not being air tight, they are obviously necessary for pressure reasons but is it air tight without considering the vents.  The things got to withstand supersonic flight can't imagine leaks would be a good thing. 

What are the g load design requirements for a typical payload.  Isn't a typical LAS is dialed in to get people out as fast as they can without the force of escape killing them.  You could probably tone down the LAS a little for cargo.

I would immagine splashdown from a parachute would be a rather soft compared with the rocket ride. 

There has always been the possibility of hazardous fluids outside of RF links in spaceflight. 

>6.  Most fairings don't handle spacecraft loads, they are shells and only handle aeroloads.  So they are relatively fragile.
  .
I wonder what the performance impact would be.  Yes you're adding mass but you also get another stage.

The idea is a non starter.  Why does everybody think they know better?

1.  Fairings aren't airtight and are not designed to be.   The vents are just holes.   The sides and bottom of the faring is not subjected to the airstream and so there is no need for air tight.  Also there are penetrations for umbilicals for AC, power, purges, data, ets.

2.  Less than 6 g's.  LAS needs higher acceleration to outrun the fireball

3.    It isn't soft.  No, splashdown is a shock load and not the same as steady state g loads.   There would have to be huge shock absorbers.

5.  No, my point was that the spacecraft is no longer in contact with its control center and it is running.    And additionally there are  hazardous fluids and the status of which is unknown.

6. No, you don't understand the interface or construction.  The fairing can't survive splash down.  The payload is already attached at the base.  There needs to be something to keep the fairing from hitting the spacecraft.

7.  No, you are adding unnecessary complexity and cost for no return.  LV's are 96-98% reliable.
You have increased costs on every launch and reduced performance for something that might not even work.

[Adaptation]

>The idea is a non starter.  Why does everybody think they know better?
It's just a line of enquiry, please don't get upset I mean you no malice.  I apologise I'm not so great at deference, I wish to understand rather than just accept.

>1.  Fairings aren't airtight and are not designed to be.   The vents are just holes.   
>The sides and bottom of the faring is not subjected to the airstream and so there is no need for air tight. 
Some payloads require inert gas atmospheres, there has to be a way to accommodate them.

>2.  Less than 6 g's.  LAS needs higher acceleration to outrun the fireball
Well cubesats are required to withstand at least 8.3g in all three axes.  But they have to be built to fly on any vehicle.  Falcon throttles back for max-g of 5 late in flight.  I'm sure a margin is required for payloads 17% seems low but not entirely infeasible. 

>3.    It isn't soft.  No, splashdown is a shock load and not the same as steady state g loads.   
>There would have to be huge shock absorbers.
I would think shock would be easier to qualify for than steady state g-loads.  I'm sure there are vibrational acceptance requirements for payloads that would exceed static requirements.  I would have imagined chute deployment to be a higher stress event than splashdown.  How I would love to find some dragon telemetry data right about now. 

>5.  No, my point was that the spacecraft is no longer in contact with its control center and it is running.   
>And additionally there are  hazardous fluids and the status of which is unknown.
And what happens if the rocket fails catastrophically without a las, did those tanks rupture, are they slowly leaking in a field somewhere.  I don't see how a las compounds the problem.  It's a hazard, you mitigate it to a reasonable degree but it's always there. 

>6. No, you don't understand the interface or construction.  The fairing can't survive splash down. 
>The payload is already attached at the base.  There needs to be something to keep the fairing from hitting the spacecraft.
The payload is not attached to the base of the fairing, the payload is attached to a stage the fering is also attached to a stage, you would just it all up the stack.  The falcon is already designed to accept a third stage, that is effectively what dragon already is, dragon trunk is the interstage.  Move the fering and payload mounting hardware to the dragon truck and put the les in the dragon trunk.  I don't think there is a huge innate incompatibility here.  If the fering needs to be beefed up a little doing so has a reduced mass penalty because its dumped soon after leaving the atmosphere anyway. 

>7.  No, you are adding unnecessary complexity and cost for no return.  LV's are 96-98% reliable.
Then why are las's used on human flights at all?  If you can go from 96% to 99.6% don't you think that could have some value?

>You have increased costs on every launch and reduced performance for something that might not even work.
You give me far too much credit.  All I'm proposing is to consider offering an optional add on product to be used when bean counters decide the reduced risk to be worth the added cost. 

[Jim]

1.  Some payloads require inert gas atmospheres, there has to be a way to accommodate them.

>2.  Less than 6 g's.  LAS needs higher acceleration to outrun the fireball
 

>5.
And what happens if the rocket fails catastrophically without a las, did those tanks rupture, are they slowly leaking in a field somewhere.  I don't see how a las compounds the problem.  It's a hazard, you mitigate it to a reasonable degree but it's always there. 

>6. No, you don't understand the interface or construction.  The fairing can't survive splash down. 

The payload is not attached to the base of the fairing, the payload is attached to a stage t

>7.   
Then why are las's used on human flights at all?  If you can go from 96% to 99.6% don't you think that could have some value?
8. All I'm proposing is to consider offering an optional add on product to be used when bean counters decide the reduced risk to be worth the added cost. 

I work with launch vehicles for a living

1.  Fairings are either supplied with air or GN2.  In either case, it is not recirculated but supplied at rate on the order of 150 lb/min.  Fairings are not sealed.

2.  Manned LAS use 15 gs for acceleration

5.  The spacecraft tanks will rupture during destruct.   The additional issue that there will be no insight into the payload for status nor will there be a way to command it.

6.  Currently, spacecraft are not connected to the fairing.  The issue is that it will need to be to keep the fairing and spacecraft from hitting each other during abort, parachute deployment and splashdown.
7.  Because humans don't want to risk their lives on 4-6%.   The system will cost too much, be too heavy and require too many test flights to provide the extra 3.6%. 

[llanitedave]

It would be useful for pressurized cargo flights to ISS using Dragon if SpaceX ends up consolidating the manned and unmanned versions. But its value would be somewhat limited, since usually the pressurized cargo is less valuable than a typical commsat.

I think it would be quite useful. Don't forget the value of the Dragon capsule in addition to the value of the cargo.

I think this is a good point.  A LAS may not be appropriate for a generic satellite launch with a fairing, but a reusable Dragon is worth saving, even if the cargo may not be.

[Adaptation]

>1.  supplied at rate on the order of 150 lb/min.

I was not aware they did it that way.  So probably ~400 lbs would be manifest for purge gas and the tanks. 

>2.  Manned LAS use 15 gs for acceleration

I was aware. 

>5.  The spacecraft tanks will rupture during destruct.   
>The additional issue that there will be no insight into the payload for status nor will there be a way to command it.

Isn't the payload in some kind of sleep mode until it's delivered in orbit? 

>6.  Currently, spacecraft are not connected to the fairing.  The issue is that it will need to be to keep the fairing and spacecraft from hitting each other during abort, parachute deployment and splashdown.

Are you saying its not connected to the rocket at all?  It just sits there and hopes there is no wind to push it over before launch, and hopes acceleration keeps it in place during accent? 
How I have been assuming it worked - the halves of the fairing are connected together, faring is connected to final stage, payload is connected to final stage.  During ascent the fairings disconnected from each other, then they hinge apart from the final stage with a hinge mechanism that releases after a partial rotation.  I don't understand why the faring would need to be connected to the payload if that's what your trying to assert.  It just needs to hold together and hold to the stage.

>7.  Because humans don't want to risk their lives on 4-6%.   
>The system will cost too much, be too heavy and require too many test flights to provide the extra 3.6%. 

The only document I could find specifying the insurance cost is a bit dated but indicated a cost 17% of the value for the payload and launch vehicle and covered launch failures and the satellite for one year of functionality but did not cover lost revenue. 

If you have a $700 million comsat and launch that's a $120m insurance bill.  Let's say only half of it represents the risk of launch failure.  That's still $60m for that 5% chance of launch failure, a 3.6% reduction in risk should be worth about $40m. 

The weight doesn't intrinsically matter much, what matters allot is the mass penalty imposed on payload capacity.  Even if adding las degraded payload capacity by 15% that would be a value cost of just $8.25m.  If it means fitting on the rocket or not then sure it could be a deal breaker but if it means kicking off a secondary payload that you had to subsidized anyhow then it would matter even less. 

It will be interesting to see the price difference in dragon and dragon rider.  Could give us a ballpark on the cost of a las.

[NovaSilisko]

I would venture that a manned dragon would weigh much less than a fully loaded cargo dragon. As in, potentially too heavy for the existing dragon LAS to handle. You could modify it for purposes of aborting specifically for cargo flights, but that sort of messes up the prospect of doing it for reasons of commonality...

[Adaptation]

I kind of thought they where planning on adding propulsive landing to all the dragons, is it just for the dragon riders? 

[Lars_J]

No, cargo dragons will not have a LAS in the near future.

And can this topic please die? This keeps being brought up by people over and over who do not seem to be aware of the search function - and it always shot down with good reason.

Why? For the same reason that 747's don't carry massive parachutes that can slowly descend the aircraft to the ground in case of trouble. It just ISN'T PRACTICAL. The same applies for a universal payload LAS.

[QuantumG]

No, cargo dragons will not have a LAS in the near future.

Yeah they will. I heard from multiple people that SpaceX will be moving to Dragon v2 with Superdracos for both crew and cargo, so an abort-for-cargo mode is essentially free. It's not official yet, but Shotwell said something similar in a post-flight briefing.. can't remember which one.

[Jim]

I was not aware they did it that way.  So probably ~400 lbs would be manifest for purge gas and the tanks. 

No, it is purged on the ground at that rate from the time payload is placed in the fairing until launch, on the order of 10-14 days.  Don't you think there has to be some way for all that air to escape the fairing?

[Jim]

Isn't the payload in some kind of sleep mode until it's delivered in orbit? 

It is operating waiting to get into orbit.  Commanding and insight is lost at T-0, so how would it be regained?  The spacecraft is below the line of sight of any tracking station

[Adaptation]

No, cargo dragons will not have a LAS in the near future.

And can this topic please die? This keeps being brought up by people over and over who do not seem to be aware of the search function - and it always shot down with good reason.

Why? For the same reason that 747's don't carry massive parachutes that can slowly descend the aircraft to the ground in case of trouble. It just ISN'T PRACTICAL. The same applies for a universal payload LAS.

But what about on a 787 

From what I can tell the reasons not to offer it are.
A. the fering is not water tight/structurally able to withstand splashdown
B. the g-load requirements are too high for current payloads

Both of these are serious problems but I don't think they are insurmountable. 

No, it is purged on the ground at that rate from the time payload is placed in the fairing until launch, on the order of 10-14 days.  Don't you think there has to be some way for all that air to escape the fairing?

But some payloads would require it to be purged until it leaves the atmosphere, that requires it to switch over to an onboard tank. 

[Jim]

If you have a $700 million comsat and launch that's a $120m insurance bill.  Let's say only half of it represents the risk of launch failure.  That's still $60m for that 5% chance of launch failure, a 3.6% reduction in risk should be worth about $40m. 

The weight doesn't intrinsically matter much, what matters allot is the mass penalty imposed on payload capacity.  Even if adding las degraded payload capacity by 15% that would be a value cost of just $8.25m.  If it means fitting on the rocket or not then sure it could be a deal breaker but if it means kicking off a secondary payload that you had to subsidized anyhow then it would matter even less. 

1.  your 3.6% increase is unfounded.
2.  You are forgetting all the money to refurb the spacecraft. 
3.  The payload mass is going to be greater than 15%
4. You are forgetting the redesign of the spacecraft to allow for the loads and retrieval and the functionally lose from the mass increase of payload
6.  The mods costs are going to be as much as the rocket development cost.

[Jim]

But some payloads would require it to be purged until it leaves the atmosphere, that requires it to switch over to an onboard tank. 

No payloads do.  All purges are disconnected at liftoff, since the vehicle will be out of the atmosphere in a few minutes.  The purges that you are thinking of is GN2 and it is not for the whole spacecraft, but for science instruments and that is a few magnitudes of difference.  One is a kin to blowing though a straw and the other is like being behind a propeller aircraft.