Author Topic: ITS LEO Cruise: Cost and Feasibility  (Read 3398 times)

Offline docmordrid

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #20 on: 03/09/2017 03:49 PM »
I wonder if an separate crew launch vehicle with an LAS couldn't just be another ITS, but with a separable crew cabin and a ring of the 10 ton LOX/methane thrusters as an LAS. Would they be responsive enough?

The Spaceship's seam line between the cargo and passenger areas looks like an obvious separation point. Add D2 style thruster quads and fairings with prop tanks and there's a possible not-yet-revealed abort mechanism.

Perhaps this same seam could mount a custom nose with a half-clamshell satellite deployment door, mounted opposite from a fixed section which has the heat shield. Instant CommX constellation bulk deployer.
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Offline CraigLieb

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #21 on: 03/09/2017 03:56 PM »
Is it much more likely they launch a ITS direct to orbit with minimal crew  where it stays for longer periods of time and then ferry-resupply passengers with Dragon 2, or other vehicles including an additional ITS. Reminds me of the 5th element. Stock the ITS with a bunch of Dragon 2 emergency return capsules on the sides. 
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Offline philw1776

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #22 on: 03/09/2017 05:22 PM »
They could build a separate launch vehicle and send the passengers up with that. It would probably add another launch for sending one passenger ITS to Mars. It could be a tanker with a passenger capsule on top that can do a reasonably fast abort. But with its size it would probably need propulsive assist for watering. It would cover only the earth launch part of the flight but it would not need to drag unused hardware all the way to Mars and back. It would be a major development effort. I believe by the time so many people fly to Mars it would already be a well proven system with many launches.

The trouble with that scenario is that as you say it addresses mostly booster failure and just the first ITS lightup.  If it's the ITS that fails, the ITS first fires on the way to LEO.  Then fires for a big burn for TMI, then coast to Mars several months, Martian re-entry, fires for landing.   The booster gets used so much more often (tankers) that it should if designed properly be the most flight proven part of the system.
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Online guckyfan

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #23 on: 03/09/2017 05:48 PM »
The trouble with that scenario is that as you say it addresses mostly booster failure and just the first ITS lightup.  If it's the ITS that fails, the ITS first fires on the way to LEO.  Then fires for a big burn for TMI, then coast to Mars several months, Martian re-entry, fires for landing.   The booster gets used so much more often (tankers) that it should if designed properly be the most flight proven part of the system.

Exactly. That is why I have argued all the time that reliability is more important than a LES. Yes it is true that this suggestion will only mitigate the risk of launch to LEO. How much of the total risk is that? 20%? 30%? But still a lot of people keep arguing that it is irresponsible to launch without LES. I just laid out how this can be done, if someone demands it and not burden the whole trip wíth a lot of heavy hardware that is not useful for most of the trip.

All the rest of the trip can be assured only with reliability.

Offline DnA915

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #24 on: 03/10/2017 12:20 AM »

The Spaceship's seam line between the cargo and passenger areas looks like an obvious separation point. Add D2 style thruster quads and fairings with prop tanks and there's a possible not-yet-revealed abort mechanism.

Perhaps this same seam could mount a custom nose with a half-clamshell satellite deployment door, mounted opposite from a fixed section which has the heat shield. Instant CommX constellation bulk deployer.

Interesting find with the seam line. There does seem to be a large structural divide there. However, in other parts of the presentation, these lines are not present from the outside renders. Obviously that could just be an oversight.

Offline CuddlyRocket

Re: ITS LEO Cruise: Cost and Feasibility
« Reply #25 on: 03/10/2017 03:33 AM »
Is it much more likely they launch a ITS direct to orbit with minimal crew  where it stays for longer periods of time and then ferry-resupply passengers with Dragon 2, or other vehicles including an additional ITS.

Sounds expensive! SpaceX is aiming to make the trip to Mars affordable.

Online su27k

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #26 on: 03/10/2017 04:49 AM »
The trouble with that scenario is that as you say it addresses mostly booster failure and just the first ITS lightup.  If it's the ITS that fails, the ITS first fires on the way to LEO.  Then fires for a big burn for TMI, then coast to Mars several months, Martian re-entry, fires for landing.   The booster gets used so much more often (tankers) that it should if designed properly be the most flight proven part of the system.

Exactly. That is why I have argued all the time that reliability is more important than a LES. Yes it is true that this suggestion will only mitigate the risk of launch to LEO. How much of the total risk is that? 20%? 30%? But still a lot of people keep arguing that it is irresponsible to launch without LES. I just laid out how this can be done, if someone demands it and not burden the whole trip wíth a lot of heavy hardware that is not useful for most of the trip.

All the rest of the trip can be assured only with reliability.

But we're not talking about trip to Mars here, we're talking about a LEO cruise of 2 weeks, having cocktail parties, playing around in zero-G, etc. The acceptable risk for a leisure cruise of this kind is completely different from a Mars trip.

Offline envy887

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #27 on: 03/10/2017 02:45 PM »
Is it much more likely they launch a ITS direct to orbit with minimal crew  where it stays for longer periods of time and then ferry-resupply passengers with Dragon 2, or other vehicles including an additional ITS.

Sounds expensive! SpaceX is aiming to make the trip to Mars affordable.

By the time such trips are affordable ITS will have flown thousands of times, because the only way to get that kidk of price is extremely high flight rates.

With those kinds of flight rates, very high reliability is required and can be demonstrated.

Online guckyfan

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #28 on: 03/10/2017 05:12 PM »
But we're not talking about trip to Mars here, we're talking about a LEO cruise of 2 weeks, having cocktail parties, playing around in zero-G, etc. The acceptable risk for a leisure cruise of this kind is completely different from a Mars trip.

If the risk is regarded not acceptable cost would go up by a lot. First that variant with abort capability needs to be developed and then there would be 2 launches instead of one.

Maybe the cruise ship stays up for 3-5-10 visits before landing for major cleanup and the launcher with abort capability brings up supplies and brings down garbage along with the passengers.

Offline DnA915

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Re: ITS LEO Cruise: Cost and Feasibility
« Reply #29 on: 03/10/2017 05:24 PM »
If the risk is regarded not acceptable cost would go up by a lot. First that variant with abort capability needs to be developed and then there would be 2 launches instead of one.

Maybe the cruise ship stays up for 3-5-10 visits before landing for major cleanup and the launcher with abort capability brings up supplies and brings down garbage along with the passengers.

Regardless, if you have to make a new ship or do multiple launches, it really makes such an enterprise way less likely as it is not their primary goal, but rather a fund raising activity. My personal belief is that there is likely more safety built in or is going to be built it. All we have is that one presentation and they certainly were just scratching the surface details wise.

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