Author Topic: Could the ITS Booster do Mars Direct?  (Read 4351 times)

Offline Patchouli

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Re: Could the ITS Booster do Mars Direct?
« Reply #20 on: 05/03/2017 02:53 AM »
The ITS booster isn't going to exist without the ITS spaceship. If the ITS spaceship exists what's point in developing the Mars Direct departure, transit, EDL and Earth return hardware? It's all grossly out-classed by the ITS ship. The Mars Direct surface ops and refueling hardware would still be useful, but could at that point just be delivered to the surface by ITS.

Every now and then I do seem to see hints that SpaceX is building the ITS spaceship first rather than the booster.  Doing the opposite would make better sense to me.  I will admit though, if the spaceship is up and running and operating with the same engines it would serve as a SSTO LEO launcher which could be where Elon seeks to get most of his money; the booster solo would be overkill for a small-payload-rich v.s. large-payload-poor economy.

I figure it would be most logical to do the booster first as any performance shortfall will effect  the spaceship's design.
Plus the spaceship would be largely useless without it's booster but the latter can be used as a standard LV with the addition of an upper stage.

« Last Edit: 05/03/2017 02:59 AM by Patchouli »

Offline JamesH65

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Re: Could the ITS Booster do Mars Direct?
« Reply #21 on: 05/03/2017 11:56 AM »
They clearly need to be designing and building the booster and ITS in parallel.

It's not a question of which comes first - they need to ensure that they are both ready to go at the same time. You cannot have one without the other. I'd expect the ITS to start manufacture first since it is more complicated and therefore clearly on the critical path.

Engine design is mostly the same for both of course (apart from Vac differences), so that's one development path that fits both streams.

Offline sevenperforce

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Re: Could the ITS Booster do Mars Direct?
« Reply #22 on: 05/03/2017 02:19 PM »
They clearly need to be designing and building the booster and ITS in parallel.

It's not a question of which comes first - they need to ensure that they are both ready to go at the same time. You cannot have one without the other. I'd expect the ITS to start manufacture first since it is more complicated and therefore clearly on the critical path.
On the contrary: you certainly can have the ITS Spaceship and Tanker without the booster. Both can launch and undergo testing (suborbital testing, at least) without the booster.

Offline JamesH65

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Re: Could the ITS Booster do Mars Direct?
« Reply #23 on: 05/03/2017 03:38 PM »
They clearly need to be designing and building the booster and ITS in parallel.

It's not a question of which comes first - they need to ensure that they are both ready to go at the same time. You cannot have one without the other. I'd expect the ITS to start manufacture first since it is more complicated and therefore clearly on the critical path.
On the contrary: you certainly can have the ITS Spaceship and Tanker without the booster. Both can launch and undergo testing (suborbital testing, at least) without the booster.

But you cannot do the job they are being built in any sensible timescale for if you do one then the other. If you want to go to Mars, you have to have both ready at the same time.

Offline sevenperforce

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Re: Could the ITS Booster do Mars Direct?
« Reply #24 on: 05/03/2017 08:14 PM »

On the contrary: you certainly can have the ITS Spaceship and Tanker without the booster. Both can launch and undergo testing (suborbital testing, at least) without the booster.

But you cannot do the job they are being built in any sensible timescale for if you do one then the other. If you want to go to Mars, you have to have both ready at the same time.
Certainly. Just saying, the Spaceship can be flying, at least Grasshopper-style, before the Booster is constructed.

Offline TomH

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Re: Could the ITS Booster do Mars Direct?
« Reply #25 on: 05/03/2017 08:16 PM »
... you cannot do the job they are being built in any sensible timescale for if you do one then the other. If you want to go to Mars, you have to have both ready at the same time.

For Mars, they will both have to be operational at the same time. That does not mean they have to be in simultaneous development. That would, in fact, be inadvisable for several reasons. Technology difficulties related to the first can be avoided for the second. One team of engineers can design the first, then design the second with compatible technology. Separate teams working at the same time may drift into divergent technology; they require twice the salaries and work space. Sequential development is far more prudent.

Post Script. Multiple parallel development was required for the Apollo program, but that was necessary in order to meet Kennedy's deadline. In regards to differential technology, look at the problem Apollo 13 had with non-compatible CO2 scrubbers. Having one team develop ITS and its booster sequentially allows engineers to utilize commonality.
« Last Edit: 05/04/2017 01:09 AM by TomH »

Offline JamesH65

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Re: Could the ITS Booster do Mars Direct?
« Reply #26 on: 05/04/2017 09:55 AM »
... you cannot do the job they are being built in any sensible timescale for if you do one then the other. If you want to go to Mars, you have to have both ready at the same time.

For Mars, they will both have to be operational at the same time. That does not mean they have to be in simultaneous development. That would, in fact, be inadvisable for several reasons. Technology difficulties related to the first can be avoided for the second. One team of engineers can design the first, then design the second with compatible technology. Separate teams working at the same time may drift into divergent technology; they require twice the salaries and work space. Sequential development is far more prudent.

Post Script. Multiple parallel development was required for the Apollo program, but that was necessary in order to meet Kennedy's deadline. In regards to differential technology, look at the problem Apollo 13 had with non-compatible CO2 scrubbers. Having one team develop ITS and its booster sequentially allows engineers to utilize commonality.

But takes twice as long.

Note, engines are the same so that development path is the same for booster and spaceship. Composite tank development is the same, so that applies to both. In fact most of the composite work is applicable to both.

I don't think it make sense to do one then the other since a lot of the work is already automatically parallel. Just chop the job up in to chunks, use the lessons learn from each chunk apply to the next chunk rather than wait until the end of one program (booster) to apply lessons to the next program, the ITS. Agile rather than waterfall.

Offline TomH

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Re: Could the ITS Booster do Mars Direct?
« Reply #27 on: 05/05/2017 06:36 AM »
But takes twice as long.

Whereas parallel development costs twice as much. I'm not sure Elon has the money to do this all at one time. Apollo was only going to the moon, and the parallel development cost 4.5% of the entire federal budget. I think parallel development is cost prohibitive.
« Last Edit: 05/05/2017 06:57 AM by TomH »

Offline Kaputnik

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Re: Could the ITS Booster do Mars Direct?
« Reply #28 on: 05/05/2017 09:12 AM »
But takes twice as long.

Whereas parallel development costs twice as much. I'm not sure Elon has the money to do this all at one time. Apollo was only going to the moon, and the parallel development cost 4.5% of the entire federal budget. I think parallel development is cost prohibitive.

And an established team will be more productive working on their second project than their first*

* in SpaceX's case ITS is obviously not their first project overall, but certainly the first of this scale using these materials and propellants, etc.
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Online MickQ

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Re: Could the ITS Booster do Mars Direct?
« Reply #29 on: 05/06/2017 12:53 AM »
If the Spaceship is developed first then it can be doing landing cradle testing ( Dare I say a Crash Test Dummy ) and development while the booster is being finished.

Offline JamesH65

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Re: Could the ITS Booster do Mars Direct?
« Reply #30 on: 05/09/2017 11:30 AM »
But takes twice as long.

Whereas parallel development costs twice as much. I'm not sure Elon has the money to do this all at one time. Apollo was only going to the moon, and the parallel development cost 4.5% of the entire federal budget. I think parallel development is cost prohibitive.

No, because they are not independent. Lots of the stuff developed for one will be relevant for the other.  You also only need one set of autoclaves, just schedule appropriately.

I don't think you can compare with the Apollo program, different driving forces, and technology is very different now.

Tags: SpaceX Mars ITS Mars Direct