Author Topic: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal  (Read 51594 times)

Offline Torbjorn Larsson, OM

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #120 on: 06/06/2014 01:26 PM »
Since DC and CST also have up to 7 seats, was it a demand of NASA?

No. NASA needed just 4 and 4+ is what it specified.

I'm trying to see if someone has asked SpaceX why the design choice, but came up blank. It is a major one. So it would be interesting to know what sets the limit, assuming they are maximizing the seats to cheapen travel for some customer cases as seems likely then. (And I think the competitors do something similar.)

It isn't safety, because the egress path(s) are at max capacity with 1 or 2 seats.

It isn't primarily mass, if I understood the reveal correct, they can take more mass as cargo. Also, it is a whole launch system, so they decide the up mass.

It may be seating, if the windows are essential for space tourism, because they single row the seats seemingly to have window view access. The lower floor fits only 3 seats that way.* [ http://www.ibtimes.co.uk/spacex-dragon-v2-elon-musks-seven-seater-manned-spacecraft-pictures-1450545 ]

It may be the life support system.

Next press meeting, maybe someone can ask if not already done and I missed it.

*If that is the case, I would criticize the companies (Bigelow?) that drove that design vs camera screens & more seats. But if so, SpaceX accepted the design driver.
« Last Edit: 06/06/2014 01:39 PM by Torbjorn Larsson, OM »

Offline Nomadd

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #121 on: 06/06/2014 07:10 PM »
Since DC and CST also have up to 7 seats, was it a demand of NASA?
What would NASA do with these additional seats?
Bring all Astronauts home in one vehicle in case something happens on the ISS, maybe?
That seems like the obvious advantage, but it seems likely they wouldn't have those extra three seats in there at the cost of cargo.

Offline Joffan

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #122 on: 06/06/2014 07:36 PM »
Since DC and CST also have up to 7 seats, was it a demand of NASA?
What would NASA do with these additional seats?
Bring all Astronauts home in one vehicle in case something happens on the ISS, maybe?
That seems like the obvious advantage, but it seems likely they wouldn't have those extra three seats in there at the cost of cargo.
On the SpaceX vehicle, at least, the extra seats could easily be taken up once only to stow on the ISS and thereafter the space used for (light) cargo.
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Offline Zed_Noir

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #123 on: 06/07/2014 05:22 PM »
Since DC and CST also have up to 7 seats, was it a demand of NASA?
What would NASA do with these additional seats?
Bring all Astronauts home in one vehicle in case something happens on the ISS, maybe?
That seems like the obvious advantage, but it seems likely they wouldn't have those extra three seats in there at the cost of cargo.
On the SpaceX vehicle, at least, the extra seats could easily be taken up once only to stow on the ISS and thereafter the space used for (light) cargo.

Re-installing the seats might not be practical for quick use once the Dragon is docked to the ISS..

Offline ChrisWilson68

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #124 on: 06/08/2014 01:04 AM »
I'm surprised nobody has brought up what seems to me the most obvious reason these commercial crew vehicles are designed to seat seven: because the Space Shuttle seated seven, and they were designed to replace the crew-carrying capability of the Shuttle.

Offline Mariusuiram

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #125 on: 06/08/2014 01:37 AM »
I'm surprised nobody has brought up what seems to me the most obvious reason these commercial crew vehicles are designed to seat seven: because the Space Shuttle seated seven, and they were designed to replace the crew-carrying capability of the Shuttle.

This seems realistic.

I would also imagine the 7 seat focus, even if NASA only needs 4, is PR/Marketing. Making sure that any new projects (like Bigelow) who are doing pencil math for some commercial space venture can get the cost per person for transport low enough.

In the speculative threads about tourism (cis-lunar or to a habitat) there is usually an assumption of a single pilot. My guess, just looking at airlines, and issues of redundancy, is that you will definitely need 2 trained crew, not 1. Not just redundancy incase the pilot is incapacitated, but I imagine there may be procedures that require 2 sets of eyes and you would want to avoid training the tourists to handle anything.

With 2 dedicated crew, a 7 seater still only brings up 5 people.

Online AncientU

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #126 on: 06/08/2014 12:06 PM »
I'm surprised nobody has brought up what seems to me the most obvious reason these commercial crew vehicles are designed to seat seven: because the Space Shuttle seated seven, and they were designed to replace the crew-carrying capability of the Shuttle.

This seems realistic.

I would also imagine the 7 seat focus, even if NASA only needs 4, is PR/Marketing. Making sure that any new projects (like Bigelow) who are doing pencil math for some commercial space venture can get the cost per person for transport low enough.

In the speculative threads about tourism (cis-lunar or to a habitat) there is usually an assumption of a single pilot. My guess, just looking at airlines, and issues of redundancy, is that you will definitely need 2 trained crew, not 1. Not just redundancy incase the pilot is incapacitated, but I imagine there may be procedures that require 2 sets of eyes and you would want to avoid training the tourists to handle anything.

With 2 dedicated crew, a 7 seater still only brings up 5 people.

Maybe that's all that would fit in the available space?
Nah, too obvious.
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Offline mlindner

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #127 on: 06/08/2014 11:40 PM »
I'm surprised nobody has brought up what seems to me the most obvious reason these commercial crew vehicles are designed to seat seven: because the Space Shuttle seated seven, and they were designed to replace the crew-carrying capability of the Shuttle.

This seems realistic.

I would also imagine the 7 seat focus, even if NASA only needs 4, is PR/Marketing. Making sure that any new projects (like Bigelow) who are doing pencil math for some commercial space venture can get the cost per person for transport low enough.

In the speculative threads about tourism (cis-lunar or to a habitat) there is usually an assumption of a single pilot. My guess, just looking at airlines, and issues of redundancy, is that you will definitely need 2 trained crew, not 1. Not just redundancy incase the pilot is incapacitated, but I imagine there may be procedures that require 2 sets of eyes and you would want to avoid training the tourists to handle anything.

With 2 dedicated crew, a 7 seater still only brings up 5 people.

Volume of spacecraft / Volume of standard human tissues = # of people that can fit in spacecraft (assuming perfect flesh/volume packing)

Probably pretty cheap that way.
« Last Edit: 06/08/2014 11:41 PM by mlindner »
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Offline NovaSilisko

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #128 on: 06/08/2014 11:43 PM »

Volume of spacecraft / Volume of standard human tissues = # of people that can fit in spacecraft (assuming perfect flesh/volume packing)

Probably pretty cheap that way.

By that metric, the ISS can be occupied* by 12,610 people. Better get launching!


*assuming every cubic meter of pressurized volume is occupied, probably brought down to only several thousand when you take into account equipment
« Last Edit: 06/08/2014 11:45 PM by NovaSilisko »

Offline darkenfast

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #129 on: 06/09/2014 03:10 AM »
Assuming that Dragon V2 can carry the weight that Elon says it can, then four people will leave capacity for a nice chunk of cargo with three seats removed.  Size-wise, it seems to be the equivalent of a custom passenger van with seven "captain's chair" style seats and headroom.

Offline InfraNut2

I'm surprised nobody has brought up what seems to me the most obvious reason these commercial crew vehicles are designed to seat seven: because the Space Shuttle seated seven, and they were designed to replace the crew-carrying capability of the Shuttle.

This seems realistic.

I would also imagine the 7 seat focus, even if NASA only needs 4, is PR/Marketing. Making sure that any new projects (like Bigelow) who are doing pencil math for some commercial space venture can get the cost per person for transport low enough.

In the speculative threads about tourism (cis-lunar or to a habitat) there is usually an assumption of a single pilot. My guess, just looking at airlines, and issues of redundancy, is that you will definitely need 2 trained crew, not 1. Not just redundancy incase the pilot is incapacitated, but I imagine there may be procedures that require 2 sets of eyes and you would want to avoid training the tourists to handle anything.

With 2 dedicated crew, a 7 seater still only brings up 5 people.

First: NASA needed 4 seats for ISS and therefore specified 4+ for commercial crew. It was the CC contestants themselves that more or less independently decided that 7 was a more optimal number, presumably for market/economic reasons and given launcher limitations. But, thats not the main thing I wanted to say:

My guess about loss of revenue to accomodate pilots is a bit different. Here is why:

There are 2 pilots for airlines because even with autopilots, the planes cannot yet reliably fly themselves from takeoff to landing and in all relevant atmospheric/weather conditions. Therefore, there is not always a backup unless there is a second pilot that can take over.

Dragon V2 (and already V1) is designed to fly itself reliably and automatically with nominally only very minimal help from ground control. Additionally Ground control has deep insight and extensive control options in most off-nominal situations. This will be equivalent to having a primary pilot from a safety perspective, as soon as the system has been proved by ground testing, athmospheric+space test flights and a few early operational flights.

Therefore only one pilot is needed for adequate redundancy once the system is sufficiently tested. The pilot and vehicle automatic systems with ground control can back each other up. This is good enough because the risk of both an incapacitated pilot (or severe pilot interface failure) and severe automation-related failures (that is addressable by pilot intervention but not by mission control help or automatic recovery) occurring at the same time, will be a very tiny part of overall mission risks (unless the design is severely flawed).

When it comes to economics: When there are national space agency astronauts or for-hire astronauts or similar professionals involved, those would happily learn to pilot the spaceship, while their employers will pay for their trips. Excess seats on flights for NASA will likely be replaced with either cargo or spaceflight participants, but are expected to be paid for either way. For commercial space stations, they will probably have to rotate at least one astronaut/professional operating the station on each flight which again would give no lost revenue. Only for free-flier flights or very frequent short-stay flights to space hotels/stations will a not-paid-for pilot be needed. (BTW: It is also possible some of the spaceflight participants would agree to pilot training and certification, just for the bragging rights and adventure, since the emergency "pilot" training will be much shorter and less demanding than Soyuz training, maybe as little as the equivalent of a month of full-time training).

So to sum up the economics: IMHO: Except for the first few flights, just about all LEO flights will likely have at most 1 non-paying person on board and often none. So there will be relatively small revenue loss from non-paying flight participants.  ...Unless government forces excess human redundancy for non-rational reasons, of course...

(BTW: fully automatic spaceships without on-board human backup could also happen some time in the future, but that is probably only after the Dragon V2 and other contemporary systems have been replaced with a next generation of systems at least once).

 
« Last Edit: 06/11/2014 03:21 PM by InfraNut2 »

Offline RanulfC

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Re: Full Video of Elon Musk Q&A Session Post Dragon V2 Reveal
« Reply #131 on: 06/11/2014 07:54 PM »
At a "guess" I'm suspecting that the majority would be to and from orbit, not any particular "destination" as it were. While he might not expect a great increase in the number of "dedicated" satellite launches hes got to "see" an increased requirement for payload to LEO including space stations, cargo and people to get to the point that something like the MCT is "justified" in operation. Its a simple matter of the scales (of economy and operations) needed to support the activities he sees.
<snip>
The kicker in the mix is that unlike any other transportation system we've ever dealt with on Earth, space travel doesn't have any "pre-existing" transportation market/system to tap into with the promise of increased "efficiency" over the "old" system in order to fund itself. There are no pre-existing destinations that will be faster or more economic to "get-to," no pre-existing market of goods and materials that can be transported at "reduced" cost, nothing. The ONLY current customer is really NASA for cargo and personnel, and the ONLY current market is commercial satellite launch. Everything and anything beyond those currently is going to require some sort of "bootstrapping" program to PROVIDE the basis for commercial space flight as envisioned by Musk. Its a "do-or-die" situation in that the only way to get there from here is to TRY it and see if it works.
Your 2 comments fall together quite neatly. But I don't think he means LEO launches. (edit: but he was saying 100s of Dragon V2 launches?)

That's what I got, and that would be directed to LEO...

Quote
On a related note, you say "space stationS". The old ideas of space stations had an industrial base (Mars/Moon/Asteroids) as part of their history, but the recent interest has approached them as a first step.
ie: Mars comes first, then space stations built with Mars materials.

Actually the "Old" idea is that LEO and Near-Earth space stations came FIRST before we even went to the Moon! The space stations (and reusable passenger/cargo rockets to build and service them) were the first step in an intergrated plan where we would build up infrastructure and "capability" in depth before we proceeded to the "next" step in the plan. Space Stations constructed using marterials and parts shipped up from Earth were proposed all the way back in the very first books on space flight. The use of off-Earth materials didn't show up until the mid-70s with the "Space Colony" suggestions. Currently we're back to putting Earth made "space stations" and/or "advanced space bases" in places like L1 or L2 to allow more efficent departures and arrivals for deep space missions and to get experiance with the same in a nearer to "interplanetary" environment.

Quote
Of course it was based on the premise that launch from Mars was far cheaper than launch from Earth, but perhaps that assumption will need to be revisited in the near future.

Moon actually, or asteroids. Mars launch for materials isn't really that much cheaper than getting materials from the asteroids, (and actually the deeper gravity well makes it somewhat worse) while getting materials for Cis-Lunar construction sourced from the Moon makes the most sense once you have the needed infrastructure.

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