SpaceX and cis-lunar Space Tourism

[Burninate]

I will present another tourist mission concept for you though:

The Lunar Cruise
After burning initially on a free return trajectory, a crew capsule + inflatable hab transfer into a highly elliptical Lunar orbit on the order of 24 hours orbital period (compare to minimum LLO period: ~2 hours).  Every morning, the tourists wake up to begin another very close Lunar approach, and get a very good look at the terminator.  The cruise lasts ~4 weeks, the passengers get to see the Lunar surface from all sides, and by the end, the orbit is aligned such that a low-dV transfer back to Earth is possible.

12 cruise windows per year, each several days long (the constraint being full daylight during the closest approach).  The inflatable hab burns up in the atmosphere.  The Dragon comes down to a spaceport pad.

Semimajor axis for 24hr orbit calculated at 9750km.
Periapsis: However close ops dares, plausibly even closer than a LLO, which has to deal with masscons.
Apoapsis: 16000km above the surface, a vew of the night side of the Moon.

Does anyone have the tools to calculate how much additional dV this would require on top of the free return trajectory?  I'm hoping something on the order of hundreds, rather than thousands, of meters per second?

[Dave G]

... odds are you won't be able to fit 7 people on that mission and some of the Dragon's systems are going to need to be upgraded.

For a Lunar free return, what specifically would need to be upgraded?

[cryptoanarchy]

... odds are you won't be able to fit 7 people on that mission and some of the Dragon's systems are going to need to be upgraded.

For a Lunar free return, what specifically would need to be upgraded?

I think paying customers would want more space.  Two or three customers only and one pilot.  I think SpaceX would have several groups willing to pay the higher price.  With two customers the Dragon would be comfortable enough and there would be no need for a habitation module. 

[Herb Schaltegger]

The ECLSS will almost certainly need to be upgraded.  A 6 hour rendezvous profile is one thing - a week in transit to and from the Moon is something else - you need active THC (temperature and humidity control); the ability to either filter and purify the condensate to drink it or provision to vent it; the ability to store/vent urine; food storage; solid waste storage and/or disposal; provision for expendable LiOH cartridge storage or a LOT more power and mass for active CO2 removal ...

[Mongo62]

The ECLSS will almost certainly need to be upgraded.  A 6 hour rendezvous profile is one thing - a week in transit to and from the Moon is something else - you need active THC (temperature and humidity control); the ability to either filter and purify the condensate to drink it or provision to vent it; the ability to store/vent urine; food storage; solid waste storage and/or disposal; provision for expendable LiOH cartridge storage or a LOT more power and mass for active CO2 removal ...

From the Dragon v2 unveiling: "It'll be capable of carrying seven people - seven astronauts for several days." Would this mean that it has a capacity of 14 to 21 person-days of life support and consumables? (Assuming that "several days" means 2-3 days.) With a three-person load, that would be 5-7 days. Apollo 13, which of course used a free-return trajectory, lasted a bit under 6 days from launch to splashdown. So if my assumption is true, then a Dragon v2 with a pilot and two paying passengers on a Lunar free-return voyage could indeed sustain the people on board for the duration of the trip. I would want to increase the margin of safety though, if this is feasible.

[Herb Schaltegger]

From the Dragon v2 unveiling: "It'll be capable of carrying seven people - seven astronauts for several days." Would this mean that it has a capacity of 14 to 21 person-days of life support and consumables? (Assuming that "several days" means 2-3 days.) With a three-person load, that would be 5-7 days. Apollo 13, which of course used a free-return trajectory, lasted a bit under 6 days from launch to splashdown. So if my assumption is true, then a Dragon v2 with a pilot and two paying passengers on a Lunar free-return voyage could indeed sustain the people on board for the duration of the trip. I would want to increase the margin of safety though, if this is feasible.

Maybe. My concern is that not all ECLSS requirements scale equally and smoothly up and down as you add or remove crew-days to the mission profile; some things are just more granular than that. It really bugs me when I see armchair experts talk about "installing an ECLSS" like it's plugging a cable box into your TV.  It ain't nearly that simple in practice.

[yg1968]

Up till now, we really only talked about SpaceX in the context of ISS Taxi, comsats, and Mars.

With Dragon V2 coming up, and Bigelow at the unveiling event, and interpreting comments by Elon regarding the moon, it's a fair question:

Suppose a VC puts up the funds to do a space tourism company.   Trips to LEO, GTO, and lunar-free-return.   "In high volume, single-digit-Million".    Will people put down $10-$20M for a trip?

In the Bigelow report, Bigelow offered NASA transportation around the Moon. But if Soyuz is offering it for $150M, you have to expect it to cost about 3 times as much as a LEO flight. The trip would be on a FH and Dragon would have to be slightly upgraded. 

http://www.nasaspaceflight.com/2014/02/affordable-habitats-more-buck-rogers-less-money-bigelow/

[QuantumG]

In the Bigelow report, Bigelow offered NASA transportation around the Moon. But if Soyuz is offering it for $150M, you have to expect it to cost about 3 times as much as a LEO flight. The trip would be on a FH and Dragon would have to be slightly upgraded.

I'd expect the price to be completely unrelated to Soyuz.. it's a completely different system by a completely different company in a completely different country, after all.

[yg1968]

In the Bigelow report, Bigelow offered NASA transportation around the Moon. But if Soyuz is offering it for $150M, you have to expect it to cost about 3 times as much as a LEO flight. The trip would be on a FH and Dragon would have to be slightly upgraded.

I'd expect the price to be completely unrelated to Soyuz.. it's a completely different system by a completely different company in a completely different country, after all.

Yes I know but I am saying that it's likely to cost at least 3 times as much as a SpaceX LEO flight because of distance, less astronauts, FH price, etc.

[Dave G]

... odds are you won't be able to fit 7 people on that mission and some of the Dragon's systems are going to need to be upgraded.

For a Lunar free return, what specifically would need to be upgraded?

I think paying customers would want more space.  Two or three customers only and one pilot.  I think SpaceX would have several groups willing to pay the higher price.  With two customers the Dragon would be comfortable enough and there would be no need for a habitation module.

Could they use the upper stage tanks as a hab module?  What if it were hydrolox?

[spacetraveler]

... odds are you won't be able to fit 7 people on that mission and some of the Dragon's systems are going to need to be upgraded.

For a Lunar free return, what specifically would need to be upgraded?

I think paying customers would want more space.  Two or three customers only and one pilot.  I think SpaceX would have several groups willing to pay the higher price.  With two customers the Dragon would be comfortable enough and there would be no need for a habitation module.

Could they use the upper stage tanks as a hab module?  What if it were hydrolox?

SpaceX has no interest in hydrolox. They seem to be pursuing methane.

[meekGee]

The condition I'd imagine they'd put up for participating in this is that it will not be a distraction.

So my guess, as much as you can do with a modified DV2, on a FH.   So maybe crew of 4, and the back region converted to storage and facilities for an extended flight, but that's about it.

Docking with Bigelow - sure - if Bigelow can take care of his stuff himself, which is far from proven at this point.

[ChrisWilson68]

If Musk can bring down the cost of taking people to LEO by a wide margin, then it seems axiomatic that there could be some comparable lowering of the cost to take people to the Moon.

Musk and other multi-planetarists may not see the Moon as being terraformable or ocean-izable or icecap-meltable as Mars is, according to their far-flung ambitious timelines. But let's face it, for the near-to-medium term, the Moon is no less habitable than Mars. Right now, Mars is a vast airless megadesert, and so is the Moon. Yes, Mars has water, but the amount of water on the Moon isn't insignificant either.

So if you have to pick between 2 vast airless megadeserts, then go for the one that's mere days away, rather than for the one that requires months of travel time.

Musk wants spaceflights to become routine, numbering in thousands of flights per year by 2030. Well, that's more likely to happen by luring potential customers with the exotic-yet-nearby destination of the Moon, as compared to the very-exotic-and-very-far destination of Mars. Lower the difficulty barrier, and more trips become possible at lower cost. The famous "Forcing Function" then continues its work at faster pace.

The Moon is lower-hanging fruit than Mars is, even if Mars is the better-quality fruit in the long run.

Use the Moon to lure more customers into spending on trips there, and then re-invest that money into the better-quality equipment that will be required to reach faraway Mars and live that much farther away from the support of Mother Earth.

I agree that there are some advantages for tourism of the Moon versus Mars.  But I don't agree that "for the near-to-medium term, the Moon is no less habitable than Mars".  Mars is dry, but the Moon is drier, and that matters.  Mars has little atmosphere, but the Moon has far less, and that matters.  Methane can be produced fairly easily on Mars.  Try that on the Moon.  Mars also has more gravity.  We don't really know the long-term health effects of either Mars' or the Moon's gravity, but Mars gravity is closer to Earth's, so it may well be that Mars is significantly better for your health.  Mars has a day-night cycle similar to Earth's.  The Moon doesn't, and it is hard to bake in the direct sun for two weeks, then shiver through a two-week night.

All of these have big effects in the near and medium term, not just when we're ready to terraform.

[Mader Levap]

All of these have big effects in the near and medium term, not just when we're ready to terraform.

Cost is all that matters. I can bet large sum of money on this:
- 500k ticket to Moon will be achieved way, way earlier (possibly decades) than 500k ticket to Mars. Well, duh.
- Flying to Mars will always (read: in any sensibly predictable future) be many order of magnitude more costly than flying to Moon.
It is enough and Mars Firsters should get over this. They already lost to laws of physics already before start of whole debacle Moon vs Mars.

Conclusion: Musk will have to settle for retirement on Moon. He simply was born too early to die on Mars (not on impact, of course). Such is life.

[InfraNut2]

The ECLSS will almost certainly need to be upgraded.  A 6 hour rendezvous profile is one thing - a week in transit to and from the Moon is something else - you need active THC (temperature and humidity control); the ability to either filter and purify the condensate to drink it or provision to vent it; the ability to store/vent urine; food storage; solid waste storage and/or disposal; provision for expendable LiOH cartridge storage or a LOT more power and mass for active CO2 removal ...

From the Dragon v2 unveiling: "It'll be capable of carrying seven people - seven astronauts for several days." Would this mean that it has a capacity of 14 to 21 person-days of life support and consumables? (Assuming that "several days" means 2-3 days.) With a three-person load, that would be 5-7 days. Apollo 13, which of course used a free-return trajectory, lasted a bit under 6 days from launch to splashdown. So if my assumption is true, then a Dragon v2 with a pilot and two paying passengers on a Lunar free-return voyage could indeed sustain the people on board for the duration of the trip. I would want to increase the margin of safety though, if this is feasible.

"several" means around 7. So about a week with full crew.

I think have also seen/heard 7-10 days, but I might remember wrong. I do not know if that includes the extra (likely optional) O2 (+air?) tanks in the top of the trunk, that the DV2 kremlinology thread seem to have revealed, or if that is part of an additional long-duration option.

[meekGee]

All of these have big effects in the near and medium term, not just when we're ready to terraform.

Cost is all that matters. I can bet large sum of money on this:
- 500k ticket to Moon will be achieved way, way earlier (possibly decades) than 500k ticket to Mars. Well, duh.
- Flying to Mars will always (read: in any sensibly predictable future) be many order of magnitude more costly than flying to Moon.
It is enough and Mars Firsters should get over this. They already lost to laws of physics already before start of whole debacle Moon vs Mars.

Conclusion: Musk will have to settle for retirement on Moon. He simply was born too early to die on Mars (not on impact, of course). Such is life.

Medar, this is an old, old argument. 

Of course travel to the moon is cheaper.  But for the reasons CW68 counted above (and more), a long duration stay on Mars is cheaper.

We will have tourists around the moon, and maybe even on the moon, before we'll have any person in Mars orbit.   But we will have a Mars colony a lot sooner.  As a matter of fact, I see a moon colony as about as difficult as a space colony.

Since this thread is about LEO/lunar tourism, we're all good though.

[RanulfC]

I agree that there are some advantages for tourism of the Moon versus Mars.  But I don't agree that "for the near-to-medium term, the Moon is no less habitable than Mars".  Mars is dry, but the Moon is drier, and that matters.  Mars has little atmosphere, but the Moon has far less, and that matters.  Methane can be produced fairly easily on Mars.  Try that on the Moon.  Mars also has more gravity.  We don't really know the long-term health effects of either Mars' or the Moon's gravity, but Mars gravity is closer to Earth's, so it may well be that Mars is significantly better for your health.  Mars has a day-night cycle similar to Earth's.  The Moon doesn't, and it is hard to bake in the direct sun for two weeks, then shiver through a two-week night.

All of these have big effects in the near and medium term, not just when we're ready to terraform.

"Terraforming" aside the fact that the Moon is so much closer to Earth is a big factor that kind of makes it stand out very much over Mars. Granting the various "differences" you've pointed out, I'll point out that travel time and round-trip time and energy tend to "trump" Mars as a destination if they are "compared" straight up against each other. Degrees of "difficulty" don't necessarily lead to actual "advantages" and "disadvantages" when compared directly AND all other factors are considered. In the end what a lot of folks who "favor" Mars over any other destination end up not realizing is that when comparing "advantages" and "disadvantges" among various locations are by their nature rather "subjective" to the ones doing the argument. Change a single "factor" and the "argument" tends to boil down to "because I say so" more than anything else

But as meekGee points out this is an old, old argument, one that "I" personally think is rather silly. We're not going to make the "final choice" here on these forums and really "I" don't see there being a "choice" other than we're either GOING to colonize space or we are NOT going to do so with no in-between or differention between "destinations" in space. All or nothing. It's a "no-brainer" not worth expending effort over.

Tourism, specifically "Cis-Lunar" tourism is something different and I'm of the opinion that EM specifically isn't interested in such an effort. The "main" question of the day is however would he be "willing" to sell D-V2 flights to LEO in order to facilitate such efforts? From a business point of view it would make little sense for him (and SpaceX) to NOT support such efforts, but I don't see (frankly I've never seen any "real" efforts) him actually offering such services himself or "selling" equipment to be used for such efforts.

By that I mean where as SpaceX would offer launch services for whomever was organizing such a business, I don't see them selling D-V2's or engines/tanks/etc to such a business. I'm thinking that outside offering the flights to and from LEO everthing else would not be within SpaceX's business model at the moment. (This would change if MCT were capable of being used for Lunar transport as well but it remains to be seen WHAT its capabilities are going to be )

Randy

[Lar]

The moon is closer from a travel time, and communication perspective but it's not that much closer from a deltaV perspective, as upthread analysis shows. 

[ChrisWilson68]

All of these have big effects in the near and medium term, not just when we're ready to terraform.

Cost is all that matters. I can bet large sum of money on this:
- 500k ticket to Moon will be achieved way, way earlier (possibly decades) than 500k ticket to Mars. Well, duh.
- Flying to Mars will always (read: in any sensibly predictable future) be many order of magnitude more costly than flying to Moon.
It is enough and Mars Firsters should get over this. They already lost to laws of physics already before start of whole debacle Moon vs Mars.

Conclusion: Musk will have to settle for retirement on Moon. He simply was born too early to die on Mars (not on impact, of course). Such is life.

If flying to Mars will always be "many orders of magnitude" more costly than flying to the Moon, why is it that unmanned orbiters and landers on Mars haven't been many orders of magnitude more costly than those going to the Moon?

Nobody is disputing that getting to Mars is harder.  The question is the trade-off between harder-to-reach Mars and harder-to-live on Moon.  There's no one answer to that question.  It depends on the goals and scale of the project.

[guckyfan]

Nobody is disputing that getting to Mars is harder. 

Actually I do, to some extent. Going to the moon and back is harder delta-v wise if there is fuel ISRU on Mars and not on Luna. And that too will be much easier on Mars. Of course there is always the longer flight time to Mars as an obstacle.

The question is the trade-off between harder-to-reach Mars and harder-to-live on Moon.  There's no one answer to that question.  It depends on the goals and scale of the project.

Agree. You can support a research station on the moon with lower cost transport but a larger size settlement or colony is much harder on  the moon due to the harsh conditions.