Apollo 8, redux

Terraformer · 2017-01-07 05:47:31

SpaceNut wrote:

Not sure that Elon Musk at Trump Tower would mean that he would want to be the head of Nasa thou.....

I don't think that's on the cards.

I'm hoping that they were discussing marking the 50th anniversary of Apollo 11 with at a minimum a Lunar flyby, Apollo 8 redux. If Dragonrider and Falcon Heavy get flying soon,,then maybe it would be possible? The Dragon heatshield is designed to withstand a direct entry from a Lunar mission, and the capsule has more pressurised space than the Apollo Command/Service Module. Could it be done with two launches, one for the crew in the Dragon Capsule (hmmm, can we make them water bags for sleeping in and too protects against solar flares, using the mass freed up by cutting 4 passengers?), and a propulsion unit launched on a Falcon Heavy?

SpaceNut · 2017-01-07 09:32:03

From what I have been reading the EDS stage is not enough to get a dragon there and back so that is still an item needed even with a Red Dragon docked to a cargo dragon for a full up 6 man mission. So a modified cargo needs to be created with the correct EDS stage for such a mission.

GW Johnson · 2017-01-07 10:25:35

According to Spacex's web site Falcon-Heavy can send 13.6 metric tons to Mars. The payload sendable to the moon should be about the same number plus a tad, but far short of the 22 tons sendable to GTO. My best guess is that a Dragon v.2 maxes out fully loaded just under 13 tons, the payload to GEO of the Falcon-9 said to be capable of sending it there.

What that means, is that Falcon-Heavy/Dragon v.2 is capable of a lunar swing-by, but not entry into lunar orbit. For entry and exit into lunar orbit, you need delta-vee capability about twice the difference between lunar escape (near 2.4 km/s) and lunar orbit speed (near 1.7 km/s). So you need twice 0.7 for about 1.4 km/s sec capability.

My numbers are faked-up best guesses, but with 2 tons on board out of the rated 6, and with no trunk to act as dead inert weight, the Super Dracos have about 0.85 km/s delta-vee available. I actually was estimating Red Dragon, but the numbers are fuzzier than the differences between them. With a reduced crew and no trunk, it can enter lunar orbit, but it is stranded there. One-way trip.

Net result: lunar swing-by is possible with Falcon-Heavy/Dragon v.2, but entering lunar orbit is not unless more delta-vee (to the tune of 1.4 km/s) can be supplied separately. The Falcon second stage is restartable in space, but not configured for on-orbit refuelling, so sending up more propellants in a Falcon-9 or -Heavy wouldn't work. It would take more than a year or so to modify the stage for this refuelling and man-rate it. And a proper set of tanks to fit the payload shroud has to be designed from scratch.

You would need another small stage "ready to use" from somewhere to be sent up on a second launch. The Dragon v.2 would have to dock with it. But the acceleration under thrust would be 180-degrees out the wrong direction for the seats in the Dragon.

The only possibility might be to modify the Dragon v.2 slightly so that it could draw the added propellant directly from the extra tanks in the trunk, with a disconnection either automatic or by astronaut intervention, at the time the trunk is shed, before entry upon return. My numbers are just too fuzzy to evaluate whether a reduced crew and 2-3 tons of NTO-MMH in the trunk added to the 1.8 tons in the Dragon v.2 could get you up past the 1.4 km/s delta-vee required.

Not sure where the extra life support supplies would be stored. It's a 6 day mission, min. Dragon was not really intended for that.

But it does sound barely doable, if such a stunt is deemed desirable.

GW

Terraformer · 2017-01-07 12:14:15

But you think a Lunar flyby might be possible?

I would love it if they did a flyby next year, just as a demonstration that America can still do it (well, lost the capability and recently regained it). Moving on later to an orbital mission, though I doubt we'd be able to see a landing to mark the 50th anniversary.

How much mass are we looking at for a solar storm shelter? I was only half joking with the water suit idea.

SpaceNut · 2017-01-07 13:50:10

I think this image from Nasawatch says it best...

admin.wheel.2.jpg

Any how do we turn a Dragon of any version into the Apollo LM scaled to what we know...

While I would like a 3 man mission that would do the flyby and lunar landings..maybe we can do it with 2 as we would not want an extra man just circling the moon while the others get to be on its surface.....

The dragon might barely be possible if the life support does not run out.....Strip the crew size back to 3 and remove the seats in exchange for more oxygen and it may just do it.

Can we also look at if we used a dragons engine as a 1st stage LM with a new landing stage under it is that possible on a falcon heavy....

GW Johnson · 2017-01-09 15:48:10

My best guess is that you could do a swing-by mission with a Falcon-Heavy and a Dragon v.2 and 2-3 crew. No orbit. Not quite Apollo 8.

My other best guess is that if you could modify the Dragon to accept extra Super Draco propellant from extra storage in its trunk, you might possibly have the delta-vee to get into and out of lunar orbit with a crew of 1. But I could not confirm that, because I do not have reliable weight statements for the Dragon v.2. It would be questionable whether the propellant feed modifications could be done and verified reliable in only a year; Spacex has an awful lot on its plate besides an Apollo reprise stunt.

As for two shots of Falcon Heavy to add a modified Centaur stage and a lander to the cluster, well, it should be feasible to do that eventually, but certainly not in a years' time. Both the modified Centaur and the lander have to be proven reliable, and the lander starts essentially from scratch.

Space is hard. Being overly optimistic in your schedule expectations kills crews.

GW

Last edited by GW Johnson (2017-01-09 15:49:31)

Terraformer · 2017-01-09 17:15:10

Eh, I'd settle for marking the anniversary with a flyby. At least it would be a deep space mission, which hasn't been done for quite a while. The main reason would be a demonstration that America can still do it, though it would awkwardly draw attention to the fact that that's all that America can do...

RobertDyck · 2017-01-09 17:38:36

My understanding is Dragon v2 on Falcon Heavy could do a lunar fly-by with 4 crew. As GW said, no service module means no delta-V to enter/depart lunar orbit. However, Falcon Heavy definitely has the lift capacity to do it. The issue is Dragon. I was thinking of a service module, GW is thinking of propellant feed. Either would work.

elderflower · 2017-01-09 18:29:06

What's the point, guys?

SpaceNut · 2017-01-09 19:19:36

Well I would say that Nasa can not do it as well even frankenstiening a monster for launch as well using Orion.
Not sure if the larger Atlas V would place a Dragon on the path any better but its still a goal and one that should be repeated on the aniversary dates which are slowly marching on....

Dragon – Cargo Version

Length 2.9m
Diameter 3.6m
Sidewall Angels 15 Degrees
Pressurized Volume 10m³
Unpressurized Volume 14m³
Trunk Extension 34m³
Sensor Bay 0.1m³
Mass 4,200kg
Launch Paylaod 6,000kg
Return Payload 3,000kg
Endurance Up to 2 Years
Maximum Crew 7
Avionics Full Redundancy
Reaction Control 18 Draco Thrusters
Propellant Hydrazine/Nitrogen Tetroxide
Propellant Mass 1,290kg
Docking Mechanism LIDS or APAS
Power Supply 2 Solar Arrays – 1,500-2,000W
Power Buses 28V&120V DC
Batteries 4 Li-Polymer Batteries
Cabin Pressure 13.9-14.9psi
The arrays provide 1,500 to 2,000 Watts of power peaking up to 4,000 Watts. Two Power Buses are part of Dragon’s electrical system, providing 120 VDV and 28 VDC respectively. 4 redundant Lithium-Polymer Batteries provide power during orbital night, ascent and re-entry.

Oldfart1939 · 2017-01-09 20:04:18

Dragon 2 would require some additional life support facilities/equipment. More onboard oxygen, water, food and some additional thermal insulation. The service module could carry all this and do a separation/180 reorientation/re-dock on the way and the ISS access hatch could allow utilization of that space for equipment/supplies, etc. The service module would also require pressurization.
This little jaunt around the moon could provide some excellent learning experience for SpaceX.

Atlas V doesn't have the ability to do this. Only Falcon Heavy.

Last edited by Oldfart1939 (2017-01-09 20:05:37)

Terraformer · 2017-01-10 05:19:00

It would certainly give SpaceX a lot of credibility. Since they'd be the only US company capable of actually doing such a thing.

Though, it would need some sort of solar storm shelter ('There is nothing more expensive than a dead crew').. Can the life support be arranged to produce one? Or would we need to load up an additional tonne of water (that would be enough for a 1.8 m side cube with 10cm walls of water, which I think is enough?)?

RobertDyck · 2017-01-10 08:51:04

elderflower wrote:

What's the point, guys?

The next flight of Orion will be an unmanned lunar flyby, launched on SLS block 1. Do it first, do it better, show up Lockheed-Martin. One New Mars member already recommended the first launch of Falcon Heavy do this unmanned. After all, the first launch of Falcon 9 carried Dragon v1.

The Orion service module has enough propellant to depart lunar orbit, but not to enter lunar orbit. So it will require SLS block 1B to enter lunar orbit. Exploration Mission 2 (EM-2) will be the first launch with crew. If Dragon v2 were modified to have a service module instead of a trunk, with enough propellant to depart lunar orbit, then the upper stage of Falcon Heavy could do the same job as the Exploration Upper Stage of SLS block 1B. SpaceX documents claim it is capable of multiple restarts. Again, do it better, do it first.

Last edited by RobertDyck (2017-01-12 23:05:42)

Oldfart1939 · 2017-01-10 10:39:00

Lockheed-Martin and NASA have both become mired in their own inertial wells. There is really nothing motivating them anymore--just long term employment and of course...money. My WAG is SpaceX could do this for less than$200MM. The stated price of a Falcon Heavy launch (per SpaceX website) is $95MM.

GW Johnson · 2017-01-10 13:07:58

Well, using the first flight test of Falcon-Heavy to fling a Dragon on a lunar swing-by might be a good stunt to pull off, but at the risk of embarrassing NASA (and indirectly USAF), who are supposed to become among Spacex's biggest, most lucrative customers. Especially if they do it manned, which I would not recommend.

That means it could be a cargo Dragon v.1. Or a Dragon v.2, but unmanned, billed as some sort of flight test. That might done to (1) accomplish something useful anyway from a flight test standpoint, (2) upstage the unmanned Orion flight around the moon, and (3) celebrate in some way the early Apollo stuff. If they actually fly Falcon-Heavy this year, that sort of thing could be done on this flight.

Besides, I bet there's something in the NASA contract for the manned Dragon program that prevents any early manned flight tests of Dragon v.2, except those specifically on the program, and only at NASA's schedule. NASA knew that Spacex could be ready to fly long before the big boys.

The history of it is that Spacex does what they say they will do, but the promised schedules are about 50% too optimistic. Falcon-Heavy was originally supposed to fly about 3 years ago.

GW

Last edited by GW Johnson (2017-01-10 13:09:19)

Oldfart1939 · 2017-01-10 17:00:07

GW-

Just guessing here, but my bet is Musk will attempt doing something spectacular. It certainly won't be a manned Dragon 2 around the Moon, but something representing a major step forward. Also, it's ABOUT TIME someone embarrassed NASA; that agency has become hyper stodgy. Ditto the 2 major contractors whom I'll allow to remain nameless.

Terraformer · 2017-01-10 17:26:05

Perhaps his discussion with the President-elect had something to do with whatever he's planning, if he's planning something? Some kind of guarantee, maybe, a deal to ensure that NASA won't seek revenge for being upstaged...

(Speaking of which, who's going to be the new admin at NASA?)

GW Johnson · 2017-01-12 12:54:40

Spacenut:

Do you have any idea what is actually in that "mass 4200 kg" figure in your post quote just above? What's included, and does it apply to capsule-only or to capsule-plus-trunk? That sort of thing.

GW

Last edited by GW Johnson (2017-01-12 12:55:49)

RobertDyck · 2017-01-15 23:21:09

That's interesting. Similar to a design I proposed: Moon mission today - Dragon & Mars hab
My idea was based on the old Soviet LK architecture. Use a separate stage for LOI and de-orbit, then the lander is single stage. Also use LCH4/LOX. They call the separate stage an SLS 3rd stage, and looks like LH2/LOX. They claim this 3rd stage is based on tooling for Ares I upper stage. However, my idea was to make the lander minimal, rely upon a Mars Direct hab for surface habitation. This proposal would make the lander as heavy as the Apollo LM. A lot better than Altair, but still big considering it relies upon a separate stage for de-orbit. And they want another station in Earth-Moon L1, based on ISS components. A reusable lunar lander does make sense, but why does it need a space station? Why not just park it in lunar orbit?

Their graphic shows a single spherical tank coloured yellow, presumably LCH4, surrounded by several cylindrical tanks coloured green, presumably LOX. But above that are several grey spheres, then above the spheres is the cabin. Around the lower part of the cabin are 4 yellow tanks, and a couple smaller grey spheres. Presumably the tanks around the cabin are oxygen for breathing. So what are the grey spheres? They certainly take a lot of room, make the lander very tall compared to the Apollo LM.

kbd512 · 2017-01-16 00:00:54

Why can't we just send the astronauts back to the orbiting capsule using the man-on-roman-candle method (LESS)?

Why must we glorify man-on-roman-candle with a giant pressure vessel just to send the astronauts back to orbit?

If the rocket fuel leaks... you're dead.
If the rocket doesn't ignite... you're dead.
If you fail to attain orbit or if the guidance system fails and you're inserted into the wrong orbit... you're dead.
If you can't rendezvous with the orbiting capsule... you're dead.

Does anyone else see a pattern there?

We don't need a massive ascent stage just to deliver two astronauts to LLO from the surface of the moon. The simpler, smaller, and lighter, the better, easier, and more achievable the goal of returning humans to the moon and then on to Mars.

Use Falcon Heavy to deliver the capsule and Atlas V to deliver a Cygnus surface stay module. The astronauts LOR with Cygnus, descend to the surface in Cygnus (landing thrusters and tanks on top, ADEPT style landing gear on the bottom), perform surface activities, and then use LESS or something similar to it to ascend to orbit, rendezvous with the capsule in LLO, and then come back to Earth... That's remarkably similar to the real Apollo missions, except the astronauts stay in their suits for ascent.

SpaceNut · 2017-01-16 21:12:29

Risk aversion for landing or ascending to orbit with regards to engines or fuel type is the same as Apollo and we can not change that the moon has no possibility for survival if you crash and can not make it back to redevous orbit.

Making a lunar ascent vehicle capable of abort would increase launch mass as well as the same for the descent as well. The lunar landing is full retropropulsion no adept possible as there is no atmosphere.

Cynus converted for a lunar lander is interesting from the stand point of its a COTS item made by Thales Alenia Space the same maunfacturer of the ISS modules. This would make the module very much adaptable for use.
I think this is version 1
https://www.orbitalatk.com/space-system … Cygnus.pdf
http://spaceflight101.com/spacecraft/cygnus/

Quite adaptable for launch vehicles as well.
https://en.wikipedia.org/wiki/Cygnus_(spacecraft)

GW Johnson · 2017-01-20 13:55:02

I have found a quote for unladen dry weight of 4200 kg for Dragon 1, and 6400 kg for Dragon 2. But, it was completely unspecified as to how much of these figures is capsule and how much is trunk. And there is an extended trunk for Dragon 1 available as an option. Anybody have any better figures?

I rather doubt the heat shield on Dragon is 2000-3000 kg. You're talking about something maybe 3-4 inches thick, and the density of PICA or PICA-X is just not all that high. It's under a cubic meter of material, with a specific gravity less than water. Gotta be under 1000 kg for the entire layer of PICA. Maybe well under.

But, I don't have the real numbers.

GW

Last edited by GW Johnson (2017-01-20 13:56:12)

SpaceNut · 2017-01-20 18:51:57

Pica and Pica x found more accurate information for the mass of the heat shield material.

Comparing Heat Shields: Mars Science Lab vs. SpaceX Dragon

SpaceX, PICA-X is made in-house and at a fraction of the cost of NASA’s PICA. Produced in large pieces and then cut into tiles about the size of a cafeteria tray they are placed, in a similar fashion to the MLS shield, on to a carbon-composite mold. The tiles are about 3 in (8 cm) thick, and weigh about 2 lbs (1 kg).

http://spaceflight101.com/spacerockets/falcon-9-ft

http://spaceflightnow.com/falcon9/009/dragon.html

Payload capability. Dragon carries cargo in a pressurized capsule and an unpressurized trunk. It can carry 6,000 kilograms (13,228 pounds), split between pressurized cargo inside the capsule and unpressurized cargo in the trunk, which also houses Dragon's solar panels.
Dimensions. Dragon is 4.4 meters (14.4 feet) tall and 3.66 meters (12 feet) in diameter. The trunk is 2.8 meters (9.2 feet) tall and 3.66 meters (12 feet) wide. With solar panels fully extended, the vehicle measures 16.5 meters (54 feet) wide.

The dragon with truck and payload can only be 12,000 kg max wet....

SpaceNut · 2017-01-21 23:09:37

I found this page that does rocket launch equations
http://silverbirdastronautics.com/LVperform.html
It allows for several rockets which are in current manufacturing use and for payload calculations....

SpaceNut · 2017-01-23 10:38:46

https://en.wikipedia.org/wiki/Falcon_9_v1.1

https://en.wikipedia.org/wiki/Falcon_9_Full_Thrust
https://web.archive.org/web/20131129020 … om/falcon9

https://en.wikipedia.org/wiki/SpaceX_Dragon
Dry mass 4,200 kg (9,300 lb)
Payload to ISS 3,310 kg (7,300 lb),

https://en.wikipedia.org/wiki/Dragon_2
Dry mass 6,400 kg (14,000 lb)
Payload to ISS 3,310 kg (7,300 lb).

https://web.archive.org/web/20110518075 … asheet.pdf

https://web.archive.org/web/20120320032 … V7_All.pdf

I have been reviewing the payload links for payload shroud use to a capsule and here is the first and second (v1.1&V1.2 or full) Payload to LEO 13,150kg or 28,991 lb being the same. The payload is the max that the first and second stage can loft to LEO.

The cargo truck payloads are the same as above which says the capsules are the dry mass numbers and the truck is about 1,000 kg less.....

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#1 2017-01-07 05:47:31

Apollo 8, redux

#2 2017-01-07 09:32:03

Re: Apollo 8, redux

#3 2017-01-07 10:25:35

Re: Apollo 8, redux

#4 2017-01-07 12:14:15

Re: Apollo 8, redux

#5 2017-01-07 13:50:10

Re: Apollo 8, redux

#6 2017-01-09 15:48:10

Re: Apollo 8, redux

#7 2017-01-09 17:15:10

Re: Apollo 8, redux

#8 2017-01-09 17:38:36

Re: Apollo 8, redux

#9 2017-01-09 18:29:06

Re: Apollo 8, redux

#10 2017-01-09 19:19:36

Re: Apollo 8, redux

#11 2017-01-09 20:04:18

Re: Apollo 8, redux

#12 2017-01-10 05:19:00

Re: Apollo 8, redux

#13 2017-01-10 08:51:04

Re: Apollo 8, redux

#14 2017-01-10 10:39:00

Re: Apollo 8, redux

#15 2017-01-10 13:07:58

Re: Apollo 8, redux

#16 2017-01-10 17:00:07

Re: Apollo 8, redux

#17 2017-01-10 17:26:05

Re: Apollo 8, redux

#18 2017-01-12 12:54:40

Re: Apollo 8, redux

#19 2017-01-15 23:21:09

Re: Apollo 8, redux

#20 2017-01-16 00:00:54

Re: Apollo 8, redux

#21 2017-01-16 21:12:29

Re: Apollo 8, redux

#22 2017-01-20 13:55:02

Re: Apollo 8, redux

#23 2017-01-20 18:51:57

Re: Apollo 8, redux

#24 2017-01-21 23:09:37

Re: Apollo 8, redux

#25 2017-01-23 10:38:46

Re: Apollo 8, redux

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