Author Topic: Minimal mass - Mars fly-by with current space hardware  (Read 4383 times)

Offline alexSA

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The most interesting threads normally surround discussions of missions using actual existing space hardware.

Using existing hardware, could a 450-day Mars flyby be carried out?

7mt Soyuz with modified crew capsule - crew of 2
5mt ISS-module based in-deep-space hab (structure only)
10mt (life support system, science racks, etc.)
12mt (supplies for a crew of 2 - water, food, other consumables, clothes etc. - 14kg per person per day)
6mt service module for in deep-space corrections (hypergolics)
-------------
40mt

5 times 22mt Briz-M stages
110mt
-----------
150mt total mass in LEO

Mission profile:
1. First Proton launches 21mt module (Deep-Space Module - DSM) with life support systems, some science racks installed
2. First Progress docks with DSM.
3. Second Progress launches, docks with DSM (other side).
4. First Soyuz mission, one Progress undocks, Soyuz docks, crew unloads first Progress cargo, undocks first Progress which is discarded, docks second Progress, unloads cargo and discards of second Progress. DSM now 27mt.
5. Procedure 2 to 4 again. DSM now 33mt.
6. Five additional Protons launch Briz-Ms (longer battery lives), which are docked to the DSM.
7. Soyuz launches with 2 crew and docks to other end of DSM.

Mission profile:
First Briz-M fires, provides 400 m/s (with margins) for stack. First Briz-M discarded. Total stack weighs 128mt.
Second Briz-M fires - provides 500m/s... discarded
Third Briz-M fires - provides 600m/s
Fourth Briz-M fires - provides 800m/s
Fifth Briz-M fires - provides 1200m/s
Course corrections along the 450 days in space. While near Mars, some remote sensing operations, maybe picking up a Mars sample return probe.

Only real problem with the hardware for this plan is having the Soyuz capsule doing re-entry with a lot higher speed than from LEO.
« Last Edit: 10/31/2009 05:04 pm by alexSA »

Offline Ben the Space Brit

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #1 on: 10/31/2009 07:05 pm »
Using existing hardware, could a 450-day Mars flyby be carried out?

Yes.  It wouldn't be easy or cheap.  Furthermore, it would be a lot of work for just ~36-48 hours usable science time in the Mars vicinity.  However, it could be done.

With regard to your proposed profile, using an ISS-style transhab module would be a bad idea.  The dense metal structure would create 'cascades' of dangerous particles when struck by high-energy galactic cosmic radiation.  Using composite 'inflatable' transhabs of the sort being developed (and flown in prototype form) by Bigelow would be better.  They are effecitvely transparent to GCR so the likelihood is any incident radiation would just fly right through.

As far as crew return vehicles go, Soyuz is pretty much the only game in town although, hopefully, Orion-Lite and Dragon will be around before very long.

So...

* Transhab;
* Consumables store/SM (ATV-derived) - Includes Hall Effect SEP engine group for course corrections;
* ESA Spacelab-derived node;
* EDS (I've heard suggestion that an ATK Castor-120 might be sufficient for a one-burn TOI);
* Soyuz crew vehicle;

Call that 2 EELV, 2 Ariane-5 and 5 Soyuz launches (the first four being two Soyuz with outfitting crews and two Progress launches carrying stores for outfitting the Transhab pre-mission).

Mission Profile
1. Transhab (BA-330) & node launched by EELV-heavy from KSC;
2. ATV/service module launched by Ariane-5 from Koyoru;
3. EOR of transhab and SM;
4. Outfitting crew and stores launched from Baikonour;
5. Rendezvous with node 'nadir' and 'zenith' ports.  Stores on Progress and some stores launched in node used for outfitting inflatable.  Outfitting crew then returns to Earth.  Progress remains to maintain orbital stability;
6. EDS launched by EELV from KSC
7. After rendezvous, EELV upper stage detaches from EDS and de-orbits
8. ATV launched by Ariane-5
9. ATV Rendezvous and docks at forward port; Progress undocking an de-orbit;
10. Outfitting Crew 2 launches from Baikonur; Docks at node zenith
11. Outfitting crew transfers stores from ATV to transhab;
12. Outfitting crew departs, ATV remains on station to maintain orbital stability;
13. Progress containing perishable stores launches from Baikonour;
14. Progress docks at node nadir; ATV undocking and de-orbit
15. Crew launch from Baikonour in modified Soyuz;
16. Crew vehicle docks with node forward port;
17. Stores transferred from progress to transhab and SM;
18. Progress undocking and de-orbit
19. After crew settles in and system check-out complete, vehicle performs TOI into free-return trajectory to Mars via Venus flyby;
20. Upon return to Earth vicinity, there are two possible return strategies using current tech:
(a) Use inflatable TPS ballute for aerocapture.  Followed by standard Soyuz return to Earth;
(b) Soyuz un-docks from crew module, performs 'skip' direct re-entry.

Further launches could be used to attach sensors or probes to the node side CBMs (similar technology as that used to install the Pirs docking module to the ISS).  Further modules could be attached if a second node is set in between the transhab and SM.

Another possibility: Instead of a second Progress and Soyuz, use an Excalibur Almaz as the crew launcher and launch some of the cargo with the crew.  Earth return would be using the Almaz's own crew return vehicle.  Excalibur Almaz seems confident that their CRV can handle a return from a lunar return orbit and the delta-v for an interplanetary flight isn't that much different.  That would replace two Soyuz launches with one Proton.
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Offline alexSA

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #2 on: 10/31/2009 07:41 pm »
We don't have the technology right now for using a cryogenic EDS on such a mission. We would need to use storable propellants and stages that exist already. That's why I was using 5 Briz-M in my example. They can stay on orbit for several month if they have access to a power source (which would be on the deep-space hab).

Anyways, using one ATV to replace 2 Progress is certainly a possibility in getting supplies up to the in-deep space hab. The mission profile could change this way.
« Last Edit: 10/31/2009 07:53 pm by alexSA »

Offline Jorge

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #3 on: 10/31/2009 07:44 pm »
Using existing hardware, could a 450-day Mars flyby be carried out?

Yes.  It wouldn't be easy or cheap.  Furthermore, it would be a lot of work for just ~36-48 hours usable science time in the Mars vicinity.  However, it could be done.

With regard to your proposed profile, using an ISS-style transhab module would be a bad idea.  The dense metal structure...

You are confused. "Transhab" by definition is inflatable, not metal.
JRF

Offline Archibald

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #4 on: 11/01/2009 08:45 am »
Zubrin Athena sounds good

http://www.astronautix.com/craft/athena.htm

EDIT: here's the link to the Athena paper itself (better than astronautix summary).
http://pdf.aiaa.org/getfile.cfm?urlX=85%26%5D0%3BU%2BDN%26S7R%20CMU%24CBQ%3A%2B64K8%26%5FOGJ%0A&urla=%25%2ARH%27%21P%2C%20%0A&urlb=%21%2A%20%20%20%0A&urlc=%21%2A0%20%20%0A&urle=%27%2B%22D%22%23PJCU0%20%20%0A


4*18 tons storable propellant stages, ISP 326 seconds
1* hab, 26 tons
Two men crew

I'm not sure Zubrin "double flyby" would work thus I would "uprate" that to Sun-Mars L1 halo orbit. Use two Jupiter 130 for fuel, plus a thrid for the hab / crew.
Something like 40 tons hab plus 2*45 tons chemical propulsions stages.
« Last Edit: 11/01/2009 08:49 am by Archibald »
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Offline alexSA

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #5 on: 11/01/2009 12:20 pm »
Zubrin Athena sounds good

http://www.astronautix.com/craft/athena.htm

EDIT: here's the link to the Athena paper itself (better than astronautix summary).
http://pdf.aiaa.org/getfile.cfm?urlX=85%26%5D0%3BU%2BDN%26S7R%20CMU%24CBQ%3A%2B64K8%26%5FOGJ%0A&urla=%25%2ARH%27%21P%2C%20%0A&urlb=%21%2A%20%20%20%0A&urlc=%21%2A0%20%20%0A&urle=%27%2B%22D%22%23PJCU0%20%20%0A


4*18 tons storable propellant stages, ISP 326 seconds
1* hab, 26 tons
Two men crew

I'm not sure Zubrin "double flyby" would work thus I would "uprate" that to Sun-Mars L1 halo orbit. Use two Jupiter 130 for fuel, plus a thrid for the hab / crew.
Something like 40 tons hab plus 2*45 tons chemical propulsions stages.

Some aspects of the Athena plan are very interesting - especially the trajectory used to "shadow" Mars for about one year with several months of really short response times (<20 seconds) to Mars rovers.

The real problems for a 900 day mission that Zubrin proposes are of course a. GCR exposure and b. zero-g exposure. Zubrin basically ignores GCR exposure and says 900 days in-deep-space only adds 1-2% to cancer risk, which is quite a generalized statement that really isn't true. As to zero-g, Zubrin's suggestions of 4 to 8rpm for artifical gravity are unworkable, the human body can't take that kind of spin due to vertigo experienced at such high spin rates.

Regarding using J-130, this vehicle is not available. What I liked about Zubrin's proposal is that he at least was trying to show that with currently available launch vehicles and hardware (despite his overly optimistic consumables estimates) we can do in-deep space exploration. We just need to have the will to do such precursor missions.

Going back to Zubrin's proposal, if the mass budget was taken at face value, the overall mission I outlined above would just be a lot less complicated.

For a RSA/ESA mission:

Hab structure: 4mt
Life support systems: 2mt
Consumables: 6mt (50% more than the per-day budget from Zubrin)
Electrical power: 1mt
RCS: 2mt (different trajectory requiring more course corrections)
Comm, computers, science equipment: 0.5mt
Interior:  0.5mt
Spares and Margin (20%): 3.2mt
-----------------------------------
Hab total: 19.2mt

Modified Soyuz: 6.5mt (orbital module discarded before docking)

Propulsion elements: 4 times modified Briz-M (with docking system): 23mt fueled (19.8mt dry)

Mission profile (4 Protons; 4 Soyuz; 1 Ariane 5):

A. 3 Soyuz launch (or 1 Ariane 5 and 1 Soyuz) the 2 small twin Mars rovers and the 1 small Venus surface vehicle into a slow trajectory towards the respective target planets.

1. Ariane 5 launches Hab module
2. Four Protons launch Briz-M propulsion stages
3. Soyuz launches with crew and docks (discards of orbital module before docking)
4. Briz-M fire in sequence
5. 450 day mission (thereof about 10-20 days in vicinity of Mars with a Venus flyby on the return trip to reduce re-entry speed)
6. Soyuz capsule (capsule protected by service module during mission) undocking from hab and re-entry.

Zero-G effects: extensive, but we know from Mir that 450 days in zero-g can be managed without suffering permanent health effects

GCR effect: 450 days is above NASA's and ESA's tolerance limit, but for a crew older than 45 life-time cancer risk does not increase very much - ESA and RSA could find the radiation exposure acceptable.

Storm shelter for SPEs required - located towards the hatch where the Soyuz is located - water tanks and supplies stored there to form a shelter with the Soyuz and the supplies and water providing one-sided protection if the vehicle is pointed towards the sun.

Costs:
4 Proton launches with 4 modified Briz-M as payloads: 400 million USD
1 Ariane 5-ES: 150 million USD
1 Soyuz launch with Soyuz spacecraft: 70 million USD
3 Soyuz launches for 2 rovers to Mars and 1 spacecraft to Venus: 150 million USD
2 Mars rovers (required operating time: 20 days): 200 million USD
1 Venus surface rover (required operating time: 3 days): 150 million USD
Soyuz spacecraft mods: 20 million USD
Hab module development based on Columbus/ATV/Node 2/3/MPLM: 600 million USD
Mission operations: 350 million USD
Contingency (20%): 420 million USD
----------------------------------------
Total: 2510 million USD

Offline Archibald

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #6 on: 11/01/2009 02:14 pm »
Quote
Some aspects of the Athena plan are very interesting - especially the trajectory used to "shadow" Mars for about one year with several months of really short response times (<20 seconds) to Mars rovers.

I've never been able to find such trajectory outside this paper. However here's my take on how Zubrin imagined it.

You have some asteroids that trail closely Mars, Earth or Jupiter orbit around the sun. They are on unstable orbits; for some years they are in the Sun sphere of influence, then a planet change their trajectory, and they follow it for decades, before being ejected back into solar orbit.
Remember this Apollo 12 S-IVB they found again some years ago ? Kind of unmanned "Athena" trailing Earth.
IMHO of course.

Quote
Regarding using J-130, this vehicle is not available. What I liked about Zubrin's proposal is that he at least was trying to show that with currently available launch vehicles and hardware (despite his overly optimistic consumables estimates) we can do in-deep space exploration. We just need to have the will to do such precursor missions.

Amen to that.
I think it was Zubrin objective writting the paper ;)
« Last Edit: 11/01/2009 02:16 pm by Archibald »
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Offline Danderman

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #7 on: 11/20/2009 05:57 am »
"6. Five additional Protons launch Briz-Ms (longer battery lives), which are docked to the DSM."

This part is magic.

How do the Briz-Ms connect to anything?

Offline Downix

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #8 on: 11/20/2009 01:58 pm »
"6. Five additional Protons launch Briz-Ms (longer battery lives), which are docked to the DSM."

This part is magic.

How do the Briz-Ms connect to anything?

Well, normally the Briz-M has something on top of them.  I assume they be modified.  I personally would not use the Briz-M for such a launch, unless they are sticking to pure russian equipment in which case it is the main game in town.
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Offline Danderman

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Re: Minimal mass - Mars fly-by with current space hardware
« Reply #9 on: 11/20/2009 02:32 pm »
"6. Five additional Protons launch Briz-Ms (longer battery lives), which are docked to the DSM."

This part is magic.

How do the Briz-Ms connect to anything?

Well, normally the Briz-M has something on top of them.  I assume they be modified.  I personally would not use the Briz-M for such a launch, unless they are sticking to pure russian equipment in which case it is the main game in town.

I was really too pithy, since some percent of the readers here understand what is "handwaving". Since most do not, I should explain further.

When someone trots out a new architecture or a new technical concept, they need to explain any parts therein that are not fully defined; in aerospace, discussing systems without explaining the stuff that is not yet designed in some detail is called "handwaving". For example, in my thread about lunar ice, there is a requirement for a machine that makes propellant out of ice; such a machine in this form does not exist yet, so I call it "magic", and if I did not do so, I would be "handwaving".

I started another thread, about returning the Pirs module in the Shuttle, and I was basically accused of handwaving the fact that Pirs does not contain a Shuttle keel pin or trunnions. In short, unless you can show that all of the elements of your concept or architecture are defined, you are handwaving, and the down side of handwaving is once of your elements is shown not to be workable, you are done. And, probably ignored after that, even if your next concept is truly great.

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