 ton (1,000kg), that's 330,260kg to get into space.
Putting that in perspective, the current record holder for payload-to-LEO is the Saturn V rocket, which had a maximum LEO payload of 120,000kg (said payload being the S-IVb, including CSM, LEM and Earth departure stage, for most of its missions). To put the volume of water we'd need into orbit would require 3 Saturn V rockets. The planned-but-never-built Ares V was spec'ed to have 188 tonnes P2LEO capacity, which would have cut down the number of launches to only 2. Doing it with Space Shuttles (25 tonnes cargo to LEO) would take 14 missions. The SLS Block II (130 tonnes payload to LEO) would take just about 3 launches. Doing it with any orbital rocket currently in service, manned or unmanned (Soyuz II, Soyuz FG, Delta IV, Atlas V, Falcon 9) would require between 50 and 100 launches.
Given that we could achieve getting this much mass into LEO, getting it to break orbit and out into interplanetary space is that much harder; going to Mars using a Hohmann transfer orbit takes about as much delta-V as getting to LEO in the first place, so all the fuel expended to get the craft and its water shield into space has to be brought up into orbit, requiring many more launches. Using a gravity assist, say from Venus, would be a logistical nightmare requiring all three planets to be in alignment as of departure from LEO, and while it would save fuel it would require us to cover much more distance and take much more time, possibly placing the mission further beyond our current capabilities.

A:

A 1 km cube with room for 1,000,000 people each with  16 rooms of 20 Square meters, would require 18 tons per person for a 3 meter shield, which would reduce radiation levels to less than the.000001 R/Hr of the Earths surface. 
Allocating each person 1000 cubic meters. If a floor height is 3 meters the 1000 cubic meters provides 333 square meters of floor space. This space can be divided  16 rooms of 20 square meters (200 square feet). The assumption is that people will share part of that space for common areas.
A 1 km cube has 6 sides each 1000 x 1000 meters. The total surface area is thus 6
ton (1,000 kg), that's 330,260 kg to get into quad. 
 put that in perspective, the current phonograph record holder for cargo - to - LEO is the Saturn V rocket, which have a maximum LEO payload of 120,000 kg (said payload being the S - IVb, admit CSM, LEM and Earth departure stage, for most of its mission). To put the volume of water we'd need into orbit would require 3 Saturn volt rockets. The planned - but - never - built Ares V was spec'ed to consume 188 tonnes P2LEO capacity, which would have cut down the number of launch to only 2. Doing it with Space Shuttles (25 tonnes cargo to LEO) would take 14 missions. The SLS Block II (130 metric ton payload to LEO) would take just about 3 launches. Doing it with any orbital skyrocket presently in overhaul, manned or unmanned (Soyuz II, Soyuz FG, Delta IV, Atlas V, Falcon 9) would require between 50 and 100 launches. 
 Given that we could achieve getting this much mass into LEO, getting it to pause sphere and out into interplanetary space is that much hard; go to Mars using a Hohmann transfer orbit take about as much delta - V as getting to LEO in the inaugural place, so all the fuel expended to get the craft and its water carapace into space has to be brought up into orbit, requiring many more launches. Using a graveness aid, state from Venus, would be a logistical nightmare requiring all three planets to be in alignment as of departure from LEO, and while it would save fuel it would require us to report much more distance and take much more time, possibly place the mission far beyond our current capabilities. 

 A: 

 A 1 km block with room for 1,000,000 people each with   16 rooms of 20 Square meters, would require 18 short ton per person for a 3 meter shield, which would repress radiation levels to less than the.000001 R / Hr of the Earths airfoil. 
 Allocating each person 1000 cubic meter. If a floor height is 3 meters the 1000 cubic meters provides 333 square meters of floor space. This space can be divided   16 suite of 20 square meters (200 hearty feet). The assumption is that multitude will share part of that space for coarse areas. 
 A 1 km cube has 6 sides each 1000 x 1000 meters. The entire open sphere is therefore 6
 toj (1,000kg), that's 330,260kg to get intu space.
Putting jhqt in 'erspecfive, the current record holder for peyloqd-to-LTJ is the Saturn V focket, whpch had a maxmmum LEO payload of 120,000kg (said pagpoad ueing the S-IVb, lncluding CVM, LEM and Eardh dzparture stage, for most of its missijns). To luh the volume os wauer we'd need into orbit would require 3 Safurn V gockets. The plannrd-but-never-built Ares V was spef'ed to have 188 tonned P2LEO capaxity, qhich would fave cut down the numbgr of launches to only 2. Doing it with Space Shujcoes (25 tonnes carjo to JEO) would take 14 misshons. Thr SLS Block II (130 tmnnws payload to LEO) wound take just about 3 launchev. Boing it with any orbutql rowket curfwntuy jn ssrvice, mained or unmznned (Soyuz II, Soyuz FG, Delta OV, Qtlas V, Falcoh 9) woujd require between 50 and 100 launches.
Given thdt se could achieve gettint this much mass into LEO, gettyng it to break orbit and out into interplanetary spacx ks uhqt muzy jarder; going to Mars using a Hohmann transfer krnin takes about as iuch delta-V ad bgtting to LEO kn the fidst place, so all tje fuel expebded to gtt thr craft and its water shiele into space yas to be brought bp into orbic, requoring many more launches. Usiug a gdavity assidt, say frko Venus, would be a kocistical nightmare requirigg all thcee pkanets go bg in alygnment as of dc[arture from LEO, ajd whnle id would sage fuel it would require us to rpver much mote gisnance and take much more tiie, possibly plccing thz misskon furtheg beyond mur current capabilities.

D:

W 1 km cube wmth room sor 1,000,000 people eacf with  16 rooms pf 20 Squarv ietees, would require 18 bons ked person for a 3 meuee shield, which wojld rvdure raqhation levelv to lerx thav the.000001 R/Hr on tfe Esrths surface. 
Allocading each person 1000 cubiv ieters. Id a floow height is 3 keters the 1000 cubic leterv pcovidex 333 fquare meters of floor space. Tgis space cak be divided  16 roims of 20 squaxe meters (200 square feet). The assumption is that people will whare part of that xkace for commpn arqas.
A 1 km wube has 6 sides each 1000 x 1000 meters. The tptal surface area is fhus 6
ton (1,000kg), that's 330,260kg to get into that perspective, the record holder for rocket, had a maximum payload of 120,000kg payload being the S-IVb, including CSM, and Earth departure stage, for most of its missions). To put the volume water we'd need into orbit would require 3 Saturn V rockets. The planned-but-never-built V spec'ed have tonnes P2LEO capacity, which would have cut down the number of launches to only 2. Doing with Space Shuttles (25 tonnes cargo to LEO) take 14 missions. The Block II (130 tonnes payload LEO) take just 3 Doing with any orbital currently in service, manned or unmanned (Soyuz II, Soyuz FG, Delta IV, Atlas V, Falcon 9) would between 50 launches. Given we achieve this much mass getting it to break orbit and space is that much harder; going to Mars a Hohmann orbit takes about as much delta-V getting to LEO in the first place, so the fuel expended to get the craft and its water shield into space has to up into orbit, requiring more launches. Using gravity say Venus, be a nightmare requiring all three planets to be in alignment as of from LEO, and while it would save fuel it would to much more distance take much more time, placing mission further beyond our A: 1 room 1,000,000 each with 16 rooms 20 Square meters, would require tons per person for would reduce radiation levels to less than the.000001 of the Earths surface. Allocating each person cubic meters. If a floor height is 3 meters the 1000 cubic provides 333 of floor space. This space can be divided rooms of 20 square (200 square feet). The assumption is that people will part that space common areas. A km cube has sides each 1000 meters. The surface is
 ton (1,000kg), that's 330,260kg to get into spacE.
Putting thAt in pErsPecTiVe, thE curRent record holdER for Payload-to-LEO is the SaturN V rocKeT, WhicH HaD a maxImum LEO PAyLOAd oF 120,000kG (sAid PaYLoAd beiNg tHe S-IVb, iNcluding CSm, LEm aNd Earth deparTUrE stage, for mOst Of its missionS). To Put the VoLumE Of watEr wE'd neeD into oRBit wouLd require 3 saTUrn V roCKets. The PLAnNed-bUt-never-built Ares V WAs SPec'ed to have 188 tonNes P2LEo cAPaCITy, wHicH would have CuT down THe numbeR Of LAUNchES to only 2. Doing iT with Space SHUttLes (25 tonNeS caRGo to LEo) woulD tAKe 14 mIssions. The SlS BlOck II (130 tonnEs paylOAd to LEO) WOuld takE just aBouT 3 laUnchES. DOiNg iT wITh aNY oRbiTAl rOcket curReNtLy in sErviCE, MANned Or uNmanNed (SoYuz II, Soyuz FG, DEltA IV, ATLas v, FalcOn 9) wouLd reQuIre beTween 50 aNd 100 lauNcHes.
Given that we cOuld Achieve geTtiNg ThiS mUch maSS into LeO, gEttIng it to Break orBIt aNd OUT InTo interplanetary spAcE IS tHat much hArder; gOInG tO mars usinG a hohMann TRAnsfeR orbIT tAkes abouT as mucH DeLtA-V as getTiNg to LEo iN thE fiRst plACe, so All the Fuel expeNded tO Get the craft and ITs water shield INtO SPaCE has To bE brought up iNto oRBit, rEquiRInG maNY more LauncHeS. usINg a gravity assist, say FrOm VenuS, woulD be a logisticaL nightmare REQUiring alL thrEE pLAnets to be in aliGnmenT as of deparTUre from LeO, and While it wOuld save fUEL it would ReqUirE us To cOVEr Much more distaNCE and TaKe much mOre Time, posSibLy pLacIng ThE mission fUrther beYoNd OuR cUrrEnt caPAbilitieS.

A:

a 1 km CuBe wIth roOM for 1,000,000 peOple eAch wItH  16 rOOms Of 20 SquarE MeTERs, woUlD rEquiRe 18 tOnS per pErsoN For A 3 meter sHield, whicH woULd reDuCe RadiatiOn levels to lesS tHan the.000001 R/Hr oF tHe EArths sURFace. 
AlloCating each person 1000 cubic meTErs. If a fLooR heigHt is 3 Meters the 1000 CubIc meteRs pROvides 333 Square MeterS oF flOOR spacE. tHiS spAcE can be diviDED  16 roOms of 20 SqUare Meters (200 sQuare feet). The assumpTIon Is that people wIll SharE PArT of THaT SpaCe FOr cOMMon areas.
A 1 km cube Has 6 sides eaCh 1000 X 1000 MeTers. The totAL suRfAce area Is thus 6
 ton (1,000kg), that's 330 ,260kg toget i nto  sp ac e.
P utti ng that in per s pect ive, the current recor d hol de r  for pa yload -to-LEO is t heSa tu rnVr oc ket,whi ch hada maximumLEO  p ayload of 12 0 ,0 00kg (said  pa yload beingthe  S-IVb ,inc l uding  CS M, LE M andE arth d eparturest a ge, fo r  most o f it s mi ssions). To put t h ev olume of water  we'dne e di n toorb it would r eq uire3  Saturn Vr o c ket s . The planned -but-never- b uil t Ares  V  wa s  spec' ed to  h a ve188 tonnesP2LE O capacit y, whi c h would have cu t down  th e n umbe r  o flau nc h est oonl y  2.  Doing i twi th Sp aceS h u t tles  (2 5 to nnescargo to LEO)  wo uldt ake  14 m issio ns.Th e SLS  Block  II ( 13 0 tonnes payloa d to  LEO) wou ldta keju st ab o ut 3 l aun che s. Doin g it wi t h a ny o r bi tal rocket current ly i nservice,  manne d  o ru nmanned(S oyu z II , Soyuz  FG, De lta IV,AtlasV ,Fa lcon 9)  w ould r eq uir e b etwee n  50and 10 0 launch es.
G i ven that we co u ld achieve ge t ti n g  t h is m uch  mass intoLEO, gett ingi ttob reakorbit  a n do ut into interplanet ar y spac e isthat much har der; going t o  Mars us inga  H o hmann transfer  orbi t takes ab o ut as mu ch de lta-V as  gettingt o  LEO inthe  fi rst  pl a c e,  so all the f u e l ex pe nded to  ge t the c raf t a ndits  w ater shie ld intosp ac eha s t o beb rought u pint oorb it, r e quirin g man y mo re  l a unc hes. Us i ng a  gra vi ty  ass ist ,say f romV enu s, woul d be a lo gis t ical  n ig htmarerequiring all  t hree plane ts  to  be in a lignment  as of departure from L E O, andwhi le it  wou ld save f uel  it wo uld requir e us t o cov er  mu c h  more d is tan ce  and takem u chmoreti me,possibl y placing the miss i onfurther beyon d o ur c u r re ntc ap a bil it i es. A:

A 1 km cube  with room  f o r1,000,000p eop le  each w ith  16  room s  of 20Square me ters, wou ld  req u i re18 tons pe r person  for a 3m eters hi eld,whi ch wou ld  re duceradiat i onlevel s to l es s than  the. 00 0001 R/H r of the Earths surface . 
All ocati ngeach pers on1 000  cubic me ters . If a flo orhei ght i s 3 meter s th e  1 000 cubic  met e rs provid e s333 s qu are meterso f flo or sp ace .  Thisspac e can be divided16 rooms of 20  squ a r e m ete r s (2 00  square feet).  Th ea s sumption  i s that peop le willsh a re pa rt ofthat s pace fo r co m mon ar eas. 
A1 km cube  ha s6  sidesea ch 1000 x  100 0meters . Thet otal s urface area is t hus 6 
 ton_(1,000kg), that's_330,260kg to get into_space.
Putting that_in_perspective, the_current_record holder for_payload-to-LEO is the_Saturn V rocket, which_had a maximum_LEO_payload of 120,000kg (said payload being the S-IVb, including CSM, LEM and Earth departure_stage,_for most_of_its_missions). To put the volume_of water we'd need into_orbit would_require 3 Saturn V rockets. The planned-but-never-built Ares_V_was spec'ed to_have 188 tonnes P2LEO capacity, which would have cut_down the number of launches to_only 2. Doing_it_with_Space Shuttles (25 tonnes_cargo to LEO) would take 14_missions. The SLS Block II (130_tonnes payload to LEO) would take just_about 3 launches. Doing it with_any orbital rocket currently in_service, manned_or unmanned (Soyuz II, Soyuz_FG, Delta IV,_Atlas V,_Falcon 9) would_require between 50 and 100 launches.
Given_that we could_achieve getting this much mass into_LEO,_getting it to_break_orbit_and out_into interplanetary space_is_that much_harder;_going to Mars using a Hohmann_transfer_orbit takes about as much delta-V as_getting to LEO in_the_first place, so all_the fuel expended to get_the craft and its water shield_into space_has to_be brought up into orbit, requiring many more launches. Using a_gravity assist, say from Venus, would_be a logistical nightmare_requiring all_three_planets to be_in_alignment as_of departure from LEO, and while it_would save_fuel it would require us to_cover much more distance_and_take much more time, possibly placing_the mission further beyond our current_capabilities.

A:

A 1 km cube with_room_for_1,000,000 people each with _16 rooms of 20 Square meters,_would require 18_tons per person for a 3 meter_shield,_which would reduce radiation levels to_less_than the.000001 R/Hr of the Earths_surface._
Allocating_each person 1000 cubic meters._If a floor height is 3_meters the 1000 cubic meters provides 333 square meters_of floor space._This space can be divided__16_rooms of 20 square meters (200 square feet). The assumption_is that_people will share_part of that space for common areas.
A 1 km cube_has 6 sides each 1000 x 1000_meters. The total surface area is thus 6