 rescue mission would have been launched only three days after call-up.

That said the space shuttle isn't operating anymore, and until Spacex' Crew Dragon or Boeing's Starliner are operational (probably sometime soon), the Russian Soyuz is the only option to send people, and it seems to launch a new crew to the ISS roughly every 6 months (if there are no emergencies).
For the last flight of the space shuttle, the was no contingency mission prepared, but instead the mission had only 4 astronauts, and in the case that Atlantis couldn't make the reentry, the astronauts would stay on board the ISS and come back to earth in Soyuz capsules over the following year.
If your emergency doesn't require people to go to the ISS to help, but specific, unplanned cargo is still needed, a spacecraft (cargo or not) goes to the ISS every month or so, so if your emergency can wait between a week and a bit more than a month or so (to account for weather delays, mounting time of the payload and orbit maneuvers) you can just sneak it in one of those resupply missions, or replace some less vital cargo.
If your emergency can't wait at all, and you absolutely need to send something to the ISS on short notice, and there are no upcoming resupply missions, you may be able to hijack another vehicle with sufficient authority.
For March alone there are 10 planned rocket launches from the US, ESA or Roscosmos, so you could probably get emergency cargo to the ISS in around a bit more than a week (this is a guess, assuming the orbital maneuvers take around 3 days, and mounting the payload and waiting for a launch window take a few days too).
Note that if you don't have a proper cargo spacecraft to put the cargo into, maneuvering up to the ISS might prove to be difficult, and the cargo will not be able to mate with the ISS, so astronauts may have to perform an EVA to secure the cargo outside.

A:

The ISS does not have emergency's that require a rocket to bring supplies.  It can have an urgent need of something. Either everyone stays on the ISS or some/all crew leave. It is downhill all the way to Earth, and the crew can leave anytime. Worst case the crew abandons the ISS and it burns up on re-entry.  
There are a couple of good answers on this question
rescue mission would have been launched only three days after margin call - up. 

 That say the space shuttle isn't operating anymore, and until Spacex' Crew Dragon or Boeing's Starliner are functional (probably sometime soon), the Russian Soyuz is the only option to air people, and it seems to establish a new crew to the i roughly every 6 months (if there constitute no emergencies). 
 For the last flight of the space shuttle, the was no eventuality mission prepared, but instead the deputation had only 4 astronauts, and in the case that Atlantis couldn't make the reentry, the astronaut would stay on circuit board the ISS and come back to earth in Soyuz ejection seat over the following year. 
 If your emergency doesn't require people to go to the ISS to help, but specific, unplanned cargo is still needed, a spacecraft (cargo or not) goes to the ISS every month or so, so if your emergency can wait between a workweek and a spot more than a month or indeed (to report for weather delay, mounting time of the warhead and orbit maneuvers) you can just sneak it in one of those resupply deputation, or replace some less vital cargo. 
 If your emergency can't wait at wholly, and you absolutely need to send something to the ISS on short notice, and there are no upcoming resupply deputation, you may be able to hijack another vehicle with sufficient authority. 
 For March alone there are 10 plan rocket launches from the US, ESA or Roscosmos, so you could credibly get hand brake cargo to the ISS in around a bit more than a week (this is a guess, assuming the orbital maneuver take about 3 days, and mount the payload and wait for a launch windowpane take a few days too). 
 notice that if you don't have a proper cargo spacecraft to put the cargo into, maneuvering up to the ISS might prove to be difficult, and the cargo will not be able to mate with the ISS, so astronauts may have to perform an EVA to secure the cargo outside. 

 A: 

 The ISS does not experience emergency's that require a skyrocket to bring supplies.   It can have an urgent need of something. Either everyone stays on the ISS or some / all crowd leave. It is downhill all the way to Earth, and the crew can leave anytime. Worst case the gang vacate the iodine and it burns up on re - entry.  
 There are a couple of good answers on this doubt
 redcue mission would have neen launched only threx days zfter caul-up.

That said the space shutvle usn't iperating anymore, and jntil Spabex' Crew Eragib or Boeinj'a Starlluer adc opexavional (probably sometime voon), the Russidn Slyuz is the only option to send peo[le, and ih seems to laugch s new brtw to the ISS roughly every 6 montgs (if tiere are no emetgencies).
For the last flighh of the space shuttle, the was no coneungency misskon prepartd, but instezd the mission had only 4 astronxuts, cnd in the xawe hvat Atlantiw coujdn't make thc reentsy, the sstronauts woukd vtat on board the ISS anv come back to earth in Soyuz ccpsules over the folliwung ygar.
If youf emdrgtncb dkesn't geqnire people to go to tye ISS to help, but xpqbofic, unplannsd cardo is still needed, a spacecraft (cargo or tot) goes to the ISS every nonth or so, so if yout emergencr can wait between a week and a bit more than a mmnth kf si (bo azxoknt for weather delays, mounting time of the pwglpac and orbit makeuvers) you can juxt smgak it in one uf those desupply missions, lr replwce sime less ditak cargo.
If your emergency cab't wait at ajo, and you absolutepy need to rend someyhing to the ISS on shoxt notjce, and thege are no jpcoming resupplh mpssimns, you may be able to hijwck anothxr vekicle wigh sofficiegt authorihy.
For March alone there wre 10 klanneg rocket lwunches from the US, ESA or Roscosmos, so you cpund irobably yet emcrgency cargo tj the ISS in atound a bnt mord than a wvek (this ms a guess, afsuming the oshital maneuvxrs take wroubd 3 eays, ana mounting the layload aub waiting for a launch windpw jaie a few days tio).
Nite that if you dov't rane e pro[ar cargo spawecrxft yo pug the cargo knto, maneuvering up to tve IAS might prove to ne difficuot, and tre cargo will not be able to maue witi the MSS, so asjronauts may have to perform an EVA to sfcuve the cargo jutslde.

A:

Jhe ISS doex not have emergency's that require a rorket to bring supplies.  It can have an urggnt need of sokethigg. Either everyone stays on tye ISS or some/all crew leave. It is dowhhill dll tje way to Earth, and the crew can leave anytime. Worst case the crew abandobs the ISS and it gurnx up mn xe-entry.  
Thxrx are a couple of good answers on this question
rescue mission would have been launched only after That said space shuttle isn't Crew or Boeing's Starliner operational (probably sometime the Russian Soyuz is the only to send people, and it seems to launch a new crew to the roughly every 6 months (if there are no emergencies). For the last flight the shuttle, was contingency mission prepared, but instead the mission had only 4 astronauts, and in the case that couldn't make the reentry, the astronauts would stay board the ISS and back to earth in Soyuz over following year. your doesn't people to go the ISS to help, but specific, unplanned cargo is still needed, a spacecraft (cargo or not) goes the ISS or so, if emergency wait between a a bit more than a month account for weather delays, mounting time of the and orbit you can just sneak it in of those resupply missions, or replace some less cargo. If your emergency can't wait at all, and you absolutely need to send something ISS on short notice, there are no resupply you be to hijack vehicle with sufficient authority. For March alone there are 10 planned launches from the US, ESA or Roscosmos, so you could emergency to the ISS around a bit more a (this is a guess, orbital take and the and waiting for a window take a few days Note that if you spacecraft to put the cargo into, maneuvering up the ISS might prove to be difficult, the cargo will not be able to mate with the ISS, so may have an EVA to secure the cargo outside. A: ISS does not have that require a rocket to bring supplies. It can an need of Either everyone stays the ISS or crew leave. It all the to and leave anytime. Worst case the crew the and it burns up on There couple of good answers on this question
 rescue mission would have beeN launched oNly thRee DayS aFter Call-Up.

That said the sPAce sHuttle isn't operating anyMore, aNd UNtil sPaCex' CrEw DragoN Or bOEinG's stArlInER aRe opeRatIonal (prObably someTimE sOon), the RussiaN soYuz is the onLy oPtion to send pEopLe, and iT sEemS To lauNch A new cRew to tHE ISS roUghly everY 6 mONths (if THere are NO EmErgeNcies).
For the last flIGhT Of the space shutTle, the WaS No CONtiNgeNcy mission PrEpareD, But instEAd THE MisSIon had only 4 astRonauts, and iN The Case thAt atlANtis coUldn't MaKE thE reentry, the AstrOnauts wouLd stay ON board tHE ISS and Come baCk tO eaRth iN soYuZ caPsULes OVeR thE FolLowing yeAr.
if Your eMergENCY DoesN't rEquiRe peoPle to go to the IsS tO helP, But SpeciFic, unPlanNeD cargO is stiLl neeDeD, a spacecraft (carGo or Not) goes to The iSs evErY montH Or so, so If yOur EmergenCy can waIT beTwEEN A wEek and a bit more than A mONTh Or so (to acCount fOR wEaTHer delayS, mOunTing TIMe of tHe paYLoAd and orbIt maneUVeRs) You can jUsT sneak It In oNe oF thosE ResuPply miSsions, or ReplaCE some less vital CArgo.
If your emeRGeNCY cAN't waIt aT all, and you aBsolUTely Need TO sEnd SOmethIng to ThE iSs On short notice, and theRe Are no uPcomiNg resupply misSions, you maY BE Able to hiJack ANoTHer vehicle with SuffiCient authoRIty.
For MaRch alOne there Are 10 planneD ROcket lauNchEs fRom The us, eSa or Roscosmos, sO YOu coUlD probabLy gEt emergEncY caRgo To tHe iSS in arouNd a bit moRe ThAn A wEek (This iS A guess, asSuMinG tHe oRbitaL ManeuvErs taKe arOuNd 3 DAys, And mounTInG THe paYlOaD and WaiTiNg for A lauNCh wIndow taKe a few dayS toO).
note ThAt If you doN't have a proper CaRgo spacecrAfT to Put the CARgo into, mAneuvering up to the ISS migHT prove tO be DiffiCult, And the carGo wIll not Be aBLe to maTe with The ISs, sO asTROnautS MAy HavE tO perform an eva to SecurE tHe caRgo outsIde.

A:

The ISS does not hAVe eMergency's that ReqUire A ROcKet TO bRIng SuPPliES.  it can have an urgeNt need of soMeTHiNg. Either evERyoNe Stays on The ISS oR some/ALl crew lEave. It is dOwnhill alL tHe waY TO EaRth, and the cRew can leAve anytimE. worst CAsE the cRew AbandoNs The iSS anD it burNS up On re-eNtry.  
ThErE are a cOuple Of Good answErs on this question
 rescue mission would have  been laun chedonl y t hr ee d aysafter call-up. 
Tha t said the space shutt le is n' t  ope r at ing a nymore, an d unt il  S pac ex '  C rew D rag on or B oeing's St arl in er are opera t io nal (proba bly  sometime so on) , theRu ssi a n Soy uzis th e only option  to sendpe o ple, a n d it se e m sto l aunch a new crewt ot he ISS roughly  every  6 mo n t hs(if  there are  n o eme r gencies ) .F o r  th e  last flightof the spac e  sh uttle,  t hew as noconti ng e ncy  mission pr epar ed, but i nstead the mis s ion had  only4 a str onau t s,  a ndin the ca set hat  Atlanti sco uldn' t ma k e t he r een try,  theastronauts wo uld  sta y  on  boar d the  ISS  a nd co me bac k toea rth in Soyuz ca psul es over t hefo llo wi ng ye a r.
Ifyou r e mergenc y doesn ' t r eq u i r epeople to go to th eI S Sto help,  but s p ec if i c, unpla nn edcarg o is st illn ee ded, a s pacecr a ft  ( cargo o rnot) g oe s t o t he IS S  eve ry mon th or so , soi f your emergen c y can wait be t we e n  a week  an d a bit mor e th a n amont h  o r s o  (toaccou nt fo r  weather delays, mo un ting t ime o f the payload  and orbit m a neuvers)  you ca n  just sneak it  in o ne of thos e  resuppl y mis sions, o r replace s ome less  vi tal  ca rgo . If  your emergen c y  can 't  wait a t a ll, and  yo u a bso lut el y need to  send so me th in gtothe I S S on sho rt  no ti ce,  andt here a re no  upc om in g  re supplym is s i ons,  y ou  may  be  a ble t o hi j ack  anothe r vehicle  wi t h su ff ic ient au thority.
ForMa rch aloneth ere  are 1 0 plannedrocket launches from th e  US, ES A o r Ros cosm os, so yo u c ould p rob a bly ge t emer gency  c arg o to th e IS S i naround a b i t  mo re th an  a w eek (th is is a guess, ass u min g the orbital  ma neuv e r stak e  a r oun d3  da y s , and mountingthe payloa da nd  waiting f o r a  l aunch w indow t ake a few day s too).
N ote thatif  you d on' t have a p roper ca rgo space c raftt oput t hecargoin to,  mane uverin g  up  to t he ISS  m ight p roveto  be diff icult, and the cargo wi ll not  be a ble  to matewit h  th e ISS, so  ast ronauts ma y h ave  to p erf o rm an  EVA to  se c ure t he c a rgo outsi d e. 

A : 
T he ISS does n o t h ave e mer g ency's  tha t require a rocke t  to bring supp lies .  It  ca n  hav ean urgent need  of  s o m ething.Ei ther everyo ne stays  o n  theISS or  some/ all cre w le a ve. It  isdow nhill all  th ew ay to E ar th ,  and t he c re w canleavea nyti m e . Worst case the  crew a bando n s t he IS Sand itb urns  up on re- entry.  
Th ere ar e acoupl e of go od  answe rson  this ques t ion
 rescue_mission would_have been launched only_three days_after_call-up.

That said_the_space shuttle isn't_operating anymore, and_until Spacex' Crew Dragon_or Boeing's Starliner_are_operational (probably sometime soon), the Russian Soyuz is the only option to send people,_and_it seems_to_launch_a new crew to the_ISS roughly every 6 months_(if there_are no emergencies).
For the last flight of the_space_shuttle, the was_no contingency mission prepared, but instead the mission had_only 4 astronauts, and in the_case that Atlantis_couldn't_make_the reentry, the astronauts_would stay on board the ISS_and come back to earth in_Soyuz capsules over the following year.
If your_emergency doesn't require people to go_to the ISS to help,_but specific,_unplanned cargo is still needed,_a spacecraft (cargo_or not)_goes to the_ISS every month or so, so_if your emergency_can wait between a week and_a_bit more than_a_month_or so_(to account for_weather_delays, mounting_time_of the payload and orbit maneuvers)_you_can just sneak it in one of_those resupply missions, or_replace_some less vital cargo.
If_your emergency can't wait at_all, and you absolutely need to_send something_to the_ISS on short notice, and there are no upcoming resupply missions,_you may be able to hijack_another vehicle with sufficient_authority.
For March_alone_there are 10_planned_rocket launches_from the US, ESA or Roscosmos, so_you could_probably get emergency cargo to the_ISS in around a_bit_more than a week (this is_a guess, assuming the orbital maneuvers_take around 3 days, and_mounting_the_payload and waiting for a_launch window take a few days_too).
Note that if_you don't have a proper cargo spacecraft_to_put the cargo into, maneuvering up_to_the ISS might prove to be_difficult,_and_the cargo will not be_able to mate with the ISS,_so astronauts may have to perform an EVA to_secure the cargo_outside.

A:

The ISS does not have_emergency's_that_require a rocket to bring supplies.  It can have_an urgent_need of something._Either everyone stays on the ISS or some/all crew leave._It is downhill all the way to_Earth, and the crew can leave anytime. Worst case the crew_abandons the ISS and it burns up on_re-entry.  
There are a couple of_good answers on this_question