First of all, unless you're an absolute moron, we certainly do not actually require ISS placed on station at VL2, not even of any other satellite if we bothered to put two and two together. It would however greatly extend our interplanetary window of opportunity from a few months out of every Earth/Venus orbit encounter to perhaps 16 months by having a communications relay platform (sort of TRACE-II) stiuated at VL2, even full time could be accommodated if we also had something other in between VL2 and Earth.
I'm obviously thinking (that's always a bad sign), if the Venus environment remains as hot and nasty as everyone except myself seems to believe, their (Venus lizard folk) only option may reside with remaining as elevated, as well as safely situated within the relatively cooler season of nighttime, which cuts our laser communications window off at Venus sunrise.
Actually, VL2 radiation has been somewhat overstated, as I've calculated at 1.9 times that of Earth L2 (EL2). As for being 90+% shielded by Venus itself (that's at least 5% better shielding than EL2), that's not to mention having one of those nifty space rocks on hand to hide ISS behind whenever there's a significant solar flare output, or there's even the other possibility of simply moving ISS inward to 0.95 VL2 or perhaps even as close as 0.9 VL2, where obviously we'll need that nuclear pumped xenon array of thrusters online in order to hold onto such a position.
The following is simply another "what if", barring the chemotherapy aspects and counting on there being a positive force of motivation making this VL2 venture worth while, as opposed to our otherwise spendy glaring at multi-hundred million lightyear distant targets or tentative (wishful thinking) goals and, even of other planets much further than Venus, where in either instance those sofar being humanly unobtainable, not to mention risky goals that'll drain hundreds of billions if not trillions away from what's morally needed right back here on Earth.
If the ISS mass of this mission to VL2 (hell L2) were to become 1000 t
If the current ISS velocity is roughly 7682 m/s
If the added (continuous) thrust of 0.1 t per sec. were applied:
This following conjecture is based upon a lack of medication as well as my understanding or perhaps misunderstanding of what little it is that I've come across and, since few will openly share their "all knowing" expertise in favor of their prefference of tossing as much orchesterated flak as possible and, otherwise I'm still on that nifty "need to know" basis. So, I could be wrong (wouldn't be the first nor the last time) but, there's another darn good chance that in principal I'm a whole lot more right then you might care to think.
Perhaps in raw theory (excluding anything Earth), if the proposed mass of 1000 t were at speed, and if to be applying a mere 0.1 t thrust, I believe it will logically require 10,000 seconds as to double upon that speed to 2 * 7682 m/s.
In other village idiot words; I'm thinking that after 10,000 seconds or 2.777 hours into ignition, we'd have doubled ISS to a new orbit speed of 15,364 m/s and, as such headed for the Van Allen zone, a well documented zone of death ranging from 1000 to 70,000 km.
Being that Earth is still representing an initial mission drag and gravity pulling factor, at least until we've sufficiently exited EL2 (presumably as headed towards a lunar near miss), let us presume upon obtaining but half those results for the first 10,000 seconds worth and, perhaps equally another 50% improvement as for the second 10,000 period and so on until we've exited Earth's gravity altogether. From the gravity free position of 1.01 EL1 as headed towards the moon, where that continuous thrust of 0.1 t ott to put on some good speed. In fact, it could become way too much for ISS as headed towards the lunar gravity encounter. Once ISS is gravity flung as passing nearby the lunar surface (a 1+km near miss should do nicely), hopefully ending up by heading our fearless chemotherapy needy crew towards something Venus. Then once again as headed outbound towards our exiting lunar gravity, the 0.1 t nuclear pumped thruster could be switched back on, at least until ISS obtained 100,000 m/s, as much beyond that could become a detriment, where any faster and a mere grain of sand might impact like a neutron bomb.
Even at the modest speed of 100,000 m/s, the forward shield for radiation ott to be constructed of multi-layered alloys, not only for fending off the sorts of primary radiation but, also for suppressing those secondary forms of radiation and, perhaps mostly as for collision endurance. Perhaps this multi-layer alloy shield of titanium and aluminum and then perhaps an inner layer of leaded-UHMW ott to become something very pointed, so as to glance off anything along the path, as otherwise my previous idea of latching onto a good sized space rock might remain as the only viable alternative to our having to launch a modular (some assembly required) multi-hundred tonne shield, which ott to choke the rest of us back here on earth with 100 times greater amounts of CO2.
So, of what we need is obviously some of that wizardly rocket engineering expertise, along with another substantial batch of Prozac. That rocket engineering team also needs to contemplate exactly how to stop ISS at VL2, as it's one thing getting something massive up to speed and, quite another to parallel park the damn thing, especially if there's trailers involved.
Not because I actually need to know all this but, I'd like to learn how much the 0.1 t thrust will affect upon a 1000 t ISS, as intended for a mission sending it to VL2. Any other suggestions as alternatives will be equally of interest.
I'd also be interested in hearing about other rocket engine powered craft alternatives, including of what it's going to take in order to get the spent crew back from VL2. I'm assuming a great deal more energy per tonne, as if the return mission craft were but 100 t, it seems we may be in need of those solid fuel rockets plus additional alternatives such as a 1 t nuclear pumped xenon array (that's 100 times greater in proportion to the ISS 0.1 t thruster to mass ratio), where the outbound (return-home) mission could still require twice the amount of inbound time per distance, thus twice the radiation exposure, unless the majority of the craft were involved in shielding those already radiated crew members.
The other ongoing research pages related to Venus L2 (VL2) and ISS:
Radiation (TBI) dosage; the good, the bad and the ugly.
Somewhere on this internet, there's a rocket propulsion and space travel simulator that'll permit this level of insanity, of applying engines to ISS, sort of a Microsoft "flight Simulator" that allows a student to construct and fly his own custom airplane, into the ground if need be (I believe that's called a RESET!).