Kronos 1, Deep Space Exploration Vehicle.
This is probably my most ambitious space project so far. I've been working on this spacecraft for quite a while now, several months of all the design work that includes the spacecraft design, interiors, mission structure and goals, functional design of different sections of the vehicle and some other technical details. For now I wanted to present to you a 3d model that took almost a month to make and there are still lots of stuff to do. Anyway, I wanted to tease you a bit and share some of my excitement for this project, full presentation of the Kronos 1 mission coming later this year.
PS - Any resemblance to Hermes spacecraft from The Martian is pretty much coincidental and mostly comes from the research and lots of thinking about realistic long duration crewed space missions. It just means that both me and The Martian crew, did their research on space vehicles
You’re quite right to shy away from Nuclear Lightbulb.
In a recent discussion on my G+ Winchell Chung had the following to say about Nuclear Lightbulb: the uranium handling system is going to be a nightmare.
On engine shutdown the design calls to vacuum the uranium vapor out of the reactor. As Winchell observes: You'll have to gather hot uranium vapor, and somehow condense it back into metal without it
[a] plating itself all over the interior of the condensation chamber
[b] accumulating a critical mass anywhere in the condensation system.
For VASIMR the big problem is power. To create the thrust it has to process its fuel (including heating it to plasma state) and create the magnetic field with powerful electromagnets. These take a substantial amount of power. How much? For the hypothetical 39 day Mars mission its creators advertise it would require energy production on the order of 1 kilowatt per 1 kilogram of reactor mass (1kg/kW). That means there needs to be a kilowatt of power for every kilogram of mass in the reactor.
To put this in perspective, under the most optimistic projections with current energy production technology, 20 kilograms per kilowatt is that best we've engineered. A reactor on that scale would need to be 4,000 tons to output the amount of energy needed to reach Mars (in the 39 days VASIMR proponents advertise). They're looking at 600 tons as an ideal overall weight. Presently we are far from the efficiency we need for VASIMR. We have to find a way to pump out more energy with less mass.
The question I have regarding Kronos 1 is, this appears to be a very large and massive spacecraft. It seems quite beyond the propulsive capabilities of a single VASIMR engine.
The radiator panel configuration, while it looks cool, is problematic. The panel’s look like the low-energy radiators on the ISS, which would not be suitable for a high-energy system like a nuclear reactor.
Also, as I’ve learned, white is probably the worst color for a high-energy radiator system, white is fine for low power-density heat radiators like those on the ISS, however it will not do for high-energy radiators, deep non-reflective flat black would be more appropriate.
Additionally, on your design, the radiators appear far too small in area to manage the high thermal output of a reactor capable of powering that drive, and, finally, the three panel configuration is an issue, the panels will radiate waste-heat onto each other. A cruciform configuration of four panels, keeping in mind their relationship to the radiation shadow-shield, would be better.
Getting back to the original thread, if you are talking about hundreds or thousands of tons of payload/propellant mass, for the energy density required to move very large spacecraft, you probably want a high thrust, high energy-density, nuclear thermal propulsion system, and likely in a clustered engine configuration.
You cannot cluster VASIMR for the same reason you cannot cluster fusion rockets, the magnetic fields interfere with one another… which would be bad.
Ion is off the table (for very heavy payloads) because, while very efficient, it is very low thrust, so it takes a very long time to build up appreciable momentum, hold a sheet of paper in your open palm, the weight you feel is about what an Ion drive, at present levels of development, can do, although Ion can keep up thrusting for a very long time. It works great for light-weight robotic probes.
Fusion is off the table until we actually build an operational fusion reactor. Although there are design studies, a realistic fusion rocket of comparable payload capacity to what you have pictured here would have radiator panels the size of Long Island. See Winchell Chung’s post nyrathwiz.deviantart.com/art/A… and the Atomic Rockets page here www.projectrho.com/public_html… for the Boeing design it is based on.
Open Cycle Gas Core, or NERVA style nuclear thermal, or Nuclear Pulse propulsion, are the feasible near-horizon high energy density propulsion systems for propelling high mass spacecraft. Of these Open Cycle GCR and NERVA can be clustered – so long as the engines are spaced apart with neutron attenuating panels between them.