Not quite home built but this just got some attention at nasa
https://www.nasa.gov/directorates/spacetech/niac/2021_Phase_I/Extrasolar_Object_Interceptor_and_Sample_Return/
*Christopher Morrison*
USNC- Space
Extrasolar Object Interceptor
<https://www.nasa.gov/sites/default/files/thumbnails/image/morrison_graphic_2021_ph_i.png>
Artist’s depiction of the Extrasolar Object Interceptor
Credits: Christopher Morrison
USNC-Tech is proposing a compact 20 kWe, 500 kg dry mass,
radioisotope-electric-propulsion spacecraft design powered by a novel
Chargeable Atomic Battery (CAB) that is capable of ∆Vs on the order of
100 km/s with a power system specific mass of 5-8 kg/kWe. A spacecraft
powered by this technology will be able to catch up to an extrasolar
object, collect a sample, and return to earth within a 10-year
timeframe. The data collected from samples and data from interstellar
objects has the potential to fundamentally change our view of the
universe and our place in it. Two of these objects ‘Oumuamua and C/2019
Q4 (Borisov) have passed through our solar system in the past three
years, and we must be ready for the next one. The core innovation of
this spacecraft architecture that makes this amazing mission possible is
the CAB, which has a power density of over 30 times that of Pu-238. The
CAB is easier and cheaper to manufacture than Pu-238 and the safety case
is greatly enhanced by the CAB's encapsulation of radioactive materials
within a robust carbide matrix. This technology is superior to fission
systems for this application because fission systems need a critical
mass whereas radioisotope systems can be much smaller and fit on smaller
launch systems reducing cost and complexity.
On 2021-02-27 9:29 am, William Claybaugh wrote:
Since we are not talking about homebuilt rockets, I was wondering if we might talk about homebuilt space missions:
A top level analysis suggests it would take about 60 Km / sec to catch Oumuamua in about 20 years.
Another very top level analysis suggests that a gravity assist at Jupiter (solely to turn the plane from near ecliptic to near that of Oumuamua; near to but less than 90 degrees) followed by a 50 solar radii assist at the Sun (Parker is doing 10 radii as I recall but it carries way too much heat shield for this mission) can pretty certainly get to 50 km / sec.
One of NASA Glenn’s Stirling cycle RTG’s tied to an existing commercial electric thruster appears capable of making up the difference with a big fuel tank.
Assuming a New Horizons-like spacecraft, but much smaller, a flyby seems possible based on this very top level analysis.
I’d be real interested in helpful comments.
Bill
