Based on today's technology (requiring no new engineering hurdles to be solved), could a new interstellar space probe overtake Voyager 1's distance? It doesn't need to go in the same direction, but just achieve a further distance from Earth than Voyager 1? I assume the answer is yes, and if so, with today's technology how quickly could this be accomplished?
Ultimately, I'm curious if Voyager 1 is destined to be the furthest man-made object from Earth in my lifetime.
Voyager 1 received gravitational assists increasing its velocity from both Jupiter and Saturn.
Opportunities for such a Jupiter-Saturn trajectory occur about every 20 years, so we don't have to wait too long to launch, at least; in order to outperform Voyager we merely need to launch a probe of about the same total mass as Voyager, at the same initial velocity, with the same gravity-assist parameters, but including a propulsion system in place of the 105kg of scientific instruments carried by the earlier probe. An ion engine would give the most ∆v for the mass; something like an NSTAR thruster of 25kg plus 80kg of Xenon propellant, on a total spacecraft mass of 773 kg, firing for about a year, would yield an additional 3km/sec above Voyager's speed. (Power would be a bit of a problem; Voyager produced only ~430W from its radiothermal generators, while NSTAR wants 2100W for maximum efficiency, but we can handwave this away by assuming a smaller thruster operating for a longer period of time.)
Improvements in computer and other technologies over the last 40 years should make it possible to shave off additional mass from the probe, of course. Those mass savings could pay for additional propellant on the probe.
The Titan IIIE booster that launched Voyager is no longer in service; the Atlas V 551 configuration that launched New Horizons slightly outperforms the Titan in mass-to-LEO, so I assume it could serve this role.
Voyager 1 does have a substantial head start, however, so it could take something like 200 years for this speedy little probe to outdistance it.
A larger booster -- Delta IV Heavy, Falcon Heavy, SLS, or SpaceX's future rockets -- could of course lift a very powerful upper stage that could give the probe another substantial boost, perhaps cutting the outdistancing time in half or further.
So, with no major technological advances, I estimate it should be no more than 20 years from budget approval to launch, and 100-200 years from launch to outdistancing depending on the budget.
APL is studying an interstellar mission with a speed goal of 20 AU/year, 5 times faster than the Voyagers. This is feasible with minimal development of current technology.
At that speed, it'd need about 9 years to overtake the Voyagers.
Yes you could do it the question would be why?
An ion drive could give you an ISP of around 90km/s the problem is getting a high mass fraction of fuel. Ion drives have limit of about 100kg of fuel per KW of power and since you will be a long way from the sun you need a nuclear power plant which is space tends to be very heavy.
If we use 90km/s for ISP 40KW reactor power (using HiPEP ion drive) 670mN thrust equalling 79% efficiency
That implies 4000kg of fuel, which will take 17 years to consume! If the argon is stored at 700bar in the most advanced CF tank it will weigh in the region of 250kg. The best postulated near term space reactor is about 30W/kg. (1320kg). The ion drive is trivially light so I allocate 100kg for the probe structure.
Dry mass = 1670kg Wet mass = 5670kg
Plug that into the rocket equation and it is 115km/s
If we assume 10 years to launch (flybys do relatively little just launch it) from 2024. And then another 17 years for the probe to get up to speed Voyager is now 39.3bn km away.
However assuming linear acceleration because I'm lazy our probe has covered 30bn km already. It covers the final 9bn km gap in under 3 years and passes voyager at 98km/s. So it passes it in 2044.
Since we are evil we make it hit Voyager, this releases around 1 kilotonne of energy and is detectable if we know where the look.
We know how to build mass drivers (basically, a very high power maglev train that doesn't stop accelerating until it runs out of track.)
Long ago I saw a 100g version on TV. There's basically zero issues with making it longer until the surface curvature of the body you mounted it on matters.
Thus we could build such a system on the moon and launch something that can overtake Voyager. There's nothing we don't know how to do but it's a pretty massive engineering project. (However, unless it becomes obsolete before being built I think it's something that will be done. While using it to overtake Voyager would be a waste it can boost payloads elsewhere in the solar system.)
