Adam Hibberd
Deep in my schizophrenia-afflicted mind I have been experiencing wild imaginings of a particular and frequent celestial visitor as it approaches on its inward path towards the Sun and I have been asking the question: will humanity ever be able to visit it?
Its frozen surface, now a cold, inert and desolate block of ice and dust will reawaken after God-knows how many previous close Sun encounters, slowly sparking into a spectacular show at perihelion (closest solar approach), observable yet again from around the planet in a display lighting up the sky.
But my task at hand is far more prosaic, how do I exploit my astrodynamical and engineering skills to solve the problem of meeting and staying with Halley’s Comet as it approaches the Sun and then swings away from it again?
By the time this happens, no-doubt I will have kicked the bucket, but as the epitaph of Sir Christopher Wren states: “Si monumentum requiris, circumspice”, though when this rendezvous actually takes place, my magnificient creations and engineering monuments – including my “Optimum Interplanetary Trajectory Software” (OITS) – will probably be perceived as laughably crude.
And the other question is: will humanity still exist at Halley’s next perihelion in 2061? I have to say, the way things are going with Earth’s most brilliant and arrogant species, the likelihood could well be exceedingly low.
Nevertheless I have, using OITS, designed a trajectory to rendezvous with Halley pre-perihelion meaning we can send a probe to check-it-out and monitor the object through the important close solar encounter and beyond.
There is a straight-forward enough low rocket impulse trajectory to Halley exploiting a Jupiter gravity assist (GA) followed by a Uranus GA taking the probe way beneath the orbital plane of all the planets to catch Halley as it rises upwards from an aphelion which is way below the ecliptic plane.
The DeltaV to match Halley’s velocity is about 4 km/s and I dabbled with the idea of using Nuclear Electric Propulsion (NEP) to apply it.
So I, in conjunction with AI, developed some software which solves the extremely challenging low-thrust optimization problem represented by the NEP rendezvous with Halley in as little thrust time as possible. The solution trajectory and relative speed plots are shown below:
