A Mission to Meet Halley’s Comet in 2061
Every 76 years, Halley’s Comet makes a dramatic return to the inner Solar System. In 2061, it will once again be visible from Earth, passing even closer than it did in 1986. A group of researchers, led by Cesare Barbieri, has proposed an ambitious space mission to rendezvous with the comet long before it reaches the Sun. Unlike past missions that quickly flew by Halley’s nucleus, this mission, called HCREM (Halley Comet Rendezvous Mission), would travel alongside the comet for years, capturing groundbreaking observations of its activity.
Why Visit Halley Again?
The last time spacecraft visited Halley’s Comet was in 1986, when five different missions from Europe, the USSR, and Japan made quick flybys. The most famous of these was ESA’s Giotto mission, which provided the first close-up images of a comet’s nucleus. These missions revealed that Halley has a dark, peanut-shaped core about 16 km long and that only a small part of its surface is active, releasing jets of gas and dust. However, many mysteries remain, including details about its internal structure, its rotation, and the exact processes driving its activity.
A new mission to Halley could answer these questions by studying the comet in greater detail and over a much longer period. Scientists are particularly interested in what happens when the comet is still far from the Sun, where volatile gases like carbon monoxide and carbon dioxide begin to escape from beneath the surface. Studying these early changes could help us understand the fundamental properties of comets—frozen remnants from the birth of the Solar System.
How Will the Spacecraft Get There?
Halley follows a retrograde orbit, meaning it moves in the opposite direction of the planets, making it difficult to match its speed. HCREM would launch in the late 2030s, using a flyby of Jupiter to adjust its trajectory and enter Halley’s orbital plane. The spacecraft would rely on electric propulsion and radioisotope thermoelectric generators (RTGs) for power instead of solar panels, allowing it to operate even when far from the Sun.
If launched in 2036, the spacecraft could rendezvous with Halley in 2056, when the comet is still beyond Saturn. By arriving this early, the spacecraft could witness how the comet awakens as it moves closer to the Sun. HCREM would continue traveling alongside Halley through perihelion (closest approach to the Sun) in 2061, and then follow it on its outbound journey, providing a unique opportunity to study how cometary activity changes over time.
A New Kind of Camera
One of the most exciting features of HCREM is its Very Wide Angle Camera (VWAC), an innovative imaging system with a 100° field of view. This is about eight times wider than Rosetta’s cameras, allowing the spacecraft to capture both the comet’s nucleus and the surrounding jets of gas and dust in the same frame. Unlike previous comet cameras, VWAC is designed to have minimal distortion and no moving parts, making it highly reliable for long-term observations.
The Race Against Time
The team emphasizes that if we want to send a spacecraft to Halley’s Comet, planning must start now. A mission like HCREM would need to launch before 2040 to arrive in time to study Halley before it gets too close to the Sun. If we wait too long, we may miss a once-in-a-lifetime opportunity to witness the early activity of one of the most famous comets in history.
Source: Barbieri
