The solar system’s first interstellar visitor, which could be detected from Earth, was spotted last month. The history-making discovery of an asteroid called Oumuamua was a delight for astronomers and opened a new window to study the formation of stars systems beyond the solar system.
Following the discovery, the Initiative for Interstellar Studies announced the ambitious Project Lyra. This project has the goal to assess the feasibility of a mission to Oumuamua with the help of current and near future technology and to propose mission concepts for achieving a fly-by or rendezvous.
However, the interstellar asteroid is moving really fast at 138,000 kmph. It is likely to pass the orbit of Jupiter in May next year, indicating that any mission would have to be assembled fast. The probe itself would have to move faster than any other human-made object to catch up.
“Besides the scientific interest of getting data back from the object, the challenge to reach the object could stretch the current technological envelope of space exploration,” the Lyra project researchers said. “Hence, Project Lyra is not only interesting from a scientific point of view but also in terms of the technological challenge it presents.”
The main reason for an Omumuamua probe lies in the fact that no one knows when an interstellar object will visit the solar system or be detected again. It could be 10, 100, or 1000 years. Scientists, therefore, feel Oumuamua presents the opportunity of a lifetime to observe an interstellar visitor closeby.
Also, even if the Breakthrough Initiatives’ Project Starshot is successful in launching its interstellar mission, it will still take many decades to study interstellar objects.
SpaceX Big Mars Rocket
The interstellar asteroid is currently traveling away from Earth at a very high speed, which is much faster than any spacecraft has ever traveled upon being launched until now.
However, according to the Project Lyra research team who recently published their study, SpaceX’s huge Mars-colonization rocket, Big Falcon Rocket, and their in-space refueling technique with a launch date in 2025 could be an option for a mission to Oumuamua.
The BFR is SpaceX's launch vehicle, spacecraft and space and ground infrastructure system of spaceflight technology, which is going to replace the aerospace company’s existing spacecraft and launch vehicles by the early 2020s.
While the new vehicle is smaller than an earlier version of SpaceX composite material vehicle design, it is much bigger in comparison to the existing SpaceX operational vehicles that it is going to replace. The planned payload of 150 tonnes makes it a super-heavy-lift launch vehicle more powerful than all rockets ever made.
Using the BFR will eliminate the need for multi-planet flybys to build up momentum for a Jupiter trajectory. Rather, a “direct launch from a Highly Eccentric Earth Orbit (HEEO) the probe, plus various kick-stages, is given a C3 of 100 km²/s² into an 18 month trajectory to Jupiter for a gravity assist into the solar fryby.”
"The KISS Interstellar Medium study computed that a hyperbolic excess velocity of 70 km/s was possible via this technique, a value which achieves an intercept at about 85 AU in 2039 for a 2025 launch," the authors wrote, explaining the BFR’s speed. “More-modest figures can still fulfill the mission, such as 40 km/s with an intercept at 155 AU in 2051."
Breakthrough Starshot Laser-Propelled Sail Craft
The authors also suggested another option for an Oumuamua mission could be tiny, laser-propelled sail craft, similar to the ones that the Breakthrough Starshot project aims to launch to other planetary systems.
Sending a sail craft swarm in 2025, however, is an unrealistic goal because the probes by Starshot would be ready only in 20 years or so, and that too if all goes well.
Project Lyra’s future work will focus on studying the different mission concepts and technology options in more detail. Subsequently, the researchers will select two or three promising concepts for further development.