Speed, acceleration and other reasons to think it is an alien solar sail
The reasons for this are:
1. It came in at a speed of 58,000 mph (26 kilometers per second) which meant it had to come from outside the solar system
2. Between the orbit of the Jupiter and Earth it nearly doubled its speed to 111,000 mph (49 km per second)
3. It reached a peak speed of nearly 200,000 mph (87 km per second) and then went around the sun and is leaving the solar system
4. It would have taken 600,000 years to reach the Solar System from the direction of Vega. Vega was not in the right location 600,000 years ago. It was at the average speed for material in the Milky Way. It has probably circulated the Milky Way several times and may have originated from an entirely different part of the galaxy.
The strange movement and speed up of the object can be explained if the 1000 meter long by 35-meter wide object was a 100-300 kilogram solar sail.
Another explanation is that it was a lot heavier (made of near solid rock) and had massive outgassing. However, the outgassing should have happened at other times and provided a very visible comet tail.
Just the fact that it is the first definitely an object of interstellar and galactic origin makes it worth chasing. It is an alien solar sail, then we should definitely chase it.
If it is an alien solar sail there could be many, many more alien solar sails out there. But we cannot be certain there are many more. We need to have telescopes scanning for such interstellar objects. We could spot the next one far earlier and setup an easier intercept mission. However, we need to chase this one.
The world went a little crazy over a WTF radio signal a few decades ago. SETI got substantial funding for a radio signal search.
This is a WTF object and possibly a giant alien spacecraft. This is worth a few billion dollars for a mission to check it out. Such a mission is possible.
Others have said that we should not leap to the conclusion that it is an alien solar sail. They also say we cannot catch up to it with chemical rockets. We can catch up to it with chemical rockets if we use two gravity slingshots.
They assessed the feasibility of a fly-by or rendezvous mission using current and near-term technology. Oumuamua is at 26 km/s (58,000 mph). It moves 5.5 times the distance from the Earth to the Sun every year. It will be beyond Saturn’s orbit late in 2019.
Launch within the next 4 years would be very, very tough. Launching with 9 years would be challenging. New technologies will probably need to be developed.
One potential mission architecture is to make use of SpaceX’s Big Falcon Rocket (BFR) and in-space refueling with a launch date in 2025. A Jupiter flyby combined with a close solar flyby (down to 3 solar radii), nicknamed solar fryby, could get the needed speed.
Direct launch of a chase probe from a Highly Eccentric Earth Orbit (HEEO) plus various kick-stages would work. The probe would have a C3 of 100 km²/s² into an 18-month trajectory to Jupiter for a gravity assist into the solar fryby. A multi-layer thermal shield protects the spacecraft, which is boosted by a high-thrust solid rocket stage at perihelion. The hyperbolic excess velocity of 70 km/s was possible with this technique, a value which achieves an intercept at about 85 AU in 2039 for a 2025 launch. More modest figures can still fulfill the mission, such as 40 km/s with an intercept at 155 AU in 2051. With the high approach speed a hyper-velocity impactor to produce a gas ‘puff’ to sample with a mass spectrometer could be the serious option to get in-situ data.
Advanced solar sails, laser sails, magnetic sails and electric sails could work but we do not have those technologies yet. The longer it takes to develop the technology and launch then the faster the mission has to be.
2025 to 2030 Launch window would mean two Blue Origin New Armstrong or Two Long March 9 Super heavy lift rockets would also work
Any two super-heavy lift rockets would work for the mission. One to launch toward the gravity slingshots and one for the refueling to have a fully fueled rocket.
Reusability would not be needed for the rockets.
Two Space Launch Systems would also work.
The Solar Fryby probe would need to adopt the solar shield of the Parker Solar Probe.
The Parker solar probe was launched and it will approach to within 9.86 solar radii (6.9 million kilometers or 4.3 million miles) of the Sun. At its perihelion, the Parker Solar Probe will enter a region of space where temperatures can reach over 500,000 degrees Celsius.