Inspiration4 will likely be visible to the naked eye, but astronomers will have to wait until launch to get a better prediction of when we can see it
A team of four astronauts – including a teacher, a cancer survivor, a raffle winner, and an internet entrepreneur – will leave Kennedy Space Center in a SpaceX Dragon capsule on top of a Falcon 9 rocket.
They will journey upwards to a maximum of 600 kilometres from Earth, and tgeb descend into the Atlantic Ocean after three days.
It is difficult to know when the Inspiration4 will be visible until it launches, but experts say it is likely it will be visible. SpaceX has said that the journey will “continually eclipse more than 90 per cent of the Earth’s population”.
Its large size, and white, reflective colour, as well as its 590-kilometre apogee low-Earth orbit means that “in principle” it will be bright enough to see, Royal Astronomical Society vice president Dr. Paul Daniels told The Independent.
The three-day flight of the craft means approximately 45 orbits of the Earth – one every 90 minutes – and as such there is a “good chance” it will pass over the UK at some point.
Jonathan McDowell, an astronomer at the Centre for Astrophysics, agrees that it will “certainly [be] bright enough” but without orbital data its difficult to say which content it will be over, and at what time of night it will be visible – “but it would be naked eye bright if it goes over you at night while it is in view of the sun.”
It will not be easy to spot as other bodies though; “while it will only be a few hundred kilometres higher than the International Space Station, a common bright sight in the night sky, Inspiration4’s small size will make it a much harder target to spot once in orbit”, Greg Brown, an astronomer at Royal Observatory Greenwich, told The Independent.
Once the craft is in the air, the craft will be much easier to track through websites such as Celestrak, Heavens-above, or N2YO – and special equipment is likely not to be needed.
“It’ll almost certainly be naked eye brightness,” Dr Daniels said. “Binoculars can be used but won’t have a high enough magnification to see any details”, and telescopes “could be used but the much higher magnification and smaller field-of-view will make it harder to track”.