Can Elite Dangerous approach a star really that close ?

[skysurfer]

On Youtube I found some nice recordings of the Elite Dangerous spacecraft game depicting flybys of stars.
This one shows a very close approach to Arcturus where the star covers a considerable part of the sky, like Earth from ISS.

https://www.youtube.com/watch?v=8iPNBFLbOAU

Is this actually possible ? I don't think, as the immense radiation and heat would vaporize any material even with the hottest melting point like Tungsten or Silicon Carbide.

What are your thoughts ?

[xelasnave]

What is your data?
Alex

[tonybarry]

Howdy skysurfer,

You are likely correct. The biggest issue in space is being able to lose excess heat by radiation. At the point you mention, the spacecraft would be within the corona, and enduring very high temperatures (the Sun's corona is around 10^6 degrees C). Heating would be via radiation and conduction. The influx of heat would need to be re-radiated into space or the craft will boil inside.

Arcturus is a red giant, and so has *slightly* cooler surface temperatures than our sun (4300 K vs 5800 K). This difference is not appreciable to humans - it's entirely too warm to survive for even a second.

The radiation flux is even more lethal.

Isaac Asimov wrote a very good SF story which passed on this topic - Lucky Starr and the Pirates of the Asteroids. It provided a good rundown on the science, in a very entertaining way. Asimov made use of a perfect mirror for the outside of the ship to reduce the influx of radiant heat.

In real life, NASA is sending the space probe "Parker" to the sun sometime in 2018. It will be much further away from the sun (10 solar radii) than Elite Dangerous would appear to be from Arcturus.

http://www.abc.net.au/news/science/2017-06-01/parker-solar-probe-nasas-journey-to-touch-the-sun/8572540

http://parkersolarprobe.jhuapl.edu/Spacecraft/index.php#Extreme-Environments

[Eratosthenes]

Dielectric mirrors can reflect infrared radiation which is the wavelength that carries the bulk of the heat:D

[skysurfer]

True, but .... I even saw a similar video about Rigel (https://www.youtube.com/watch?v=b8H5PO3xC2Q), which covers a considerable part of the sky seen from Elite Dangerous, probably at 1AU distance, where Rigel covers a ball of 35 degrees across in the sky (these data from the largest online astronomy textbook). (https://en.wikipedia.org/wiki/Rigel)

Rigel us MUCH more powerful than Arcturus, and at 1 AU distance the energy flux is 100MW/sq m (from the Sun it is 1.4kW/m2 and Rigel has 70000 times the power output of our Sun). Consider a spaceship is 100 m2 in surface which means it has to reflect 10GW (equivalent to a large power station), which cannot be achieved by a dielectric mirror. That mirror will be fried and vaporized. Period.

Even the Parker probe (https://en.wikipedia.org/wiki/Parker_Solar_Probe) to flyby the Sun at 5.9 mln km in 2024, receives 900kW/m2 and requires very strong insulation and heat shields, and yet that is only 1% of the energy flux of Rigel at 1AU.

[xelasnave]

This may be of interest.
https://www.sciencedaily.com/releases/2017/06/170623132954.htm
Alex

[Eratosthenes]

at the energy intensities you quote, it is highly unlikely that a material can be designed as a heat shield

perhaps some sort of magnetic shield - similar to the containment fields used in experimental fusion reactors where temperatures approach that of the Sun.

I also have a very good umbrella in my garage:D