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Comment by starfallg | Hacker News Reader

Wouldn't Virgin Galactic's flight be the first for this then?

Depends on your definition of ‘space mission’, I suppose.

But clearly there is a difference between a suborbital flight with a few minutes of weightlessness and a flight that orbits for three days.

Well that's exactly the point. GP didn't state whether a private space mission meant achieving orbit or not.

That would be the first private space flight, while this is the first private orbital flight.

Surely the SpaceShipOne flight whose tech the Virgin Galactic’s flight was based on?

Virgin Galactic only reached Mach 3 speed and was nowhere near achieving orbital velocity which requires Mach 23 (28,000 kph) ie order of magnitude more difficult.

Serious question: while I understand making the comparison in Mach number to illustrate the difference in speed, is the speed of sound actually well defined near or above the Karman line?

I had no idea either so I asked, apparently it's about 0.85 Mach:

https://www.wolframalpha.com/input/?i=speed+of+sound+at+100+...

They didn't even hit 100km mark, leave alone making an orbit.

Not sure why you've been downvoted, but the world classes space at the Kármán line, 100km above Sea Level. Spaceship One reached this back in 2003, but Virgin Unity didn't.

Blue Origin's New Shepard did reach 100km though, so was a "space trip". It was sub orbital though, so more Freedom 7 than Vostok 1 (Freedom 7 reached a far higher apogee and speed than New Shepard)

SpaceX has the civilian equivalent of Vostok 1, albeit larger and far more advanced. It's an order of magnitude more impressive.

How often the VSS Unity fly around the planet?

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