Does Virgin Galatic go into space high enough to experience real weightlessness?

A CNBC article states it's more microgravity centrifugal:

The spacecraft essentially does a slow back flip at the edge of space, with passengers spending a few minutes floating in microgravity

How SpaceX, Virgin Galactic, Blue Origin and others compete in the growing space tourism market (CNBC)

  • 19
    $\begingroup$ Note that any effects of acceleration, whether due to a thrusting force or a gravitational force are the exact same thing. This is the core tenet of General Relativity, and is fairly hard to conceptualise as someone stuck on the surface of a planet. $\endgroup$
    – throx
    Jul 7 at 5:33
  • 12
    $\begingroup$ The term "microgravity" has done incalculable harm to people's understanding of spaceflight. $\endgroup$ Jul 7 at 16:02
  • 5
    $\begingroup$ Height has nothing to do with it. "Weightlessness" is experienced whenever you are free-falling, no matter where that is. $\endgroup$
    – OrangeDog
    Jul 8 at 11:51
  • 2
    $\begingroup$ It is nearly impossible to experience "actual weightlessness". Probably even impossible for humans (at least at this juncture). Lagrange point? Still subject to the gravity of the galaxy (not to mention it's a point, as in only one infinitesimally small point of your body would actually be at "no net gravity"). Nor is there any practical difference between "zero gravity" and "free fall". So if you want to experience "weightlessness", a ride on the Vomit Comet is going to be the most cost-effective option for some time... $\endgroup$
    – Matthew
    Jul 8 at 13:59
  • $\begingroup$ When I was 11 years old, I read the most juvenile of what most people call Heinlein's "juvenile novels": Space Cadet. (His other juveniles can easily be enjoyed by adults; this one is better read when you're 11.) That story refers to the weightlessness experienced in space as "free fall" and at the time I wondered why. I discussed this with my older brother and the whole thing abruptly fell into place in my mind. Astronauts in space are "weightless" because they are falling at the same rate at which the spacecraft around them is falling. $\endgroup$ Jul 9 at 17:35

Yes, for a few minutes. It is similar to what is done in a zero gravity airplane flight, but a longer period of time.

Also, orbital weightlessness is basically the same thing, the spacecraft and you are falling at the same rate.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage
    Jul 8 at 15:03

This is a point worth emphasizing: When you dive off a high dive, or go on a free fall ride at an amusement park, or fly on Virgin Galactic, you are experiencing weightlessness in exactly the same way as the astronauts on the ISS.

At the height of the ISS, the earth's gravity is about 90% of what it is at sea level. You could launch a rocket straight up and hover until your engines ran out, and be walking around in your spacecraft while the ISS whizzed by at 5 miles a second. The reason the astronauts float around in the ISS is that they, like the space station, are themselves in orbit. When you dive off a diving board, you are technically in orbit too, but it is a very skinny orbit that intersects the surface of the earth.

So the answer to your question is yes, the weightlessness advertised by Virgin Galactic is real. But they may not want you to think about how you could get the same weightlessness more cheaply (but without the probably amazing view).

  • 20
    $\begingroup$ The difference with a high dive or amusement park is the presence of wind, which can make a huge difference, and the duration. But otherwise I agree. $\endgroup$
    – PearsonArtPhoto
    Jul 7 at 0:27
  • 2
    $\begingroup$ @PearsonArtPhoto, not only winds, but also the vibrations, the high-g, people's excited screamings, ... Anyway, I do not think people pay and take the risk of riding a rocket for the same "fun" and sensations as in an amusement park. It could well be the contrary. After the roaring noise, high-g accelerations and vibrations of the ascent, then the constrasting floating sensation, silence, with the view of the Earth spinning "below" (or "above"). $\endgroup$
    – Ng Ph
    Jul 7 at 9:39
  • 2
    $\begingroup$ Don't forget "vomit comet" flights, and a rapidly descending elevator. $\endgroup$
    – RonJohn
    Jul 8 at 20:28

Virgin Galactic's flights are sub-orbital and pass below the Kármán line (about 100 km up), so technically the passengers don't qualify as astronauts in space, but while they experience weightlessness, this is a consequence of the trajectory of their spacecraft rather than them being unaffected by Earths gravity.

The force of gravity on the occupants of their craft is actually very similar to that acting on us on the surface, but the astronauts are in freefall along with the spacecraft - this is exactly the same as what happens to occupants of the aircraft that follow a freefall trajectory (vomit comet) who also experience what is referred to as weightlessness.

There is little difference between these two situations, and that of someone in deep space (say on route to Mars). However, the article you read is correct and the effect is really an effective matching of the force of gravity with the force that is attempting to keep them travelling in a straight line (as per Newton's first law of motion). Gravity is what is preventing the occupants and spacecraft from following the straight line they would otherwise have.

Theoretically you can experience the same effect travelling on a train at hypersonic speeds on the surface of Earth. If the train was able to travel fast enough you would experience the same thing on a train (even if it was at same altitude throughout). Actually, if it was possible for the train to travel fast enough you could even experience -1g and be sat on the roof of the train (the -1g would in reality be centripetal force being twice the force of gravity, but in the opposite direction, and producing an overall force of -1g).

p.s. Updated answer after obtaining confirmation that they only reached 53 miles altitude. It would seem that the astronaut wings awarded to the passengers are more symbolic than official recognition of entering space (it would seem a different standard it being met here).

  • 6
    $\begingroup$ Virgin Galactic's flights do not pass the Kármán Line $\endgroup$ Jul 6 at 16:53
  • 5
    $\begingroup$ Virgin Galactic does not pass the Karman line (100 km). It only passes the 80 km altitude which is the definition of space by some organizations (I forget which one - U.S. Air Force?). $\endgroup$
    – JohnHoltz
    Jul 6 at 16:54
  • 9
    $\begingroup$ "is a consequence of the trajectory of their spacecraft rather than them being unaffected by Earths gravity" --> Also true for regular astronauts in orbit experiencing free fall $\endgroup$ Jul 6 at 20:21
  • 2
    $\begingroup$ @JohnHoltz: Scott Manley covered the history and arguments on how they arrived at it (from 10 min 28 secs) - "50 miles ... rounded to 80 km.". "...SpaceX ... yeah, but you didn't go orbital" $\endgroup$ Jul 7 at 11:07
  • 1
    $\begingroup$ I thought your original answer said that Virgin Galactic will fly higher than 100 km. Since VG does not exceed 100 km, that portion of your answer is incorrect. If you are saying that the Karman line is a fluid boundary subject to interpretation, then you should write that VG will exceed 80 km, their definition (and the U.S. Air Force) of space. You should leave "Karman line" out of the answer to avoid confusion. $\endgroup$
    – JohnHoltz
    Jul 7 at 14:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.