Thoughts on the Virgin Galactic "space" flight

Thread Starter

BobTPH

Joined Jun 5, 2013
4,030
I am writing this as Richard Branson is about to take off in his rocket plane and make a trip to the "edge of space".

Really? The edge of space? To visualize how far they are going from earth, do this:

1. Draw a circle of diameter 80 mm.
2. Place a dot 0.5 mm above the top of the circle.

That is how far they are going into "space".

We also hear about them experiencing weightlessness, with the implication being that there is no gravity where they are going. Wrong!

If you weight 100 lbs on the surface of earth, you will weight, wait for it, 99.6 lbs where they are going.

They experience weightlessness for 4 minutes because they are in free fall for that amount of time.

By this definition, everyone has experienced weightless if they have ever jumped in the air. I used to do trampoline. I calculated that I was weightless for 1/2 a second every time I jumped 8 ft off the mat.

So, what we have here, in my opinion, is all about a billion dollar carnival ride.

Edited: Corrected some numbers.

Bob
 
Last edited:

Suncalc

Joined Mar 23, 2021
2
I think you've missed the mark. This is really about competition to reduce the cost of access to orbit. Yes, with Branson, Musk, and Bezos in the mix there is much posturing and bravado. And each of them profess grand visions of 1950s style interplanetary exploration and colonization. But the real value in all this is reduced access cost. There are many opportunities to perform unique and beneficial sensing and communication jobs in orbit to the benefit of all. But most of those opportunities wither on the vine due to cost to orbit.

So let the billionaires bloviate. After all, half their job is to serve as carnival barkers for their cause. But as the cost to orbit comes down, we will all benefit.
 

eetech00

Joined Jun 8, 2013
2,644
I think you've missed the mark. This is really about competition to reduce the cost of access to orbit. Yes, with Branson, Musk, and Bezos in the mix there is much posturing and bravado. And each of them profess grand visions of 1950s style interplanetary exploration and colonization. But the real value in all this is reduced access cost. There are many opportunities to perform unique and beneficial sensing and communication jobs in orbit to the benefit of all. But most of those opportunities wither on the vine due to cost to orbit.

So let the billionaires bloviate. After all, half their job is to serve as carnival barkers for their cause. But as the cost to orbit comes down, we will all benefit.
I agree that its all PR.
What I disagree with is the promotion of the event as a trip to "space". According to Neil Tyson, the internationally recognized operational boundry for space flight is 100KM. Today's flight will be released from mothership at 12KM, burn for 60s, then begin descent. So, they'll never really leave the atmosphere.

I guess they'll get a pin....
 

Thread Starter

BobTPH

Joined Jun 5, 2013
4,030
Weather balloons have reached as high as 32 miles above the surface, i.e. 2/3 of the height they are going, at a lot lower cost.

Bob
 

Suncalc

Joined Mar 23, 2021
2
Keep in mind that the ISS orbits at only ≈340km. Today Virgin got to ≈86km; this is a little over 25% of the ISS stable LEO. This flight is a validation of the Virgin technological approach. As to weather balloons and such, it is important to keep in mind that orbital conditions are about velocity and not height. A certain delta-v is required to reach orbit. And it takes a set amount of energy to accelerate a given mass to that velocity. If you don't have the delta-v, then you can't achieve orbit.
 

Thread Starter

BobTPH

Joined Jun 5, 2013
4,030
Keep in mind that the ISS orbits at only ≈340km. Today Virgin got to ≈86km; this is a little over 25% of the ISS stable LEO. This flight is a validation of the Virgin technological approach. As to weather balloons and such, it is important to keep in mind that orbital conditions are about velocity and not height. A certain delta-v is required to reach orbit. And it takes a set amount of energy to accelerate a given mass to that velocity. If you don't have the delta-v, then you can't achieve orbit.
Exactly. The energy energy needed for today’s flight was only 2% of that needed to orbit.

Bob
 

BobaMosfet

Joined Jul 1, 2009
1,896
While I value research done, and the benefits that may result in such, I think that the billionaires would spend their money more wisely on problems that exist in every culture- from hate, to war, to petty. They gain more in interest on their money, than they can spend, and yet we still have people starving, being preyed upon, raped, beaten, murdered, tortured, defiled, humiliated, hated upon, bullied, etc.

For but a fraction of the cost of what they do in this grand 'adventures', which is nothing more than a crotch-sizing contest among people of no real value, many, more global issue could be utterly _solved_.

IMHO.
 

Deleted member 115935

Joined Dec 31, 1969
0
To orbit, you need the height and the speed,
they had not the height to reach space,
and they were stationary at the top of the parabola.

To carry sufficient fuel to get to space, then you have no weight for payload ( humans )

As for the very un british sportsmanship , the less said the better,
 

MaxHeadRoom

Joined Jul 18, 2013
23,906
While I value research done, and the benefits that may result in such, I think that the billionaires would spend their money more wisely on problems that exist in every culture- from hate, to war, to petty. They gain more in interest on their money, than they can spend, and yet we still have people starving, being preyed upon, raped, beaten, murdered, tortured, defiled, humiliated, hated upon, bullied, etc.
I am not sure money will erase a basic animal trait, namely Tribalism, Inherent in humans and many other animals, also particularly evident in our closest DNA relatives.! ;)

https://en.wikipedia.org/wiki/List_of_conflicts_by_duration
 
Last edited:

ElectricSpidey

Joined Dec 2, 2017
1,961
I've always liked the idea of going into space in a vehicle that takes off like a plane, It's a damn shame research into this kind of thing has to include all of the BS.
 

Reloadron

Joined Jan 15, 2015
6,204
1961 Alan Shepherd anyone recall how long his first flight into space was? I know it was just a short ride, made it to space but not orbit and the craft (Freedom 7) returned to earth. I was 11 at the time and here we are today with what amounts to a repeat performance but in the private sector.

Ron
 

Thread Starter

BobTPH

Joined Jun 5, 2013
4,030
1961 Alan Shepherd anyone recall how long his first flight into space was? I know it was just a short ride, made it to space but not orbit and the craft (Freedom 7) returned to earth. I was 11 at the time and here we are today with what amounts to a repeat performance but in the private sector.

Ron
Except that that was simply an early test of a rocket that would eventually take us into orbit. Branson’s space plane cannot be scaled up to that.

Bob
 

Deleted member 115935

Joined Dec 31, 1969
0
Question,
to me orbit is two things, height and "ground speed"

A ballon can not go into orbit, as it has no speed ,
thats why you can parachute off one without a heat shield

Or am I worng ?
 

Thread Starter

BobTPH

Joined Jun 5, 2013
4,030
You are correct. That is why it takes way more energy to get into orbit than to get up 50 miles.

And the reentry heat is going to also depend on the square of that speed, so the "space plane" does not require 3 inch thick tiles like the space shuttle to keep it from melting.

Bob
 

Reloadron

Joined Jan 15, 2015
6,204
Except that that was simply an early test of a rocket that would eventually take us into orbit. Branson’s space plane cannot be scaled up to that.

Bob
Yes, I remember it and I was 11 years old delivering newspapers. The headline for Long Island Newsday read "Our Shep Does It". Redstone rocket I think? Figure 60 years ago I am surprised I remember that. Currently trying to remember what I did yesterday or maybe it was the day before. :) The beginnings of some interesting years with the space race. I was 7 in 1957 when Sputnik went up and it was showtime for the space race.

I wonder how the private sector will fare in all of this.

Ron
 

ElectricSpidey

Joined Dec 2, 2017
1,961
The private sector will do just fine as long as there is profit in it...the real big bucks will probably come when we start mining asteroids and such, because I don't flying passengers is a working business model.

But, that is just my opinion.
 
Top