Build a Hypersonic Orbital Sky Hook
Post Reply
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
03-04-2013, 09:50 PM
Build a Hypersonic Orbital Sky Hook
Possible using todays technology but I haven't seen much information on it. There seems to be no interest in developing it and I wonder why.

[Image: 220px-Skyhooks.gif]

From Wiki: A variation of this technique that appears to be currently possible is to have the tip speed of the cable lower than the orbital speed and use hypersonic aircraft to catch the tip while it is in the upper atmosphere.
This is probably possible with current technology as it doesn't need such high strength materials for the cable.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
03-04-2013, 10:51 PM
RE: Build a Hypersonic Orbital Sky Hook
Yes, but you still need hypersonic aircraft to deliver cargo and passengers to the hook, and such a transfer would likely be exceedingly difficult. It's feasible to construct, but probably not practically useful in the same way as a space elevator would be.


Not to say that sky hooks don't have applications. Read Larry Niven's Descent of Anansi for one practical use (it's near the end of the book; the rest is a rather decent sci-fi plot).

E 2 = (mc 2)2 + (pc )2
614C → 714N + e + ̅νe
2 K(s) + 2 H2O(l) → 2 KOH(aq) + H2 (g) + 196 kJ/mol
It works, bitches.
Find all posts by this user
Like Post Quote this message in a reply
04-04-2013, 12:07 AM (This post was last modified: 04-04-2013 12:56 AM by DeepThought.)
RE: Build a Hypersonic Orbital Sky Hook
(03-04-2013 10:51 PM)Phaedrus Wrote:  Yes, but you still need hypersonic aircraft to deliver cargo and passengers to the hook, and such a transfer would likely be exceedingly difficult. It's feasible to construct, but probably not practically useful in the same way as a space elevator would be.


Not to say that sky hooks don't have applications. Read Larry Niven's Descent of Anansi for one practical use (it's near the end of the book; the rest is a rather decent sci-fi plot).

I'm thinking it would make for significant cost reductions, since special aircraft could transfer cargo to it. Main advantage - It's possible with todays technology.

It would separate the atmospheric stuff from the space stuff. The plane would return to refuel for the next delivery.


The cost of a hypersonic flight + skyhook is still massively lower than the cost of a LOX-Kerosene rocket taking you to orbit.

Read Decent of the Anansi. Loved it, although the shuttle program was a total disaster. It was more of an employment program than practical. NASA bought into the Specific Impulse hydrogen religion, and it cost them big time.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
04-04-2013, 01:39 AM
RE: Build a Hypersonic Orbital Sky Hook
(04-04-2013 12:07 AM)DeepThought Wrote:  
(03-04-2013 10:51 PM)Phaedrus Wrote:  Yes, but you still need hypersonic aircraft to deliver cargo and passengers to the hook, and such a transfer would likely be exceedingly difficult. It's feasible to construct, but probably not practically useful in the same way as a space elevator would be.


Not to say that sky hooks don't have applications. Read Larry Niven's Descent of Anansi for one practical use (it's near the end of the book; the rest is a rather decent sci-fi plot).

I'm thinking it would make for significant cost reductions, since special aircraft could transfer cargo to it. Main advantage - It's possible with todays technology.

It would separate the atmospheric stuff from the space stuff. The plane would return to refuel for the next delivery.


The cost of a hypersonic flight + skyhook is still massively lower than the cost of a LOX-Kerosene rocket taking you to orbit.

Read Decent of the Anansi. Loved it, although the shuttle program was a total disaster. It was more of an employment program than practical. NASA bought into the Specific Impulse hydrogen religion, and it cost them big time.

I agree with phaedrus. The logistics of synchronizing a capture by the hook would be daunting. There really is no margin for error. A head, tail or side wind could easily cause your craft to miss the rendezvous even if you launched precisely at the moment you needed too.

Vosur, Anjele, Hanoff.....have you learned nothing in my absence?
Find all posts by this user
Like Post Quote this message in a reply
05-04-2013, 03:23 PM
RE: Build a Hypersonic Orbital Sky Hook
(03-04-2013 09:50 PM)DeepThought Wrote:  Possible using todays technology but I haven't seen much information on it. There seems to be no interest in developing it and I wonder why.

[Image: 220px-Skyhooks.gif]

From Wiki: A variation of this technique that appears to be currently possible is to have the tip speed of the cable lower than the orbital speed and use hypersonic aircraft to catch the tip while it is in the upper atmosphere.
This is probably possible with current technology as it doesn't need such high strength materials for the cable.


Interesting. But as an aerospace engineer myself, I'd have to say a direct runway to orbit vehile would be more efficient for LEO payload delivery and a space elevator would be more feasible for geosynchronous orbit delivery.

Reasons: if you're going to build a hypersonic aircraft (Mach 10-15) which rides in the uppermost layers of the atmosphere (>130,000ft), why not include a combined cycle power plant which can use rocket engines for the final boost from there until orbit. By reaching that point in flight you've already accomplished 70% of the work to get out of the atmosphere and gravity well of the earth and into orbit. Why not go the final step and push all the way into LEO for a small payload reduction? Even better, just design a hypersonic mothership carrying a rocket propelled daughter craft that can reach orbit from there.

"IN THRUST WE TRUST"

"We were conservative Jews and that meant we obeyed God's Commandments until His rules became a royal pain in the ass."

- Joel Chastnoff, The 188th Crybaby Brigade
Find all posts by this user
Like Post Quote this message in a reply
05-04-2013, 07:29 PM
RE: Build a Hypersonic Orbital Sky Hook
I don't really know much about it.

I was thinking along the lines of aircraft being able to use atmospheric oxygen to burn its fuel and large wings to take advantage of the atmosphere and efficiently carry a payload/spacecraft near the skyhook.

The spacecraft is capable of thrust vectoring for accurate control. The spacecraft has no need for wings - that would make it vulnerable to wind and would make it needlessly heavier.

In theory multiple of these skyhook systems could be used in different orbits. The first takes you to LEO, and a couple more steps take you to GEO.

The spacecraft could control when to let go of the cable so it would just take a bit of accurate number crunching to time the release properly and attach to the next skyhook.


Isn't it inefficient to have spacecraft with wings? The shuttle demonstrated this. The Soyuz could launch in almost any weather with 0 visibility and high winds.
The shuttle launches were frequently rescheduled because of wind - (the wings would snap off in high wind while bolted to the launch structure and full hydrogen tank.)

Soyuz: 7.8 tonnes to LEO, Total Mass 305 tonnes, Launch Cost ~$40million
Space Shuttle: 24.4 tonnes to LEO, Total Mass 2030 tonnes, Launch Cost ~$450million

If you do the maths you can do 11 soyuz launches for the price of one shuttle launch. Thats ~85 tonnes in orbit vs 25 tonnes.
In terms of payload vs total mass the soyuz is 2.6% efficient. The shuttle is 1.2% efficient.

So, from that perspective it look like a massive benefit to separate atmospheric stuff from the space stuff. Could save allot of fuel with a skyhook system.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
05-04-2013, 07:50 PM
RE: Build a Hypersonic Orbital Sky Hook
(05-04-2013 07:29 PM)DeepThought Wrote:  I don't really know much about it.

I was thinking along the lines of aircraft being able to use atmospheric oxygen to burn its fuel and large wings to take advantage of the atmosphere and efficiently carry a payload/spacecraft near the skyhook.

The spacecraft is capable of thrust vectoring for accurate control. The spacecraft has no need for wings - that would make it vulnerable to wind and would make it needlessly heavier.

In theory multiple of these skyhook systems could be used in different orbits. The first takes you to LEO, and a couple more steps take you to GEO.

The spacecraft could control when to let go of the cable so it would just take a bit of accurate number crunching to time the release properly and attach to the next skyhook.


Isn't it inefficient to have spacecraft with wings? The shuttle demonstrated this. The Soyuz could launch in almost any weather with 0 visibility and high winds.
The shuttle launches were frequently rescheduled because of wind - (the wings would snap off in high wind while bolted to the launch structure and full hydrogen tank.)

Soyuz: 7.8 tonnes to LEO, Total Mass 305 tonnes, Launch Cost ~$40million
Space Shuttle: 24.4 tonnes to LEO, Total Mass 2030 tonnes, Launch Cost ~$450million

If you do the maths you can do 11 soyuz launches for the price of one shuttle launch. Thats ~85 tonnes in orbit vs 25 tonnes.
In terms of payload vs total mass the soyuz is 2.6% efficient. The shuttle is 1.2% efficient.

So, from that perspective it look like a massive benefit to separate atmospheric stuff from the space stuff. Could save allot of fuel with a skyhook system.

I'm sure you could save a lot of fuel with a skyhook system. However if you are Verizon and you want a new satellite placed in geosynchronis orbit, its just cheaper to pay for a tried and true booster stage to take it there then it is to developed a skyhook system and hope it works.

Vosur, Anjele, Hanoff.....have you learned nothing in my absence?
Find all posts by this user
Like Post Quote this message in a reply
05-04-2013, 07:52 PM
RE: Build a Hypersonic Orbital Sky Hook
Now when I think about how much money NASA has sent on a conveyor belt straight into a furnace thanks to the Shuttle program it makes me want to cry.

If that money was spent on soyuz launches instead we would have enough tonnes up there to create an asteroid mining industry and space factories to create spacecraft and space stations out of asteroid materials. We'd have thousands of extra tonnes up there.

NASA - The money burning experts. Burning money - ok... Burning money and having nothing to show for it... not ok.

Fucking NASA Dodgy

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
05-04-2013, 07:55 PM
RE: Build a Hypersonic Orbital Sky Hook
(05-04-2013 07:50 PM)Heywood Jahblome Wrote:  I'm sure you could save a lot of fuel with a skyhook system. However if you are Verizon and you want a new satellite placed in geosynchronis orbit, its just cheaper to pay for a tried and true booster stage to take it there then it is to developed a skyhook system and hope it works.

The skyhook system works with the already well known laws of physics. It's also a much smaller undertaking than a space elevator project. Takes allot less infrastructure and money upfront.

If it is used it saves fuel. ALLOT of fuel.

“Forget Jesus, the stars died so you could be born.” - Lawrence M. Krauss
Find all posts by this user
Like Post Quote this message in a reply
05-04-2013, 07:56 PM
RE: Build a Hypersonic Orbital Sky Hook
(05-04-2013 07:52 PM)DeepThought Wrote:  Now when I think about how much money NASA has sent on a conveyor belt straight into a furnace thanks to the Shuttle program it makes me want to cry.

If that money was spent on soyuz launches instead we would have enough tonnes up there to create an asteroid mining industry and space factories to create spacecraft and space stations out of asteroid materials. We'd have thousands of extra tonnes up there.

NASA - The money burning experts. Burning money - ok... Burning money and having nothing to show for it... not ok.

Fucking NASA Dodgy

NASA is part government jobs program.

Vosur, Anjele, Hanoff.....have you learned nothing in my absence?
Find all posts by this user
Like Post Quote this message in a reply
Post Reply
Forum Jump: