Thursday, April 12, 2007

Happy Anniversary


April 12 is Yuri's night, celebratingh the anniversary of Gagarin's 1961 flight. Exactly 20 years later April 12, 1981 was Space Shuttle Columbia's first flight. This was no design, but an accident caused by combinations of flight delays. The Shuttle did make Space flight more routine than it was for Gagarin, but never achieved the hope of airline-like access.

Many errors were made in the shuttle programme. Abandoning the Apollo/Saturn hardware was a huge mistake. It would have benefitted the US to develop a smaller spaceplane first, like the X-20 Dyna-Soar. A spaceplane came in handy during the movie MAROONED. ISS is limited to a crew of three because a spaceplane escape vehicle was cancelled for budget reasons.

The big delta wings are not necessary. Originally Shuttle was designed with stubby wings, like the X-15. When the US Government Accounting Office concluded that Shuttle was only economical if it replaced every other booster, NASA responded by cancelling every other booster. This forced the Air Force to adopt Shuttle, for which they demanded a larger payload diameter and cross-range capability. Supposedly the heavy wings would allow Shuttle to land at Air Force bases, a capability that was never used. The wings add weight and drag, but do provide a big target for foam strikes.

Today I've been working on a technology that will make human spaceflight safer, cheaper and far more comfortable. I hope to be able to write about it sometime.

Labels: ,

8 Comments:

Blogger nige said...

"Many errors were made in the shuttle programme. Abandoning the Apollo/Saturn hardware was a huge mistake."

I agree. The problem with the shuttle is that its maximum altitude is about 1,000 km. That's only about 15% of earth's radius. So they can't even get up high enough to see the whole earth without having to turn the head.

Gravity is of course the problem. You need 60 MJ to send one kilogram into deep space, ignoring atmospheric drag.

You need big rockets to do things, not small ones. Nuclear power is controversial for rockets, but space is anyway full of extremely intense radiation that only gets shielded from us by the atmosphere (equivalent to 10 metres of water shielding) and by the magnetic field which deflects, traps (in the van allen belts) and slows down a lot of the lower energy charged cosmic rays. The ionizing radiation background on the moon at solar minimum is about 1 mR/hr which is 50 times higher than the normal background on the earth.

There's a pro-nuclear http://www.nuclearspace.com/ for nuclear spacecraft ideas, particularly see the Project Orion animation at http://www.nuclearspace.com/gallery_orion_movie.htm.

A far more crazy idea is the space elevator which has a long Wikipedia page at http://en.wikipedia.org/wiki/Space_elevator.

The idea is nice: you avoid having the problems of gravitational potential energy by using a belt between two pulley's and hauling people up at the same time as allowing others to descend, so the system is in balance and the only losses are friction on the bearings. However, to work it needs the upper part to be in geostationary orbit at 35,786 km altitude. It's obviously not going to work because the thickness of the belt or pulley cables would be immense to avoid the risk of breakage, and the weight would be astronomical.

It would be highly sensitive to motion caused by the earth's spin and the moon, since its mass and length would amplify effects such as those you get with the Foucault pendulum. Basically, it's a crackpot idea.

The only practical way to get into space with a view of getting to the moon or planets is with really big rockets like the Saturn V or bigger.

7:12 AM  
Blogger nige said...

By the way, Project Orion is fairly interesting. I read about it first in the book "The Curve of Binding Energy" by John McPhee.

The book is about Dr Theodore Taylor, who headed Project Orion until it was scrapped by NASA and the U.S. Department of Defense in 1963 because the nuclear test ban treaty prevented it being tried with nuclear explosives.

The basic idea was based on experiments during 1956 Redwing nuclear tests where it was found that the nuclear fireball could impart momentum to things without destroying them. Ablation of the surface by x-ray and thermal radiation creates a reaction force, while the cloud of ablated material automatically cuts off further damage, so only a thin surface layer is affected. There's also a film declassified showing an instrument pod which was in the fireball region of a high altitude 3.8 megaton nuclear explosion at Operation Hardtack in 1958. The pod was dented by x-ray ablation, but it wasn't totally vaporized: http://www.archive.org/details/OperationHARDTACK_HighAltitudeTests1958.

Project Orion envisaged exploding nuclear bombs slightly off a spring-loaded thick steel pusher plate, which would gain momentum. Because nuclear bombs are now very lightweight and pack a big punch, it would be more efficient to use them to power a spacecraft, than to use thousands of tons of chemical fuels.

7:26 AM  
Blogger L. Riofrio said...

Thanks, nige. A future post will deal with the Space Elevator and something even more advanced.

8:18 AM  
Anonymous Darnell Clayton said...

Hey Louise,

Regarding this:

Today I've been working on a technology that will make human spaceflight safer, cheaper and far more comfortable. I hope to be able to write about it sometime.

I'll be looking forward to that post!

Thus far, I've only heard of Space Elevators, Magnetic sleds, Magnetic Lifters and nuclear powered rockets as possible solutions at reducing the cost.

Chemical rockets could work as long as there is an enormous amount of economics of scale (i.e. thousands of companies using it every year) to cheapen the fuel costs, but aside from that I do not see that happening in the next 50 years.

PS

You said space elevators? ;-)

3:38 PM  
Blogger L. Riofrio said...

Darnell, it is always nice hearing from you. Your blog entertains every day. A post on Space Elevators (and something even more futuristic) is coming soon.

The other technology I'm currently working on will hopefully be ready for unveiling by midyear, though I can't make any promises. You will love it, and it is far more advanced than anything on the market.

7:12 PM  
Blogger Kea said...

Louise, the participant list for GRG18 is up and I don't see your name on it - remember to register! Same goes for Carl B et al.

3:05 PM  
Blogger CarlBrannen said...

Kea, they extended the deadline for signing up. This means that I get to think more carefully before sending them in a paper.

Carl

5:37 PM  
Blogger L. Riofrio said...

Thanks Kea, am working on that by end of next week.

7:16 PM  

Post a Comment

Links to this post:

Create a Link

<< Home

Locations of visitors to this page