Tuesday, June 30, 2009

IEEE Spectrum on Mars

Over the last month IEEE Spectrum have been doing a special on "Why Mars, Why Now"

They don't seem to have a permanent home for all the articles, so here are a few links in case some disappear:

http://spectrum.ieee.org/mars (actually returns a 404 error, but this link was found on an IEEE page and was redirected to previous link. Maybe they intend to make a new page with this link in the future.)

I'm putting their spaceflight section in the sidebar links.

Monday, June 22, 2009

Amazing artificial muscle made from CNT

If half the claims in this article at IEEE Spectrum (actually from March, but I only discovered it a couple weeks ago) are true, we may be about to enter a new era of biomimetic robotics. In my robotics class last year, I learned that robots are usually quite weak for their size. To design a robot that can pick up another robot the same size and weight is still a difficult challenge. This invention may change that. The only thing is I can't see how the wine-rack explanation for how it works matches the claim of 220% dimensional change made in this video, unless they are referring to lateral dimensional change which doesn't seem to be very useful.

There must presumably be some more development work before they can be set to use, otherwise if it were me, I couldn't wait to try putting them into robotic arms and fingers and make a much more impressive demo.

Importantly this could be a good initial application for long nanotube fibers. In the video, those fibers look so much like space elevator cable sections!

Thursday, June 04, 2009

X37 - some speculation

I'm pretty pleased about the story about the X37B in space.com. It's funny how USAF and DARPA seem to be playing tortoise to NASAs hare. While the US military may not be the most efficient organization either, at least they seem have a good handle on what 'operational' means and the importance of having a well thought out plan for maintaining and running a system when it gets past the development stage, and how important it is to design a system with operational requirements in mind. The X37B is, of course, an experimental platform but it is interesting to speculate on what it might develop into in conjunction with a suitable heavy lift launcher.

I assume that the planned tests will involve integrating the X37B into an EELV as purely a payload, ie the current 1st and 2nd stages of the launch vehicle will be used. This will put a small winged return vehicle into LEO. It is interesting to compare the possible capabilities of a hypothetical, operational follow up to this system with the needs of USAF in space.

As I understand the USAF would like to have the following:
-ability to protect/replace assets in space,
-rapid and repeated delivery of munitions anywhere, anytime,

A followup system to the X37 could possibly have the following capability:
-rapid launch to orbit via heavy lift including possible recovery of the first stage if SpaceX are eventually successful with that,
-rapid turnaround between flights if the turnaround time between heavy lift launches can be reduced,
-ability to insert an object into orbit and return to a designated landing site,
-(maybe) launch to a suborbital trajectory over a target location, followed by powered return to CONUS.
-ability to loiter in orbit, with scope for limited orbit changes,
-ability to drop a payload during some sections of its non-orbital flight path.

some limitations:
-Whether you think this limitation is a good or bad thing depends on your point of view, but I can't see this hypothetical system becoming a 'space weapon' capable of dropping munitions from orbit simply due to the impracticability of having to decelerate the payload from orbital velocity, and only being over the target every 90 minutes or so. (although I suppose such a system might solve a need to avoid overflights of aircraft or missiles of other non-participating nations)
-The second stage will be disposable for any standard launch system in the forseeable future.
-In the event of a full fledged attack on space borne assets, it would be vulnerable to orbital debris.

The best part is that a successful operational system will be a good demonstrator for a commercial reusable orbital stage so I'm hoping that something practical comes out of this program. Who knows if one day we might be seeing routine launches of winged orbiters atop VTVL launchers.

changed my links again

After I got in email contact with the author of the ISS blog offering me a 'link exchange' (see 2 posts back in comments) I strongly suspected based on the email I received that the blog was a mashup done by a group of professionals, probably in a poor part of the world where the work involved might actually pay enough to be worth it. This was confirmed by a google search of a text sample from the blog that returned an article in the NASA site. I should have guessed it before due to the odd nature of the blog's own links. (men's suits indeed!) The link is gone and I've replaced it with a couple of links to sites that make their own content.

To anyone who wants to propose a link exchange, the site you want me to link to needs to have 3 qualities:
-be interesting to me,
-be maintained by a human,
-be of sufficient quality.

frankly I would probably fail my own blog based on the last point (and yes I am human :-) )

Tuesday, June 02, 2009

Relay board completion

I've finished the relay board and it's been working well for several weeks. We can now independently control up to 32 24V valves, expandable to 35, plus 3 spark plug igniters. I discovered that I had made some mistakes with the PCB design after all, when I received it which was a bit disappointing. Fortunately there were some relatively simple workarounds that didn't require carving up the board. I'm not sure if I subconsciously screened the design for really bad errors and just ignored the others. It just goes to show that absence of anxiety about a design should not be the only indicator of the quality of said design!

A reader asked me if we could swap links, so I have put a link to his ISS blog in the sidebar. Somehow, when I changed the blog design the old links were lost. I'll have to get around to adding some more soon.

I'm heading into a period of reduced busy-ness, especially following my final exam next week, so hopefully I can start posting a bit more often. There is certainly no shortage of topics to post about at the moment!