Showing posts from May, 2010

NASA FTDP, find out what it means to me

In 18 months time it is almost a law of nature that computer power will double. The same (with a smaller number of months) is true for DNA sequencing, and many other technologies follow exponential development curves. Why?To many of us it seems like magic, but there's a lot of work that goes into achieving these modern miracles. In 18 months time a new chip manufacturing technology will be available because years ago engineers started working on it. Other engineers are now working on the technology which will be used 18 months later. Some future technology which isn't even envisioned yet will build on the work of these technologies that have come before. When we peg dates to them, this is a Technology Roadmap.So, when some people talk about the NASA robotic exploration program being a success because it only develops technology as necessary to complete a mission, it ignores the primary driving factor of robotic capabilities: that law of computer power doubling every 18 mo…

The Radiation Exposure Numbers Game

The effect of prolonged radiation exposure on the human body is one of the potential show stoppers of long term human spaceflight. Yesterday we heard Zubrin present his traditional "don't worry about it" speech and another speaker refer to his reasoning as "the numbers game". By this, he meant that no-one in the audience is going to check those numbers so Zubrin can say whatever he wants. I think this speaker was missing the point. Let's look at what Bob was actually saying.
Zubrin's AssumptionsSix month transit times to Mars are available every 2 years
Radiation exposure on the Mars surface is negligible due to the availability of dirt for shielding
Solar radiation in deep space can be shielded against, so galactic cosmic radiation is all that matters
The GCR dose in LEO is about half that of deep space. It's about 55%
Mars crews would consist of 5 people
The ISS will continue to be crewed permanently by 7 people
Under these assumptions, a Mars progr…

Mars Direct vs FY11 NASA Direction

This morning Bob Zubrin will be arguing the case for Mars Direct over the NASA future direction. This is what I'd really like to be able to talk to him about but probably won't get a chance to. [About an hour after I wrote this post a friend of mine decided it would be hilarious to introduce me to Bob Zubrin and then run away. I started the conversation by saying that I thought he had too many strong, stupid and offensive opinions, but rather than punch me in the face or walk away he suggested we discuss our differences. And so we did.. for about 2 hours. He agreed with many of these points but insisted that new NASA administration won't actually be doing any of the stuff they say they will.. we'll see.]

There's a lot of common ground between the two plans but all the focus is, of course, on the differences. Dr Zubrin can't be happy that NASA is doing work that supports his plan, only being appointed the Space Czar will do.

Common Ground

"Mars as destin…

Gravity Plating Part 2

In an earlier post I described a system for generating zero-g in the laboratory and how this might be used to generate a standard gravity on-orbit and for deep space missions. Today, Narayanan Ramachandran of NASA-Marshall gave a talk at ISDC and I had the opportunity to ask him a few revealing questions. As I expected, there is few technical problems with operating a system such as this in space. Superconducting magnets of sufficient size to levitate a human exist and, although they cost a lot for laboratory use, they are chump change for a human spaceflight program. The power requirements are not excessive for the advanced solar power systems NASA is planning to bring online over the next few years, or for the in-space nuclear power systems that may become available eventually. There was also some discussion about how much gravity humans need to maintain healthy bones, which was the primary motivation for the technology. Not for the first time I'm tempted to look up suppli…

Hitching Rides

Too many times I have read the claim that with the retirement of the Space Shuttle this year NASA will be "hitching rides with the Russians" to the International Space Station. A number of writers have taken it upon themselves to stress that Shuttle retirement was a decision made by the Bush administration, not by the Obama administration, and although this is true I think it is really beside the point.

It has always been the plan to fly expedition members to the ISS on the Soyuz. That was the deal, the Shuttle builds the station and the Soyuz rotates the crew. Since late 2000, that's exactly what the Soyuz has done, and a permanent human presence has been maintained on the ISS. Every time the Shuttle flies to the ISS it is for a visit, of no more than 10 days as that is the limit of on-orbit endurance of the Shuttle.

If the shuttle wasn't retiring this year the missions they would be doing would be resupply - and maybe some more experimental hardware installatio…

Planetary Protection

Planetary protection is something for which, I think, a broad base of support exists. It has many facets:

earth monitoring
solar monitoring
potentially hazardous NEO monitoring
basic science for the understanding of the sun and asteroid/comet composition
high performance computer simulation and prediction of solar and NEO threats
technology development and demonstration for the purposeful diversion of NEO threats
harnessing of solar power
utilization of extraterrestrial resources; and
eventual migration of polluting industry off-earth.

Quite a number of these are best done using robotic tools, satellites for example, but some of them are what we could call "exploration" and can be done most effectively, in terms of time, with human missions – and time matters. Every day we don’t have a good understanding of NEO composition, for example, we’re in danger of incorrectly characterizing those threats.

When we start recognizing that external threats to the earth are real and require con…

Gravity Plating

A common plot device in science fiction like Star Trek that allows crew to walk around in full gravity on spaceships is Gravity Plating. The idea is simply that the ship is plated with some magical technology that dramatically decreases the strain on the show's special effects budget :)

Having just this technology would have a major effect on NASA's future long duration missions asteroids, Mars and beyond, not to mention stays on the International Space Station.

Serious discussions of artificial gravity generation today are based on the concept of rotating the habitation module. Either a big torus like in 2001 A Space Odyssey, Mission To Mars, Red Planet, and Babylon 5 or, more practical, using a long tether between the habitat and a counterweight, say the expended trans-mars injection stage. Both options are incredibly difficult to do and dangerous. As such, their discussion in NASA circles has been virtually taboo for decades.

Which is why recently, while thinking abou…

Birds Of A Feather

Scott "Doc" Horowitz recently [1] published a rant on The Mars Society, and among the stupidity was this gem:
The COTS providers (Orbital and SpaceX) were awarded firm fixed price contracts totaling $3.5B to deliver approximately 40MT of cargo to the ISS. This, plus the $500M already invested in COTS, results in a cost of $100,000/kilo ($45,000/lb) to deliver cargo to ISS. If the Ares I/Orion were flown at a similar rate (6 flights/year) the fully-burdened government cost for delivering cargo to ISS would be about $70,000/kilo ($32,000/lb)!

Totally ignoring that there was no cargo block for Orion, what about the estimated $35B to $40B that Ares I + Orion is expected to cost? How about adding that in?

It's just like how Zubrin claims that NASA's budget today is the same as it was during Apollo [2].. by cherry picking 13 years from the Apollo period [3] (and in some retellings the 90s too) and then defining "the same" as 21% more. [4]

You'd think that c…