NASA designs an actual spaceship

The Nautilus-X MMSEV is the closest NASA has come to a design for an honest-to-goodness spaceship in decades. There has already been extensive discussion over at Selenian Boondocks and Hobbyspace, and this is probably a couple weeks late on the subject. However, this is an idea that has considerable merit and deserves further study. So, I uploaded the Holderman powerpoint to Google Docs, and here it is:



If you click on the "open in new window" button, then you can view it in full screen.

There is a lot that I like about this design - in fact, much of it looks like items on my list of technological stepping stones to space. For one thing, it is modular. Yes yes absolutely yes. Several launches are required to put it together, all of which could be done with existing vehicles (with one exception which I'll get to later). It includes a centrifuge, which might mitigate some of the bone loss effects of microgravity. It includes inflatable modules. Above all it is a spaceship - its environment is space, it has no landing gear or reentry heat shield.

Now, there are some things I don't like about the Nautilus-X.

That big core section would require a single launch, probably on something heavier than anything in stock today. It has RV-style slide-outs for the command deck and a large airlock. Worst of all, it has flat walls - probably due to the slide-outs. The flat walls and slide-outs are brand-new technology that introduce unnecessary failure modes and complexity. This could be redone as two pieces with curved walls: the radiation mitigation chamber is one piece, the airlock and command deck are another, set "sideways" to make a T shape. These two smaller pieces could then probably be launched on existing launch vehicles.

The centrifuge radius is an educated guess. We don't know the minimum gee required to reduce or eliminate bone loss. That particular centrifuge would produce no more than a few percent of a gee (i.e. about lunar gravity at 4RPM by my estimate) before problems due to high angular velocity start to occur. If a few percent gee is enough to slow or stop bone loss, great! If not, then this centrifuge would be an added layer of complexity for limited benefit. There would be benefits, no doubt, particularly for things like eating and ablutions, but the primarily-intended benefit would be missing. The bearings on the centrifuge - allowing nearly frictionless rotation while not allowing atmosphere to escape - are going to be a novel engineering challenge.

The MMSEV is intended for very long duration missions, up to two years. Unlike satellites in low earth orbit, which spend half their time in Earth's shadow, the MMSEV would be out in cislunar space or interplanetary space constantly being exposed to the sun. The entire craft would have to do a slow "barbecue roll" to avoid overheating one side, most likely along its long axis in the opposite direction of the centrifuge. Canfield joints at the end of the beams holding the big solar panels would allow them to continuously track the sun during the barbecue roll.

It's a good start.

Update Mark Holderman responds.

demolishing global warming

The theory of anthropogenic global warming (AGW) is based upon the following principles:

• the global climate is changing
• carbon dioxide content of the atmosphere is increasing due to human industrial activity
• the increase in CO2 concentration increases the amount of heat trapped in the atmosphere
• this could cause a runaway effect making the earth uninhabitable

This is all presented as though it is established fact, and that the obvious conclusion is that we must greatly decrease the amount of industry worldwide -- achieved through regulation, internationalism, and so-called "green" activity.

But what if one of those principles above is wrong? What if CO2 concentration is not correlated to average global temperature? What if the current variation is in fact insignificant?

The glaciers of Greenland have yielded thousands of ice core samples to scientific survey. Significantly, the Oxygen-18 isotope concentration in the ice is a good proxy for average global temperature over a long timescale. A water molecule containing O-18 is 11% heavier than the O-16 water molecule, so it takes more energy to get a water molecule containing O-18 to evaporate into the atmosphere than it does for O-16. This heavier isotope is more abundant in the snow when the temperatures are warmer, and less abundant when it is colder globally. The ratio of O-18 to O-16 in the ice corresponds to a temperature at ancient glaciers in Greenland - a yearly average high-resolution record going back over 100000 years.

Dr. Don J. Easterbrook has an analysis of these ice core samples, analyzing the rates of change of temperature:

Temperature changes recorded in the GISP2 ice core from the Greenland Ice Sheet show that the magnitude of global warming experienced during the past century is insignificant compared to the magnitude of the profound natural climate reversals over the past 25,000 years, which preceded any significant rise of atmospheric CO2. If so many much more intense periods of warming occurred naturally in the past without increase in CO2, why should the mere coincidence of a small period of low magnitude warming this century be blamed on CO2?

So that about does it for anthropogenic global warming.

Update: Here's another view, looking at ocean sediments, providing a temperature reading dating back 65 million years. And here is the GISP2 data; see for yourself.

civility in politics?

Ya gotta be kidding me. After eight years of reading about Chimpy mcBushitlerburton? After seing how the Left conducts demonstrations (oh yeah, all those balaclava-garbed idiots throwing firebombs at G20 meetings are "anarchists"), Obama's frequent threatening tone ("... so we know whose ass to kick"), and an incident where Sara Palin was hung in effigy ("For weeks the life-size mannequin of Republican vice presidential nominee Sarah Palin that hung from a noose around its neck in front of Morrisette's West Hollywood home caused little controversy.")- now you want civility?

Lemme tell ya something, princess. Politics ain't ever been civil:



update the next day: remember this from just a few months ago? I could probably dig up a hundred more examples if I wanted to.



I'm with Don Surber. Bite me.

Messing with the template. Again.

Longtime readers (yes, there are a few) will notice something different today; I've changed the blog template again. This is an old tradition here at Robot Guy, going back to the very first days of this blog; the stable template of the last few years has been the anomaly.

The change was forced on me by Blogrolling.com; while I had displayed rather a lot of blogrolls, many relied upon blogrolling.com to supply their innards. Alas, blogrolling.com has performed rather flakily for a while, and I just can't use it anymore. This is unfortunate, as the Space Blogroll was ensconced in blogrolling.com, and hundred of blogs out there were showing up as a big blank.

Well, Google Reader to the rescue. I had already entered as many blogs for which I could find an RSS feed as I possibly could over the course of the last several years. Now it turns out that Google Reader can produce a blogroll from the spaceblogs feed; the new Space Blogroll now resides on the left sidebar. I will probably be adding quite a few feeds to the blogroll over the next few months. I have also added the latest posts from space blogs and space news sites over on the right sidebar, also courtesy Google Reader.

Merry Christmas

An Inexpensive Space Infrastructure Improvement

Recently Jon Goff, Trent Waddington, and others have proposed some innovative space missions, space business strategies, and vital space technology tests that could be undertaken within the next few years. While I agree with much of what they propose, each proposal has a significant disadvantage: they all cost some entity a lot of money, more than seven digits after the dollar sign, up front.

One of the big expenses associated with any space mission is communication with the spacecraft. I think I have an idea that will bring down part of the cost of operating spacecraft communications with the ground, one that won't break the bank in up-front costs, and which will provide a boon to radio astronomy.

Currently NASA uses the Tracking and Data Relay Satellite System (TDRSS) for communications with manned missions and the Deep Space Network for communications with missions outside cislunar space. The TDRSS consists of several satellites in geosynchronous orbit and several ground stations each consisting of several large satellite dishes, and the DSN is three satellite dish complexes in California, Spain, and Australia.

It costs a lot of money to operate these big facilities. Anyone who wants to communicate with and control their satellite either has to build their own communications systems or rent the use of NASA facilities (or their Russian equivalents). As the number of launch providers and satellites launched increases, the scheduling on the TDRSS and DSN facilities will become tighter and tighter, the cost will rise, and eventually more and bigger dishes will need to be built.

However, there is another approach that takes advantage of an Army of Davids.

Currently there are about two million ham radio operators worldwide, and millions more electronics enthusiasts. There are many successful volunteer distributed processing efforts and open source collaborative software projects. And, take a bunch of widely-separated radio telescopes and combine their data using interferometry, and you end up with the equivalent of a telescope with an effective diameter equal to the largest distance separating the individual telescopes.

What if electronics/HAM/space enthusiasts worldwide were to be involved in a collaborative effort to improve communications with spacecraft? Each person involved would need a satellite dish, a way of pointing it controlled by software, and a connection to the internet. As a satellite orbits overhead and the earth turns below, multiple small radio dishes would work in concert to act as a much bigger virtual ground station. Each individual station would track a given satellite for a short time before moving to track the next one to come along, handing off communications to other stations down the line. Encrypted uplink and downlink data would travel over the internet (peer to peer?) to wherever the control center for a given satellite happened to be - a satellite could be controlled from a home office.

Satellite operators could then simply use an online satellite control and communications service. So who would be these satellite operators? Clearly the people operating billion dollar machines are going to continue to use the TDRSS and DSN for a while yet.

If we think of big expensive satellites like Hubble and Galileo as the equivalent to mainframe computers, then the "laptop computer" version of a satellite is the nanosatellite. For such small satellites, it simply doesn't make sense to have the same operational costs for communications as for the big satellites, nor does it make sense to use the big NASA facilities for such low-value targets.

However, a network of amateur ground stations running on open-source software over the internet would provide nearly worldwide coverage for these small satellites. Over time, as the network grows it would eventually become more robust (more fault-tolerant, better coverage, higher bandwidth) than the handful of big ground stations maintained by NASA and the Russians.

A second application of this satellite dish network exists. If a ground station isn't busy communicating with a satellite, it still has to point somewhere. If two such idle ground stations are separated by a thousand kilometers and pointing in the same direction, they can act as a single radio telescope a thousand kilometers across. The more widely-separated telescopes pointing in the same direction, the better the resolution. The network of small satellite dishes thus acts both as a highly-responsive very large array radio telescope and a robust satellite communication system.

Now, how will all of this be paid for? The individual dish operators would essentially be "Outernet Service Providers" (I wish I could claim credit for the clever name Outernet, but at least one company already had that idea; feel free to suggest another name). The software and electronics and so forth might be open source, but the service provider is still investing their bandwidth and electricity on a continuing basis, and they should be paid by the megabyte for their efforts. I'm thinking that the best way to do this is to set up an organization (non-profit? a business? more than one such entity?) that charges customers (astronomers or satellite operators) for data on a per-gigabyte basis and then reimburses the dish operators on a per-megabyte basis.

Such a network of ground stations would provide greater flexibility to researchers, and lower costs and improve service for satellite operators and their customers. The technology is fairly mature, the up-front cost for an individual ground station could be very low indeed (even zero), and there could be thousands of operational stations in as little as a year from now.

update December 23: Apparently the idea has some merit, because I'm not the only one to come up with it. Anonymous posted a comment over at HobbySpace about GENSO, a "software standard which allows each ground station on the network to communicate with non-local spacecraft and share data with the spacecraft controllers via the internet". This is an ESA-led project. And Trent Waddington points out the UNIFORM project being led by Japan.

Both of those projects share the idea of a distributed network of small ground stations linked by the internet for satellite data relay. I especially like the GENSO standard - at least someone has come up with the standard already, and they have 8 ground stations already operational (6 universities and two amateurs).

What I am proposing differs in scale - instead of a handful of ground stations, I'm proposing hundreds in the short term and eventually tens of thousands of ground stations. With that kind of redundancy and global coverage, one could conceivably make an entire hemisphere into a vast virtual deep space antenna or radio telescope. The availability of such a large network would lead to a dramatic drop in communications costs, extra redundancy for the Deep Space Network, and much greater flexibility in scheduling time for the big radio telescopes.

And while the GENSO and UNIFORM efforts are ESA-led and Japan-led, I'm calling for the open-source community to step up. I'm thinking that this is a job for the crowd at Hack A Day.

Falcon 9 test launch #2

What follows is the launch of the Falcon 9 carrying the Dragon capsule, followed by the post-flight press conference.