Category: Space and flight

Posts about flying in atmospheres, or outside of them

Little-known feature of the GPS constellation

The Global Positioning System (GPS) is a constellation of twenty-one primary satellites, and three spares, in near-circular orbits 11,000 miles above the earth at an inclination of 55 degrees to its equator. While the satellites are best known for their role in allowing the precise location of individuals and objects, by 1995 they had been performing an important secondary mission for over a decade. Every GPS satellite since GPS-8, launched in 1983, had carried a Nuclear Detonation (NUDET) Detection System (NDS) package on board. The NDS includes x-ray and optical sensors, bhangmeters, electromagnetic pulse sensors, and a data-processing capability that can locate a nuclear explosion to within one hundred meters. Data is reported on a real-time basis directly to either AFTAC or ground stations at Diego Garcia, Kwajelein Atoll, Ascension Island, or Keana Point, Hawaii. See Jeffrey T. Richelson, The U.S. Intelligence Community, 4th Ed. (Boulder, Colo.: Westview, 1999), pp. 218-219.

Richelson, Jeffrey T. Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea. W.W. Norton and Company; New York. 2007. p. 403-4 (paperback)

The Vela double flash

During the readout of Vela 6911, AFTEC personnel watched as a stylus drew a figure representing the variations in light intensity, as monitored by the two satellite bhangmeters. There was no data from a third optical sensor, whose mission was to provide the geographic origin of any noticeable flash of light, because it was out of commission. Nor would there be any reading from the satellite’s electromagnetic pulse sensors, which were no longer functioning. But what the technicians saw was sufficient cause for concern. The stylus drew a figure with a double hump, indicating a brief intense flash of light, a dramatic decline in intensity, and then a second, longer-lasting flash. Such double flashes had always been associated with nuclear detonations, where the fireball’s surface is rapidly overtaken by the expanding hydrodynamic shock wave, which acts as an optical shutter and hides the small but extremely hot and bright early fireball behind an opaque ionized shock front which is comparatively quite dim. The initial flash normally lasts only a millisecond and emits about only 1 percent of the total thermal energy, although it is the point of maximum intensity. It appeared that some nation or nations, in some part of the world covered by Vela 6911, had detonated a nuclear device in the atmosphere.

Richelson, Jeffrey T. Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea. W.W. Norton and Company; New York. 2007. p. 285 (paperback)

Watching the aurora

Thanks to the intervention of my friend Amanda, I spent the weekend at my friend Sabrina’s cottage on Paugh Lake, near Barry’s Bay, Ontario.

I had high hopes for a clear view of the fading Perseid meteor shower on Friday and Saturday night. Friday night was overcast and raining, though it was still remarkable to be in a place where rain falling on roofs and water, along with animal noises, were the only things audible. I am not sure when I was last outside a major urban area, but there haven’t been many cases since I moved to Toronto.

Saturday gifted us with perfect astronomical viewing conditions: far from city lights, and untroubled by the moon. We didn’t see a lot of meteors, but the sky was so full of stars that it made identifying familiar constellations a challenge. Across the sky, the band of the Milky Way was clearly visible, wheeling above us as the night went on.

Experimenting with some long exposures with my Fuji X100S (and a stepladder and dishcloth as an improvised tripod) I was surprised to see that the vague light in the northern sky came out as brilliant colour when photographed at 1600 ISO with a 30″ exposure.

I ended up spending hours photographing the aurora. There will be high quality images soon (and animated GIF is a terribly low-quality format for something so beautiful), but I wanted to put something up right away that would show the movement of the lights.

You may need to click the thumbnail to see the animation:

Aurora Borealis from Paugh Lake, Ontario 1/3

Aurora Borealis from Paugh Lake, Ontario 2/3

Aurora Borealis from Paugh Lake, Ontario 3/3

Aside from reducing the resolution and converting them to GIF format, these images are straight from the camera, not manipulated with any sort of software.

Out in the Edgeworth–Kuiper belt

NASA’s New Horizons spacecraft has been returning some exciting data, after a long flight through the solar system:

This documentary provides illuminating background on the mission: The Year of Pluto.

It is much to be hoped that the New Horizons craft will be able to observe other Kuiper belt objects.

Prism Designs “Quantum” two-line kite

I have had so much fun with my $17 Toys ‘R Us DC Sport 60 delta wing kite that I am thinking about getting something more sophisticated to play with: the Quantum two-line kite from Prism Designs. It’s another delta wing, so the basics of control will be similar. It’s tough enough to let other people crash, and has enough power to lift a light still or video camera.

I considered parasail-style kites, but while they may offer a great deal of power, they seem to have a narrower range of acrobatic possibilities.

I basically want something that I can fly in a range of wind conditions, let total amateurs learn on, and possibly use for some aerial photography. I will start setting aside a fraction of what I earn in commercial photography as a kite fund.

It even seems possible that regular kite-flying could have a therapeutic effect on the chronic pain from my collarbone injury. It’s plausible that it could help with both strength and range of movement.

STS-27/107

I fear that my list of project ideas, which I assemble out of an optimistic hope that the future will bring a long span of free time for such undertakings, includes an idea for a screenplay.

It would be a film in the style of Apollo 13 (technically and historically accurate, and developed with lots of research in collaboration with the people involved) based on the STS-27 and STS-107 Space Shuttle missions.

I have a bunch of ideas, but I definitely don’t have time to write such a script, given my work with Toronto350.org, photography, and being on strike as a TA at U of T.

Still, I think it could be a powerful story. Ultimately, it’s a sadder story than Apollo 13, which may limit its aesthetic and commercial appeal. Still, like any story about crewed spaceflight, this is a story of courage and dedication applied in the pursuit of scientific understanding. Twelve amazing people: 5 who lived and 7 who died.

I can provide a more detailed breakdown of the screenplay idea, if someone wants to try working on it a bit.

First Kerbal Space Program Mun return vehicle

The category ‘Geek stuff‘ doesn’t begin to cover this one. At the same time, I am grateful when ‘Bombs and rockets‘ isn’t about killing real people.

I used to take breaks from academic work by playing Starcraft II, but I haven’t loaded that game once since I got the demo and eventually the full version of Kerbal Space Program (KSP). It’s unambiguously one of my favourite games of all time. Nonetheless, there are several steep learning curves. Each stage of your development in KSP roughly approximates an area of knowledge necessary for real rocket science: maneuvering, orbital mechanics, rocket design, the understanding that a lot of your astronauts will die because of your mistakes (especially if you tinker with spaceplanes).

The full version of the game doesn’t come with a craft that has a decent chance of landing on the Mun and returning safely to Kerbin. I have modified the Kerbal X to be able to do this with amateur piloting skills.

This craft relies on a couple of plugins: MechJeb (fly to the Mun, land, and return home without using it at all for major geek points) and Kerbal Joint Reinforcement (your rocket may shake apart and explode without it).

Here it is: Modified Kerbal X with more fuel and engines and extras to help you land on the Mun (version IV)

Don’t kill the Webb!

With the last Space Shuttle mission ongoing, people are naturally asking what the future of space exploration is going to be. It seems clear that ambitious plans like a manned mission to Mars are a non-starter in the current fiscal climate. That being said, one of the major reasons why such missions are basically off the table is because they are not very useful. It would be very difficult to get human beings to Mars and then return them alive to Earth, but it wouldn’t teach us much about the universe.

By contrast, the James Webb Space Telescope is designed to be the successor to Hubble: one of the most successful scientific instruments of all time. Much of what we know about the universe has been established, confirmed, or refined using data from that instrument. As such, it is saddening to hear rumours that the Webb telescope may be scrapped fur budgetary reasons, if NASA experiences funding cuts of a certain magnitude.

It seems to me that would be a great shame. While the Webb will cost billions of dollars, it will also actively push forward the boundary of human knowledge and give us a better sense of what the universe is like. Launching it is something that humanity ought to do, even if we are experiencing economically difficult times. Basic science is something that builds upon itself, as new data is collected and new experiments are carried out. It is impossible to know in advance what the consequences of some seemingly obscure bit of cosmology or astronomy or physics will be. For instance, who would have predicted that special relativity would one day permit the precise geographic location of inexpensive receivers, using coordinated time signals from satellites (GPS).

For the sake of the important human undertaking of understanding our universe, we should find the money for the Webb.

Retiring the Shuttle

This year, after 29 years in operation and two catastrophes, the American Space Shuttle program is shutting down. The Shuttle was always a hacked-together prototype vehicle, never the cheap and dependable satellite-launching workhorse that NASA seemed to promise Congress. Lots of effort and brilliance went into the thing – make no mistake – but trips to space have never been safe or routine.

The Wikipedia entry on the Shuttle details just how costly the thing was, as a way of putting objects 300 or so kilometres above the Earth:

When all design and maintenance costs are taken into account, the final cost of the Space Shuttle program, averaged over all missions and adjusted for inflation, was estimated to come out to $1.5 billion per launch, or whopping $60,000/kg to LEO [low Earth orbit]

There are things that are worth putting into orbit at those prices – chiefly communication satellites and others designed to observe our planet and the wider universe. Human beings probably aren’t worth it, for now at least. The process of getting out of the atmosphere is perilous and costly, and there is nowhere remotely habitable to go, once you get up there.