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Space

GOCE – the hidden life of a satellite

Published in Space


GOCE SpacecraftA number of years ago I worked for Astrium Space, a member of the ESA and EADS developing models and simulations of spacecraft attitude sensing and dynamics. “Attitude” meaning the orientation: roll, pitch, yaw, rates, sensors, and control algorithms.

Specifically, I worked on a revolutionary new Drag-Free and Attitude Control Subsystem, DFACS, that performs autonomous determination and control of the spacecraft’s attitude pointing, angular movements and linear and angular accelerations. You can download an article describing the system that was used for HYPER .

It was at this time, living and traveling extensively through Europe on short trips, constantly connected with a mobile phone, a cheap GPS receiver, and blogging and photo sharing that you could see the convergence and emergence of Where2.0. Fortunately the Wayback machine has my old blog “An American Engineer in Germany” recorded for posterity.

In addition, I was quite frustrated with the satellite industry. The politics and budgets that inexplicably cancel projects years, and millions of dollars/euros – or even when physics gives you a swift kick and dooms your satellite to a 30-minute flight before immediately de-orbiting. Not a rewarding way to end 10 years of hard work.

At Astrium, I was a member of the GOCE satellite team. The goal of GOCE, Gravity field and steady-state Ocean Circulation Explorer, was to utilize a very high precision gradiometer in order to measure the magnetic characteristics of the Earth. The benefit is a highly detailed gravitational model of the Earth’s geoide which can then inform ocean circulation and sea-level models, orbital predictions, space-time drag, and more. Since the force of gravity falls off at a cubic rate inverse square from the distance to the mass, GOCE must fly at a relatively very low altitude. It therefore uses continuous ion thrusters to compensate for atmospheric drag, and another reason the DFACS is so important.

About 6 months after leaving Astrium, I had been told that the project was shelved, and never wondered about it.

Then surprisingly, while at the UNGIWG workshop in Rome last February, a director of UNOSAT told me that GOCE was in fact completed and being boxed up for shipment to the launch site! Again I didn’t track it until a couple of weeks ago, twitter showed it’s power again and Astronautics pointed out that GOCE was launching!

On March 17, GOCE launched from the Plesetsk Cosmodrome in Northern Russia. GOCE is the first of ESA’s Core Missions of the Earth Explorer programme – others including atmospheric dynamics, ice sheet thickness measurement, radiative balance, and ocean salinity.

Gravitational Constituents of g

So while the space industry can be quite frustrating, it is undeniably exciting to see something you helped build hurtling around the Earth at approximately 7,700 meters per second just 170 miles above us. GOCE is even using GPS to track its own position in space.


Happy Space Race Day!

Published in Space


In deference to the title of this blog, my consulting company, and my profession – Happy Space Race Day! Today marks the 50th anniversary of the Sputnik launch – proving that we could achieve at least Low-Earth Orbit (and that it wasn’t full of scary space monsters)

Of course, besides very brief forays to nearby celestial bodies we have relegated ourselves to primary the same orbit we reached 50 years ago.

Here’s to hoping we have the vision and execution to go back to deeper space – both for knowledge and to spread ourselves into more than one basket. :)


NASA & SL

Published in Engineering, Simulation, Space, Technology


I’m a big fan of the acronyms NASA and SL and was really interested to read the article on NASA’s SecondLife Presentation of their work on Synthetic Worlds. (via Slashdot)

The details are fairly light, but it seems as though NASA is building a VR game on space exploration (remember Microsoft’s Space Simulator, or the free and open-source Orbiter?). I wonder why NASA is rebuilding their own engine rather then picking up and using existing simulators (like Open-SESSAME) on top of the Unreal graphics/physics engine.

I also wonder if, given their presentation venue in SL, if they are considering integration of their space simulator with SecondLife itself. Apparently right now it is possible in SL to have some sort of orbital platform. But imagine if they actually opened up Space Stations, or other planets/moons for exploration/colonization.


Interplanetary Mapping

Published in GeoRSS, Maps, Project, Space


All the emerging standards for simple markup and syndication of location are Earth-centric (and sometimes just US/North American-centric). Granted, most people are probably only interested in locations that they can actually go to anytime soon.

However, with the increasing number of interplanetary rovers, observations of moons, and perhaps future excursions, it is still useful to define how to properly handle these other reference frames. Luna and Mars are two suggested Microformats that are starting the discussion on how one might mark locations on the two bodies. Additionally, the OGC is working now on determining standards for scientists and developers to publish and share data sources of planets, moons, asteroids, comets, ‘oh my’.

And why does the Earth have to be the only one with cool, “slippy maps”. I quickly put together a map of Mars. It uses the powerful OpenLayers Javascript mapping library to display the tiles from a NASA WMS server.

Mars Map screenshot
To produce the locations for the map, I put up a Space Blog, using WordPress and a slightly modified GeoPress to publish Mars lander locations and landing dates. I altered the published Microformats produced by GeoPress to make the class “geo mars” as a suggested way to markup Mars coordinates. The published GeoRSS feeds from the Space Blog then produce the locations and layers automatically on the OpenLayers Mars Map.

To Do: CRS and You

So this is all very neat, and in the end, really easy to setup. However, this is just a demonstration and in no way should be construed as “the way to do it”. Specifically, there are these questions left unanswered:

  1. How to define the Microformat and GeoRSS for non-Earth (and non-WGS84) reference frames
  2. How to define the Microformats and GeoRSS/Geonames location for non-Earth locations (like “Ares Vallis”)
  3. More sources for interplanetary map servers
  4. Ways to syndicate, and subscribe to, specific bodies
  5. Support for publishing, consuming, and drawing lines – in order to plot out mission profiles
  6. Support for publishing, consuming, and drawing areas – in order to plot out mission profiles, landing sites, and expected areas of “mission failures”

I’m sure there are more issues, so please speak up. You know who you space geeks are.


Beautiful Sky

Published in Environment, Society, Space


Andri Snaer talks about how last night, all the lights were turned off in INSERT_ADDRESS. Then a famous astronomer talked about the night sky over the radio for people to enjoy the natural beauty of the cosmos.

I think this is a simply marvelous idea. I’ve been in several European cities when they’ve had “Car Free days”, most recently in Brussels during EuroOSCON. The idea is one day of the week that everyone will go car free, and enjoy the relative quiet and easy biking/strolling about town.

Overall, I am an idealistic technocrat. I really enjoy technology, gadgets, programming, etc. However, I also enjoy natural beauty and the environment as it is. I hope that towns here in the US start promoting these sorts of activities. I mean, what’s the worse that can happen, people actually think its a good idea and turn off their lights at night? :)