Landsat 8 Launches Successfully!

The title of this post could actually be "Live video of Landsat launch blows my mind". Landsat was launched atop a United Launch Alliance (ULA) Atlas V 401 rocket with live video coverage from aboard the rocket throughout the various stages of the launch streaming to the web for anyone to watch. The best part of the coverage was the end, when a camera on the rocket booster showed the separation of Landsat 8 from the booster, with a backdrop of the rising sun above a crescent Earth. See for yourself, and just try to hold your jaw closed:

Those flashes visible in the lower right hand corner as the satellite drifts away are not UFOs, as some might think, but are likely tumbling space junk catching the light of the rising Sun.

NASA reports that the satellite began communicating with Earth and charging its batteries shortly after separation from the booster rocket, and is doing well. However, the mission has been having issues with its remote ground stations in Fairbanks, AK and Sioux Falls, SD, which pose little threat to the spacecraft and will hopefully be sorted out soon.

The Landsat Data Continuity Mission will be renamed to Landsat 8 and handed off to the US Geological Survey after the satellite has been commissioned. The Landsat program has been imaging the entire globe every 8 days since 1972 at a 30 meter resolution, providing beautiful and informative pictures and enabling scientists to track the evolution of the Earth due to both natural and unnatural causes. Here are a couple of my favorite Landsat pictures:

The shrinking of the Aral Sea due to the diversion of its waters for irrigation in central Asia.
Source: NASA/GSFC

A complete, cloud-free image of Antartica, pieced together from hundreds of images taken over time.
Source: NASA/GSFC

Proba-1 is Back in Business.

ESA's Proba-1 microsat was built and launched by the ESA as a proof-of-concept for semi-autonomous Earth observation - operators can upload coordinates and the satellite will autonomously image that location. The satellite ended up turning into a heavily-used science tool, but it almost shut down in May due to star tracker degradation. 

Proba-1 captured this image of London's Olympic Park
 neighborhood.   Credit: ESA 

Many small satellites use star trackers to orient themselves. The star trackers point behind the satellite (away from the Sun and Earth) and take pictures of star fields, which they can identify and use to calculate the satellite's orientation.  The CCD camera's attached to Proba-1's star trackers had sustained severe radiation (they were 5 years older than the planned lifetime for Proba-1), and the radiation had created permanent damaged or "hot" pixels which  show up in images as white spots. The star trackers were mistaking hot pixels for stars, and sending incorrect coordinates to the main satellite computer, causing it to error out or mispoint. 

Proba-1 was saved by a software patch written specifically for the satellite, which - once loaded - allowed the star trackers to distinguish between hot pixels and real stars. The star trackers are apparently working "as good as new" now, even with degraded CCDs. The proof is in the pudding - at the right is a farewell shot of Olympic Park that the satellite shot last week.

Envisat Redlines

Yesterday operators called off the resuscitation effort on Envisat, the European Space Agency's massive Earth-imaging satellite, after a month of unresponsiveness from the 10 year old satellite. There are several possible causes of the loss of communication. According to space.com, "The failure of a power regulator may be blocking the satellite's telemetry and telecommand systems, ESA officials said. There may have also been a short circuit on board that plunged Envisat into a protective "safe mode," then a second malfunction that left the satellite in an unknown state, incapable of receiving commands from Earth. As a fellow operator, my heart goes out to the Envisat Ops team. I can't imagine anything more frustrating than troubleshooting an unknown anomaly in the blind, with the whole space world watching. 

Despite having no comms, the ESA was able to verify that the solar arrays were still deployed thanks to a neat photo from the CNES Earth-observing Pleiades satellite:

Envisat, as images by Pleiades. Source: CNES 

The ESA says that operators will continue to command in the blind and consider failure scenarios for the next couple months. (I imagine they will also be job hunting!) Assuming they cannot raise Envisat from the dead, the satellite will be the latest casualty in the shrinking fleet of Earth-observation satellites. 

Source: Nature.com

Looks like there's going to be a vacuum in the industry pretty soon. Hmmmmm. Maybe an innovative startup could find a way to take advantage?



Though Envisat's death is sad, we should remember that it had a meaningful and long life, (it's initial lifetime projection was only 5 years) and it died doing what it loved.