Artist’s rendition of satellites orbiting the Earth – rottenman/123RF Stock Photo
Spaceway-1 is a television satellite owned by DirecTV, which in turn is owned by AT&T, and DirecTV recently filed a request with US Federal Communications Commission (FCC) for permission to make an emergency deorbit Spaceway-1. This is because, in December, the satellite suffered a major anomaly resulting in significant and irreversible thermal damage to its batteries.
The company has described that if the satellite is able to recharge its batteries then there is potential it could blow up! It should be noted that Boeing, who built the satellite, has suggested that risk of explosion is ‘very low’.
Currently, the satellite is using solar power, but in the last week of February, it moves into the Earth’s shadow and it’s then that the batteries will try to operate. Spaceway-1 was launched on the 26th April 2005 and is one of three almost identical satellites with the other members of the trio being launched on 16th November 2005 and 14th August 2007 respectively. It’s not known if the fault could also affect the other satellites – although Boeing is issuing an operating update.
Whilst we all hope that Boeing is correct with its risk assessment, the potential damage from any explosion is obvious. In 2007, China conducted an anti-satellite missile test which created over 2,000 golf ball size pieces of debris and over 150,000 pieces of debris in total. Last year India also used a missile to hit a satellite in a low Earth orbit, and although a lot of the debris burned up in the atmosphere there were at least 50 pieces in orbit many months later.
Spaceway-1 is currently in a geostationary orbit at 22 000 km, and the intention is to bring it down to around 300 km. Many satellites undergo these movements as they reach end of life, the difference here is the speed. Satellites normally vent any remaining fuel they have in their tanks as they descend, a process which takes many months, whereas in this case there will only be time for a nominal amount of venting. Having a satellite descending with around 73 kg of fuel onboard does mean that severity of any potential collision or explosion would be increased.
A second, albeit less dangerous, but equally concerning problem is the increasing number of low Earth satellites going up for satellite broadband. This week SpaceX will launch another 60 Starlink satellite constellation, and there will be further launches this year. This latest batch will take SpaceX’s total to 240 satellites, still a long way from their stated aim of towards 10,000 satellites.
Many astronomers have complained that this will impact their ability to see the stars and into space. We were surprised to see that this was even picked up on a local news website here in rural Devon! Over the last few weeks, there have been a number of reports of a line of bright dots of light following each other in the Devon night sky, which are believed to be SpaceX Starlink constellations.
There is a tracking website that can give you a guide as to when the Starlink constellations will be visible from your location, although obviously you need appropriate weather conditions to see them. This impact on the night-sky is recognised by SpaceX who are trying to mitigate the impact of their satellites. However, if they are being spotted when only a couple of hundred are in space, clearly having ten thousand is a different level altogether.
This will have impacts on astronomers as there will less time available for them to have unobstructed views of space, plus the movement to increase the locations of dark skies to view the stars will be impacted if the lights are already in space!
The satellite industry is growing rapidly, but with this development, we need to be mindful of the potential damage we can be doing both in space and on Earth.
