This week, an enormous cloud of volcanic ash is sweeping over Northern Europe, grounding aeroplanes and bringing the jet-setters to a standstill. One could be forgiven for taking it all for a hoax – there’s nothing for the common Earth dweller to see – but it’s bringing some businesses to a standstill as they struggle to make their meeting’s commitments.

The reason this ash cloud cannot be seen is that the ash cloud is moving relatively high in the atmosphere, although meteorologists say there are signs some dust is settling at lower levels, which could begin affecting the health of those with respiratory conditions such as asthma. However the risk to aircrafts is very real as reported in the excellent BBC News online article: Icelandic volcanic ash alert grounds UK flights

But what about satellite communications? Could the dust in the atmosphere affect the control of space missions, your Sky receiver or GPS? Pete Garner, SSTL’s Radio Frequency (RF) team leader commented:

Satellite comms could easily be affected, but the impact would depend primarily on weather conditions, which would determine how the volcanic ash is dispersed in the air.

Additionally - it would also depend upon the robustness of the comms links in question. I know personally that my Sky signal degrades or even drops out periodically if there is heavy rain in our area and the volcanic ash could cause similar problems as the density and composition of the ash cloud would reduce the link margin and therefore affect the quality of any transmitted signals.

SSTL tracks and controls many satellites from its Guildford-based ground station, but Pete explained that their systems are designed to cope with environmental factors – even if no-one expects clouds of volcanic ash over the green hills of Surrey:

SSTL ensures its LEO [Low Earth Orbit] comms links are robust enough to cope with heavy rain in most cases by sizing the whole comms system appropriately for the mission including environmental factors. Making sure there is adequate additional margin in the link budget design is a key factor from the early stages of any mission to ensure SSTL can continually control the satellites and obtain the important image data when required.

In some cases there is also a level of redundancy. For example, Earth observation satellites such as Nigeria’s new NigeriaSat-2 satellite that is scheduled for launch in Q4 2010 have the facility to download images to multiple groundstations around the world. Some satellites can also be tracked and controlled from more than one groundstation when required.

SSTL founder, and Director of the Surrey Space Centre, Professor Sir Martin Sweeting gave a talk on small satellites for the Appleton Lecture organised by the IET on 19th January.

The Appleton Lecture was established in 1965 to commemorate the life and work of Sir Edward Appleton, a widely honoured physicist and Nobel Prize winner who is mainly noted for research into the upper atmosphere. In keeping with this theme, Sir Martin was invited as a world renowned expert on satellites, to give an hour long talk Small Satellites - Big Future. For anyone who missed the lecture on the 19th January, the IET has made it avaliable online at IET.tv.

If you have an interest in SSTL, satellite engineering and the future of space technology to tune in online - it's a very good watch. Just click on Small Satellites - Big future.

Space Blog readers from the US might be interested to learn that SSTL and its earth-imaging subsidiary DMCii will be featured in the Discovery Channel series program “How Do They Do It?”. The show has already aired in Europe, and now as promised in our August blog Watch SSTL and DMCii on TV, here's an update on the first US broadcast.

The episode is due to receive its first US transmission on Discovery Science Channel on Thursday 1st October at 9pm Eastern Time. It will also be repeated at midnight that day and then on Saturday 3rd October at 4am Eastern Time. Tune in with your family and friends for a lighthearted insight into how SSTL is changing the economics of space and see a hyperspectral imager being assembled at SSTL's optical payloads group.

Nigeria’s space programme has made further progress this month, as the NigeriaSat-2 and NX Earth observation satellites passed environmental tests.

Environmental tests comprise a series of rigorous checks that are conducted to simulate the environment in which the spacecraft will operate in space. All spacecraft undergo these tests to validate the designs and to ensure quality control. It is a formal review milestone and a point at which SSTL engineers can identify potential issues for correction.

The NX satellite has been integrated and tested by Nigerian engineers working at SSTL during the past 2 years as part of their training and development programme.

This is the second such programme that SSTL has supplied to NASRDA. In 2003, NigeriaSat-1 was launched into the Disaster Monitoring Constellation (DMC) and remains operational. The launch of two further Nigerian satellites into the DMC will ensure continuity of the nation’s space assets as well as a significant advancement in capability through NigeriaSat-2’s high-resolution capability.

Under the current contract with the National Space Research & Development Agency (NASRDA), SSTL is providing a high-resolution Earth observation satellite, NigeriaSat-2, based on the SSTL-300 platform – the first to be built by SSTL. NX is based on the SSTL-100 platform, which has gained flight heritage through existing satellites in the DMC. Under the supervision of SSTL engineers, NX was built by the Nigerian training engineers, who also took the satellite through its test programme. A Nigerian operations team will also be on hand throughout the launch and commissioning phase, learning the necessary skills to operate the new spacecraft..

The tests include thermal simulation, taking the spacecraft through the extreme ranges of temperature that they will experience in low earth orbit. These tests were conducted in the large space test chamber at Rutherford Appleton Laboratory in Oxfordshire. Each spacecraft was subjected to hot and cold cycles within a temperature range of +60dC to -20dC. Vacuum tests replicated the non-atmospheric environment in which the satellites will operate some 686km above the Earth. Thermal vacuum tests ran over a 5-day, 24-hour period with each subsystem tested individually within the extremes of environment.

The two satellites were then taken to EADS Astrium’s Portsmouth facility for vibration tests that simulate the challenging conditions of launch.

NigeriaSat-2 was then moved to the QinetiQ facilities in Chertsey where electromagnetic compatibility (EMC) tests were carried out to simulate interference and radiation effects that the satellite and subsystem electronics will face in orbit.

This is an exciting time for the 25 Nigerian engineers who have spent varying periods of time at SSTL and the University of Surrey over the past 2 years, working and studying to achieve the skills that will underpin Nigeria’s ongoing space programme. Both NigeriaSat-2 and NX are now nearing completion with the Flight Readiness Review (FRR) this month.

On September 22nd the training and development programme will reach completion and a new generation of highly skilled engineers will return to Nigeria to resume their work at the National Space Research & Development Agency (NASRDA) whilst they wait with anticipation for the launch of the two new satellites.

Just over a month ago, on July 30, 2009 Visit NASRDA website marked its 10 years of existence as a National Space Research & Development Agency, with mandate for the implementation of the Nigeria National Space Policies and Programmes