Solar Weather

Preparing For Solar Weather

• Effects of Solar Weather
• Intelsat Q&A

Tobias Nassif, Intelsat’s Vice President, Satellite Operations & Engineering, talks about solar weather, the company’s ongoing efforts to build a better spacecraft and the fate of Galaxy 15.

What are some of the potential dangers of solar weather on satellites?

The environment in space can be very harsh, especially during certain peaks in the 11- year sunspot cycle or during solar flares that emit electromagnetic radiation at high frequencies and the electrons, protons and ions they sometimes sends through space. That type of space weather can have some severe consequences on satellites and aircraft, as well as terrestrial systems such as the power grid.

So what steps does Intelsat take to prepare its satellites for that environment?

We have always designed our satellites to handle the possibility of severe solar weather and the harsh space environment. They are engineered with those criteria in mind. As an industry, we work in close cooperation to share knowledge about the space environment and its weather patterns, incorporating what is learned as part of an ongoing effort to build better spacecraft.

How does the current solar cycle compare to past events?

According to the latest NASA reports, Solar Cycle 24 will peak in 2013 with a below-average number of sunspot activity.

What about the recent Naval Research Laboratory’s press release citing solar storm activity as the likely cause of the Galaxy 15 anomaly?

As far as we know, there is no hard evidence that solar storm activity was the cause of the G-15 anomaly. It is certainly one of the possible causes, but there is nothing conclusive.

What is the process normally used to investigate an anomaly?

We rely on a scientific process using fault tree analysis. That process has been refined through the years to look at all possible causes, both what is likely and unlikely. We essentially test for both to follow through on every branch of the fault tree. It takes more time but we want to get it right. All too often, expediency leads to the easy and wrong conclusion.

The Naval Research Laboratory report mentioned a specific solar storm on April 5 as the probable cause of the satellite anomaly, did it not?

Yes, it did. However, we are saying it is way too early to speculate on probable causes until all of our investigations are completed. While we take every reasonable precaution to mitigate solar weather on our spacecraft, the likelihood that such a storm actually impacted G-15 is fairly remote.

So how did this story about the solar storm knocking out G-15 get its start?

A trade magazine wrote an article about the possibility of solar weather as the root cause of the G-15 anomaly shortly after the event occurred. It was based on pure speculation, but it sounded plausible and made for good headlines.

Has this incident changed the way we prepare our satellites for space?

This is an evolving science. If our investigations reveal something we can do differently, we will certainly do it. However, these are state-of-the-art spacecraft built to withstand the space environment, and they have by and large served the industry well through the years. They have a very high rate of mission success.