Saturday, April 24, 2010
BBC news has an article with a video here about an infrared telescope 2.7 metres in diameter named Sofia (Stratospheric Observatory for Infrared Astronomy) that will go into use starting next year, for an expected period of 20 years. It's kind of like a space telescope except it doesn't go all the way into space, just 13.7 km above the ground in a regular jet airplane. That altitude is enough to get above 99.9% of the interfering water molecules in the atmosphere, so the telescope has just about all the benefits of being in space except that it doesn't actually have to go there.
The video shows the inside of the airplane and definitely needs to be watched to appreciate the project. The telescope has a device that neutralizes the vibrations from the plane, so no problem there either.
Total cost for this will be about $100,000 to $150,000 per flight, and it should fly every second night. This is quite a cheap price, since even a space telescope with a short mission like WISE works out to $300 million, so Sofia would have to carry out a full 2400 days of observations just to equal that. At that rate, the total cost for flying every second night for 20 years will work out to about $450 million. The Hubble Space Telescope for comparison has cost about $4 to $6 billion, plus a bit over half a billion euros on the European side too. So Sofia really is a steal compared to actually sending a telescope to space.
One other huge advantage is its ability to be anywhere in the world. Observatories in the northern hemisphere can't see stars like Alpha Centauri that are only visible in the south, and vice versa for those in the south. A flying telescope though has no problem being wherever it needs to be.
This isn't a new concept, by the way - the Kuiper Airborne Observatory was pretty much the same concept, except it flew in the 1970s and was smaller.