Comments on: SOFIA Lives! http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/ I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog. Sun, 05 Jul 2009 08:29:41 +0000 http://wordpress.org/?v=2.3.1 By: Jack Hagerty http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17050 Jack Hagerty Wed, 12 Jul 2006 01:48:28 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17050 OK, it didn't work. What was quoted above was my responses to Johnny Vector's description of flying on the KAO. I guess I really don't understand how this works. What I thought I was quoting gets deleted and what I was adding gets quoted. [Sigh] - Jack OK, it didn’t work. What was quoted above was my responses to Johnny Vector’s description of flying on the KAO. I guess I really don’t understand how this works. What I thought I was quoting gets deleted and what I was adding gets quoted. [Sigh]

- Jack

]]> By: Jack Hagerty http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17049 Jack Hagerty Wed, 12 Jul 2006 01:45:52 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17049 Here's my attempt at using the HTML tags. Apologies in advance if it's not readable. <blockquote cite="I flew on the KAO back in 1994, out of New Zealand, where driving on the left didn’t bother me, but the upside-down moon was weird! At the time, the aircraft was being refurbished, and there was no internal skin or insulation at the experimenter’s station. So there was only 6 feet of air and a sixteenth inch of aluminum between us and the port inboard engine. It was seriously loud! And cold!"> This is seriously cool! I got a tour of the KAO when it was parked at NASA Ames a couple years earlier. I was amazed at how spartan the interior was, but at least the 'scope had a pressurized enclosure around it (actually a depressurized enclosure) so that the crew didn't have to wear pressure suits. (that big square hole in the side was just that, the 'scope was open to the air.) </blockquote><blockquote cite="The magnetic torquers that keep the telescope pointed as the aircraft jiggles were on the pressurized side of the bulkhead, so you could watch them move. Even though the mirror was only about 1m diameter (IIRC), that was still a lot of mass, and moment of inertia, to be yanked around as fast as it was. "> That is the one part of the tour that has stayed with me vividly. I was talking with one of the mission specialists (to use a shuttle term), who said that it's amazing, when flying through turbulence on the way up to mission altitude, to watch the telescope mount. As you watch it bouncing up and down at several Hertz, you realize that it's not the 10,000 lb (5,000 Kg) 'scope that's bouncing, but the 400 ton/tonne airplane! The telescope is standing still, relatively. - Jack</blockquote> Here’s my attempt at using the HTML tags. Apologies in advance if it’s not readable.

This is seriously cool! I got a tour of the KAO when it was parked at NASA Ames a couple years earlier. I was amazed at how spartan the interior was, but at least the ’scope had a pressurized enclosure around it (actually a depressurized enclosure) so that the crew didn’t have to wear pressure suits. (that big square hole in the side was just that, the ’scope was open to the air.)

That is the one part of the tour that has stayed with me vividly. I was talking with one of the mission specialists (to use a shuttle term), who said that it’s amazing, when flying through turbulence on the way up to mission altitude, to watch the telescope mount. As you watch it bouncing up and down at several Hertz, you realize that it’s not the 10,000 lb (5,000 Kg) ’scope that’s bouncing, but the 400 ton/tonne airplane! The telescope is standing still, relatively.

- Jack

]]> By: Bored Huge Krill http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17051 Bored Huge Krill Tue, 11 Jul 2006 04:56:33 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17051 wow. I'm stunned that this would even work. Seriously, how exactly do you build a mount system that will retain any useful pointing accuracy when on board an aircraft? As an amateur astrophotgrapher, I'm well aquainted with the challenges of tracking at even modest focal lengths whilst sitting on *solid ground*. That this can be made to work just boggles the mind. It saddens me a little that most people will be completely oblivious to the magnitude of engineering challenge that this represents... but I sincerely wish the team the best, and I'm looking forward to the results. wow. I’m stunned that this would even work.

Seriously, how exactly do you build a mount system that will retain any useful pointing accuracy when on board an aircraft?

As an amateur astrophotgrapher, I’m well aquainted with the challenges of tracking at even modest focal lengths whilst sitting on *solid ground*. That this can be made to work just boggles the mind.

It saddens me a little that most people will be completely oblivious to the magnitude of engineering challenge that this represents… but I sincerely wish the team the best, and I’m looking forward to the results.

]]> By: Johnny Vector http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17052 Johnny Vector Mon, 10 Jul 2006 21:01:20 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17052 dre, yes it's shorter than a typical 747. According to <a href="http://www.sofia.usra.edu/Sofia/aircraft/sofia_ac.htm" rel="nofollow">the official site</a>, it's an "SP" model, extra stubby for longer range. <a href="http://www.sofia.usra.edu/Gallery/featuredimages/fuel_leak_check.jpg" rel="nofollow">Here's a nice big photo</a> of the plane. dre, yes it’s shorter than a typical 747. According to the official site, it’s an “SP” model, extra stubby for longer range. Here’s a nice big photo of the plane.

]]> By: dre http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17053 dre Mon, 10 Jul 2006 19:45:32 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17053 i have a question: is that artist's rendering of the 747/scope combination accurate? it sure looks like a stubby plane. maybe a few (or 30) feet of fuselage behind the wing got left out in the picture? i don't know, i'm just asking because it doesn't really look like a <i>flyer</i>. i have a question: is that artist’s rendering of the 747/scope combination accurate? it sure looks like a stubby plane. maybe a few (or 30) feet of fuselage behind the wing got left out in the picture? i don’t know, i’m just asking because it doesn’t really look like a flyer.

]]> By: Johnny Vector http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17054 Johnny Vector Mon, 10 Jul 2006 15:12:04 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17054 <blockquote cite="Jack Hagerty">This looks like the same basic design as the Kuiper observatory (which I’m sure has been decommissioned by now). That one was based on a C-141 Starlifter and had the ’scope port in front of the wing (to cut down diffraction from turbulence).</blockquote> Yeah, SOFIA is basically the KAO follow-on. KAO was decommissioned many years ago, as SOFIA was starting. More or less, the money that was supporting KAO became SOFIA money (or so I understand it). I flew on the KAO back in 1994, out of New Zealand, where driving on the left didn't bother me, but the upside-down moon was <em>weird</em>! At the time, the aircraft was being refurbished, and there was no internal skin or insulation at the experimenter's station. So there was only 6 feet of air and a sixteenth inch of aluminum between us and the port inboard engine. It was seriously loud! And cold! The magnetic torquers that keep the telescope pointed as the aircraft jiggles were on the pressurized side of the bulkhead, so you could watch them move. Even though the mirror was only about 1m diameter (IIRC), that was still a lot of mass, and moment of inertia, to be yanked around as fast as it was. Very impressive. Also it was fun knowing that the plane's navigation system was being controlled by the experimenter's telescope guide system. We laughed at the commercial airlines' "shut off all electronic devices"! "Ha ha!" we went. Sure am glad SOFIA is back on, even though I stay away from those wimpy infrared photons these days.

This looks like the same basic design as the Kuiper observatory (which I’m sure has been decommissioned by now). That one was based on a C-141 Starlifter and had the ’scope port in front of the wing (to cut down diffraction from turbulence).

Yeah, SOFIA is basically the KAO follow-on. KAO was decommissioned many years ago, as SOFIA was starting. More or less, the money that was supporting KAO became SOFIA money (or so I understand it).

I flew on the KAO back in 1994, out of New Zealand, where driving on the left didn’t bother me, but the upside-down moon was weird! At the time, the aircraft was being refurbished, and there was no internal skin or insulation at the experimenter’s station. So there was only 6 feet of air and a sixteenth inch of aluminum between us and the port inboard engine. It was seriously loud! And cold!

The magnetic torquers that keep the telescope pointed as the aircraft jiggles were on the pressurized side of the bulkhead, so you could watch them move. Even though the mirror was only about 1m diameter (IIRC), that was still a lot of mass, and moment of inertia, to be yanked around as fast as it was. Very impressive.

Also it was fun knowing that the plane’s navigation system was being controlled by the experimenter’s telescope guide system. We laughed at the commercial airlines’ “shut off all electronic devices”! “Ha ha!” we went.

Sure am glad SOFIA is back on, even though I stay away from those wimpy infrared photons these days.

]]> By: JusANuttaBackYahdah http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17055 JusANuttaBackYahdah Sun, 09 Jul 2006 00:33:38 +0000 http://blogs.discovermagazine.com/badastronomy/2006/07/07/sofia-lives/#comment-17055 I'll be off-topic also. Keep looking up Wendy, the ISS is only one of many marvels (most of which are not man-made) to look at. I too love watching flyovers of the ISS and imagining what it would be like to be on board or seeing an Iridium flare (man-made object) is also lots of fun but get your eyes to some good binoculars or a telescope and really be amazed. It's a big universe out there. Clear skies ;-) I’ll be off-topic also.
Keep looking up Wendy, the ISS is only one of many marvels (most of which are not man-made) to look at. I too love watching flyovers of the ISS and imagining what it would be like to be on board or seeing an Iridium flare (man-made object) is also lots of fun but get your eyes to some good binoculars or a telescope and really be amazed. It’s a big universe out there.
Clear skies ;-)

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