Tour of the Yuan-Tseh Lee Array on Mauna Loa, and a Job Offer

Two weeks ago, as part of the job interview process for the operator job I applied for, I got to go on a tour of the Yuan-Tseh Lee Array facilities on Mauna Loa. The weather was absolutely gorgeous, so I took my camera along and got some pictures.

Mauna Kea from the road up to the Mauna Loa Observatories. This is facing basically due north.

The drive up from Saddle Road to Mauna Loa never fails to give me a sense of (wonder at) the size of Hawaiʻi island. From the turn-off point at Saddle Road, it's a mere 10–15 minutes' drive to get to Hale Pōhaku at ~9,200 feet. From the turn-off (only a few hundred feet down the road) to go to Mauna Loa it takes a solid 40–50 minutes to get to the Mauna Loa Observatories at ~11,200 feet.

(Part of this has to do with how the Mauna Kea access road is much steeper and more direct, while the Mauna Loa road winds, twists, and takes a much less steep path. Now that it's paved the entire way, I'd say it's actually an easier road overall due to never really getting as steep as the Mauna Kea road.)

Mauna Kea from inside the gated Mauna Loa Observatories area.

Have I mentioned the weather was amazing? Barely a cloud in the sky other than some off the west coast of the island (and some annoying vog in Hilo). You can see the peak of Kohala (the northern-most volcano of the five that make up Hawaiʻi) to the left of Mauna Kea in the picture above. Once we got past the gate blocking off access to the Mauna Loa Observatories (where I'd never been before), we got a tour of some of the various buildings at the site.

Some of the buildings at the Mauna Loa Observatories site. Check out Maui in the background there! That's Haleakalā.

Something I wasn't really aware of is just how many small observatories of all stripes there are on Mauna Loa. There's a weather station, a small solar telescope, several other domes (I have no idea what the three in this picture are, for instance), and some various other monitoring equipment and buildings scattered around. (I presume some of them are geophysical monitoring stations keeping tabs on Mauna Loa itself.)

The Yuan-Tseh Lee Array, or YTLA for short, was formerly known as AMiBA, or the Array for MIcrowave Background Anisotropy (astronomers will do anything for a tortured acronym!)

The original sign, still up.

The new name.

The YTLA hangs out under a strange, shell-like dome of PVC fabric, as seen in the image below:

That pill-bug-like shell is the housing for the YTLA.

For observing the covering curls over and folds up, allowing the telescope to see the sky. (The process is entirely manual, and operator-controlled.) We got to go in and see the telescope itself, on its central pedestal.

Apparently when it was first built, it was discovered that the telescope was about four feet too tall to fit in the enclosure. The solution? Lift the enclosure up by four feet! The original design also called for zippered holes in the fabric to enter and exit by, but that didn't work out so great so the entrance now is by bending over and clambering through a four-foot hole left from lifting up the enclosure. It's definitely one of the zanier telescopes I've had the pleasure of touring!

The YTLA, seen from the back. The various receiver elements are mounted on the top of that hexagonal platform.

After seeing the control room for the YTLA (a Matson shipping container) and the rooms for the operators (a Matson container split down the middle), we had an hour free to wander around while our guides did some work on the telescope.

Unlike the area around Hale Pōhaku, which is lightly wooded and has plenty of vegetation, the 11,000-foot mark on Mauna Loa might as well be the surface of the moon when it comes to flora (in fact, astronauts came here to prepare for the moon landings, as it's considered one of the best moon-analogs on earth). There are some very pretty pieces of lava lying around, however!

I love the brilliant green-blue-yellow iridescence of this tiny chunk of basalt.

Finally, as I often do when confronted with a vista and a camera in my hand, I ended up taking some pictures to put together as panoramas. I'm not entirely happy with either of these; they both have their flaws, but I've put them together as best I can, so here they are:

The second one comes from a bit higher up the mountain; the building visible on the far left in the first one (the YTLA breakroom) is just behind the right-most dome near the center of the second one. You can see the peaks of Mauna Kea, Kohala, Haleakalā, and Hualālai (from right to left) in both pictures.

All in all it was a great tour, and, between the genesis and the completion of this post, just this afternoon, I got a call to let me know that they were offering me the job, so it looks like I'll be becoming a lot more familiar with the area in the near future! A hui hou!

Edit (3/19/18): The second panorama there has now been recreated using Hugin, but you can mouse over it to see what the original version looked like! I couldn't get Hugin to recreate the first one—I had a dickens of a time doing it manually, and I think it has to do with a number of curving elements (like the road and the power lines) that I just didn't take enough photos of to transform smoothly.