UH-Hilo’s Hoku Kea telescope still inoperable
HILO — The University of Hawaii at Hilo’s troubled Hoku Kea telescope is still in pieces and is on its third director, with extensive problems that have included an improperly shaped primary mirror, a damaged secondary mirror and no operating system to control the telescope.
Pierre Martin became the observatory director Aug. 1, replacing Joshua Walawender, who was hired on an 11-month contract to evaluate the telescope and make it work. Walawender had applied for a renewal of the contract but did not get it.
Four days later, Jay Slivkoff, a UH-Hilo observatory technician who was handling much of the work on the telescope, fell off a ladder while working on a roof and died.
In an interview with the Tribune-Herald last November, Walawender identified four areas of Hoku Kea that needed work — rebuilding the optical system, fixing the leaking dome, fixing the dome drive system and rebuilding the telescope control system. He also estimated the telescope could have basic operations by this summer.
Martin, hired on a two-year renewable contract, isn’t going to offer any time frame on fixing Hoku Kea. He identified the same four issues on Hoku Kea that have plagued the telescope since Walawender began working there.
“This thing is going to take time before the telescope becomes an observatory. It’s as simple as that,” Martin said.
Martin spent the last few weeks examining the serious defects in the 36-inch diameter primary mirror and the 12-inch secondary mirror. In Hoku Kea’s design the concave primary mirror collects the starlight and concentrates it onto a convex secondary mirror, which reflects the light to an imaging instrument. Both mirrors must be manufactured to extraordinary standards and precisely aligned to produce meaningful scientific data.
The warped primary mirror has been reconfigured and repolished by Star Instruments, a telescope company in Newnan, Ga., Martin said, and “looks very sharp, very productive. There’s no doubt about that.” It’s now in Pennsylvania, undergoing a new reflective coating, and should be shipped back to Hilo sometime this week, he said.
“The initial mirror was really a problematic — it was improperly done and now it looks very, very cool,” he said.
The damaged secondary mirror has been rebuilt and should arrive todayTuesday, Martin said.
But the optics are just one part of the problem.
“The dome has some issues. The design of the dome is unusual in several ways,” he said. “It has some leaking issues, for sure, so a solution will have to be found for that.”
“There are issues with the ways the motors, the driving motors, are mounted on the dome right now,” he said. Martin is meeting on Thursday with a contractor who has been working on the dome to get an update on work done.
A new dome control system has been installed, and there are plans to operate the telescope remotely from the UH-Hilo Science and Technology Building in Hilo. But that’s something to be addressed in the future.
“There’s many issues with the telescope, for sure, some we may not be aware of. So I’m not going to paint a very pretty picture. I’m just trying to assess what’s wrong with it and make a plan,” Martin said.
He’s in charge of assembling a road map for the time and money needed to make Hoku Kea work, “not for me to take some pictures, but to be a real observatory for students, and that’s the main goal. So that’s going to take some time.”
Among the other problems: Some of the gearings and the lubricant in the telescope mount might need to be replaced. But even the best telescope in the world would be useless without the means to point it at a particular object.
“To my knowledge, there is no software available to control the telescope yet,” Martin said. While Walawender said this software would be developed in-house, Martin is looking at purchasing something from a third-party vendor.
Martin also has to hire a replacement for Slivkoff. After all those things, he will not estimate a date of completion.
“People have been waiting for it for quite some time,” he said, “but I don’t think I would serve the University of Hawaii if I put something that worked for a week and is a problem for the rest of the year.”
“We’ll try to make progress, is all I can say at the moment,” he said.
Martin says he won’t leave any option out. If the dome enclosure has to be replaced, for example, he’ll say it.
“It’s important to do that thing well,” he said.
Martin formerly worked with the 3.5-meter WIYN Observatory in Arizona and before that was the director of science operations at the Canada-France-Hawaii Telescope on Mauna Kea for 11 years.
Bill Heacox, chair of the UH-Hilo Department of Physics and Astronomy, is the former principal investigator for Hoku Kea.
“With the deaths of two members of the department (Richard Crowe, who died in a vehicle rollover accident May 27, and Slivkoff), things have slowed down a lot,” Heacox said. “So at the moment we’ve got a new director, a new observatory director who’s picking up the pieces.”
Heacox said he’s been “overwhelmed” trying to keep the department running despite the two accidental deaths.
“But by and large, things are coming along,” he said. “Not as fast as we would like.” He couldn’t comment on specific problems with Hoku Kea.
“One very important point of view and one very powerful voice is now lost to us,” said Norman Purves, a UH-Hilo astronomy instructor, referring to his friend, Slivkoff. “We’re going to miss him a lot.”
Purves is familiar with the problems of Hoku Kea. He said that tests of the primary mirror showed it was even worse than he had expected.
“Instead of being kind of a concave bowl shape paraboloid, it was actually shaped more like a spoon. Very, very bad from any reasonable standpoint, and the mirror never should have been accepted from the contractor,” Purves said.
The tests confirmed Purves’ suspicions that no amount of adjustment of the mirrors could have fixed the telescope. The first director of the telescope, David James, spent several months trying and “spinning his wheels.”
In the process, James damaged the secondary mirror, Purves said. The process of adjusting the mirror involves the turning of three hex screws that hold the glass to its mounting, Purves said. “He wasn’t able to get the correction that he wanted, so he just kept torquing down on that screw.” Eventually the pressure on the mirror “popped out a circular chip out of the surface about 2-3 centimeters (1 inch) in diameter.”
Purves said Hoku Kea is already five years past its original delivery date (it was installed on Mauna Kea in 2010), and he guesses it could take five more years. More than $1 million has been spent on the telescope to date.