Hubble Telescope turning 25 this week
Posted April 21, 2015
The Hubble Space Telescope (HST) turns 25 this week. Mononyms are usually the stuff of entertainers: Beyoncé, Madonna, Cher, Fishel, but Hubble has risen to that level in its first quarter century.
Launched April 24, 1990 at 8:33:51 a.m. aboard STS-31 from the Kennedy Space Center, Hubble was released into orbit the following day, at 19:38 UTC. But it started a long time before that.
Hermann Oberth wrote about the benefits of putting a telescope in orbit in 1923. Twenty-three years later, astronomer Lyman Spitzer agreed in a paper he wrote. Spitzer would later be the namesake for space telescope focused on the infrared range. Congress approved funds for the construction of a “Large Space Telescope” in 1977. Construction began on the primary mirror in 1979, and the Hubble Space Telescope was completed in 1985 with a launch planned for the following year.
The Challenger disaster put the space shuttle program on hold, along with Hubble, in 1986. The project would have to wait until 1990 for launch, where deployment from the shuttle's cargo bay went off without any problems. Teams back on the ground awaited “first light,” a momentous occasion for any telescope, but there was a problem.
While still providing clearer images than ground based telescopes of the time, Hubble had a spherical aberration. A tiny flaw in the primary mirror, about 1/50th the thickness of a sheet of paper, effectively rendering the telescope nearsighted. A November 1990 report on the failure concluded sub-contractor Perkin-Elmer repeatedly ignored data provided by it’s own quality control measurements and polished the mirror into the wrong shape. A fix was created in the form of Corrective Optics Space Telescope Axial Replacement (COSTAR), essentially glasses for the telescope. Astronauts spent nearly a year training for the repair, the first of five servicing missions. COSTAR was installed in December 1993, along with an upgraded Wide Field/Planetary Camera and various other tuneups were performed (solar panels, fuses, etc.) A better than new Hubble capable of seeing five times sharper than ground based telescopes was released from the shuttle bay. Results of the mission were released about a month later, but NASA wasn’t done improving Hubble.
Servicing missions returned in 1997, 1999, 2002, and 2009 with improved instruments that could see beyond visible light into ultraviolet and infrared, data switching, power systems and the reaction control wheels which orient the telescope. That last mission, STS-125 was originally scheduled for 2004 but nearly didn’t happen after the loss of the space shuttle Columbia. Columbia made it clear that crews needed some way to get home should their orbiter be crippled. While missions building the International Space Station (ISS) could stay there while help was sent, Hubble's orbit 150 km above that prevented the ISS from being used as a life boat. A suitable procedure was created and Space shuttle Endeavour was rolled out alongside Atlantis for a launch in May 2009. Thankfully, Endeavour was rolled back unused to the massive vehicle assembly building after Atlantis successfully returned from Hubble’s most challenging servicing missions.
Astronaut Drew Feustel who, along with crew mates Michael Massimino (also of “Big Bang Theory” fame), John Grunsfeld (who would later lead the Space Telescope Science Institute which manages Hubble), and Michael “Beuno” Good, conducted five space walks, including installing grappling points for a future robotic mission to attach to when the time comes to deorbit Hubble safely. I had the chance to sit down with Feustel when he spoke at January’s Astronomy Days. We talked about the intense training for servicing missions underwater in the 40-foot deep Neutral Buoyancy Lab at the Johnson Space Center in Texas. Crews practice each move they’ll make in space over and over on a full size mockup of Hubble. When asked if it felt very different working without resistance in the vacuum of space after training for so long under water, he responded “muscle memory really takes over there.
"You’re so focused on the job at hand, you don’t notice little things like that," he added. "I really wish I had more time out there just to look at the Earth below.”
Shuttle missions to Hubble’s have been well documented for the really big screen. Astronauts used a specially designed IMAX camera to document the mission that deployed HST, STS-31, as well as the final servicing mission, STS-125. The results compiled into Hubble 3D, narrated by Leonardo DiCaprio. In addition to stunning images of astronauts working with the telescope in orbit, the film takes audiences on a fly-through the Orion Nebula based on real Hubble images.
I recently spoke with Dr. Summers about Hubble and his role in the film where he served as scientific visualization supervisor. Summers enthusiastically told of experiencing that fly through, something that had only been in the imaginations of the scientists who studied the nebula.
He also described the history of Hubble in 25 iconic images, one for each year of operation, to a class studying Solar System Exploration in the Osher Lifelong Learning Institute on the North Carolina State Campus. When asked what his favorite image was, he couldn’t pick just one.
“The images of the galaxy cluster Abell 2218 returned after the third servicing mission are incredible. The streaks of light in the image were created by gravitational lensing. So many galaxies with so much mass that Einstein’s General Relativity comes into play," Summers said.
Summers added that the infrared images produced of the M16 Eagle Nebula also known as the Pillars of Creation are among his favorites.
Competition for Hubble’s limited resources is fierce. Astronomers submit proposals for time with the telescope’s instruments months in advance. Software behind the opitimzation use of the instruments aboard Hubble was later spun-off by medical software company Allocade in their On-Cue system which optimizes resources such as Computerized tomography (CT), agnetic resonance imaging (MRI), ultrasound, interventional radiology, nuclear medicine, positron emission tomography (PET), radiography, radiography-fluoroscopy, and mammography, reducing wait times at hospitals and clinics.
By 2011, Hubble had made it’s millionth observance and the 10,000th scientific paper based on Hubble data was published.
There are several Hubble artifacts and full sized high fidelity models you can visit:
- Kennedy Space Center Visitors Complex, Florida: a high fidelity model of HST alongside space shuttle Atlantis
- National Air and Space Museum, National Mall, Washington DC:
- Hubble Space Telescope Structural Dynamic Test Vehicle (SDTV), essentially a copy of the spacecraft used for testing everything from handling procedures to ensuring wiring harnesses bound for the flight vehicle fit properly. After sitting outside the Lockheed facility in Sunnyvale, Calif. it was donated to the museum where it was refurbished by museum staff and volunteers.
- Primary Mirror (flight spare), correctly polished
- IMAX camera used by shuttle crew
- HST-PCU Trainer, used by astronauts on the ground to practice the difficult task of replacing the Power Control Unit during servicing mission
Closer to home, there are several events around Raleigh celebrating Hubble’s anniversary:
- This week only, Monday, Tuesday, Wednesday and Friday at 6:20 pm: The IMAX Theater at Marbles Museum is showing Hubble 3D at 6:20 p.m.
- Thursday April 30th, 7:30 pm: The North Carolina Museum of Natural Sciences Science Café hosts Dr. Evan O’Connor a Hubble Fellow in the Physics Department at North Carolina State University. The free talk will showcase some of the most important and exciting scientific discoveries made with the Hubble Space Telescope and how observations from Hubble will continue to aid scientists far into the future.
If you still haven’t gotten enough Hubble, you can see the telescope itself passing over North Carolina this week. HST (bus size) is more difficult to see than the space station (football field size) but those in dark location should be able to see it. The orbit of the telescope will make it appear less bright each day this week.
- Tuesday 4:51 a.m., look to the south. The telescope will appear about 30º above the horizon as it exits Earth’s shadow and will move to the east-southeast over about 3 minutes. This will be the brightest pass of the week.
- Wednesday 4:43 a.m., look to the south-southeast, HST will appear again about 30º above the horizon before setting in the southeast 2.5 minutes later
- Thursday 4:35 a.m., look to the south-southeast, HST will appear again about 20º above the horizon before setting in the southeast two minutes later