8 May 2009

NASA's Most Difficult and Perhaps Most Important Shuttle Mission

Posted by Dan Satterfield

When I was young, if you were an Astronaut, you were famous. Everyone knew what you looked like. Not so anymore. The public fascination with space waned after the Moon landing and it has not recovered. These days, the only way an Astronaut gets famous, is if he dies or gets caught in a sordid love triangle. Astronauts are not household names anymore.

Some of the reasons for this may be the general lack of Science education in this country. Some have called it a war on Science. Based on some emails  I get from this journal, I tend to agree with them. It extends beyond climate change, and Biology to almost every facet of Earth Science. Some of the statements I hear political leaders make on Science, are stunningly ignorant of the very basics.

The Astronauts flying on the next Shuttle mission deserve some REAL public recognition. This mission is going to be one of the most difficult and dangerous missions ever attempted by NASA. The previous administrator of NASA (Sean O’Keefe) cancelled it for just that reason, but the public and (especially) the scientific community pushed hard for it to be flown. A new NASA Administrator put it back on the schedule. An article in SCIENCE this week suggests that it was his reluctance to approve the mission led to him being replaced.

I’ve had the privilege of talking with two Apollo Astronauts and even strapped into some simulators. (Zero G movement is easy, as long as you don’t care where you go. Try a task and it’s much more difficult than you can imagine). These Astronauts have trained very hard for these 5 days. The risk of death is about 2% for each Shuttle mission. Would you drive to work tomorrow if you had a 2% chance of dying? I wouldn’t.

They will.

NASA picture of the Hubble Telescope.

NASA picture of the Hubble Telescope.

You probably know already the task ahead for these Astronauts. They are going to repair the Hubble Space Telescope. No telescope has done more to answer the fundamental questions of Physics since Galileo’s (Which is still working in Italy, but good luck getting to look through it!).

Two new cameras will be added along with fresh batteries and new gyroscopes. The new Wide Field Camera will be 10-30 times more sensitive than the previous one! If it all goes well, Hubble will be astoundingly better than before. It’s hoped that it will last until 2014.

It might still be working when the new James Webb telescope sees it’s first star light. The JWT will be the most advanced telescope ever made and will no doubt make profound discoveries. Testing for this telescope is going on only 9 miles away from where I sit writing this, at NASA’s Marshall Space Flight Center.

From NASA web.

From NASA web.

This mission will use dozens of tools made especially for the mission. It will indeed be dangerous. Remember that satellite collision awhile back? Well some of that debris is orbiting at around 500km. Where Hubble is. When this flight launches, a rescue Shuttle will be on the pad at KSC, just in case. (Addition May 9th: Former Mission Control Scientist James Oberg wrote more about the rescue possibilities and orbital mechanics on MSNBC’s web site.

It will take multiple space walks to do the job, and NASA has collected the best and the brightest of the “Right Stuff” to do it. Two members of the crew have repaired Hubble before. It will be the last repair mission on Hubble. The Shuttle is about to be retired and when the computers and the gyros fail in about 5 years, Hubble will see no more light from across an unimaginable distance of Space and time.

Just 100 years ago, astronomers thought that the Universe and the Galaxy we inhabit, were one and the same. Those fuzzy spiral “nebula” visible in the best telescopes were thought to be relatively nearby. We really had no idea of just how far away they were and how big the galaxy was. It was Astronomer Edwin Hubble who figured out a way to measure the distance to these galaxies. He used a type of star called Cepheid Variable. He realized that these gave him what astronomers now call a standard candle.

In 1998 Hubble stared at what looked like an empty spot in the sky near the Big Dipper. The 10 day exposure showed millions of galaxies at distances too great to fathom.

In 1998 Hubble stared at what looked like an empty spot in the sky near the Big Dipper. The 10 day exposure showed millions of galaxies at distances too great to fathom.

Think of  it this way. Look at a street light in the far distance. You can tell if it’s near or far, because you know from experience how bright street lights are. If you had some good scientific equipment, you could measure the light from a nearby street light and assuming the distant one is about as bright, you could with some fairly simple math, get a very good estimate of the distance to the far one.

This is exactly what Edwin Hubble did! He found out that these so called nebula were galaxies like our own, but at incredible distances of 250 million light years, and even further. We have now made measurements of galaxies nearly 13 billion light years away. We can only see 13.5 billion light years, because the universe is that old. Light from farther away, could not have reached us yet! (See my previous post on this).

From NASA web site. Click image to go there.

From NASA web site. Click image to go there.

Now we know that we truly are, a grain of sand, in a vast cosmos. There are, however, still fundamental questions to be answered. Most of the universe is invisible to we humans. It’s full of what Cosmologists call dark matter.

What is it?

NOBODY knows. The newly improved Hubble Telescope just might answer that question.

For 7 NASA Astronauts. That’s worth the 2%.

On behalf of Scientists, and Science lovers world wide.