Rocket Scientist

Kathleen asked how we were going to service the Hubble and the ISS. It’s a fine question with an easy answer, but I think a lot of people will be dismayed to realize that Hubble is going to be out of reach for future servicing. After all, the gorgeous photographs coming from Hubble are one of the ways NASA touches regular folks. For those that are worried, don’t be.

For Hubble, the upcoming servicing mission (4, sort of) later this year, it’s unlikely we’ll ever service Hubble again. There were only planned to be four servicing mission (this will actually be the fifth). Of course, we had to make repairs and adjustments we never planned, like the corrective optics installed on Servicing Mission 1. Servicing Mission 3 also became servicing missions 3A and 3B because of the need to replace ailing gyros sooner rather than later (SM 3A). Unfortunately, the time in safe mode affected the electronics, so additional fixes were required for SM 3B, in addition to planned upgrades. As the EVA Safety lead for the last two missions, SM 3A and SM 3B, I can tell you they’re tough. Usually at least EVAs back to back, that are long, arduous, complicated and challenging. Fortunately, the Hubble folks are very responsive at finding ways to fix what was never planned to be fixed and we usually have exceptional EVA astronauts doing the work. It was a pleasure to work with all of them.

Hubble is the only one of the Great Observatories that had a low enough orbit to service or required it. The other great observatories: The Gamma Ray Observatory, The Chandra Observatory, and the Spitzer Space Telescope. Those were all in orbits out of reach of the Shuttle or, in fact, any manned craft today. All but the Gamma Ray Observatory is still in service.

But never fear, Hubble lovers, work is underway building the James Webb telescope (in fact, one of my colleagues is working that now) that will do more than Hubble. They’re planning to launch that in 2013 and hopefully Hubble will survive until then.

Now, ISS is a real problem. The hope is that we will have another crew vehicle within a few years of the Shuttle’s retirement and people are working to achieve it. But the Crew Escape Vehicle (CEV) is a multipurpose craft that must also support Lunar missions. Multitaskers are not only challenging to build, but also tend not to be optimized.

In addition, the Russians can still send up Soyuz and Progress crafts, and the European Space Agency has already launched one Automated Transfer Vehicle (no crew) and JAXA, Japan’s Space Agency, is planning to launch their transfer vehicle, H-II Transfer Vehicle next year.

Having said that, none are a true replacement for Shuttle. She brings up more and brings down more: experiments, samples, crew, logistics, and even modules for assemblies. When the Shuttle retires, assembly will be effectively complete. We’ll be stuck with what we have unless it can be brought up in an automated fashion. And that will make a difference.

The Shuttle was definitely filling a niche and we just don’t have anything to replace her. Not now, probably never…

Unless the Commercial Human Spaceflight folks figure out something we haven’t. But, then, that’s an entirely different blog.

Baron Rochester asked me about Shuttle reusability. I gave him a quick answer, but, really, I think his question deserves a more complete answer because the Shuttle is a rather unique vehicle.

As the Apollo program came to an end (and you don’t want to ask me how I feel about that), much of the space focus turned to the highly lucrative but very expensive world of satellites. Up until then (and in fact, continuing on today), most space craft were launched into space using staged expendable rockets. From the beginning, an orbiting space station built with help from the Shuttle was part of the vision, but the US was also very interested in finding a more cost effective method for getting satellites into space and even bringing them back down. Additionally, they hoped to use the Shuttle as an orbiting laboratory for larger scale experiments than ever possible before. It cannot be stressed enough that, with the possible exception of being “cost effective,” the Space Shuttle system has achieved all of these far reaching goals.

The Space Shuttle is a complex system. It includes the reusable Orbiter, the refurbishable Solid Rocket Motors, and the expendable External Tank which supplies the fuel (cryogenic oxygen and hydrogen) for the Orbiter’s main engines. The Orbiter’s main engines are among the most efficient chemical engines ever.

There were a total of seven Orbiters built. The first one, Enterprise, was used for testing but never flew in space (sorry, Roddenberry).The other five were put into use as they were completed: Columbia, Challenger, Discovery, Atlantis and, after Challenger was lost, Endeavour. We are down to three now, Discovery, Atlantis and Endeavour.

Of course, I could talk more about the Orbiter, about their lightweight, but delicate thermal tiles and surfaces, some capable of withstanding nearly 3000 deg F (1650 Deg C), which are engineering marvels all their own, despite their vulnerabilities. But Kathleen asked a good question and I have to get to that.

Even so, I have to mention the two Orbiters we lost, with their full complements. The first, on January 28, 1986, was the Challenger accident when the Shuttle broke up 73 seconds into the launch due to a leak/burnthrough of the Solid Rocket Motor. We lost seven astronauts on that flight: Michael J. Smith, Dick Scobee, Ronald McNair, Ellison Onizuka, Christa McAuliffe (a teacher), Gregory Jarvis, Judith Resnik. I wasn’t here for that. I was a freshman in college and it’s still hard to believe that it happened more than 20 years ago.

Then, there was the loss of STS-107, Columbia, the oldest of our Orbiters during reentry. I was here for that one. In fact, it was my flight (EVA Safety Lead). Columbia was destroyed when damage to her wing leading edge lead to burnthrough and eventual destruction of Columbia on her way in. I knew this crew personally and I still can’t think of it without tears coming to my eyes. Those lost were David Brown, Laurel Clark, Michael Anderson, Ilan Ramon, Rick Husband, Kalpana Chawla, William McCool, another seven.

I don’t know how many of you feel about the Space Shuttle. I’ve been working in the space industry for nearly 20 years and my own feelings are not clear cut. I read the blog for Wayne Hale (which you can find in my blogroll) yesterday. Wayne Hale was the manager for the Space Shuttle. I know him and I know he cares deeply for this program, for what he did. He knows the end is inevitable.

The Shuttle program is coming to an end. People are talking about extending it like that’s a viable option. But the people who supported this program and provided eighty kagillion [kagillion is a technical term] tiny custom parts have moved into other business. Some are suppliers that have moved to more viable customers, providing materials that will be in demand for the long haul. Or they’re retiring. After all, the Shuttle’s been around for more than twenty years. Or they’ve already become part of the exploration effort.

The decision can’t be undone.

Truthfully, I’m not as fond of the Shuttle as Wayne is. Since my focus has been safety, it’s hard for me to look at it without seeing as a collection of things that can go wrong, some of which we didn’t see coming. I see it as a technological achievement that has also killed fourteen astronauts and I, like Wayne, never want that to happen again.

I see it as a mishmash of conflicting requirements, an exceptional engineering feat that was sold as more than a single item can be. Those unrealistic expectations have tarnished it despite the hard work it has done year after year, coming home chipped and worn from the horrendous environments of space and reentry. Yet, battered and limping somewhat from the clever workarounds we need to keep it’s aging systems working effectively and reliably, it can still do what nothing else we have can do: take big loads into orbit and bring them back down safely. And it can protect crews as large as seven going up and down. Building a replacement has been a nontrivial task and we’re not there yet.

No, I’m not as fond of the Shuttle as some. But a lot of good people have devoted decades to her care. And she has done some damn fine work. I know her problems, but I respect her and the job she’s done.

Here’s hoping her last few flights go off without a hitch.

I do not and never really have written nonfiction. Oh, I’ve written technical papers and many a dull government report, but, for fun, it is rarely nonfiction. Actually, unless I’m studying something (and yes I do that for fun), I rarely read nonfiction.

So why write it? Well, I’m trying something different. I like to try something different. For instance, I was once challenged to write a story that followed a set theme in exactly 100 words. Now, I’m a wordy type and I routinely write sentences longer than that. I didn’t think I could do it, to be honest, but I decided to try.

You know what? It was easy. I did a number of them, got a first, a second and a third in weekly challenges and then, well, was done. I’d done what I’d set about doing. I learned something (which is always a cool thing) and then moved on.

Actually, much of my writing has been like that. When I was in high school, I wrote poetry. Oh, not greeting card ditties or the kind of deep poetry that gives most people a headache. I wrote long stories via poetry, poetry with meter and rhyme in an Alexander Pope or Edgar Poe kind of way. To my mind, poetry’s real purpose is to evoke emotion, so that’s what I was teaching myself, but I was also teaching myself to be very cognizant of sound and of choosing the right word. Those lessons have served me well. I read everything I write now, prose or otherwise, out loud. Things that aren’t quite right sound wrong.

Later on, when I had apparently learned all I wanted to from poetry, I stopped almost cold turkey and moved toward short stories. Unlike novels, short stories need to paint a picture, tell a story and bring a character to life with an economy of words. I learned about adding drama to my writing with short stories and how to make a reader identify with a character without making it obvious.

I wonder what I’ll be learning from this little excursion. If you think of it, do leave me a comment and let me know.

By the way, for those that love space imagery, NASA has consolidated their image archives and made them available on the net. They are generally not copyrighted, but you should read their terms and conditions before using them.

These and many other images can be found at the NASA Images Archives

Enjoy!