Rocket Science for the Rest of Us

This week's "current" event comes from NASA, which launched its GRAIL mission on September 10. Here's a video of the launch. It's awesome to watch, and I love the sound of the rocket engines. (Frankly, that's my favorite part of being in the Air Force, too; living on or near a base and hearing the jet engines. Air Power--rrroawr!)




GRAIL stands for Gravity Recovery and Interior Laboratory, and really what NASA hopes to do is make a gravity map of the moon. GRAIL consists of two satellites that will fly the exact same orbits, one following the other. As the composition of the moon changes, whether because they are overflying a mountain or something beneath the surface is more massive than the stuff around it, one satellite's orbit will be affected slightly. By recording the differences, they'll be able to better figure out the composition of the moon.


Scientists believe this can also help us understand other planets as well; sadly, the video doesn't really say what or how. However, the key lies in the fact that the moon has no atmosphere, so it holds an accurate history of the past 4.5 million years of our universe. If we know what's inside the moon, we know what's been around, when and what it did. For example, did you know the moon isn't round? It actually has a bump on the far side. In fact, there's one theory that earth had two moons once upon a time and that one hit the other. A gravity map might shed some light on this and other questions.

My friend Virginia (and that's her actual name this time) asks, "Why are they taking months to get there? Are they driving?" Those who remember the Apollo missions know that we got to the moon in a matter of days, but the GRAIL probes will take three and a half months.

Are we there yet?

Not driving, but they are trying to save on fuel. Unlike when you drive on earth, the direct route from A to B isn't always the most fuel-efficient. That's partly because as the satellites are moving, so is their target, but mostly because you want to be able to slow down and get into orbit. Slowing down takes a lot of fuel, and the spacecraft don't have it. So they make use of a nifty astronomical feature called a LaGrange point.

The LaGrange point is a kind of null space, gravitationally. If you put something there, it will stay there. So NASA is using that to help slow the satellites down. I couldn't find a good explanation for how this works, but my guess is that it gives the ships time to coast, and they can make fewer course changes and don't have to use as much power to slow down to get into lunar orbit. Also, it takes a less powerful rocket to send something up to the LaGrange point than it does to get to the moon.

The other thing it does is give the satellites time to "out-gas." Gas gets caught in the spacecrafts, even on the molecular level, and will sublimate in vacuum. They need the satellites to do this first to make sure they get accurate readings when mapping the moon. You can find fuller details here: http://www.spaceflightnow.com/delta/d356/preview.html.

For further reading:
http://science.nasa.gov/missions/grail/
http://moon.mit.edu/objectives.html
http://www.spaceflight101.com/grail-mission-design-timeline.html

What could be more representative of the American space program? Yet  it is so much more!

When I told one of my friends that I was creating a blog about the space industry, she asked, "Is there a space industry after Obama killed NASA?"


First, let's assume for this article, we're talking about manned space and exploration, rather than the thriving industry of putting satellites into orbit so we can get better cell phone reception.


She's referring to Obama's 2010 budget proposal that cancelled the Constellation program, which was supposed to replace the space shuttle and eventually get us to the moon (2020.)  Here's an article in Discovery about it.  And another in Scientific American.  This might indeed seem a death knell for space, or at least for manned space, but there are several things to consider.


First, the Constellation program was already overbudget and experiencing a lot of technical problems.  (Universe  Today reported in Feb 1, 2010, "Also, its estimate costs through 2015 have risen from $28 billion in 2006 to $44 billion today.")  There was also doubts about it being able to meet its deadlines of manned flight by 2015 and the moon by 2020.


What about the shuttle?  It was simply at the end of its life.  The technology was so old, that to repair the shuttle, NASA was having to search the Internet for spare parts.  President Bush actually canceled the shuttle program because we couldn't physically support the craft any longer.  


However, at the same time that President Obama called for the cancellation of the program, he recommended increasing NASA's budget for it to concentrate on other things--increasing the life of the ISS, promoting innovation and technologies, and exploring further on.   As columnist Phil Plait said, "NASA can concentrate on what it should: innovation, pushing the limits, paving the road. Once the road is laid, let others use it."


So, are there others to use the road?  Let's start with the fact that the ISS is International, and other nations have been servicing it, including the European Space Agency and the Russians, who are--or rather were--flying the astronauts to the station when the Shuttle wasn't.  (They recently had trouble with their Soyuz capsules, and now we're not sure we will keep astronauts on the station--weep!--but that's another story.)  So the space industry as a whole will continue, even if NASA died, which it isn't.


In addition, American commercial space is growing--and Obama has given it a nice void to fill.  There are already many companies striving to fulfill the dream of manned space:

• Armadillo Aerospace (suborbital focused)
• Bigelow 
• Blue Origin (suborbital focused)
• Boeing
• Orbital
• Sierra Nevada Corp
• Space X
• United Launch Alliance (serves the military; not sure they're looking at manned)
• Virgin Galactic (suborbital focused)

(Rob gave me this list.  If we missed any, let me know.)  There are also a lot of budding industries to build the craft, make the fuel, create the engines, etc.


Later this week, I'll share an article about how some of these companies are already moving into Cape Canaveral (or negotiating to).  But for now, the answer to my friend's question is, "Yes, Virginia, there still is a space industry."

The SpaceX Dragon spacecraft after its test mission.

* Since I have a follower named Virginia, I'd like to state for the record that she did not ask this, but I could not resist the play off the title.