Anyone who knows me knows that I have a deep interest in space exploration. Over the past year or so, as the end of the Space Shuttle program (SSP) has approached and more and more people have become aware of it, I have found myself explaining why this is happening.
I often hear things like "it's such a shame that we're shutting down the SSP". But the more you know, the more the SSP shutdown makes sense and is actually a positive move for space exploration.
Here's why.
1. It's done. The space shuttle was designed to carry really big payloads to low earth orbit -- up to 50,000 pounds. It was intended to be used for all kinds of payloads -- scientific, commercial and even defense. Over the years various developments (including the two accidents) have caused that mission to get pared back to just science, and even just a subset of that. So having now officially completed the International Space Station (just this year), there is literally nothing major left to do.
2. It can't leave low earth orbit. The space shuttle was designed to get heavy loads up to low earth orbit, and that's it. It can't go to geosynchronous orbit (where most communication satellites reside), can't go to the moon, can't go beyond. If we want to go beyond Earth, to an asteroid or even to Mars, we will have to develop another spacecraft to do it. And the past decade or so of history has shown that as long as the shuttle keeps operating, it's going to suck all the air (funding) out of the room and starve everything else.
3. The space shuttle, while beautiful and fantastic and amazing, is colossally expensive to operate. Certainly it's far too expensive to keep operating just to bring astronauts and ISS supplies into space 2-3 times a year, now that it's done with the heavy lifting work of assembling the ISS. Thanks to various political actions over the last decade, the US federal budget simply can not support that kind of inefficiency. The SSP went on as long as it did only on the basis of political support from the regions that got a lot of the funding -- pork barrel spending, essentially.
4. The replacement system, proposed in 2004 in President Bush's "Vision for Space Exploration" plan (VSE), got its funding from Congress and then proceded to march to nowhere. An astronomical amount of money was spent on a new program (Constellation, aka Ares plus Orion) that just chewed through that money without much to show for it. Some observed that money kept flying out the window but the goalposts kept moving out on the calendar. Obama did a brave thing when he killed it. I should add that there is a lot of debate and disagreement on this.
In fact, as I type this, Congress is about to mandate that the replacement launch system, currently called the Space Launch system (SLS), be funded at higher levels and be built with certain components, counter to what NASA's engineers have recommended. These are politicians dictating engineering decisions! If you look at the early history of the space shuttle, back in the early 1970s, the same thing happened to the shuttle design -- Congress mandated certain design features and ultimately created the conditions that made the shuttle vulnerable to accidents. Those design mandates created the situation we're now in where we have to shut the program down! Sadly, it's not likely that this will change.
5. Commercial space launch is really starting to take off. By "commercial", we mean companies that are building their own launch systems. NASA is still involved, dicating safety requirements for example, but fundamentally this is work being done not by the government but by private enterprise. And THAT is going to truly drive costs down and finally give us the cheap access to space that we've dreamed of for 50 years. The funny thing is, most folks eyes glaze over when I say "commercial space launch", but it's really happening! SpaceX has had great success with their orbital test launches over the past 2 years -- the parachute photo here shows a descent test of their Dragon capsule. Virgin Galactic is busy testing their system (shown here is the spacecraft lining up on the runway during a landing test) and will soon be starting their suborbital tourist flights from New Mexico.
6. We now have lots of cargo launch capabilities. In the US, we have the Atlas V, the Delta IV, SpaceX's Falcon 1 and Falcon 9 rockets, Orbital's Pegasus and Taurus, and so on. Europe has their Ariane rocket, the Russians have the Proton, Japan and China have their launchers. We now even have multiple vehicles that can carry cargo all the way to ISS and dock/berth with it -- Europe's ATV, Japan's HTV, the Russian Progress. The next step now is to refine some of those launch systems enough that they can be safety-rated for carrying crew.
I'll leave you with a great quote from John Shannon, manager of the SSP, at a news briefing on June 30th, where he said:
"The bottom line is, there's not enough money. Would I like to fly shuttle two times a year to go insure that ISS was in the best possible shape, or maybe go back up to Hubble again, or maybe do who knows what? Sure! I think it's a national capability that we are losing, but again you weigh that against -- you've done what you set out to do with the shuttle. You've got Hubble in extremely good shape, you've got ISS in extremely good shape. Now we have other areas coming up to take over the LEO functions that the shuttle did. We can take that money, and just as importantly take that workforce, and apply it to the next leading edge and expand the sphere of operations that we do in human spaceflight. I think that is extremely important. What we're doing is we're sacrificing the shuttle to enable us to take that next step. If we were going to retire the shuttle, this is the time to do it. The ISS couldn't be in better shape than it is right now, it's pretty much out of volume, we're going to pack it full before we're done. While we can always come up with other missions, it's an OK time and I think that we're going to expand the breadth of things that we do as a nation and as an international partner. That's how I came to peace with all of the decisions that we made."
Now, enjoy the last mission of the Space Shuttle. Here's a reference I put together a couple years ago on all of the resources available online to follow a mission.