How difficult is it to recreate the Space Shuttle Enterprise drop tests?
In spite of its flaws, the Space Shuttle is undoubtedly one of the most iconic and down-right coolest spacecraft ever. If you've read the article on building a foam board Space Shuttle from a couple of weeks ago, you'll know that I'm trying to recreate the STS Program with model rocket engines and R/C gear. This week, we're testing the ship at altitude.
Mission
Most who are familiar with the Space Shuttle Program will know that it took years of research and design work before any Shuttle made it to space. In fact, it was during the Apollo missions that the Shuttle Program got the go ahead.
During the early 1970s, NASA built Space Shuttle Enterprise. It was the first Shuttle. It was primarily built to conduct flight tests in the atmosphere which included approach and landing test flights.
It was carried aloft by a Shuttle Carrier Aircraft, a highly modified Boeing 747. The tests were used to determine the flight characteristics of the spacecraft in the atmosphere and to research the landing procedure.
So, this is precisely what this project was all about. Just like the real thing, we needed to test our small scale orbiter to see if it flies from high up in the air and to practice the landings.
Bungee Testing
Before getting the high-altitude tests underway, I needed to find another pilot to actually fly the Space Shuttle. For this, I needed to train someone up from scratch, so I found a volunteer and set about doing a couple of bungee launches in a field. Initially testing the bungee myself it was clear it wasn't really working very well. So, we simply resorted to launching the shuttle into the air by hand. After around just twenty-or-so launches, we decided it was go time. Talk about a crash course!
Modding the Science Plane
Featured in another recent article, this plane designed especially for science experiments (dropping things and seeing what happens, mostly) had to be modified to carry the Space Shuttle model. It was pretty easy, but it needed some extra hardware installing.
Instead of simply using one mechanism to drop a parachute, the plane would need two seperate mechanisms to lock the orbiter in place at the nose and the tail.
Instead of an elastic band pinning around the bottom of the fuselage, a band was stretched over the top of the science plane, around the Shuttle's nose, and onto a peg on the other side of the cockpit.
Testing the drop mechanism showed that it worked, even if my catching skills left something to be desired.
At the tail, a sliding rod operated by a servo could slide into a block of balsa wood glued to the underside of the Shuttle's wing. Both servos were paired together with a 'y' harness meaning they would open at the same time.
Attempt 1
The first go at getting the Space Shuttle to detach didn't really go to plan. As soon as the pre-programmed release switch was toggled, the Shuttle refused to budge. Thinking it may just be a little stuck, I attempted to dive the plane, putting it into a negative G manouver, but this didn't work.
Attempt 2
After landing, it seemed the front mechanism had failed to release as the elastic band had snagged on a corner of the balsa frame. This meant it wouldn't 'ping off'. The second round saw the whole thing release perfectly, although the flight quickly, and quite literally, went south. A+ for effort on our Shuttle pilot Mike's part though!
Attempt 3 (it worked!)
It seemed the second attempt's spin was caused by a stall immediately after launch. To prevent this, Mike was advised to nose the plane down when released to gain some airspeed. We also reduced the throws on the elevator and moved the center of gravity forward to better penetrate into the wind. It seemed to work!
What's Next?
Now we've proved the Shuttle can fly, it's time to design a booster powered by model rocket engines to get the shuttle airborne by rocket power! Make sure to keep an eye on the progress by visiting the Articles section of www.flitetest.com over the next few weeks!
What crazy projects should we try in the future?
Let us know what we should make a video or article series about next!
Article by James Whomsley
Editor of FliteTest.com
Contact: james@flitetest.com
YouTube Channel: www.youtube.com/projectairaviation
Are you going to do more drops after you finish with the rocket power launch?
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Bob
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