SpaceX's Falcon Launches... Sort Of

JHarrison writes "Spaceflight Now is running a story on the SpaceX Falcon 1 launch yesterday. Those of you watching the stream will have no doubt noticed the telemetry failure at 04:50, and turns out that was more than them turning the webcast off.. "A year after its maiden flight met a disastrous end, the SpaceX booster lifted off at 9:10 p.m. EDT (0110 GMT Wednesday) from a remote launch pad on Omelek Island, part of a U.S. Army base at Kwajalein Atoll in the Marshall Islands. Controllers lost contact with the Falcon during the burn of the second stage that would have placed the rocket into orbit around Earth. "We did encounter, late in the second stage burn, a roll-control anomaly," Elon Musk, founder and chief executive officer of Space Exploration Technologies Corp., said in a post-launch call with reporters. Live video from cameras mounted aboard the rocket's second stage showed increasing oscillations about five minutes after liftoff, just before the public webcast was cut off. The rolling prevented the necessary speed to achieve a safe orbit, instead sending the stage on a suborbital trajectory back into the atmosphere.""

Re:That's how it works

[fbjon]

They will. In fact, Elon stated that all the difficult problems were surpassed, another test launch probably won't be needed, and the next launch will have actual payload.

Re:Rocket Science?

[savuporo]

No, its plain old engineering. There is hardly any science in building a two-stage liquid rocket in 2007. They arent doing something that isnt done before. What _is_ novel here is that for the first time, an orbital space launcher is built primarily with the profit motive in mind. No other company has really attempted that before ( or they have, but never gotten so close to pulling it off ). Thus also different design choices, different incentives and ultimately a price tag couple of times lower than your regular cost-plus aerospace contract would yield.

Engine bump and second stage control

[decaym]

Did anyone else notice the bump the Kestrel engine took during stage separation? On the 40MB video [spacex.com] from SpaceX, it happend at 3:28 in or at T+00:02:52 on the screen clock. Maybe this is normal for the engine, but it was rather odd looking to me.

Also, there was a story [space.com] earlier that the 2nd launch was delayed "due to concerns over a thrust vector control pitch actuator on the Falcon 1 booster's second stage". I wonder if this came back to bite them?

Finally, I'm impressed as hell that they could experience an abort after engine start yet still cycle back and launch in just another hour! When the Shuttle once aborted after engine start it took them a month to change out the engines and try again.

Re:What kind of comment is "Sort of"

[wjsteele]

The Space Station varies it's orbit depending on a lot of factors. It's in a continously decaying orbit (intented) which will always make it return to Earth at some point. It's orbit is occasionally boosted by the Space Shuttle or by the various Russian cargo ships. For example, right now, NASA is letting the orbit decay to around 205 miles so that the Shuttle can bring up the largest (and heaviest) component without having to push it all the way. With ISS in a lower orbit, less fuel is needed to get the heaviest components there. Later, a service module will boost it back to a higher orbit.

Bill

Re:Engine bump and second stage control

[decaym]

I had read about the Niobium nozzle being able to take a dent. I'd be more concerned about the bump damaging the vectoring hardware for the engine. It was also really interesting to see the glow coming through the nozzle. I was really worried we'd see a burn through of the nozzle, but I guess the glow is just the normal behavior.

Some of the early comments by Elon talked about spin causing centrifuge effect on the fuel supply to the 2nd stage engine. In the video, although the nozzle is oscilating back and forth the craft itself is not spinning up to the point where the video ends. You can tell by the Earth horizon staying mostly stable. It will be interesting to hear the analysis in the coming days or weeks.

Re:Insightful...?

[ePhil_One]

Haven't we been sending rockets up into space for quite some time now. I'd think the fundementals should be down pretty pat now, the time for spectacular failures has past.

And yet we've lost two Space shuttles in recent memory. Space is not easy, rockets are enormously powerful devices that require light weight and experience a vast array of environments. Here a relatively minor thing went wrong, too much rotation, and the whole thing is now gone. Knowing how to do something and actually doing it are radically different things...

Re:That's how it works

[Keebler71]

Did anyone else watching the video notice the apparent contact between the 2nd stage nozzle and the interstage? I wonder if a TVC actuator was damaged leading to the nutation...

Re:That's how it works

[khallow]

Or it means that he's out of money for more test launches. He has demonstrated two difficult aspects, liftoff and stage seperation. So I'm optimistic. But as I recall, he's said in the past that he'll evaluate the program after the first three launches. So far, he's had one utter failure and one that lost control in the second stage. He still needs to put something in orbit.

From the Website...

[Mizled]

Falcon flew far beyond the "edge" of space, typically thought of as around 60 miles. Our altitude was approximately 200 miles, which is just 50 miles below the International Space Station. The second stage didn't achieve full orbital velocity, due to a roll excitation late in the burn, but that should be a comparatively easy fix once we examine the flight data.

Re:Engine bump and second stage control

[decaym]

There is another point, which is right before the second separation events (from the nose; I don't know what it's called and can't get a timecode right now), there's a ring that comes off of the 2nd stage engine. Anyone know if this was normal?

In the transcript from a post flight interview it was said that these rings are titanium and applied to the edge of the nozzle with a bonding agent. The rings are there to protect the nozzle during the first part of the firing. Once the rings heat up the bonding agent breaks down and lets the rings fall away at the point where they are no longer needed. Apparently, this is normal behavior.

From Spaceflight Now [spaceflightnow.com]: "What you might have seen was basically titanium half-hoops that are used to stabilize the nozzle on ascent. However, once you get to a certain temperature the bonding agent for those titanium rings comes off and the titanium rings float away, which occurred as expected."

Re:Rocket Science?

[Rei]

It's not really the fact that it's not from one of the bloated aerospace giants that makes this cheap (although I'm sure it doesn't hurt). It's also not true that they're not doing something that hasn't been done before. For example, I'm having trouble thinking of any rockets that use their particular mix of pressure and structural stabilization. For example, some Atlas stages use "balloon tanks" that will outright collapse under their weight if not kept pressurized. Most other rockets are structurally stable that, were it not for the lack of propellants, they could launch without being pressurized and remain intact. Pressurization is just added support. The Falcon concept is a hybrid of this: it has enough support that it can be transported and erected unpressurized... barely. This makes transport and handling costs cheaper and less error prone than for balloon tank-based rockets, but gives a higher payload fraction than rockets which have better structural support.

It's not without it's risks, of course. For example, it made the Falcon vulnerable to an accident a while back on Kwaj in which a reduction of pressure when draining a tank caused the tank to buckle. But in general, I think it makes for a nice design.

Falcon really is, for the most part, a "from scratch" rocket, so there's a lot of new ground covered. Not everything is from scratch, of course; I seem to recall, as an example, that their pintle injectors for the Merlin were pretty much borrowed as-is from Apollo. They're also not having to do much materials science, although they helping pioneering some fields (for example, friction-stir welding; a few older rockets have switched to using it as well, but it's still pretty new to rocketry).