SpaceX Falcon 9 v1.1 - CASSIOPE - September, 2013 - GENERAL DISCUSSION THREAD

[mlindner]

and a soft water touch down. Hope we get to see that.

Now there is an optimist. 

You are aware, if that happens the largest remaining obstacle to first stage reusability would be finding a suitable landing location?

Thats only half the problem. Presumably they'd just slow themselves on the downward trajectory and land where their normal water impact would be. They still need to work out turning around and thrusting back to the landing location after that.

But I agree, if they actually manage a soft water landing my rational side will be very impressed, but my emotional side will be jumping for joy and dying of shock simultaneously.

[Mader Levap]

But I agree, if they actually manage a soft water landing

Hard water landing would be for me absolutely enough, considering currently stage just fall apart during reentry.

[douglas100]

Hard water landing would be for me absolutely enough, considering currently stage just fall apart during reentry.

Yep, one step at a time. Also, the proposed experiment has essentially zero impact on the payload.

[Zed_Noir]

With a possible water landing. Will SpaceX add some floatation gear to the 1st stage? Or will they relied on the natural buoyancy of the empty propellant tanks. Presuming the stage comes down more or less intact.

[mlindner]

With a possible water landing. Will SpaceX add some floatation gear to the 1st stage? Or will they relied on the natural buoyancy of the empty propellant tanks. Presuming the stage comes down more or less intact.

We don't know the answer to that question. I would guess "no", because I feel this test is rather ad-hoc so they wouldn't add anything that they didn't plan to have on the actual Falcon 9 v1.1. They have no plans to do water landings in the future as far as we know, so its unlikely they would design this in.

[douglas100]

Agree with that. the big unknown is how the stage will behave during atmospheric flight. If they can restart and reduce the entry speed so that it survives then they will have gained useful information. A restart just before hitting the sea would be icing on the cake.

[QuantumG]

Some details about the payload:

  http://mertensiana.phys.ucalgary.ca/cassiope.html

"CAScade, Smallsat and IOnospheric Polar Explorer" (CASSIOPE) is a made-in-Canada small satellite from the Canadian Space Agency. It is comprised of three working elements that will use the first multi-purpose small satellite platform from the Canadian Small Satellite Bus Program. This generic, low-cost platform will carry two payloads: e-POP, a scientific payload consisting of eight high-resolution instruments used to probe the characteristics of near-Earth space, and Cascade, a high data rate, high capacity store and forward technology payload from MDA Corporation.

Together, e-POP and Cascade will achieve both a scientific and a commercial objective: e-POP will provide scientists with unprecedented details about the Earth's ionosphere, thermosphere and magnetosphere, helping scientists understand the cause and effects of potentially dangerous space weather, while Cascade will demonstrate a new digital communications 'courier' service provided by MDA.

CASSIOPE is hexagonal in shape, measuring just 180 cm corner-to-corner and 125 cm high and weighing in at just over 500 kg. Partners in the mission include the University of Calgary, Commuications Research Centre in Ottawa, Bristol Aerospace of Winnipeg, and MDA of Richmond, B.C., the prime contractor for the overall mission.

See also: http://mertensiana.phys.ucalgary.ca/quickfacts.html

[Zed_Noir]

while Cascade will demonstrate a new digital communications 'courier' service provided by MDA.

Does this mean the folks at the South Pole area in the Antarctic will  get high bandwidth burst satellite communication?

[QuantumG]

while Cascade will demonstrate a new digital communications 'courier' service provided by MDA.

Does this mean the folks at the South Pole area in the Antarctic will  get high bandwidth burst satellite communication?

Maybe.

More details: http://mertensiana.phys.ucalgary.ca/cascade.html

[Prober]

anything on the timeline when the device was finished being built?

[mlindner]

anything on the timeline when the device was finished being built?

2009 is when testing finished apparently.

http://mertensiana.phys.ucalgary.ca/schedule.html

[ArbitraryConstant]

Per the CRS-2 conference call, they will be attempting a velocity reduction burn for reentry and another burn for a soft splashdown with this flight.

[8900]

I have a question:why use a launch vehicle with 8mT+ SSO capacity to launch a 500kg satellite?

[Galactic Penguin SST]

I have a question:why use a launch vehicle with 8mT+ SSO capacity to launch a 500kg satellite?

Because it was once a F1E payload, then the rocket disappeared from SpaceX's plans. Plus this is a test flight.

Such payload mismatches are rare, but not exactly a first - see Atlas V/Delta IV launching the fairly small DMSPs for the USAF (which bought a bunch of EELVs) or Ariane 5 launching the French Helios spysats (no other suitable launcher available at the time).

[kevin-rf]

I believe it was also to large for the Falcon 1 payload fairing. But my memory is fuzzy...

[mr. mark]

Once the first stage for this flight has turned around how do they plan on stabilizing the first stage end down on it's free fall. Clearly they are not lighting the center engine until the last minute. Watching all the Falcon 9 launch videos it appears that upon separation the first stage falls toward it's interstage. How do you keep the rocket from rolling over? Is SpaceX using thruster jets for stabilization on the way down?

[Ben the Space Brit]

Once the first stage for this flight has turned around how do they plan on stabilizing the first stage end down on it's free fall.

They're probably going to use the cold-gas system.  They'll need to dampen out the kick from the upper stage ignition anyway before they align for the braking burn.

[Lars_J]

Once the first stage for this flight has turned around how do they plan on stabilizing the first stage end down on it's free fall. Clearly they are not lighting the center engine until the last minute. Watching all the Falcon 9 launch videos it appears that upon separation the first stage falls toward it's interstage. How do you keep the rocket from rolling over? Is SpaceX using thruster jets for stabilization on the way down?

Cold gas RCS will be used to point it the right way.

[mlindner]

Once the first stage for this flight has turned around how do they plan on stabilizing the first stage end down on it's free fall.

They're probably going to use the cold-gas system.  They'll need to dampen out the kick from the upper stage ignition anyway before they align for the braking burn.

They won't do the braking burn right away anyway. Remember they're on a ballistic upward trajectory. They'd wait for engine re-ignite until they were on a downward trajectory near the upper layers of the atmosphere.

[aero]

They won't do the braking burn right away anyway.

You think? If I were planning the manuvers, I'd make it as close to realistic, back to the pad, as is safely practical. Maybe landing in the water a few dozen miles off the coast of Vandenburg. What would the range safety issues be there, considering that they just launched maybe 10 minutes before landing or splash down? Proving that they can get the S1 back to the area of the landing pad comes only second to proving that it doesn't break up on the way back.

If they are going to do it, they may as well do as much as they can. JMO.