SpaceX Falcon 9/Dragon COTS Demo (C2+) PRE LAUNCH UPDATES

[ugordan]

Well obviously, but where's the incremental usefulness in that. If SpaceX deemed a static fire without the payload is of any use, they would have done that in all their previous launches, possibly concurrently with WDRs.

[Robotbeat]

Well obviously, but where's the incremental usefulness in that. If SpaceX deemed a static fire without the payload is of any use, they would have done that in all their previous launches, possibly concurrently with WDRs.

They didn't have a Dragon capsule full of NASA's stuff (some of which may need to be kept cold) for the other launches.

[ugordan]

So what? That's what refrigeration and late cargo loading are for.

[mr. mark]

I think the implication is that if they light up the first stage for test fire and the rocket blows up, you lose the capsule. That's not going to happen, hopefully.

[Robotbeat]

So what? That's what refrigeration and late cargo loading are for.

Why does the spacecraft have to be on top of the launch vehicle during a static fire, again?

[Kabloona]

So what? That's what refrigeration and late cargo loading are for.

Why does the spacecraft have to be on top of the launch vehicle during a static fire, again?

I think the point is to do the static fire as late as possible in the processing flow, as near to launch as possible...ie with the vehicle fully integrated.

[Robotbeat]

So what? That's what refrigeration and late cargo loading are for.

Why does the spacecraft have to be on top of the launch vehicle during a static fire, again?

I think the point is to do the static fire as late as possible in the processing flow, as near to launch as possible...ie with the vehicle fully integrated.

...But one of the biggest reasons is just seeing if the engines work properly. Having a Dragon on top or not has basically no relevance to that.

[ugordan]

But one of the biggest reasons is just seeing if the engines work properly.

No, it's not. The engines and stage have been checked out multiple times. This is an integrated test, from an electrical, vibroacoustical and what have you standpoint. Checking everything in the system and all the interactions, not a primarily propulsion system test. Having the stack not be in the flight configuration reduces the value of such a test and obviously skews some of those measurements.

[Lurker Steve]

But one of the biggest reasons is just seeing if the engines work properly.

No, it's not. The engines and stage have been checked out multiple times. This is an integrated test, from an electrical, vibroacoustical and what have you standpoint. Checking everything in the system and all the interactions, not a primarily propulsion system test. Having the stack not be in the flight configuration reduces the value of such a test and obviously skews some of those measurements.

Do you normally get feedback from the second stage and payload after one of these tests ? To assure they can handle the launch environment obviously.

[Chris Bergin]

SpaceX: Earlier this week SpaceX and NASA successfully completed the last joint simulation before the upcoming mission.

[Kabloona]

But one of the biggest reasons is just seeing if the engines work properly.

No, it's not. The engines and stage have been checked out multiple times. This is an integrated test, from an electrical, vibroacoustical and what have you standpoint. Checking everything in the system and all the interactions, not a primarily propulsion system test. Having the stack not be in the flight configuration reduces the value of such a test and obviously skews some of those measurements.

I agree with ugordan. It's really more of an overall systems test. You're doing a full countdown, with electrical GSE doing their systems health checks, monitoring hundreds of sensors, and making sure that everything works correctly up to and including lighting the engines. Once all the other systems check out and you reach T-0, successful engine start is practically a given, but you do have a few seconds of engine health check before shutdown. So you're mainly trying to verify that you can get to T-0 successfully in flight configuration, plus a bonus of verifying nominal engine start.

[Jim]

But one of the biggest reasons is just seeing if the engines work properly.

No, it's not. The engines and stage have been checked out multiple times. This is an integrated test, from an electrical, vibroacoustical and what have you standpoint. Checking everything in the system and all the interactions, not a primarily propulsion system test. Having the stack not be in the flight configuration reduces the value of such a test and obviously skews some of those measurements.

Not really. 
a.  The vehicle isn't instrumented for such tests.
b.  This isn't going to be done for other spacecraft launches
c.  There is more risk than benefit.

[stope19]

SpaceX: Earlier this week SpaceX and NASA successfully completed the last joint simulation before the upcoming mission.

In the 'world map' at top of the image, there seems to be a circled area around what I suppose is the launch site - but there is another circle covering part of the south-east of Australia. Any ideas on what these circles represent?

[Robotbeat]

Remember, if they have an abort during a real launch this time, they have to wait 3 days for the next window. Doing a real static fire (even without the spacecraft) is a reasonably good way to avoid an unnecessary abort for the real launch without setting the abort criteria too stringently. Later flights will eventually have only a day to wait in case of abort and will be better characterized, thus making aborts less likely.

[Jim]

In the 'world map' at top of the image, there seems to be a circled area around what I suppose is the launch site - but there is another circle covering part of the south-east of Australia. Any ideas on what these circles represent?

Tracking site coverage

[mr. mark]

"SpaceX engineers have completed loading hypergolic maneuvering propellant into the Dragon capsule at Cape Canaveral, according to a company spokesperson.

The propellant will fuel the Dragon spacecraft's 18 Draco thrusters during the ship's flight to the International Space Station. The thrusters, which each generate up to 90 pounds of thrust, will regulate the craft's approach to the space station".

http://www.spaceflightnow.com/falcon9/003/status.html

[stope19]

In the 'world map' at top of the image, there seems to be a circled area around what I suppose is the launch site - but there is another circle covering part of the south-east of Australia. Any ideas on what these circles represent?

Tracking site coverage

Thanks Jim.

[Ben the Space Brit]

SpaceX: Earlier this week SpaceX and NASA successfully completed the last joint simulation before the upcoming mission.

I'm guessing here but I'll bet that the last minute software changes that led to the slip to 5/7 were as a result of analysis of the simulation.

[Jim]

SpaceX: Earlier this week SpaceX and NASA successfully completed the last joint simulation before the upcoming mission.

I'm guessing here but I'll bet that the last minute software changes that led to the slip to 5/7 were as a result of analysis of the simulation.

Unrelated.  Joint SIMs are for personnel to practice interaction and there is no hardware involved.

[corrodedNut]

I haven't seen this mentioned before:

http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=59168

"NASA’s Mobile Aerospace Reconnaissance System, or MARS, is secured aboard NASA’s Freedom Star boat near Hangar AE at Cape Canaveral Air Force Station in Florida. MARS is being prepared for a day of testing after departing from Port Canaveral out to the Atlantic Ocean. MARS, run by NASA’s Langley Research Center in Hampton, Va., with its spatial, hyperspectral, thermal, and directed energy capabilities will be used for thermal imaging testing for the upcoming SpaceX Falcon 9 and Dragon capsule test flight to the International Space Station. During today’s test, the MARS X-band radar and kineto tracking mount KTM were tested to ensure that they were synchronized to receive a rocket launch feed. The radar was used to identify an object to see if the KTM could lock on to and track it. The MARS team performed maintenance on the system, confirmed communications links, and tested the design of the mounting system and environmental enclosure."

What is this used for? Launch, orbital operations, or both? Tracking, telemetry, or both? Will this produce imagery we can "see"?

PS. Is this the same thing as HYTHIRM, on a boat?