SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION

[smoliarm]

Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.

Originally, the plan was to also include 5 tons of ballast, but I'm guessing that changed, considering the center core is able to RTLS on this launch.

That guess of 7 tons would include the ballast.  We don't actually know what the payload mass is.

Well, we do know - approximately, see attachment.
What we don't know - if the ballast is there 

[russianhalo117]

Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.

Originally, the plan was to also include 5 tons of ballast, but I'm guessing that changed, considering the center core is able to RTLS on this launch.

That guess of 7 tons would include the ballast.  We don't actually know what the payload mass is.

Well, we do know - approximately, see attachment.
What we don't know - if the ballast is there 

Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

[PM3]

Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.

[russianhalo117]

Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.

Then why does USAF and the permit state it as a CubeSat unless GPIM also has an SOS payload or there is an error in the permit text.

[gamesyns]

Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

[gongora]

Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.

Then why does USAF and the permit state it as a CubeSat unless GPIM also has an SOS payload or there is an error in the permit text.

I saw another permit the other day from Globalstar for communications with the Ubiquitilink "cubesat" on the next Cygnus mission, pretty sure that's just equipment mounted to the outside of the Cygnus.  ¯\_(ツ)_/¯

[watermod]

As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?

[pb2000]

As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?

One does not simply bolt a mothballed spacecraft to the top of a rocket (unless it contains the one ring and is a sub-orbital express to mount doom).

[envy887]

As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?

There aren't many 5-tonne military spacecraft that unexpectedly find themselves without budget for a ride to space. Building a spacecraft that size is expensive.

[Alexphysics]

Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

It's weird they move the fairing with the payload to the HIF before the static fire, that's usually done after the static fire. I guess it's to save some time. If they have the payloads ready then no need to wait.

Edit: Wait, wait. That fairing... it has no logo, it is also not the half with the US flag.
O . o

[Robotbeat]

Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.

Then why does USAF and the permit state it as a CubeSat unless GPIM also has an SOS payload or there is an error in the permit text.

I saw another permit the other day from Globalstar for communications with the Ubiquitilink "cubesat" on the next Cygnus mission, pretty sure that's just equipment mounted to the outside of the Cygnus.  ¯\_(ツ)_/¯

According to Spaceflightnow, yeah. https://spaceflightnow.com/2019/02/08/cygnus-ng10-departure/

[jjyach]

Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

It's weird they move the fairing with the payload to the HIF before the static fire, that's usually done after the static fire. I guess it's to save some time. If they have the payloads ready then no need to wait.

Edit: Wait, wait. That fairing... it has no logo, it is also not the half with the US flag.
O . o

Has encapsulation even happened yet? The fairing has to be empty and they are getting ready to roll out to the encapsulation site using the payload transporter.  Current time before launch fits that scenario and they won't want the payload around until around SF.

[yoram]

As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?

There aren't many 5-tonne military spacecraft that unexpectedly find themselves without budget for a ride to space. Building a spacecraft that size is expensive.

If the second stage tank has enough capacity they could also in theory carried more fuel, don't deorbit it, and use it as in orbit fuel tank for some future mission (similar to ULA distributed launch). Of course that would have needed significant technology development for storage and docking. But since the mission was delayed by ~5 years maybe there would have been enough time to do so.

[cscott]

KSC just put launch viewing tickets on sale. That seems to indicate a level of confidence in the current launch date.

[Alexphysics]

Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

It's weird they move the fairing with the payload to the HIF before the static fire, that's usually done after the static fire. I guess it's to save some time. If they have the payloads ready then no need to wait.

Edit: Wait, wait. That fairing... it has no logo, it is also not the half with the US flag.
O . o

Has encapsulation even happened yet? The fairing has to be empty and they are getting ready to roll out to the encapsulation site using the payload transporter.  Current time before launch fits that scenario and they won't want the payload around until around SF.

That's what I was wondering. A fairing with nothing painted on it on the HIF this early before the launch... I can only think they may be doing fairing re-rad tests but I certainly don't know if they are done in the HIF or elsewhere at the Cape. They must have a reason why that fairing is inside there.

[Mandella]

KSC just put launch viewing tickets on sale. That seems to indicate a level of confidence in the current launch date.

Not much confidence. The tickets are good for whenever the launch happens -- unless of course there is a scrub the day of, in which case there are no refunds.

[cscott]

KSC just put launch viewing tickets on sale. That seems to indicate a level of confidence in the current launch date.

Not much confidence. The tickets are good for whenever the launch happens -- unless of course there is a scrub the day of, in which case there are no refunds.

Yes, but historically KSC doesn't put them on sale until the date is nailed down.  Scrubs happen, of course, as do unexpected delays.  But we're getting closer to launch and this is just one more small sign things are still on the expected schedule.  Don't make too much of it.

[Rondaz]

A NASA Atomic Clock on SpaceX's Next Falcon Heavy Will Pioneer Mars Travel Tech..

By Meghan Bartels 17 hours ago 6/14/2019

https://www.space.com/nasa-deep-space-atomic-clock-on-falcon-heavy-stp-2.html

[Star One]

NASA Prepares to Launch Twin Satellites to Study Signal Disruption From Space

NASA's twin E-TBEx CubeSats — short for Enhanced Tandem Beacon Experiment — are scheduled to launch in June 2019 aboard the Department of Defense's Space Test Program-2 launch. The launch includes a total of 24 satellites from government and research institutions. They will launch aboard a SpaceX Falcon Heavy from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

The E-TBEx CubeSats focus on how radio signals that pass through Earth's upper atmosphere can be distorted by structured bubbles in this region, called the ionosphere. Especially problematic over the equator, these distortions can interfere with military and airline communications as well as GPS signals. The more we can learn about how these bubbles evolve, the more we can mitigate those problems — but right now, scientists can't predict when these bubbles will form or how they'll change over time.

"These bubbles are difficult to study from the ground," said Rick Doe, payload program manager for the E-TBEx mission at SRI International in Menlo Park, California. "If you see the bubbles start to form, they then move. We're studying the evolution of these features before they begin to distort the radio waves going through the ionosphere to better understand the underlying physics."

The ionosphere is the part of Earth's upper atmosphere where particles are ionized — meaning they're separated out into a sea of positive and negative particles, called plasma. The plasma of the ionosphere is mixed in with neutral gases, like the air we breathe, so Earth's upper atmosphere — and the bubbles that form there — respond to a complicated mix of factors.

Because its particles have electric charge, the plasma in this region responds to electric and magnetic fields. This makes the ionosphere responsive to space weather: conditions in space, including changing electric and magnetic fields, often influenced by the Sun's activity. Scientists also think that pressure waves launched by large storm systems can propagate up into the upper atmosphere, creating winds that shape how the bubbles move and change. This means the ionosphere — and the bubbles — are shaped by terrestrial weather and space weather alike.

The E-TBEx CubeSats send radio beacon signals at three frequencies — close to those used by communications and GPS satellites — to receiving stations on the ground, at which point scientists can detect minute changes in the signals' phase or amplitude. Those disruptions can then be mapped back to the region of the ionosphere through which they passed, giving scientists information about just how these bubbles form and evolve.

"All signals are created at the same time — with the same phase — so you can tell how they get distorted in passing through the bubbles," said Doe. "Then, by looking at the distortions, you can back out information about the amount of roughness and the density in the bubbles."

The data produced by the twin CubeSats is complemented by similar beacons onboard NOAA's six COSMIC-2 satellites. Like the E-TBEx CubeSats, the COSMIC-2 beacons send signals at three frequencies — slightly different than those used by E-TBEx — to receiving stations on the ground. The combination of measurements from all eight satellites will give scientists chances to study some of these bubbles from multiple angles at the same time.

E-TBEx's beacon was built by a team at SRI International, which also designed and fabricated the beacons on COMSIC-2. The E-TBEx CubeSats were developed with Michigan Exploration Lab at the University of Michigan in Ann Arbor. The design, fabrication, integration and testing was carried out mostly by teams of undergraduate and graduate students.

"Building and testing E-TBEx was pretty complex because of the number of deployable parts," said James Cutler, an aerospace engineering professor at University of Michigan who led the student teams that worked on E-TBEx. "The payload is essentially a flying radio station, so we have five antennas to deploy — four with two segments each — and, also, four solar panels."

What scientists learn from E-TBEx could help develop strategies to avoid signal distortion — for instance, allowing airlines to choose a frequency less susceptible to disruption, or letting the military delay a key operation until a potentially disruptive ionospheric bubble has passed.

STP-2 is managed by the U.S. Air Force Space and Missile Systems Center. The Department of Defense mission will demonstrate the capabilities of the Falcon Heavy rocket while delivering satellites to multiple orbits around Earth over the course of about six hours. These satellites include three additional NASA projects to improve future spacecraft design and performance.

[gongora]

https://twitter.com/StephenClark1/status/1140996040876863488

SpaceX’s drone ship is heading for a landing zone hundreds of miles off the Florida coast, multiple sources say. No center core landing close to shore, as suggested in an FCC filing earlier this year.