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

[cscott]

I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?

The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)

I strongly disagree and say it's the latter, for two reasons.

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

Second, SpaceX only recently added this extra metal protection to the tip to fairings which were planned to be recovered. The recent RADARSAT launch, for example, didn't sport the thermal protection cap. And in the reentry video, you can clearly see sparks coming from the tip, which is the area where air compression is highest as the fairing is moving very fast horizontally as it hits the upper atmosphere tip-first. The camera has a large field of view, it's a fisheye lens, so it is not clearly visible.

I agree in so far as the bright sparks at the end of the re-entry vehicle do look like aluminum.  But surely there must be better ablative materials?  Maybe it's a combination of high pressure on ascent combined with high heating on re-entry?  I'd expect something like RCC, but maybe a small block of sacrificial aluminum wins the trades when SpaceX does them.

[gongora]

RADARSAT fairing had protection at the tip, it just wasn't bare metal.

[envy887]

I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?

The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)

I strongly disagree and say it's the latter, for two reasons.

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

Second, SpaceX only recently added this extra metal protection to the tip to fairings which were planned to be recovered. The recent RADARSAT launch, for example, didn't sport the thermal protection cap. And in the reentry video, you can clearly see sparks coming from the tip, which is the area where air compression is highest as the fairing is moving very fast horizontally as it hits the upper atmosphere tip-first. The camera has a large field of view, it's a fisheye lens, so it is not clearly visible.

Your reasoning is logical, but I recall one of the SpaceX folks on a broadcast (perhaps the GPS launch?) said it was for ascent heating.

[soltasto]

I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?

The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)

...

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

...

The Delta IV fairing might disagree:

[gongora]

https://twitter.com/AF_SMC/status/1149786098135998465

DSX has deployed its booms! Thank you to the incredible team behind the success ensuring that everything goes according to plan!
DSX will perform 3 primary experiments: wave particle ineraction, space weather and space environmental effects!

#SpaceStartsHere #SMC #AFRL #STP2

[tyrred]

Is Lightsail 2's delayed solar sail deployment a concern?

[Pete]

Is Lightsail 2's delayed solar sail deployment a concern?

The status seems to be sat alive but
"The team is concerned with readings from the attitude control system on LightSail 2 and is conducting additional tests.They are currently configuring the control system and conducting a possible software update for the craft’s flight operating system."
and
"the ground team needs to wait at least until the 21st of July to perform the operation."

[Comga]

https://twitter.com/exploreplanets/status/1149789931453030400

From #LightSail2, with love <3

I wonder if the Planetary Society has their FCC license in place for operating a remote sensing satellite.
Someone might use this to discover North America.

Lovely image, actually.

[gongora]

I wonder if the Planetary Society has their FCC license in place for operating a remote sensing satellite.
Someone might use this to discover North America.

Lovely image, actually.

"The imaging system was developed by the Aerospace Corporation PICOSAT Project Group for
use in the LightSail program. LightSail 2 is equipped with two 2MP cameras, designed to take
images of the solar sail. The imaging system will verify the deployment of the solar sail and
validate the design of the system. "

[SkipMorrow]

How can I try to spot this? Do any of the online satellite viewing sites have a track on this?

[gongora]

How can I try to spot this? Do any of the online satellite viewing sites have a track on this?

It's in the catalog, every site should have it.
Catalog ID 44420
International Designator 2019-036AC
Name "LIGHTSAIL" or "LIGHTSAIL 2" depending on the site
24.01deg inclination, 709km perigee, 726km apogee

Can check on Celestrak.com, stuffin.space, or whatever else you use

[Be Free]

My launch video.

[gongora]

COSMIC-2/FORMOSAT-7

All satellites reached their mission orbits.
https://www.taipeitimes.com/News/front/archives/2021/02/09/2003752028

[Yiosie]

COSMIC-2/FORMOSAT-7

All satellites reached their mission orbits.
https://www.taipeitimes.com/News/front/archives/2021/02/09/2003752028

Now fully operational:

COSMIC-2 Achieves Full Operational Capability [dated Oct. 12]

The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC-2) is a network of six small satellites, each about the size of a standard kitchen oven, designed to improve weather prediction and model accuracy as well as space weather monitoring capabilities.

<snip>

Following launch on June 25, 2019, the satellites underwent an initial seven-month instrument and data evaluation process to make sure they were working properly as they were moved into their proper orbit. This was then followed by a period of software updates to enhance performance. During this time, a series of reviews were held to make sure that numerous specific milestones were being met by the spacecraft and the associated ground systems. These determined that:

• The six satellites were located where they were supposed to be in orbit
• The ground stations were functioning properly
• The data collected by the satellites was validated and correct
• The data processing centers in Taiwan and the U.S. were operational
• The backup ground station that has commanding capability will work in case the primary ground station cannot send signals to the satellites
• The data could be properly archived

On September 14 and 15, 2021 a board of scientists, engineers, and senior leadership from NOAA, USSF, UCAR, and NSPO held the Full Operational Capability (FOC) review, which verified that space weather data from COSMIC-2’s main instrument were properly calibrated and validated. This was the final major review remaining to achieve FOC status, and the review board praised the program and the team for a very detailed and meticulous presentation.