SpaceX F9 : KPLO : CCSFS SLC-40 : 4 August 2022 (23:08 UTC)

[ZachS09]

Interesting that even though this is a very low-mass spacecraft as discussed upthread, this is not an RTLS flight.

Probably need enough delta-v for TLI, hence the drone ship landing.

[ccdengr]

Probably need enough delta-v for TLI, hence the drone ship landing.

Mass to a C3 of -1 is about 1500 kg for RTLS according to the graphs upthread, and KPLO masses less than half of that AFAIK.

[LouScheffer]

Probably need enough delta-v for TLI, hence the drone ship landing.

Mass to a C3 of -1 is about 1500 kg for RTLS according to the graphs upthread, and KPLO masses less than half of that AFAIK.

One possibility is that SpaceX needs to do this to avoid crushing the spacecraft.  Merlin vacuum is about 981kN, and throttles to 64%, or about 628kN.  The end-of-burn mass of the stack is something about 4.5t empty second stage + 1000kg reserves (1%) + payload, or about 6060kg in this case.  So the acceleration would be more than 10 Gs.  With an ASDS landing, however, the payload is about 3400 kg, so they end the burn with an extra 2800 kg of fuel in the tank, and reduce the peak acceleration to about 6.3 G.

[ccdengr]

One possibility is that SpaceX needs to do this to avoid crushing the spacecraft.

Could be, thanks.  Falcon 9 user's guide gives a peak acceleration of 8.5g for "light" payloads (<4000 lbs) but cautions

for ultra-light payloads (~2,000 lb or less), coordination with SpaceX mission management is required, since these load factors may not be adequate to design the payload.

I'm sure the cost required to add ballast mass or find a secondary payload was more than the extra hassle of an ASDS landing.

[LouScheffer]

One possibility is that SpaceX needs to do this to avoid crushing the spacecraft.

I'm sure the cost required to add ballast mass or find a secondary payload was more than the extra hassle of an ASDS landing.

Adding ballast mass, or a secondary payload won't help.  If they are heavy enough to reduce the acceleration by much, they are also heavy enough to require an ASDS landing.  You may as well let the ballast be extra fuel, which needs no engineering, gives increased margins, and ensures the stage has plenty of dV to re-enter.

[ccdengr]

Adding ballast mass, or a secondary payload won't help.

I guess I'm not following exactly what the stated capability of 1500 kg to C3 of -1 for RTLS means then, but I'm sure I'm just missing something.

Perhaps you mean that even 1500 kg of payload is not really practical because the acceleration would be too high?

[LouScheffer]

It depends on how much reduction in acceleration the payload needs.   If you add enough ballast to get to 1500 kg, you bring the peak acceleration down to 9 Gs.  That's as much reduction as you can get while still keeping RTLS.  If you need more reduction than that, the amount of ballast required will require an ASDS landing anyway.

So there is a window where ballast can help reduce the peak acceleration while still doing RTLS - say the spacecraft is designed for 9.5 Gs.  But since they are doing ASDS I'm guessing they are not in that window.

[scr00chy]

Tesla is about to launch customer pictures in space on SpaceX’s lunar orbiter mission

The article has a video of the final mosaic made with the customers' photos. The result imitates the photo of Tesla Roadster from FH Demo mission.

[Rondaz]

A South Korean spacecraft set for launch to the moon next week from Cape Canaveral has been loaded with the fuel it needs to maneuver into a low-altitude lunar orbit for image-taking and scientific observations.

https://twitter.com/SpaceflightNow/status/1553719122780831746

[Rondaz]

Tug Kurt J Crosby is gearing up to depart Port Canaveral with Just Read the Instructions droneship for the KPLO mission, NET August 4th.

JRTI will be stationed approx ~640 km downrange.

https://twitter.com/SpaceOffshore/status/1553808612497260545

[FutureSpaceTourist]

https://twitter.com/spaceoffshore/status/1553822412231294980

See ya soon! 🚀

[2megs]

[...]  You may as well let the ballast be extra fuel, which needs no engineering, gives increased margins, and ensures the stage has plenty of dV to re-enter.

I don't believe we've seen a NOTMAR for second stage re-entry, though. Normally when there's a controlled re-entry burn planned, it gets announced at the same time as the first-stage recovery zone.

Pure speculation: Might be interesting to deploy the primary mission and then use the extra fuel to get additional F9S2 BEO flight data. Might be why the Tesla promo thing is on this flight particular.

[LouScheffer]

[...]  You may as well let the ballast be extra fuel, which needs no engineering, gives increased margins, and ensures the stage has plenty of dV to re-enter.

I don't believe we've seen a NOTMAR for second stage re-entry, though. Normally when there's a controlled re-entry burn planned, it gets announced at the same time as the first-stage recovery zone.

Pure speculation: Might be interesting to deploy the primary mission and then use the extra fuel to get additional F9S2 BEO flight data. Might be why the Tesla promo thing is on this flight particular.

This makes sense.  It's almost at Earth escape already - just add a little dV and dispose of the stage in solar orbit.  With such an eccentric initial orbit, this may be easier than plotting an accurate controlled re-entry.

[FutureSpaceTourist]

L-3 launch weather forecast is 80% GO, additional risk criteria all low

[Rondaz]

This Thursday, (Aug 4th) we are supposed to have 2 rocket launches in 1 day.

• At 6:29 AM ET, @ulalaunch SBIRS GEO-6 is going to launch from SLC-41.

• At 7:08 PM ET, @SpaceX Korea Pathfinder Lunar Orbiter (KPLO) is going to launch from SLC-40.

https://twitter.com/JennyHPhoto/status/1554111148370403332

[ZachS09]

This Thursday, (Aug 4th) we are supposed to have 2 rocket launches in 1 day.

• At 6:29 AM ET, @ulalaunch SBIRS GEO-6 is going to launch from SLC-41.

• At 7:08 PM ET, @SpaceX Korea Pathfinder Lunar Orbiter (KPLO) is going to launch from SLC-40.

https://twitter.com/JennyHPhoto/status/1554111148370403332

Don’t forget Blue Origin’s NS-22 mission at 13:30 UTC (8:30 AM CDT).

There’s also a Long March launch sometime within that day. Obviously, it’ll come as a surprise to us time-wise.

[Comga]

This Thursday, (Aug 4th) we are supposed to have 2 rocket launches in 1 day.

• At 6:29 AM ET, @ulalaunch SBIRS GEO-6 is going to launch from SLC-41.

• At 7:08 PM ET, @SpaceX Korea Pathfinder Lunar Orbiter (KPLO) is going to launch from SLC-40.

Don’t forget Blue Origin’s NS-22 mission at 13:30 UTC (8:30 AM CDT).

There’s also a Long March launch sometime within that day. Obviously, it’ll come as a surprise to us time-wise.

… unless “we” is meant to encompass launch observers and photographers at the Cape. 

This has been noted already elsewhere by others.

[ZachS09]

This Thursday, (Aug 4th) we are supposed to have 2 rocket launches in 1 day.

• At 6:29 AM ET, @ulalaunch SBIRS GEO-6 is going to launch from SLC-41.

• At 7:08 PM ET, @SpaceX Korea Pathfinder Lunar Orbiter (KPLO) is going to launch from SLC-40.

Don’t forget Blue Origin’s NS-22 mission at 13:30 UTC (8:30 AM CDT).

There’s also a Long March launch sometime within that day. Obviously, it’ll come as a surprise to us time-wise.

… unless “we” is meant to encompass launch observers and photographers at the Cape. 

This has been noted already elsewhere by others.

My statement has nothing to do with people at the Cape. Just us members on the forum.

[briantipton]

This Thursday, (Aug 4th) we are supposed to have 2 rocket launches in 1 day.

• At 6:29 AM ET, @ulalaunch SBIRS GEO-6 is going to launch from SLC-41.

• At 7:08 PM ET, @SpaceX Korea Pathfinder Lunar Orbiter (KPLO) is going to launch from SLC-40.

Don’t forget Blue Origin’s NS-22 mission at 13:30 UTC (8:30 AM CDT).

There’s also a Long March launch sometime within that day. Obviously, it’ll come as a surprise to us time-wise.

… unless “we” is meant to encompass launch observers and photographers at the Cape. 

This has been noted already elsewhere by others.

My statement has nothing to do with people at the Cape. Just us members on the forum.

Looks like we might add a 5th launch that day!

https://twitter.com/rocketlab/status/1554414821793140736

🚀Launch update: with strong winds forecast over the next 24 hours, we’re targeting launch for #NROL199 with @NatReconOfc on Thurs, August 4.

Launch window opens:
UTC | 05:00, Aug 4
NZT | 17:00, Aug 4
EDT | 01:00, Aug 4
PDT | 22:00, Aug 3

[Ken the Bin]

L-2 weather forecast.  80% 'Go' for August 4 and August 5.  70% 'Go' for August 6.  All Additional Risk Criteria are Low for all three days.

Note: For some reason the 45th Weather Squadron posted this as an image, exactly as I have uploaded here.