SpaceX FH - USSF-67 - LC39A

Launch Date: January 15
Launch Window: 5:56pm EST (2:56pm PST, 22:56 UTC) 4.5 hour launch window
Launch site: LC-39A, Cape Canaveral, Florida
Side Booster Recovery: LZ-1 and LZ-2
Core Booster Recovery: N/A Expended
Boosters: All new Block 5, Side Boosters: B1064.2 and B1065.2 Center Core: B1070.1
Mass: Maybe 3000 kg for CBAS 2 - ? for LDPE-3A
Orbit: GEO (Direct)
Yearly Launch Number: 3rd

A SpaceX Falcon Heavy rocket will launch the USSF 67 mission for the U.S. Space Force. The mission will launch the Space Force’s second Continuous Broadcast Augmenting SATCOM, or CBAS 2, military communications satellite and the Long Duration Propulsive ESPA 3A, or LDPE 3A, rideshare satellite hosting multiple experimental payloads.

USSF-67 – Wikipedia

de.wikipedia.org

 

[ecarfan]

Freakin’ spectacular images from Trevor Mahlmann in this Ars Technica article by Eric Berger.

This is my favorite.

 

[ecarfan]

And it’s going to be a record year for FH! Eric Berger writes:

If you missed this launch of the Falcon Heavy rocket, don't despair. Future missions this year include a commercial mission for the satellite communications company ViaSat in March, the Space Force's USSF-52 mission in April, a commercial mission for EchoStar in May, and the Psyche asteroid mission for NASA in October.

Though if Starship reaches orbit and then keeps launching, FH is not going to get the attention it deserves.

 

[808?]

 

[HVM]

 

[ecarfan]

Thanks for posting that video. Interesting to see that it clearly shows the boostback burns started within a small fraction of a second of each other (maybe 0.1s) even though the boosters touched down about a second apart.

Here is the moment of boostback burn ignition.

 

[Cosmacelf]

I think the reason the boosters were so far apart at landing is that one of them wasn’t turned in the correct orientation yet when it started the boost back burn. Basically, the nitrogen thrusters didn’t do the job on one of the boosters, and the much larger Merlin engine gimballing is what finally made it turn correctly. You can see this right after booster separation on one of the videos.

 

[Grendal]

I think the reason the boosters were so far apart at landing is that one of them wasn’t turned in the correct orientation yet when it started the boost back burn. Basically, the nitrogen thrusters didn’t do the job on one of the boosters, and the much larger Merlin engine gimballing is what finally made it turn correctly. You can see this right after booster separation on one of the videos.

Luckily, we've got a bunch more FH launches thus year to see if your thoughts are true. It's also possible that SpaceX has modified their sequence to avoid a simultaneous landing. That is my guess.

 

[scaesare]

I think the reason the boosters were so far apart at landing is that one of them wasn’t turned in the correct orientation yet when it started the boost back burn. Basically, the nitrogen thrusters didn’t do the job on one of the boosters, and the much larger Merlin engine gimballing is what finally made it turn correctly. You can see this right after booster separation on one of the videos.

Ah, I do recall one having a bit wacky orientation... so you think maybe thruster issue... that would seem to do it.

Thanks.

 

[ecarfan]

Luckily, we've got a bunch more FH launches thus year to see if your thoughts are true. It's also possible that SpaceX has modified their sequence to avoid a simultaneous landing. That is my guess.

Yes, seems possible, but what would be the concern about a simultaneous touchdown?

My guess is that the difference of about one second is simply random variation; it’s about 330 seconds from side booster separation to touchdown so the difference is only 0.3%. My brain wants a perfect simultaneous touchdown because it’s visually appealing but in reality that degree of precision is not obtainable or necessary.

 

[Grendal]

Yes, seems possible, but what would be the concern about a simultaneous touchdown?

My guess is that the difference of about one second is simply random variation; it’s about 330 seconds from side booster separation to touchdown so the difference is only 0.3%. My brain wants a perfect simultaneous touchdown because it’s visually appealing but in reality that degree of precision is not obtainable or necessary.

My guess is that it isn't about the landing itself but the sonic booms, pressure events, and entry burns of reentry. If they are close enough together then that probably creates some sort of turbulence that SpaceX would like to avoid. I'd have to go back and look but I seem to remember the last FH launch also had a staggered landing.