SpaceX Falcon 9 - EchoStar 23 - March 16, 2017 - DISCUSSION

[abaddon]

In comparison, JCSAT-14 and JCSAT-16, respectively (two of the previous heaviest GTO launches, both with edge-of-the-envelope drone ship landings):

JCSAT-14:   2016-028A/41471 in 189 x 35957 km x 23.70° OR
                  2016-028B/41472 in 187 x 35908 km x 23.73°

JCSAT-16:   2016-050A/41729 in 184 x 35912 km x 20.85°

JCSAT-14 was 4696kg and JCSAT-16 was 4600kg according to wiki.

PS: Well done Lou!

[edkyle99]

I'm wondering if Echostar 23 was the heaviest GTO payload ever launched from LC 39A.  Shuttle with IUS could get 2.27 tonnes to GEO, which I suppose would be the equivalent of about 4.9 ish tonnes to GEO. 

I'm still seeing conflicting mass information for Echostar 23.  SFN says about 5.6 tonnes.  Florida Today says "more than" about 5.57 tonnes.  SpaceX said about 5.5 tonnes during its webcast.  Etc.

 - Ed Kyle

[Jim]

I'm wondering if Echostar 23 was the heaviest GTO payload ever launched from LC 39A.  Shuttle with IUS could get 2.27 tonnes to GEO

It did a little more. See the STS parking orbit of some of the other missions.

[edkyle99]

I'm wondering if Echostar 23 was the heaviest GTO payload ever launched from LC 39A.  Shuttle with IUS could get 2.27 tonnes to GEO

It did a little more. See the STS parking orbit of some of the other missions.

Yes.  Looks like some missions may have approached 2.7 tonnes GEO, and much more was apparently possible to GTO in theory.  If one adds the 3 tonne IUS-2 mass to the 2.7 tonne presumed Orion mass, then a few STS missions may have managed 5.7 tonnes to GTO - slightly more than F9-31, but the real answer is likely classified.  DSCS pair missions likewise probably put nearly 5.5 tonnes into GTO.

Chandra weighed about 5 tonnes after a specially configured 2-stage IUS boosted it into its initial 330 x 72,030 km x 28.5 deg orbit.  But STS-93 launched from LC 39B.

So, the GTO record may have been broken by today's Falcon 9 launch, but maybe not.  It all seems a bit of a moot point, however, when the 48+ tonne Saturn 5 payload TLI mass is pondered!

 - Ed Kyle

[LouScheffer]

What's the final orbit of the space craft and upper stage. I'm really interested in the expendable performance achieved.

It does not seem like SpaceX pushed the performance envelope for this mission. Compared to SES-9, they were going 360 m/s faster at first stage cutoff.  The extra mass (assuming 5.27 tonne for SES-9 and 5.6 for Echostar) should cost about 100 m/s for the second stage.  So they should have 260 m/s to play with if they burned to depletion like SES-9.

However, assuming the same parking orbit (180km, 28 degrees), SES-9 went to 40,600 apogee and 28 degrees, about 2535 m/s.  Echostar went to 35,900 at 22.43 degrees, requiring about 2615 m/s.  So SpaceX only seems to have used about 80 m/s of the 260 m/s they potentially had available.  Also the camera showed LOX still in the tank after SECO, another indication they did not push as hard as possible.

[ugordan]

So they should have 260 m/s to play with if they burned to depletion like SES-9.

Why are you assuming the 2nd stage has the same amount of total impulse now compared to the aggressive subcooled loading procedures before Amos-6? Warmer LOX, potentially more heavy COPVs inside, etc.

[Lars-J]

Also, doesn't the impulse of the 2nd stage differ with the payload mass?

[CraigLieb]

From the updates thread

Congrats to all at SpaceX, EchoStar and Space Systems Loral!

Dateline: April 1, 2077:

"In a daring at sea operation that some old hands at NSF.com considered foolish and unnecessary, Elon Musk II, grandson of SpaceX founder Elon Musk, led a mission to raise the remains of the booster fondly known as 1030, which was just about the last expendable F9 S1 flown. Elon II was quoted as saying 'we will be funding a complete restoration and donation of the booster to the popular tourist attraction Udvar Hazy II, located halfway up Mons Olympus, using profits from the most recent sol's worth of CommsX transmissions'... stay tuned to INN (Interplanetary News Network) as we provide complete coverage of the return to the Cape of this booster."

In other words, thank you 1030, for your noble sacrifice. And to the fine folk who provided such great coverage of this mission.

While I normally don't appreciate fake news these days, this and other future news articles really are fun. Of course, discussing them is more appropriate to the discussion thread, so I put my comment about the comment here...  and congrats SpaceX on a great flight, and God Speed stage 1030 on your way to future stardom as a piece of some reef possibly.

edit/gongora: fixed quote

[meekGee]

Also, doesn't the impulse of the 2nd stage differ with the payload mass?

Technically, the delta V is affected by mass, but the impulse isn't.

(F•dt = m•dv)

[Lars-J]

Also, doesn't the impulse of the 2nd stage differ with the payload mass?

Technically, the delta V is affected by mass, but the impulse isn't.

(F•dt = m•dv)

Oh never mind then. I was equating the concepts in my mind.

[jcm]

I'll note that there are still no TLEs. In fact though, no TLEs for anything today - I suspect one of the
occasional glitches that happen between JSpoC and Space-Track.

[Herb Schaltegger]

I'll note that there are still no TLEs. In fact though, no TLEs for anything today - I suspect one of the
occasional glitches that happen between JSpoC and Space-Track.

Well, somebody seems to have some data:

42070   ECHOSTAR 23   2017-014A     632.93min   22.43deg   35903km X   179km

[jcm]

I'll note that there are still no TLEs. In fact though, no TLEs for anything today - I suspect one of the
occasional glitches that happen between JSpoC and Space-Track.

Well, somebody seems to have some data:

42070   ECHOSTAR 23   2017-014A     632.93min   22.43deg   35903km X   179km

Yes, that's from the 'satellite catalog' (satcat) page. JSPoC fills that from the TLEs and then sends the satcat and the TLEs to Space-Track and the public gets it from Space-Track. Today JSpoC sent the satcat to Space-Track but not the TLEs - actually I think they are sending 1 set of TLEs every 24 hr instead of multiple per day, that's happened in the past. So maybe we will get TLEs tomorrow morning.

[georgegassaway]

A bit late to say so but better late than never.

When the stages separated, the booster drifting away as stage 2 ignited, I thought to myself:

"Farewell booster 1030, and we thank you...."

[ugordan]

[zubenelgenubi]

Any news of the satellite raising its perigee?

[edkyle99]

Any news of the satellite raising its perigee?

If I'm reading today's TLE correctly, perigee had been raised to 3924 km as of about one hour ago (early March 20 UTC time).

Interesting, isn't it, that we've sort of forgotten to note that until now no one has ever launched this much mass to GTO using a two-stage kerosene/LOX rocket?

 - Ed Kyle

[envy887]

How many other 2 stage kerolox rockets have launched any mass to GTO?

[Dante80]

Yeah, most two stage kerolox LVs tend to be used for LEO/SSO campaigns.

A more relevant comparison would be to something like Zenit-3SL/SLB, for the title of best GTO performance for a Kerolox rocket.

Zenit wins this one I think, with Spaceway 1 (6080kg). It also wins while weighing almost a hundred tonnes less. And wins the LEO performance record too (in the two stage SB variant), with Phobos Grunt.

 F9 could possibly match that performance in expendable mode, even with one less stage. I don't think that SpaceX will fly something like this anytime soon though (the idea is to send those payloads to FH, rather than flying F9 expendable missions).   

[Robotbeat]

Yeah, most two stage kerolox LVs tend to be used for LEO/SSO campaigns.

A more relevant comparison would be to something like Zenit-3SL/SLB, for the title of best GTO performance for a Kerolox rocket.

Zenit wins this one I think, with Spaceway 1 (6080kg). It also wins while weighing almost a hundred tonnes less. And wins the LEO performance record too (in the two stage SB variant), with Phobos Grunt.

 F9 could possibly match that performance in expendable mode, even with one less stage. I don't think that SpaceX will fly something like this anytime soon though (the idea is to send those payloads to FH, rather than flying F9 expendable missions).

Zenit only wins because it is a three stager when flown to GTO, though.

That's the impressive part: just 2 stages to a high(ish) energy orbit without either stage being hydrogen fueled.

SpaceX gets dang good mass fraction. So good that it usually even recover the first stage when payloads near this big are flown.