edit2: For clarity, my belief is that SpaceX built them a legacy core (not Block 5) even if they had planned to be switched to full Block 5 production. I won't be too surprised if the same is in progress for the Air Force's GPS-3 launch. Though, they may have enough flight data by then to make that a non-issue.
NET April 28. No mention of recovery ops in this particular STA.
Quote from: vaporcobra on 03/19/2018 03:56 pmNET April 28. No mention of recovery ops in this particular STA. Recovery ops would be a separate STA (and there isn't one )
Quote from: gongora on 03/19/2018 04:06 pmQuote from: vaporcobra on 03/19/2018 03:56 pmNET April 28. No mention of recovery ops in this particular STA. Recovery ops would be a separate STA (and there isn't one )My memory may be failing me (apologies if this is a rehash), but looking through the current FCC license for seven Iridium launches from VAFB, it explicitly does not permit/mention booster landings at SLC-4's LZ, pretty much precluding any attempt at a land recovery until the license is updated/replaced. https://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/LLS%2017-096B%20Rev%202.pdf
Matt Desch is in discussions on this being Block 5, and if it is it will be a reflown Block 5https://twitter.com/IridiumBoss/status/976575188614762496
Launch date for Iridium-6/GRACE-FO mission now set: Saturday, May 19th at approximately 1:03 pm PDT (20:03 UTC). May 20th backup. Five more Iridium NEXT satellites will start shipping this week to VAFB; the 2 GRACE-FO sats are already at the base. #RidesharingMakesSense!
Is the launch vehicle at VAFB?
Yes, the first stage is there now.
Iridium satellites (5) Payload Mass: 860kg per satellite plus 500kg for dispenser. Launch orbit: 625km, 86.66 degreesGRACE-FO satellites (2) Payload Mass: 580kg per satellite plus dispenser. Orbit: 490km, 89 degrees
I’m a bit confused about this mission profile Quote from: russianhalo117 on 07/25/2014 08:34 pmIridium satellites (5) Payload Mass: 860kg per satellite plus 500kg for dispenser. Launch orbit: 625km, 86.66 degreesGRACE-FO satellites (2) Payload Mass: 580kg per satellite plus dispenser. Orbit: 490km, 89 degreesAccording to the topic post, the Iridium and GRACE-FO will be launched into orbits with different inclinations and altitudes. So even assuming a direct orbit insertion to one of the target orbits, it still requires 3 restarts of S2 in order to deliver the payloads to target orbit and then deorbit. While M1Ds on the S1 have performed multiple 4 burn RTLS and ASDS missions, have S2 and M1D Vac been verified for such mission?And besides, given the different inclinations,a plane changing maneuver in LEO is required, which is very unefficient (about 370m/s for 2.6 degrees), perhaps it would be better to deliver the heavier Iridiums first and then maneuver for GRACE-FO?
I’m a bit confused about this mission profile Quote from: russianhalo117 on 07/25/2014 08:34 pmIridium satellites (5) Payload Mass: 860kg per satellite plus 500kg for dispenser. Launch orbit: 625km, 86.66 degreesGRACE-FO satellites (2) Payload Mass: 580kg per satellite plus dispenser. Orbit: 490km, 89 degreesAccording to the topic post, the Iridium and GRACE-FO will be launched into orbits with different inclinations and altitudes. So even assuming a direct orbit insertion to one of the target orbits, it still requires 3 restarts of S2 in order to deliver the payloads to target orbit and then deorbit. While M1Ds on the S1 have performed multiple 4 burn RTLS and ASDS missions, have S2 and M1D Vac been verified for such mission?
And besides, given the different inclinations,a plane changing maneuver in LEO is required, which is very unefficient (about 370m/s for 2.6 degrees), perhaps it would be better to deliver the heavier Iridiums first and then maneuver for GRACE-FO?
This unique “rideshare” launch, will first deploy the twin GRACE-FO spacecraft, after which the Falcon 9 second stage will continue onward to the deployment orbit for the five Iridium NEXT satellites.
Please note the rather significant difference in orbital altitude between GRACE-FO and the Iridium sats and than remember that neither GRACE-FO, nor the Iridium sats have circularisation capabilities.
Quote from: woods170 on 04/10/2018 11:38 amPlease note the rather significant difference in orbital altitude between GRACE-FO and the Iridium sats and than remember that neither GRACE-FO, nor the Iridium sats have circularisation capabilities.I see what Ultrafamicom is getting at, but if you deploy the Iridium satellites first, you then require the same plane change (admittedly of less mass), combined with the additional ∆V of a reduction in perigee, a circularisation at 490kms before deployment of the GRACE-FO satellites, and ultimately a de-orbit burn. So, four S2 burns, and probably a higher ∆V requirement.
Quote from: OneSpeed on 04/10/2018 12:09 pmQuote from: woods170 on 04/10/2018 11:38 amPlease note the rather significant difference in orbital altitude between GRACE-FO and the Iridium sats and than remember that neither GRACE-FO, nor the Iridium sats have circularisation capabilities.I see what Ultrafamicom is getting at, but if you deploy the Iridium satellites first, you then require the same plane change (admittedly of less mass), combined with the additional ∆V of a reduction in perigee, a circularisation at 490kms before deployment of the GRACE-FO satellites, and ultimately a de-orbit burn. So, four S2 burns, and probably a higher ∆V requirement.Indeed. And although an F9 S2 is quite capable it does make sense to do things as efficiently as possible. Which precludes dropping off the Iridium sats first.