Quote from: Jarnis on 04/28/2017 07:03 amQuote from: Semmel on 04/28/2017 06:17 amCould this be a NRO validation flight? So no real payload but some dummy satellite. The purpose would be to establish and validate all the NRO requirements on SpaceX. Can SpaceX actually guarantee the secrecy required for an NRO mission or is there some leak?I doubt even NRO has the money to just send up a dummy payload.An experimental payload - high risk, low price - is far more likely. So, a real payload but something that doesn't matter that much if something goes wrong (or leaks). Checking out SpaceX procedures "for reals" in preparation of future missions? Maybe a secondary objective.I very much doubt that leaks on even an experimental payload would be tolerated.
Quote from: Semmel on 04/28/2017 06:17 amCould this be a NRO validation flight? So no real payload but some dummy satellite. The purpose would be to establish and validate all the NRO requirements on SpaceX. Can SpaceX actually guarantee the secrecy required for an NRO mission or is there some leak?I doubt even NRO has the money to just send up a dummy payload.An experimental payload - high risk, low price - is far more likely. So, a real payload but something that doesn't matter that much if something goes wrong (or leaks). Checking out SpaceX procedures "for reals" in preparation of future missions? Maybe a secondary objective.
Could this be a NRO validation flight? So no real payload but some dummy satellite. The purpose would be to establish and validate all the NRO requirements on SpaceX. Can SpaceX actually guarantee the secrecy required for an NRO mission or is there some leak?
If it is a higher-thrust Falcon 9, pucker up! Max-Q and landing with higher-thrust engines for the first time. Etc. - Ed Kyle
Quote from: edkyle99 on 04/28/2017 01:53 pmIf it is a higher-thrust Falcon 9, pucker up! Max-Q and landing with higher-thrust engines for the first time. Etc. - Ed KyleYou have confirmation of this?
Quote from: stcks on 04/28/2017 02:20 pmQuote from: edkyle99 on 04/28/2017 01:53 pmIf it is a higher-thrust Falcon 9, pucker up! Max-Q and landing with higher-thrust engines for the first time. Etc. You have confirmation of this?Ed said "If".Landing might actually be easier, as better launch performance will reserve more fuel for landing. I've seen no reason to believe that the minimum thrust is higher, even if the maximum thrust is higher.
Quote from: edkyle99 on 04/28/2017 01:53 pmIf it is a higher-thrust Falcon 9, pucker up! Max-Q and landing with higher-thrust engines for the first time. Etc. You have confirmation of this?
If it is a higher-thrust Falcon 9, pucker up! Max-Q and landing with higher-thrust engines for the first time. Etc.
More tea-leaf reading:The Molniya-type orbit would leave the spacecraft over the poles for long periods. Could this be a reconsat intended to keep watch on clandestine military and economic activity in the Arctic Sea? We know that the Russians have been proposing industrialise the northern polar areas for some time and it isn't unreasonable to want to keep watch on these developments.
Quote from: Ben the Space Brit on 04/28/2017 01:21 pmMore tea-leaf reading:The Molniya-type orbit would leave the spacecraft over the poles for long periods. Could this be a reconsat intended to keep watch on clandestine military and economic activity in the Arctic Sea? We know that the Russians have been proposing industrialise the northern polar areas for some time and it isn't unreasonable to want to keep watch on these developments.Molniya/Trunda orbits are two high over the poles for anything optical (early warning (SBIRS) and weather being the obvious exception). So that would leave SIGINT and communications. For a Molniya orbit that brings us back to SDS or some new SIGINT payload... No one knows of any SBIRS HEO in the works, right?
Quote from: envy887 on 04/28/2017 02:28 pmQuote from: stcks on 04/28/2017 02:20 pmQuote from: edkyle99 on 04/28/2017 01:53 pmIf it is a higher-thrust Falcon 9, pucker up! Max-Q and landing with higher-thrust engines for the first time. Etc. You have confirmation of this?Ed said "If".Landing might actually be easier, as better launch performance will reserve more fuel for landing. I've seen no reason to believe that the minimum thrust is higher, even if the maximum thrust is higher.Ah, you're right. I completely missed the "if". I think the earlier MECO might be explainable by a different throttle profile as compared to CRS RTLS missions.
I'm not sure what to think. The Orbcomm OG2 flight featured RTLS and its first stage burned for 2 minutes 20 seconds (according to the press kit). The deployed payloads only weighed about 1.9 tonnes, but the orbit was higher than Dragon insertions (620 x 660 km x 47 deg). The CRS RTLS missions saw the first stage burn for 2 min 21 sec with a probably 9-ish tonne payload. Those insertion orbits are typicaly 200 x 360 km x 51.6 deg. So, not much of a burn time difference despite the payload mass difference. Now we have NROL 76 with a shortest-ever 2 min 17 sec burn.
The CRS RTLS missions saw the first stage burn for 2 min 21 sec with a probably 9-ish tonne payload. Those insertion orbits are typicaly 200 x 360 km x 51.6 deg. So, not much of a burn time difference despite the payload mass difference. Now we have NROL 76 with a shortest-ever 2 min 17 sec burn.
I highly doubt they use a NRO payload on the first launch of updated engines / Block 4
Quote from: Johnnyhinbos on 04/28/2017 04:49 pmI highly doubt they use a NRO payload on the first launch of updated engines / Block 4Why not? NROL was first to use upgraded RS-68A engines, etc. - Ed Kyle
Three RS-68As first flew in June, 2012 on the triple bodied Delta IV Heavy launch of the National Reconnaissance Office NRO-15 spacecraft to geosynchronous orbit.NRO-15 is a massive electronic intelligence satellite with an eavesdropping antenna spanning up to 360 ft. (110 m). The uprated A version of the RS-68 was developed specifically for this mission and similar giant NRO antennas to follow. The A version will now be used on all Delta IV’s allowing ULA to standardize the assembly and internal structure of all the Common Booster Cores (CBCs) used by the launcher.
Quote from: edkyle99 on 04/28/2017 05:36 pmQuote from: Johnnyhinbos on 04/28/2017 04:49 pmI highly doubt they use a NRO payload on the first launch of updated engines / Block 4Why not? NROL was first to use upgraded RS-68A engines, etc. - Ed KyleBecause it needed it. Is anyone really suggesting this payload needs uprated thrust?In fact, the RS-68A was specifically uprated for the payload in question:QuoteThree RS-68As first flew in June, 2012 on the triple bodied Delta IV Heavy launch of the National Reconnaissance Office NRO-15 spacecraft to geosynchronous orbit.NRO-15 is a massive electronic intelligence satellite with an eavesdropping antenna spanning up to 360 ft. (110 m). The uprated A version of the RS-68 was developed specifically for this mission and similar giant NRO antennas to follow. The A version will now be used on all Delta IV’s allowing ULA to standardize the assembly and internal structure of all the Common Booster Cores (CBCs) used by the launcher. Source: http://www.americaspace.com/2015/07/24/delta-iv-using-upgraded-rs-68a-engine-launches-advanced-usaf-wgs-7-satcom/
Quote from: edkyle99 on 04/28/2017 04:11 pmI'm not sure what to think. The Orbcomm OG2 flight featured RTLS and its first stage burned for 2 minutes 20 seconds (according to the press kit). The deployed payloads only weighed about 1.9 tonnes, but the orbit was higher than Dragon insertions (620 x 660 km x 47 deg). The CRS RTLS missions saw the first stage burn for 2 min 21 sec with a probably 9-ish tonne payload. Those insertion orbits are typicaly 200 x 360 km x 51.6 deg. So, not much of a burn time difference despite the payload mass difference. Now we have NROL 76 with a shortest-ever 2 min 17 sec burn.I'm not prophet, but that seems to suggest uprated engines. They're dumping fuel a lot faster.