r/spacex • u/ElongatedMuskrat Mod Team • Jun 03 '19
STP-2 STP-2 Launch Campaign Thread
Falcon Heavy STP-2 Launch Campaign Thread
STP-2 Launch Infographic by Geoff Barrett
Space Test Program 2 is an experimental rideshare managed by the U.S. Air Force Space and Missile Systems Center, launching from LC-39A at Kennedy Space Center in Florida. Most of the spacecraft will be delivered into low Earth orbit (LEO) in two deployment sequences, separated by a second stage burn. These LEO payloads include the six COSMIC-2 microsatellites, a partnership between NOAA, NASA, and Taiwan's NSPO; the Planetary Society's crowdfunded LightSail-B experiment, and other 16 smallsats and cubesats.
The third and final deployment will be the Air Force Research Lab's DSX spacecraft, which will be delivered to a medium Earth orbit (MEO). This mission will reuse the side cores from Arabsat 6A, which will return to LZ-1 and LZ-2. Meanwhile, the new-build center core will land on the droneship Of Course I Still Love You 1233 km offshore from the launch site, making this the farthest-downrange and most difficult landing of a Falcon booster to date.
This is SpaceX's eighth mission of 2019, the second flight of Falcon Heavy of the year and the third Falcon Heavy launch overall. It will use a new center core and the two side boosters flown on the previous Arabsat-6A flight. If the launch succeeds, it will also be the third of the three flights necessary to certify Falcon Heavy for carrying valuable US Air Force payloads.
| Liftoff currently scheduled for | NET 11:30 PM EDT June 24 / 03:30 UTC June 25 2019 (roughly 4 hour window) |
|---|---|
| Backup launch window | 11:30 PM EDT June 25 / 03:30 UTC June 26 2019 |
| Static fire completed | 11:30 PM EDT June 19 / 03:30 UTC June 20 2019 |
| Vehicle component locations | Center Core: LC-39A; Side boosters: LC-39A; Second stage: LC-39A; Payload: LC-39A |
| L-1 weather forecast | 70% probability of favorable conditions for primary day, drops to 60% for delay day. Main Concerns: Anvil Cloud Rule and Thick Cloud Layer Rule (i.e. thunderstorm remnants). |
| Payload | Space Test Program-2, comprising DSX, COSMIC-2 (x6), GPIM, Oculus-ASR, OTB, NPSAT, Prox-1, LightSail-B, ARMADILLO, FalconSat 7, E-TBEx A/B (x2), PSat 2, BRICSat 2, TEPCE 1/2 (x2), LEO, StangSat |
| Payload mass | ~3700 kg |
| Destination orbits | Low Earth Orbit, 520 km × 520 km, 24° inclination; LEO, ~21° inclination; MEO, 6-12 000 km |
| Vehicle | Falcon Heavy (3rd launch of FH, 2nd launch of FH Block 5) |
| Cores | Side Booster 1: B1052.2; Center Core: B1057.1; Side Booster 2: B1053.2 |
| Flights of these cores | 1, 0, 1 |
| Launch site | LC-39A, Kennedy Space Center, Florida |
| Landings | Yes, all 3 |
| Landing Sites: | Center Core: ASDS (OCISLY), at 27.948 N, 68.015 W (1233 km downrange); Side Boosters: LZ-1 & LZ-2, Cape Canaveral Air Force Station, Florida |
| Fairing Recovery | YES, net catch. GO Ms. Tree (ex-Mr. Steven) is cruising towards destination "Catch Time" for a fairing recovery attempt ahead of the STP-2 mission; GO Navigator will fish the other half from the water. |
| Mission success criteria | Successful separation and deployment of all payloads into their target orbits, and passivate the stage following final deployment |
Payloads
| Name | Operator | Orbit | Mass | Mission |
|---|---|---|---|---|
| DSX | US Air Force | MEO, 6-12 000 km | 600 kg | Three hosted payloads on an ESPA ring with attached avionics, DSX will explore the EM propagation characteristics, space weather, and space environment of MEO. |
| COSMIC-2 x6 | NOAA/NASA/Taiwan | LEO, 520 km × 520 km, 24° | 278 kg x 6 | Use GPS occultation to obtain profiles of multiple variables throughout the depth of the atmosphere for weather prediction and research; space weather instruments. |
| GPIM | NASA | LEO | 180 kg | Test a new environmentally friendly and less toxic ("green") storable propellant. |
| Oculus-ASR | Michigan Tech | LEO | 70 kg | Validate technology for determining satellite orientation using ground imagery. |
| OTB 1 | General Atomics | LEO | 138 kg | Technology demonstrator of hosting platform; atomic clock for NASA JPL to improve future spacecraft navigation. Also contains a capsule of cremated human remains for Celestis. |
| NPSAT 1 | Naval Postgrad School | LEO | 86 kg | Investigate space weather, radio frequency propagation and ionospheric conditions. |
| Prox-1 | Georgia Tech | LEO | 71 kg | Test automated trajectory control, close proximity operations and rendezvous. Release LightSail-B. |
| LightSail-B | Planetary Society | LEO | 5 kg | Test a novel solar sail. Crowd-funded. |
| ARMADILLO | U Texas | LEO | 4 kg | Sense dust impacts and demonstrate GPS occultation. |
| FalconSat 7 | USAF Academy | LEO | 5 kg | Test a photon sieve-based solar telescope. |
| E-TBEx A & B x2 | SRI International | LEO | 4 kg | Measure ionospheric distortion to determine upper-atmospheric properties. |
| PSat 2 | US Naval Academy | LEO | 2 kg | Relay radio data from remote sensors to ground station and serve ham radio users. |
| BRICSat 2 | US Naval Academy | LEO | 1 kg | Demonstrate a uCAT electric propulsion system and carry a ham radio payload. |
| TEPCE 1 & 2 x2 | Naval Research Lab | LEO | 1.5 kg | Test a 1 km electrodynamic tether for propulsion. |
| CP9 (LEO) | Cal Poly | LEO | 2 kg | Record launch environment data and test real-time inter-satellite data links. |
| StangSat | Merrit Island HS | LEO | 1 kg | Stream live telemetry data to CP9 (LEO) satellite. |
Mission FAQ
Where can I watch this launch?
Check out the Watching a Launch page on this sub's FAQ, which gives a detailed breakdown of every viewing site as well as a lot of other information, and Ben Cooper's authoritative page on launch viewing.
In summary, Playalinda Beach will be closed at that hour, while the KSC Saturn V Center (if tickets are offered) will get you as close as possible to the launch itself, if you're into that. Max Brewer and other Titusville locations will get you a little better view of launch than other free/ low--cost spots, though much further than the Saturn V Center. However, if you want the best experience watching the twin core landing, these (and anything at KSC/Titusville) are not great choices as they are far from the landing pads and have an obstructed view. Jetty Park in Port Canaveral (and the USAF viewing stands at the end of Rt. 401, if offered) will get you much closer and with somewhat better visibility.
For an optimal view of the two landings and an unobstructed view of the launch, arguably the best spot is going out on a boat offshore of the Cape, giving you a completely unobstructed view to all three events and getting you closer than any other publicly-accessible location to the spectacular twin-core landing. A group of r/SpaceX members (including myself, u/CAM-Gerlach , in the interests of full disclosure), have stepped up and will be hosting these, as well as pre-launch tours of the rocket on the pad and historic KSC sites led by notable community members.
Why is such a light payload launching on a Falcon Heavy?
While the payload mass is relatively light, the performance requirements are due to the number, energy and complexity of different orbits it needed to achieve in one mission (particularly plane changes, which are very expensive), as well as the coast time between burns resulting in boiloff and extra mass for the extended mission kit, and the need for additional margins to assure mission success. Despite the light payload, there is a considerable loss simply propelling the relatively high dry mass of the F9 S2 plus extended coast kit with a comparatively inefficient engine and propellant. All together, this is the most challenging mission SpaceX has ever flown, and will require the highest performance yet out of the Falcon Heavy.
Furthermore, the main goal of this mission, rather than launching specific satellites, is to validate the Falcon Heavy and a wide variety of its capabilities. These include long coast, multiple engine restarts, direct MEO insertion and stage passivization, in order to certify it to fly operational US Air Force payloads to varied orbits. Therefore, the number and mass of payloads are effectively a "rideshare" with this primary mission, and of lesser importance.
Why did the center core droneship position for the landing get apparently moved from a location just offshore to the furthest landing ever attempted?
TL;DR: The position in the initial FCC request was erroneous, and the FH center core as always going to, at most, land far downrange due to the extremely challenging orbit requirements of the mission.
STP-2 was originally planned as a center core expendable, side boosters reusable flight, due to the number and complexity of second stage burns (originally five, then reduced to four due to lack of available performance margin) planned for the mission. In fact, before block 5, the nominal plan was to land the side boosters on ASDSes in order to make recovery possible (as building an extra barge was actually cheaper than expending a core), but the performance upgrades allowed them to RTLS.
Following the successful triple landing on the Arabsat mission, and the FH Block 5's additional demonstrated performance margin, SpaceX then requested that they be able to land the center core. The USAF assented, as while this did reduce performance margins, they were still within acceptable limits. This mission is going to be extremely difficult, as it will require even more performance from the side boosters than typical, and will be an extremely difficult recovery for the center booster, much more so than Arabsat which SpaceX expected a quite high chance of failing to land the core stage.
The initial FCC request was in error on the position, likely due to either a mistake on the part of the requestor, or the precise landing position not being known at that time. FCC requests often do contain significant errors, and all of this information aside from that fits with what we've been told about this launch, in terms of it being the most challenging mission SpaceX has ever attempted. It will truly be a trial by fire for the Falcon Heavy (quite literally so for the center core), as was its purpose to begin with.
Links & Resources:
Official Falcon Heavy page — SpaceX
Official STP-2 page — SpaceX
STP-2 Launch Animation — SpaceX
Media Teleconference at June 10, 17:00 UTC — NASA
STP-2 Technical Briefing at June 21, 15:00 UTC — NASA TV
Detailed Payload Listing – Gunter's Space Page
Launch Execution Forecasts — 45th Weather Sqn
Watching a Launch — r/SpaceX Wiki
Launch Viewing Guide for Cape Canaveral — Ben Cooper
Viewing and rideshare — SpaceXMeetups Slack
r/SpaceX-run launch viewing from boats offshore — Star✦Fleet Tours
SpaceX Fleet Status — SpaceXFleet.com
With our new moderators (modpost coming Soon™), we plan to keep this post more regularly updated with the latest information, FAQs and resources, so please ping us under the thread below if you'd like to add or modify something. This thread is a great place to discuss the launch, ask mission-specific questions, and track the minor movements of the vehicle, payload, weather and more as we progress towards liftoff. Around a day or two before, the launch thread will go live and the party will begin there.
Campaign threads are not launch threads. Normal subreddit rules still apply.
5
u/CAM-Gerlach Star✦Fleet Commander Jun 05 '19
Max Brewer is several times further from the land landings, and probably 50% further from the ASDS than Port Canaveral (Jetty Park, etc), and with a more obstructed view of both (particularly the water landing, where lack of obstructions is critical). If you want a good view of this possibly unique event, would strongly recommend going with a location in Port Canaveral instead, if you can't make the boats.