« Ultimo post da astro_bob il Ieri alle 22:29 »
Riciclo questo thread per segnalare che il buon Phil la settimana scorsa ha iniziato a pubblicare una newsletter:
At one stage, NASA was expecting to use the Block 1 with DCSS configuration just once, on the EM-1 mission. Now it is expected it will return to the previous plan of mirroring EM-1 (uncrewed Orion) and EM-2 (crewed Orion) on matching missions and rocket configurations. However, due to Orion readiness, it is unlikely both missions will close the previous multi-year gap by any notable margin.
What is becoming an option for bridging that gap between flights is using SLS to launch the flagship Europa Clipper mission in 2022. Originally, Europa Clipper was to use a Block 1B SLS to allow the EUS to be flight-proven before launching a crewed mission. NASA then decided that a crew could launch on the first Block 1B on a non-flight proven EUS.
Now, with Block 1B many years away, NASA is looking at launching the Europa Clipper mission on a Block 1 SLS, a flight sometimes referred to as SM-1 (Science Mission -1) on documentation. Other documentation confusingly calls it EM-2, likely in some cheeky way of satisfying politically-driven schedules for SLS to fly “EM-2” by a certain date.
Inquiries are taking place into the loss of mission performance per Europa Clipper flying on the Block 1 versus Block 1B SLS. A major selling point of flying the Europa mission on an SLS Block 1B was using the EUS to shave many years off the transit time compared to “currently” available rocket options at the time the mission’s launch vehicle was first discussed.
Block 1 performance capability for Europa Clipper may push the launch vehicle discussion into an uncomfortable debate, where SpaceX’s Falcon Heavy could force NASA’s hand based on the gulf of vehicle costs. A brand-new Falcon Heavy for a high priority science mission would cost just over $100 million, whereas the latest estimates for SLS put the per-mission cost anywhere between $500 million (from NASA in 2013) to a range between $1.5 – $2.5 billion (conservative industry estimates in December 2017).
niente riutilizzo previsto suppongo... immagino ci siano difficoltà insormontabili nel riaccendere un primo stadio a combustibile solido.
Uhmm... gli SRB Shuttle a combustibile solido, costruiti proprio della ATK, sono stati riutilizzabili per 30 anni prima che diventasse di moda fare le cose riutilizzabili...