Mi sbaglierò,ma mi sembra che questa interessante notizia sia passata inosservata:
http://www.spaceref.com/news/viewnews.html?id=1577
ExcerptsWhy Examine Propellant Depots Without HLLVs?
- Large in-space mission elements (inert) can be lifted to LEO in increments on several medium-lift commercial launch vehicles (CLVs) rather than on one Heavy Lift Launch Vehicle (HLLV)
- Over 70 percent of the exploration mission mass is propellant that can be delivered in increments to a Propellant Depot and transferred to the in-space stages
- Saves DDT&E costs of HLLV
- Low-flight-rate HLLV dominated by high unique fixed costs. Use of CLVs eliminates these costs and spreads lower fixed costs over more flights and other customers.
- Use of large re-fueled cryo stages saves DDT&E/ops costs for advanced propulsion stages (e.g., SEP)
- Provides opportunity for more easily integrated commercial and international partner mission participation
Advantages
- Tens of billions of dollars of cost savings and lower up-front costs to fit within budget profile
- Allows first NEA/Lunar mission by 2024 using conservative budgets
- Launch every few months rather than once every 12-18 months
-Provides experienced and focused workforce to improve safety
-Operational learning for reduced costs and higher launch reliability.- Allows multiple competitors for propellant delivery
-Competition drives down costs
-Alternatives available if critical launch failure occurs
-Low-risk, hands-off way for international partners to contribute- Reduced critical path mission complexity (AR&Ds, events, number of unique elements)
- Provides additional mission flexibility by variable propellant load
- Commonality with COTS/commercial/DoD vehicles will allow sharing of fixed costs between programs and “right-sized” vehicle for ISS
- Stimulate US commercial launch industry
- Reduces multi-payload manifesting integration issues