SLS launched ETLV-2 at EML1 liquid hydrogen and oxygen fuel depot (ETLV derived) while the MPCV waits to dock with the now fully fueled lunar landing vehicle |
Before the end of the decade, the heavy lift capability that America once had during the Apollo era-- will return in the form of the SLS. Some, however, have argued that because of the former Space Shuttle's ability to deploy a 94 tonne aerospace plane plus up to 25 tonnes of useful cargo to LEO that , technically, the Shuttle was also a heavy lift vehicle. But even the earliest versions of the Space Launch System will be far more capable than the Space Shuttle in their ability to lift huge payloads into orbit. Unmanned versions of the SLS should be capable of deploying at least 70 tonnes of payload to LEO. And with an SLS derived upperstage, as much as 105 tonnes of cargo could be lifted to orbit. Even when deploying the 22 tonne MPCV (Multipurpose Crew Vehicle), the SLS should still be capable of simultaneously lifting an additional 45 to 80 tonnes of cargo to orbital space.
Since I envision NASA
having at least two operational SLS launch pads by the early 2020s-- a
two launch scenario-- would be utilized for early manned missions to the
lunar surface. Such a launch infrastructure could also allow at least four heavy lift launches per year for both cargo and crew missions.
NASA's first manned lunar mission utilizing the SLS could send the ETLV-2 to TLI (Trans-Lunar Injection) where the remotely controlled unmanned crew lander will separate from the SLS upper stage and utilize some of its fuel to reach EML1. The ETLV-2 will then dock with the previously SLS deployed EML1 fuel depot in order to add the additional required fuel for its round trip journey to the lunar surface and back to L1.
A second SLS launch, probably a few days later, would send the MPCV plus a few tonnes of water to EML1. The MPCV will dock with the fully fueled ETLV-2 and the crew (up to 6 people) will transfer to the lunar lander for their journey to the Lunar surface and then, eventually, back to L1 after their lunar mission is over. The EML1 fuel depot will dock with the water tank, stored at the top of the SLS upper stage, and pump the water into the fuel depot water compartment where it will eventually be converted into liquid hydrogen and oxygen.
On their return trip to EML1, the crew will transfer back to the MPCV for their return to Earth. Under this scenario, the deployed ETLV-2 would remain at L1 until the EML1 fuel depot is finally being supplied with water from the lunar surface for the manufacture of extraterrestrial fuel. This will allow a small fleet of reusable lunar landers to be deployed at EML1 by the SLS over just a few years for future use for manned lunar missions. Once an ETLV-2 vehicle is reactivated, it will refuel at L1 and then travel-- unmanned back to the lunar surface-- to ensure that the reusable vehicle is fully functional for human use again. The ETLV-2's CECE engines could be utilized for at least ten round trips before they would be required to be replaced-- or the landing vehicle retired.
NASA's first manned lunar mission utilizing the SLS could send the ETLV-2 to TLI (Trans-Lunar Injection) where the remotely controlled unmanned crew lander will separate from the SLS upper stage and utilize some of its fuel to reach EML1. The ETLV-2 will then dock with the previously SLS deployed EML1 fuel depot in order to add the additional required fuel for its round trip journey to the lunar surface and back to L1.
A second SLS launch, probably a few days later, would send the MPCV plus a few tonnes of water to EML1. The MPCV will dock with the fully fueled ETLV-2 and the crew (up to 6 people) will transfer to the lunar lander for their journey to the Lunar surface and then, eventually, back to L1 after their lunar mission is over. The EML1 fuel depot will dock with the water tank, stored at the top of the SLS upper stage, and pump the water into the fuel depot water compartment where it will eventually be converted into liquid hydrogen and oxygen.
On their return trip to EML1, the crew will transfer back to the MPCV for their return to Earth. Under this scenario, the deployed ETLV-2 would remain at L1 until the EML1 fuel depot is finally being supplied with water from the lunar surface for the manufacture of extraterrestrial fuel. This will allow a small fleet of reusable lunar landers to be deployed at EML1 by the SLS over just a few years for future use for manned lunar missions. Once an ETLV-2 vehicle is reactivated, it will refuel at L1 and then travel-- unmanned back to the lunar surface-- to ensure that the reusable vehicle is fully functional for human use again. The ETLV-2's CECE engines could be utilized for at least ten round trips before they would be required to be replaced-- or the landing vehicle retired.
I should note that the two launch scenario can also be utilized-- even if their is only one launch pad for the SLS (delaying the next launch from the pad for a few months)-- since the ETLV-2 would be equiped with cryocoolers capable of re-liquifying ullage gasses from is fuel tanks, providing zero boil-off of fuel for several months or even several years. However, limiting the SLS to just two launches per year would substantially slow down progress towards establishing manned outpost on the lunar surface and eventually on the surface of Mars. But there's really no logical reason to limit heavy lift launches to just two a year since NASA was able to launch as many as-- four heavy lift vehicles per year-- during the Apollo era and as many as nine Space Shuttle missions per year during the peak of the Shuttle era!
Once the fleet of ETLV-2 landing vehicles are utilizing lunar fuel resources for their operation and lunar water is being exported to the EML1 fuel depot from ETLV derived lunar tankers, NASA should then be able to incorporate the use of Commercial Crew vehicles as a cheaper component for sending astronauts to the Lunar surface. Reusable, ETLV-2 derived reusable Orbital Transfer Vehicles (OTVs) equipped with delta-v reducing aerobrakers should allow NASA to travel between LEO and EML1 a lot more cheaply. NASA astronauts and possibly even space tourist could then travel to the Moon by first taking a Commercial Crew vehicle to LEO where they would dock with an ETLV-2 derived OTV that utilizes lunar fuel stored at EML1 and possibly also at LEO. Once at EML1, the ETLV-2 would take the passengers down to the lunar surface.
So under this proposed scenario, the SLS and the MPCV could be used to set up a reusable transportation infrastructure that could eventually give passengers aboard private Commercial Crew launch vehicles affordable and convenient access to the surface of the Moon-- just a few years after the SLS/MPCV/ETLV program begins.
Further details about the ETLV components that will give Commercial Crew passengers access to the lunar surface will be discussed in more detail in future post.
Marcel F. Williams
© 2013 MuOmega Enterprises
5 comments:
it's really nice. like it.
Thanks!
Hopefully, this will be the year when Congress decides to pass legislation mandating the development of a manned lunar landing vehicle-- with serious funding starting in 2015.
This should enable the lunar lander to go into operation in the early 2020s.
Marcel
Where is the budget impact analysis of what you are proposing? No reason to limit heavy lift launches to 2 per year? How about cost being a reason?
I assume that NASA will have a manned spaceflight budget that at least $8 billion a year once the SLS is fully operational and the RS-25E engines are ready(Obama inherited an $8.5 billion a year manned spaceflight budget from the Bush administration.
The cost per flight will, of course, will depend on how frequently the vehicle is flown. The Obama administrations concept of launching the SLS only once or twice every few years would be very expensive per flight. If the Shuttle program had been run that way then the cost per flight would have been well over $1.5 to $2 billion per mission.
NASA has estimated that the annual recurring cost of an SLS type of vehicle to be approximate 1.1 times as expensive as the Shuttle derived Sidemount Shuttle concept for four flights per year.
For four flights per year, NASA estimated the cost per flight for the Sidemount at more than $500 million per flight. That would probably put the cost of the SLS at nearly $600 million per flight. Four SLS flights per year would therefore cost less than $2.4 billion per year. That's certainly affordable within an $8 billion a year manned spaceflight related budget.
Because of its infrequent use, the launch of the ULA's Delta IV heavy cost over $400 million just to deploy 25 tonnes.
The SLS is only expensive-- if you really don't want to use it!
References:
Deep Space Operations Enabled By A Heavy Lift Launch Vehicle - Johnson Space Center - April 2010
Heavy Lift Launch Vehicle Study - NASA - May 2010
Thanks for sharing, this was an interesting post!
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