The NASA
Authorization Act of 2010 approved the building of a heavy lifting vehicle
under the name Space Launch System, using the hardware of the Ares rocket, and
converting the Orion capsule into the MPVC - Multi-Purpose Crew Vehicle. Today,
the Space Launch System is developed in the idea of being the first NASA’s
exploration-class vehicle since Saturn V, and the largest rocket ever built.
Although applying the same old rocketry principles and chemical propulsion, the
SLS will have a superior lift capability, and it could take the Orion capsule
to deep space destinations such as the moon, an asteroid, and Mars (Harwood,
2011, n.d.). SLS will come in two configurations: the 77 tons rocket will have
a lift capability of 154,000 pounds, while the 143 tons will be able to lift
more than 286,000 pounds. The SLS’s lift-off capacity will therefore be much
bigger than that of the space shuttle, which had a lift-off capacity of 50,000
pounds, as well as that of the Saturn V rocket that launched astronauts to the
moon at 263,000 pounds of payload capabilities (Harwood, 2011, n.d.). The core
stage and the avionics of the SLS will stand 200 feet tall, and will store the
liquid fuel which will feed the four RS-25 engines of the rocket (NASA
Marshall, 2012, n.d.). The SLS will also be equipped with two five-segment
SRB’s.
To reduce cost and
development, the SLS will be a blend of technology used by the Space Shuttle
Program, and the technology planned for the Constellation Program. The engines
used for developing this rocket will be three of the RS-25D/E shuttle main
engines for the first stage, and an upgraded Apollo J-2 X engine for the second
stage (NASA Marshall, 2012, n.d.).
The plan is that
the first unmanned test flights would take place at the end of 2017. The cost
of the first phase and test flight is expected to be $18 billion, and it would
include the cost of the SLS, the MPVC, as well as the upgrades in the
infrastructure of the Kennedy
Space Center
Some of the future
planned missions of SLS are cis-lunar space exploration, near-Earth asteroids,
Mars and its moons, as well as further deep space missions (“NASA Announces Design,” 2013, n.d.). The
schedule of these missions is nearby asteroids by 2020s, and orbit and land on
Mars in the 2030s capabilities (Harwood, 2011, n.d.). This proposed timetable will be in accord with
President Obama’s challenge that NASA would send astronauts to an asteroid by
2025, and to Mars by mid-2030s.
The
FY 2014 President’s NASA Budget Request included a budget of $1,384.9 million
for the Space Launch Systems, of which $1,339.8 million for Launch Vehicle
Development, and $45.1 million for SLS Program Integration & Support (“FY
2014 President’s Budget,” 2013, p. 8). Although the budget is about 100 million
less than the actual budged of 2012 designated for SLS, if approved, the 2014
budget will allow a continuation in the development of the future manned launch
system.
NASA will have to rely on
Soyuz flights for transportation of U.S. astronauts to ISS for as long
as no launch vehicle will be available. However, the SLS is more a deep space
vehicle than a LEO vehicle. It will of course be capable to send astronauts to
the ISS, but it would be unfortunate if that would be its main mission. The SLS
will be the new Saturn V, designed to take astronauts to the moon, an asteroid,
and Mars. For LEO the current plan involves relying on commercial space, hoping
that perhaps ULA or SpaceX will soon provide a vehicle reliable enough to
transport astronauts to the ISS. That is definitely SpaceX’s plan with the
Dragon and Falcon Heavy, so one day these may be the means to replace Soyuz.
