NASA may require two SLS rockets for each lunar mission

Analysts are saying that the SLS rocket that is under development may be too small for NASA to use a four astronaut capsule and one rocket. Each launch would require two Block 1A/B SLS rockets, and a lunar or orbital rendezvous to take place.

It's thought that even the Block 2 that would use two boosters wouldn't be big enough either. Previous studies have indicated that a 200 ton payload would be required for the moon/Mars missions, while the Block 2 is a 150 ton rocket.

They could use smaller less capable Apollo style landers, which would allow them to use one rocket instead of two, but that would probably end up requiring more launches to put more equipment on the moon, or limit the missions they can perform.

While NASA’s first manned spaceflight director, Chris Kraft, continues to be critical of the whole concept of building the new SLS heavy lift rocket system in favour of using current smaller launch vehicles, others remain concerned that NASA’s heavy lift rocket might actually still be too small itself. As Nasaspaceflight.com notes from NASA’s Concept Of Operations (CONOPS) document, using a four astronaut lunar lander similar to the origial Project Constellation Altair design would necessitate two Block 1A/B SLS launches for each mission and some complicated lunar orbit rendevous operations as well. This would be practically impossible to achieve given that six months are currently envisaged between SLS flights. It is no wonder that NASA’s Administrator, Charles Bolden, is so keen on exploring lassoed asteroids instead of going back to the Moon.

We're gonna need a bigger boat

Ughh. I hope they get this worked out, because it would be a slap to the face if they built a new heavy lift vehicle, and it could not do what they want it to do.

Zaphod --
Would the now-defunct Ares V heavy lift vehicle have been large enough for the job? I remember the Ares V was to have a 200+ ton lifting capability, so I assume it would have been able to do the job. Or -- and please correct me if I am wrong -- was the plan under the "Constellation Program" to launch some hardware (such as the Lunar Lander) using and Ares V, while the Astronauts in the Orion Capsule would have gone up separately using an Ares I? What I'm asking is this: would a manned trip to the Moon under the Constellation Program also have required at least two launches (one Ares V and one Ares I)?

reply to post by Soylent Green Is People


Ares V was going to be unmanned, and launch the cargo, while Ares I would launch the crew. They would do something like Apollo did, and the upper stage would hold the lander and the engine used to get them to the moon, and would dock with the Ares I in earth orbit.