[I Don't Know If This Counts As Science] Space Launch System's Name

[-Velocity-]

Ares I and V are not equivalent. Ares I was an LEO vehicle, Ares V comparable to SLS. Orion would have been launched on either depending on mission. In practice, Ares I underperformed and couldn't put Orion in orbit without major weight savings, hence cancellation.

It's about the same size as Ares V. In the initial configuration it's enough to send Orion to lunar orbit, in expanded configurations enough for Orion and more cargo (a lander perhaps).

We don't.

I know the difference between Ares I and V, I just mis-spoke initially, and then didn't fully fix my post.

Again, I don't see how such a huge rocket is needed to launch Orion when the Ares I was at least almost enough. Orion weighs like 24 metric tons, isn't the SLS in its inital configuration supposed to put something like 100 metric tons in LEO? Does it really take a rocket with 4X payload capacity to put something into lunar orbit and back?

[Kryten]

Payload to different energy orbits doesn't scale like that, but roughly yes, it does.

[Bill Phil]

I know the difference between Ares I and V, I just mis-spoke initially, and then didn't fully fix my post.

Again, I don't see how such a huge rocket is needed to launch Orion when the Ares I was at least almost enough. Orion weighs like 24 metric tons, isn't the SLS in its inital configuration supposed to put something like 100 metric tons in LEO? Does it really take a rocket with 4X payload capacity to put something into lunar orbit and back?

The Ares I under performed. It couldn't orbit the MPCV/Orion.

SLS Block I is 70 metric tons. And yes, it really does take that much of a rocket.

[billbobjebkirk]

I know the difference between Ares I and V, I just mis-spoke initially, and then didn't fully fix my post.

Again, I don't see how such a huge rocket is needed to launch Orion when the Ares I was at least almost enough. Orion weighs like 24 metric tons, isn't the SLS in its inital configuration supposed to put something like 100 metric tons in LEO? Does it really take a rocket with 4X payload capacity to put something into lunar orbit and back?

Because the SLS and Ares I were for different missions. SLS didn't replace Ares I, CST-100 and Dragon 2 did.

[sgt_flyer]

Yup - orion is specifically built for beyond LEO operations, with extended life support, adapted heatshield, and such - wouldn't make a lot of sense in using it in LEO. And for beyond LEO missions, the SLS block I spare dV will allow to boost orion to reach these beyond LEO objectives.

(The same way, the Apollo CSM was overkill for LEO missions and as such, they reduced a lot the CSM weight (less fluids, etc) when sending it on LEO missions on Saturn IB. Yet, even in this configuration, it was two times heavier than a Soyuz designed for LEO operations)

[B787_300]

Just a polite reminder that senate launch system (a name i totally agree with) is bordering on the edge of a political discussion which is against the community rules.

With that being said , this is the right place for the question and it is important to note that SLS is more comparable to the Aries V (Aries 1 was the constellation that everyone knew)

[vger]

Just a polite reminder that senate launch system (a name i totally agree with) is bordering on the edge of a political discussion which is against the community rules.

Hey, now... we just think that the weights of certain things would make good standards for calculating the relative Delta-V

Besides... they control NASA's budget.

[Budgie]

I dunno. I have hope for SLS (And that acronym is fine for me). I know it won't launch that often, but with the current public support for space exploration as it is, SLS is what we're gonna get. Now, who knows what'd happen if our space program had the same "cool factor" it did in the Apollo era?

[GigaG]

Did somebody ask earlier whether SLS/Orion could be configured for ISS missions? The answer is yes, but it would be overpowered-

http://en.wikipedia.org/wiki/Space_Launch_System#Proposed_missions_and_schedule

ISS Back-Up Crew Delivery – a single launch mission of up to four astronauts via a Block 1 SLS/Orion-MPCV without an Interim Cryogenic Propulsion Stage (ICPS) to the International Space Station (ISS) if the Commercial Crew Development program does not come to fruition. This potential mission mandated by the NASA Authorization Act of 2010 is deemed undesirable since the 70 t SLS and BEO Orion would be overpriced and overpowered for the mission requirements. Its current description is "delivers crew members and cargo to ISS if other vehicles are unable to perform that function. Mission length 216 mission days. 6 crewed days. Up to 210 days at the ISS."

AFAIK, the SLS will get its payload pretty close to LEO on the first stage alone, and without the weight of an upper stage, the SLS plus a kick from the Orion service module engine should be more than enough.

(I do not know if that would mean suborbital trajectory + boost + circularization (like shuttle with 2 OMS burns) or orbit with periapsis in atmosphere + boost (like shuttle with 1 OMS burn.))

[Robotengineer]

I don't have a problem with the acronym SLS, the name that has been turned into an acronym is what I have a problem with. Isn't the purpose of all LV's to be a "Space Launch System"? So why does this LV get to be the Space Launch System? It's all a big waste of time and money on NASA's part if you ask me. Spending billions of dollars to build a Launch Vehicle you don't even have a payload for yet. Bravo! /rant

[Nibb31]

1) I'm surprised that such a huge rocket is needed to send Orion to the Moon, as compared to the Ares V. Heck, I think the first stage of the Ares V was going to essentially be just ONE of the SRBs on the SLS. That's a massive increase in size. Isn't the SLS overkill for launching Orion?

SLS block I is designed to launch Orion (~20mT) and an EDS (~50mT) into LEO, not just Orion.

SLS block II is supposed be able to launch Orion (~20mT), an EDS (~50mT) and some sort of mission module (~20mT) which can be a hab, a lander, a SEP tug, or anything else...

2) What if we want to launch Orion to LEO?

Did somebody ask earlier whether SLS/Orion could be configured for ISS missions? The answer is yes, but it would be overpowered-

The US Congress insisted on a writing a "backup" role for ISS operations into the law in case the CCDev program failed to deliver. However, NASA will never ever use it in that role, nor would any administration approve of it because it would cost way to much. There will be 2 US manned vehicles for ISS crew rotations, plus 2 for unmanned cargo, and it would still be cheaper to buy seats on Soyuz than to launch Orion to the ISS.

Note that the barter agreement with ESA is only for 2 Orion service modules and only 2 flights have been manifested. Anything beyond EM-1 (an unmanned circumlunar flight in 2017) and EM-2 (a manned circumlunar flight in 2021) is pure speculation at this point because no further hardware has been funded.

Edited March 10, 2015 by Nibb31

[Kibble]

SLS block I is designed to launch Orion (~20mT) and an EDS (~50mT) into LEO, not just Orion.

SLS block II is supposed be able to launch Orion (~20mT), an EDS (~50mT) and some sort of mission module (~20mT) which can be a hab, a lander, a SEP tug, or anything else...

Actually System Block I has 5-m DCSS as its upper stage, with a gross mass of only 30mt. AFAIK Block IB will replace DCSS with EUS, with a gross mass of 105mt. It will ignite once to circularize, for a on-orbit 93mt stack. Most of the information I've seen indicates Block IB will fly for a long time as the standard configuration before Block II.