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Questions tagged [sls]

Space Launch System, the putative replacement for the Space Shuttle for future large missions.

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53
votes
4answers
46k views

Why not build Saturn V's again?

Why is the US developing a new rocket and spacecraft as opposed to building the Saturn V and Apollo stacks again? The SLS / Orion development programs certainly can't cost less than the unit cost of ...
23
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4answers
18k views

Is the SLS irrelevant if the Falcon Heavy launch is successful this year?

My take is that, like so many bad, and good, NASA ideas, the SLS will get the axe after spending billions on the NASA subcontractor(s). Regardless if the SLS comes to full life cycle, NASA will not ...
18
votes
2answers
5k views

Do the solid rocket boosters of the Shuttle and SLS have a self-destruct system and was it activated during the Challenger disaster?

Videos of the Challenger shuttle explosion show both solid boosters speeding on after the main tank detonated. Were they eventually self-destructed by the ground control, or why not, and why not ...
14
votes
6answers
8k views

Why can the Falcon 9 be reused while the SLS cannot?

In reading about SLS, I learned that the reason they won't reuse their rocket is that the weight of the parachutes to enable recovery is too much of a sacrifice. How is the weight of the hardware and ...
14
votes
1answer
2k views

Why won't the SLS boosters be recovered?

The SLS will be using five segment boosters derived from the four segment ones used during the STS program. Almost all of the STS boosters were recovered and reused, however NASA doesn't plan to ...
13
votes
3answers
669 views

What's the advantage of using an SLS system rather than a number of small lift rockets?

I just read this article, in which former director Kraft is described as deriding NASA's current plan to use a single heavy-lift vehicle (Space Launch System, or SLS) as a primary launch platform. Why ...
12
votes
3answers
4k views

What are the differences between SLS and Ares V?

SLS is to a large degree a continuation of the canceled Ares V, basically the STS without the orbiter. But what changes in design were made from Ares V to SLS? What were the reasons for those changes? ...
12
votes
2answers
824 views

What does the software quality process for NASA's SLS look like?

What does the software quality process for NASA's SLS look like? What are the relevant standards that they have to comply to? Do they have to show that they are CMMI compliant, for example? I'm ...
11
votes
2answers
1k views

How will the SLS first stage be supplied with engines? Copy manufacturing the RS-25 or replacing it?

The SLS is a very opinionated subject among bloggers. I'm looking for what substance there might be behind the following general claim (without specific source). Is it truthful and if so, what is the ...
10
votes
4answers
2k views

Could the solid boosters of SLS be replaced by reusable Falcon 9 first stages?

Is it feasible to redesign the Space Launch System to use a pair of reusable Falcon 9 first stages instead of the five-segment solid boosters now being developed? The reason would be to lower launch ...
10
votes
2answers
394 views

Which are the benefits and challenges for a new SLS rocket version with four SRB? [closed]

Which are the benefits and the challenges for a new Space Launch System (SLS) version with four Solid Rocket Boosters (SRB)? Benefits i mean what would gain in payload capabilities, how much more ...
9
votes
4answers
3k views

Why were Solid Rockets chosen for the SLS

The SLS and the STS seem to be the only rockets utilizing SRBs... Why did they choose to go with them over LH/LOX or Kerosene/LOX? Wouldn't it also be easier to upgrade those rockets in the future?
9
votes
1answer
311 views

Do Orion's solar panels have adjustable sweep?

In this video overview of NASA's proposed EM-1 mission, the solar panels on the Orion spacecraft are initially shown extending perpendicular to the spacecraft (at around 3:46). Shortly after that, as ...
9
votes
1answer
1k views

Space Launch System (SLS) costs

What is a good estimate for SLS' annual fixed cost and variable per flight cost? What references are used for these costs? I've seen uncited figures of $1B+/launch variable cost. Wikipedia quotes a ...
7
votes
1answer
486 views

RS-25 Hot Fire Test

Yesterday, NASA Stennis successfully completed a hot fire test of Aerojet Rocketdyne RS-25 a.k.a SSME. It was noted in the webcast before the test started that they were testing the 'engine controller'...
7
votes
1answer
986 views

Can the SLS reuse its solid rocket boosters?

We know that the SLS is going to use solid rocket boosters that are decedents of the boosters used on the Space Shuttle. The new version is supposed to be bigger and better, but will NASA be able to ...
7
votes
1answer
222 views

How do they simulate the SLS engine environment?

I was reading an Aviation Week article about the restart of SSME (RS-25E) production for SLS. There is a paragraph in it that is interesting to me. On the SLS, the engine inlets will receive ...
6
votes
1answer
418 views

What's next for Orion?

Orion's Exploration Flight Test 1 today appeared to go very well. The only information on future Orion flights I was able to find suggests that the next step is an unmanned circumlunar flight ...
6
votes
1answer
807 views

What is the status of the F-1B engine development?

In this article https://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ and in several answers on this site a modernized F-1 engine is ...
6
votes
1answer
578 views

Could Orion repeat any of the Hubble Space Shuttle servicing missions?

I have a distinct feeling that there's some apparent no-go on the question in the title, but currently can't put my finger on it; For the lifting mass to Low Earth Orbit (LEO), let's assume that SLS (...
6
votes
1answer
228 views

Could the SLS reach orbit without solid rocket boosters?

Could the SLS block 1 reach orbit without solid rocket boosters, and if so, how much payload could it lift? If it couldn't reach orbit in the block 1 config, could it do so with the Exploration ...
6
votes
2answers
954 views

Why did NASA design the SLS do the job of both the Ares I and Ares V?

The design of the Constellation program called for two main launch vehicles, The Ares I and the Ares V. The Ares I was said to be human-rated and was to be used to carry the Orion vehicle and its crew ...
6
votes
1answer
282 views

Do rockets have a “best before date” after assembly?

How many years can a liquid fuel rocket be safely stored (unfueled) between manufacturing and launch? Are they sensitive to slow processes like corrosion, material degradation from dehydration, other ...
6
votes
0answers
241 views

Couldn't the shuttle orbiter be replaced with a cargo bay, instead of creating the SLS?

Are there any technical reasons for not simply continuing the space shuttle production, except for replacing the orbiter with a pretty simple cargo bay (a payload fairing)? Like the Russians planned ...
5
votes
1answer
544 views

What makes SLS (Space Launch System) \$10 Billion (or \$36 Billion) project?

The SLS development budget is \$18 billion (currently \$10 billion are spent for SLS rocket), although another site shows even \$35B. If I am not mistaken SLS is a new & improved version of ...
5
votes
2answers
1k views

NASA's RS-25 Engines shut down time

As a follow up to my other question about RS-25's ramp-up time, I was wondering what would be the ramp-down times for the RS-25, i.e. what would be the time that takes to go from 100% thrust to 0% ...
5
votes
1answer
548 views

Why will SLS Block I bring less mass to LEO than the STS shuttle system did?

The Space Transportation System (STS) could bring a fully loaded shuttle orbiter of 109 tons to orbit (or maybe empty+payload 68+25=93 tons). The Space Launch System (SLS) Block I is based on STS, but ...
5
votes
1answer
462 views

What are these discs on the Crawler-Transporter?

I've just watched this footage of SLS's Mobile Launcher Platform being rolled out to LC-39B for fitting tests. On the front of the drive trucks are two rotating discs with red markings which are ...
5
votes
1answer
118 views

Did the shuttle SRBs have separation motors?

Looking at a NASA fact sheet about the SLS SRBs and I noticed it has at the bottom around the nozzle, separation motors. Watching shuttle launches It looks to me like the SRBs continue to fire ...
5
votes
1answer
236 views

NASA's RS-25 Engines

I am developing a FSX-based space flight simulator FSX SpacePort. I've been trying to get the detailed specs on NASA's RS-25 engine, namely, what were the ramp-up times for this engine? As in, how ...
5
votes
2answers
408 views

Could current (+SLS+FH) launchers use much larger diameter payload fairings?

Can launchers reasonably be equipped with wider payload fairings in order to carry larger (not heavier) payload? What would be the main problems with doing so, air resistance during the early slow ...
5
votes
1answer
608 views

How will the SRBs used by the SLS differ from those used by the Shuttle?

The Space Launch System, which recently secured funding from Congress, uses many features that were developed from the Shuttle program, including the first-stage engines and boosters, and it's overall ...
4
votes
1answer
72 views

Could the SSMEs of the SLS do retro burns?

The SLS will use the main engines of the space shuttle. Are these capable of retro-burns in the upper atmosphere like SpaceX’s Merlin engines? More broadly, could the SLS’ main engines and ...
4
votes
1answer
694 views

How does Exploration Mission 1 orbit differ from Apollo-era free-return? How far from Earth (and Moon) does it go?

I'm having trouble understanding the current orbit planned for NASA's Space Launch System's Exploration Mission 1. Is it possible to explain how the planned orbit works and what the maximum distance ...
4
votes
1answer
164 views

What naturally occurring navigational information is available for an autonomous return of SLS's EM-1?

This answer details some of the requirements that would need to be met if the Space Launch System's planned Exploration Mission 1 were to be human rated. I've further trimmed that truncated selection ...
4
votes
1answer
195 views

Will the EFT-1 mission for Orion carry an escape tower?

December 2014 is the scheduled date for the Exploration Flight Test-1 (EFT-1) mission of the Orion space capsule. It will be launched on a Delta IV Heavy rocket as a surrogate for the unavailable SLS ...
4
votes
1answer
585 views

How are SLS SRBs considered man-rated?

Using solid rocket boosters on a manned launch comes with some additional risks because they can't be turned off or throttled down once lit. For the Shuttle this created some additional failures modes ...
4
votes
0answers
66 views

Are the APUs on the SLS SRBs planned to be hydrazine powered?

I recently read that the Space Launch System core stage, which uses renamed / slightly reworked Space Shuttle Main Engines and therefore requires a hydraulic system to service said engines, will use ...
4
votes
0answers
106 views

Can Delta Heavy launch a fully fueled upper stage with no payload attached?

There is right now talk of a potential dual launch mission to fulfill EM-1, where a Delta Heavy would launch a fully fueled upper stage to LEO, to there bet met with the Orion spacecraft, likely ...
4
votes
0answers
622 views

If the J-2X is too powerful for SLS, why was it appropriate for Saturn V?

Reading an article about new engines for the SLS (Summary: There is no plan what to do once the current SSME's are expended), they mention that the J-2X is too powerful for the upper stage of SLS. ...
3
votes
2answers
371 views

Were any Components Off The Shelf (COTS) used in the Space Shuttle?

Are there examples of Components Off The Shelf (COTS) used in the Space Transportation System? And is NASA considering using COTS in future manned space flight systems like Orion and the SLS?
3
votes
1answer
155 views

Human Rate the ICPS on EM-1 of SLS

What specifically must be done to Human Rate the Interim Cryogenic Propulsion Stage (ICPS) to fly humans on Exploration Mission 1 of SLS?
3
votes
1answer
717 views

What exactly is a “Green Run test” for SLS that NASA is considering skipping?

The Ars Technica article Rocket Report: A new Delta 2, Blue Origin inks with NASA, a fiery Falcon Heavy says: Boeing seeks to ship SLS core stage by the end of 2019. With a renewed emphasis from ...
3
votes
1answer
257 views

How much will Europa Clipper weigh?

I realize that NASA will have to change Europa Clipper's loadout based on whether they are launching on the SLS 1b or the Atlas 5 backup, but does anyone know what those two mission masses will be, ...
3
votes
0answers
133 views

What is holding SLS back from launching?

I'm kind of confused on this point SLS has engines, a tank, side rocket boosters, a capsule, and seemingly all of the pieces. What is the major technical issue right now that is keeping SLS from ...
3
votes
0answers
151 views

Why isn't the Europa mission more ambitious given the capacity of SLS?

SLS Block I will have about three and Block II five times more capacity in terms of payload mass to LEO, than any launcher which has been used for an interplanetary mission to date. But the mission ...
2
votes
2answers
92 views

How does the economy of a direct launch (to the Moon) compare with two launches docking in orbit?

How much more efficient would it be to use a launcher big enough to go directly to the surface of the Moon like Apollo did, compared with using two launches with a lesser rocket, say one with the ...
2
votes
1answer
322 views

Why is there such a long delay in between test firing and launching the SLS engine No. 2059?

I was reading the press release for the recent test firing of the RS-25 engine No. 2059 at Stennis Space Center and I came across the quote: The next time rocket engine No. 2059 fires for that ...
2
votes
0answers
107 views

What is the nature of the sextant tests on the ISS for Orion cis-lunar emergency navigation?

According to the NASA Johnson video Space to Ground: A Star to Steer By: 08/10/2018: A tool that once helped sailors cross vast oceans for centuries is now being put to the test in space. The crew ...
2
votes
0answers
82 views

What is the scheduled launch date history for SLS EM-1?

The Falcon Heavy was famous for being "6 months away" for around 6 years, seen in this chart. How has the SLS maiden launch schedule changed since its first proposed date? P.S. If someone could ...