Orion and SLS - Current opinions?

[Kerbface]

I've heard a lot of doubts of the cost-efficiency, necessity and potential to actually be completed of these craft, but some people seem pretty excited about it.

So yeah. Is it the way to go?

Particularly thinking about Spacex, Dragon is often compared similarly or even favourably to Orion, and Musk has made a few references to a "Mars Colonial Transporter" in planning.

Edited July 29, 2013 by Kerbface

[Thaniel]

Well, we do need a decently priced alternative (or 3) for launching crew capsules into LEO and/or HEO. SpaceX among others can do that. Ofcourse, if there where a bunch of cheap ICBM´s available, and they where reliable, then repeats of the Gemini setup could be an option.

As for interplanetary cargoes of substantial weight, then SLS does seem like a good thing. But, like so many other NASA projects, it´s not cheap to develope. But if we are ever to get to do anything important in space, and be able to branch out to lunar and/or martian space, then we need some way of launching heavy loads.

Now, it´s not like SLS is the only option around, but it´ll be nice to have some competition in that departement.

Energia was a realy cool looking thing. It looks like it´s brimming with muscle and energy. Too bad that one got canceled. Probably because of price though.

[nhnifong]

If KSP has taught me anything, it's that you can do more and go further by making your payload smaller. We just need to work on making our robotic components as small as our cell phones. A probe the size and weight of a brick could go anywhere in the solar system on the cheapest launcher available.

[Fuzzy Dunlop]

If KSP has taught me anything, it's that you can do more and go further by making your payload smaller. We just need to work on making our robotic components as small as our cell phones. A probe the size and weight of a brick could go anywhere in the solar system on the cheapest launcher available.

It wouldn't be able to do anything there though. Miniaturization is great but some things simply have to be big enough - particularly solar pannels, communication antena and telescope mirrors (all three of which simply need the area to gather radiation).

And Humans aren't getting any smaller either.

[metaphor]

SLS and Orion might not be the most cost-efficient way to go beyond Low Earth Orbit, but they're politically viable, and that means a lot for their chances of actually being produced. I don't foresee them being cancelled anytime soon due to their strong support from Congress.

A heavy-lift rocket would be very useful to take humans beyond LEO. SpaceX can't really do that in the near future without a lot of subsidies by NASA. They just don't have the money. If they can develop a heavy-lift rocket for $3 billion (which is about 1/8 of what NASA is spending on SLS), then it would take them 120 Falcon 9 flights or 50 Falcon Heavy flights to get enough capital (assuming they make 50% pure profit on each flight). Heavy rockets are usually more cost-efficient per mass than light rockets, but require a lot more up-front capital. But there is no commercial market for heavy-lift rockets yet, since most satellites are under 10 tons. So the "Mars Colonial Transporter" is probably not coming out anytime soon.

The Orion capsule is pretty good for what it does too. It's much larger than a Dragon and together with its service module has more delta-v. Orion also has some radiation shielding for long journeys. The Dragon is a lot cheaper in getting people to low Earth orbit, but the Orion is better at being a command center/Earth return vehicle for long duration flights beyond LEO.

The problem we have now with SLS/Orion is that we will have the heavy-lift capability to do deep-space missions, but there is very little money allocated for missions. If we send people far from Earth we will need other things like a deep-space habitat, a lander, and other things, depending on the mission. None of those are in development yet, so all we can do with SLS/Orion for the time being is to go around the Moon, or maybe to a near-Earth asteroid.

[metaphor]

Yeah, miniaturization can only get you so far. We are already pretty far along with that. Robotic probes are already much cheaper than human exploration simply because they need so much less mass (and also less complexity). NASA's budget for planetary science (for interplanetary probes like the Curiosity rover, Cassini, etc) is about $1.2 billion, whereas their budget for human spaceflight is about $7 billion (and that's just for ISS maintenance and development work on SLS/Orion). A Soyuz mission (the smallest manned spacecraft available) needs about 2 tons of mass per person just for a couple days in cramped quarters. And while robotic probes are getting smaller, manned spacecraft are getting bigger, since our standards of personal comfort and privacy have increased since the 1960s.

[Mr Shifty]

And while robotic probes are getting smaller, manned spacecraft are getting bigger, since our standards of personal comfort and privacy have increased since the 1960s.

Is this really the case? Soyuz and Shenzhou are the only options to send humans to space right now. Soyuz RM + OM (7.2 m3) is smaller than Apollo CM + LM (12.9 m³). (The Soyuz RM is way smaller than the Apollo CM; it's even smaller than the Gemini capsules, which only had 2 crew.) And the Shenzhou RM + OM (14 m³) is only about 1 m³ larger. DragonRider will have a 10 m³ capsule, but is supposed to carry 7 crew, so is much smaller than Apollo per crew-member. The Space Shuttle, of course, was huge with more than 10 m³ per crew member, but no other crew carriers have been or are planned to be.

EDIT: I'm not considering crewed vessels already in orbit: ISS/Tiangong/Mir/Skylab/Salyut/Almaz. The situaton there is different: intended for long-term habitation, ISS/Mir assembled modularly, resupply used, crews not launched with the station, etc

Edited July 29, 2013 by Mr Shifty

[magnemoe]

Is this really the case? Soyuz and Shenzhou are the only options to send humans to space right now. Soyuz RM + OM (7.2 m3) is smaller than Apollo CM + LM (12.9 m³). (The Soyuz RM is way smaller than the Apollo CM; it's even smaller than the Gemini capsules, which only had 2 crew.) And the Shenzhou RM + OM (14 m³) is only about 1 m³ larger. DragonRider will have a 10 m³ capsule, but is supposed to carry 7 crew, so is much smaller than Apollo per crew-member. The Space Shuttle, of course, was huge with more than 10 m³ per crew member, but no other crew carriers have been or are planned to be.

EDIT: I'm not considering crewed vessels already in orbit: ISS/Tiangong/Mir/Skylab/Salyut/Almaz. The situaton there is different: intended for long-term habitation, ISS/Mir assembled modularly, resupply used, crews not launched with the station, etc

The Russian idea of using an orbital and return module should give more room, surprised its not so. Might be that its primary mission is space station suply and the OM is for food and other stuff on the space station. The Chinese probably thought about EVA and more advanced use. Dragon is as I understand for transfer to an space station, they have the option to remove seats if they want other uses.

[longhornchris]

The Russian idea of using an orbital and return module should give more room, surprised its not so. Might be that its primary mission is space station suply and the OM is for food and other stuff on the space station. The Chinese probably thought about EVA and more advanced use. Dragon is as I understand for transfer to an space station, they have the option to remove seats if they want other uses.

While Soyuz was born during the Russian lunar program, its design was ultimately setup to go to the various Russian space stations. The idea was that the Cosmonauts wouldn't spend much time in the capsule - so not much need for working or living space. The real time in space would be spent onboard the station, which was designed to be 'disposable' once it had reached its end of life.

As to the US approach so far, vehicles like Dragon seem to have a similar concept - limited space in the capsule and get to a station quick. As for SLS I'm not sure what the approach will be but if I had to guess it will be a hybrid - where the re-entry capsule is only a portion of the total living space.

[metaphor]

Is this really the case? Soyuz and Shenzhou are the only options to send humans to space right now. Soyuz RM + OM (7.2 m3) is smaller than Apollo CM + LM (12.9 m³). (The Soyuz RM is way smaller than the Apollo CM; it's even smaller than the Gemini capsules, which only had 2 crew.) And the Shenzhou RM + OM (14 m³) is only about 1 m³ larger. DragonRider will have a 10 m³ capsule, but is supposed to carry 7 crew, so is much smaller than Apollo per crew-member. The Space Shuttle, of course, was huge with more than 10 m³ per crew member, but no other crew carriers have been or are planned to be.

EDIT: I'm not considering crewed vessels already in orbit: ISS/Tiangong/Mir/Skylab/Salyut/Almaz. The situaton there is different: intended for long-term habitation, ISS/Mir assembled modularly, resupply used, crews not launched with the station, etc

Yes but the Soyuz/DragonRider are only supposed to be used for a few hours to a couple of days, as a shuttle from the ground to orbit and back. The Shenzhou's longest occupied time was 5 days with only 2 people inside. The Apollo capsule was designed to be used continuously for 2 weeks. And even the Gemini missions with their 1.25 m^3 per crewmember spent up to 14 days at a time in space.

The Orion spacecraft, which is designed for flights a little longer than Apollo, has about 2.5 times the volume of Apollo's command module, and it even has a toilet.

[DerekL1963]

Yeah, miniaturization can only get you so far. We are already pretty far along with that. Robotic probes are already much cheaper than human exploration simply because they need so much less mass (and also less complexity)

And, like anything else, you get what you pay for.

That being said, Orion/SLS are white elephants, but it's a good thing to have a back up. It's a Really Bad Idea to depend totally on one company not for just one component (of the booster/capsule pair), but for the whole dang package. Especially when the cruel economics of the industry means that their aren't any competitors.

[Apotheosist]

The SLS uses higher performance propellant in it's later stages (core main stage and third stage), namely LH2/LOX. This should give the SLS considerable performance/mass efficiency advantages for launching on high delta v trajectories, (moon, asteroid, mars, beyond). Higher specific impulse gets much more important in the later stages. Liquid hydrogen/liquid oxygen vacuum propulsion engines get 450-460 seconds of Isp, compared with maybe 340-350 for lox/kerosene, and 370- 380 for spacex target for their next generation lox/methane engines. As I said higher specific impulse propellants, like hydrogen, give a big boost for the higher energy trajectories. For low energy applications like LEO, things like RP1 will do, spacex is competitive. With the higher energy trajectories, NASA should have more of an edge, purely by the technology of their rockets.

As an example of the performance advantages of higher specific impulse for higher energy trajectories, just compare the Ariane V and Proton M. Ariane V uses cryogenic hydrogen/lox in core and last stage, proton uses N204/UDMH in its first three stages, Kerosene/lox in the fourth stage. Both these rockets can take about 20 tons to LEO, but Ariane V can take 10 tons to GTO (Geostationary transfer orbit), compared with only 6 tons to GTO for Proton.

[metaphor]

The SLS uses higher performance propellant in it's later stages (core main stage and third stage), namely LH2/LOX. This should give the SLS considerable performance/mass efficiency advantages for launching on high delta v trajectories, (moon, asteroid, mars, beyond). Higher specific impulse gets much more important in the later stages. Liquid hydrogen/liquid oxygen vacuum propulsion engines get 450-460 seconds of Isp, compared with maybe 340-350 for lox/kerosene, and 370- 380 for spacex target for their next generation lox/methane engines. As I said higher specific impulse propellants, like hydrogen, give a big boost for the higher energy trajectories. For low energy applications like LEO, things like RP1 will do, spacex is competitive. With the higher energy trajectories, NASA should have more of an edge, purely by the technology of their rockets.

As an example of the performance advantages of higher specific impulse for higher energy trajectories, just compare the Ariane V and Proton M. Ariane V uses cryogenic hydrogen/lox in core and last stage, proton uses N204/UDMH in its first three stages, Kerosene/lox in the fourth stage. Both these rockets can take about 20 tons to LEO, but Ariane V can take 10 tons to GTO (Geostationary transfer orbit), compared with only 6 tons to GTO for Proton.

Yes the SLS design is one of the best and most efficient expendable rocket designs ever made. The problem is that it's going to cost more than it should because of politics.

For an even more extreme example of the importance of Isp, the Delta IVH can carry more mass to GTO than the Falcon Heavy, even though the Falcon Heavy can carry more than twice as much as the Delta IVH to LEO. This is mostly because the DeltaIVH has a much more efficient upper stage.

[Apotheosist]

Yes the SLS design is one of the best and most efficient expendable rocket designs ever made. The problem is that it's going to cost more than it should because of politics.

For an even more extreme example of the importance of Isp, the Delta IVH can carry more mass to GTO than the Falcon Heavy, even though the Falcon Heavy can carry more than twice as much as the Delta IVH to LEO. This is mostly because the DeltaIVH has a much more efficient upper stage.

Wow, that is extreme, I never made the comparison to realise that. Indeed SLS will be more expensive than it needs to be. I wonder if NASA's better performance will make up for their higher cost for launches to higher energy destinations.

[Warfare319]

I am personally not the biggest fan of the SLS, but i have to say that even though right now the costs far exceed what they should, in the long run it might end up being much cheaper. THis is because with the current plan of evolution for the rocket each new design isn't that dissimilar from the last, meaning that it will cost far less to design each variant than it will to create the base design they are developing right now.

[Mr Shifty]

Yes but the Soyuz/DragonRider are only supposed to be used for a few hours to a couple of days, as a shuttle from the ground to orbit and back. The Shenzhou's longest occupied time was 5 days with only 2 people inside. The Apollo capsule was designed to be used continuously for 2 weeks. And even the Gemini missions with their 1.25 m^3 per crewmember spent up to 14 days at a time in space.

The Orion spacecraft, which is designed for flights a little longer than Apollo, has about 2.5 times the volume of Apollo's command module, and it even has a toilet.

Apollo CM had a habitable volume of 5.9 m³ for 3 crewmembers. Orion is supposed to have a volume of of about 8.9 m³ for 4-6 crew members. (I think the 2.5 number was from preliminary specifications. Current specs show 316 ft³: http://www.nasa.gov/pdf/510449main_SLS_MPCV_90-day_Report.pdf) So yeah, the Orion CM is slightly larger per crewmember (by 10%) than the Apollo CM and has a toilet (thankfully -- how hygenic was it to have Frank Borman trying to contain vomiting and diarrhea in a bag during Apollo 8? Imagine one of the astronauts aspirating floating feces.) But it's not like today's astronauts are some sort of wimps compared to the giants of old demanding comforts their forerunners grimly did without.

Edited August 1, 2013 by Mr Shifty

[metaphor]

Apollo CM had a habitable volume of 5.9 m³ for 3 crewmembers. Orion is supposed to have a volume of of about 8.9 m³ for 4-6 crew members. (I think the 2.5 number was from preliminary specifications. Current specs show 316 ft³: http://www.nasa.gov/pdf/510449main_SLS_MPCV_90-day_Report.pdf) So yeah, the Orion CM is slightly larger per crewmember (by 10%) than the Apollo CM and has a toilet (thankfully -- how hygenic was it to have Frank Borman trying to contain vomiting and diarrhea in a bag during Apollo 8? Imagine one of the astronauts aspirating floating feces.) But it's not like today's astronauts are some sort of wimps compared to the giants of old demanding comforts their forerunners grimly did without.

Yeah you're right. The Orion has 2.24 m^3 per crewmember (assuming 4 people, although the first mission will only have 2), and the Apollo had 2.07 m^3 per crewmember (assuming 3 people), according to this article.

It's not that the astronauts themselves demand more comfort, it's that mission planners now include psychological health as more of a factor in designing a spacecraft, especially for long-term missions. And I can imagine that having to scoop up and massage your poop isn't likely to be a stimulating experience.

[DerekL1963]

Yeah you're right. The Orion has 2.24 m^3 per crewmember (assuming 4 people, although the first mission will only have 2), and the Apollo had 2.07 m^3 per crewmember (assuming 3 people), according to this article.

It's not that the astronauts themselves demand more comfort, it's that mission planners now include psychological health as more of a factor in designing a spacecraft, especially for long-term missions.

Having (kinda) been there and (kinda) done that... (I'm a former submariner) I've got to agree with the mission planners.

[Apotheosist]

For an even more extreme example of the importance of Isp, the Delta IVH can carry more mass to GTO than the Falcon Heavy, even though the Falcon Heavy can carry more than twice as much as the Delta IVH to LEO. This is mostly because the DeltaIVH has a much more efficient upper stage.

I was a little suspicious of this, Wikipedia did say the falcon heavy could lift 53 tons to leo, and about 13 tons to GTO if i remember correctly. I thought perhaps Wikipedia had not updated it's GTO payload after the specs for the falcon heavy changed. I went on the Spacex website recently, saw that it had changed. It has info on falcon heavy: http://www.spacex.com/falcon-heavy and Wikipedia has now been updated, saying falcon heavy can lift 53 tons to leo, 21.2 tons to GTO. So it's not as extreme, just our information source was incorrect at the time.

[dharak1]

Imagine one of the astronauts aspirating floating feces.

I remember seeing a thread with sone mission audio about how someone on one of the Apollo missions found a turd floating. It was pretty funny.

[mobious44]

I'm personally excited for all new space developments. As for SLS, NASA has few different versions planned, including one that is a heavy lifter, with a payload of about ~75 tons or more i think.