Hey, put me down as all in favor of a Lagrange-point base — I’ve advocated it for years. But I’d like to see the trade study that says EML-2 versus EML-1. My preference is for the latter, but NASA seems focused on the former. I haven’t seen any explanation as to why. To my mind it’s a time versus delta-vee tradeoff. I’d prefer quicker trips, and better views of earth.
I also agree with Charles Lurio (quoted in the piece) that this isn’t the mission that SLS is looking for. It would be ludicrously expensive compared to using existing vehicles. There is no mission for which the Senate Launch System is cost effective.
But Trent Waddington says that Charles and I should hush our mouves.
Given that no money is left over for developing anything else, the SLS (like the Shuttle before it) is a vehicle in search of a mission. It’s the Rocket to Nowhere.
My concern is that L-2 is favored because, in a halo orbit, astronauts could teleoperate robotic explorers on the “dark side” of the Moon while being in contact with Earth. More Moon science is nearly one of the last things on the priority list IMO. We need to build capability to go anywhere in the solar system. So, we need fuel depots and telerobotic ice mining operations on the Moon.
Plus there would be no more radio blackouts when spacecraft go behind the move. And there is some useful research possible on the Moon’s interaction with the Earth’s magnetic tail. And the live images of the Moon’s Far Side with the Earth going around the limb that would come from a EM L2 Halo would be priceless. Also if I recall the delta V for deep space mission would be less, especially if you use the Moon and Earth for a gravity boost.
And as one USAF officer told me, it would be great to know if a foreign spacecraft achieved lunar orbit before their own nation knew 🙂
I should know better than to ask this, Tom, but what do you think the Gateway station would do if it detected a foreign spacecraft entering lunar orbit? You don’t think it’s going to have weapons, do you?
What is Trent saying, that we should shut up so Congress will not waiver in its determination to build this base (whatever the launch system)?
What world is he living in? If only…!
They just heard about it this week and your opening salvo is “awesome, we don’t need SLS for that!”
What do you think there response is going to be?
I think it will be: NASA has been working behind our back on a plan to dejustify SLS!!!
Here’s what you should be saying: We support Gateway and hope SLS is available to make deployment of the station faster and safer. It’s not lying, it’s politics.
We support Gateway and hope SLS is available to make deployment of the station faster and safer. It’s not lying, it’s politics.
Hope is a wonderful thing. Vegas was built on guys like you. 🙂
Faster? Perhaps if SLS was actually built on schedule. Is there a schedule?
Safer? Not really.
My understanding is a 70-mT to LEO SLS (with an existing-design Delta IV upper stage; a J-2X powered stage is off the schedule chart to the right, today), along with the current design of the Orion SM, do not have enough delta-vee to get an Orion to EM L1 and back. Going to L2 with the above combo is possible if you use a fancy lunar flyby trajectory. Takes a little longer, but less delta-vee. In other words, the plan is to first go to L2 rather than L1 or the lunar surface because it’s the only BEO place NASA can afford to get to before about 2025 with the Orion launch and propulsion hardware they can afford and have been told to build by the Senate.
When I did the sums a while ago it seemed possible, though not with a whole lot of margin. It did require offloading some of the propellant so you had just enough to insert into a Lagange orbit and then to deorbit, rather than the full load needed to insert into LMO and then to push through TEI to get back. The DIRECT people also found they could insert into a highly elliptical lunar orbit and then return to Earth, or to LMO without return capability, but not to LMO with return capability.
Of course, the Orion CM is unneeded and could be replaced by the smaller Dragon which is also designed for use beyond LEO. It would require a SM which could be designed by SpaceX, or perhaps it could be a universal NASA Glenn-designed Orion SM. The Orion CM is a threat to commercial space, unless it is turned into just another commercial crew entrant, with no spcial privileges and no special oversight. The SM is not a big problem, in fact it could be a great help.
L1 vs L2 doesn’t matter much and moving something from one to the other or to SEL1/2 doesn’t take much delta-v with chemical propulsion and could be even cheaper with SEP.
An L1/L2 gateway is an excellent idea (unlike a government funded HLV), but I think it’s too soon for it. It would consume a lot of money, but would not provide a lot of extra demand for launch services. Consequently it would not accelerate the development of radically cheaper space launch. And since that is the #1 capability we lack for meaningful manned spaceflight, all our efforts should be directed towards it. That means spending as much money as possible on commercially procured launches, and as little as possible on expensive space hardware like a gateway station. Propellant in support of exploration is the most plausible payload, since it’s cheap and we’d need lots of it. Even an unmanned program could make use of it, and that may be our best bet given the budget situation.
Once we have cheap lift (or at least a large and fiercely competitive launch market to bring it about), an L1/L2 gateway station is the obvious next step for manned exploration, but not before then.
SEP is likely to be used to deliver the gateway man-tended craft to L2, since the plan is to send it un-manned, so it can take a long time to get out there, and it can be loaded-up with prop instead of food, water, and oxygen. Those consumables would be delivered later, but before Orion arrival, using TBD launcher and cargo carrier. Once you get something to L2 or L1, you’re right, it does not take much delta-vee to move between those locations and other remote locations in the Earth-Moon vicinity, even the Sun-Earth L2. Getting from E-M L1 or L2 to low lunar orbit, or to the lunar surface, then back to L1 or L2, takes a lot, lot more delta-vee than cruising around between Lagrange points and maintaining halo or Lissajou type orbits at a Lagrange point.
If there was an infrared telescope on the lunar surface on the dark side, would it matter much if we had a station and other infrastructure at L2, or would the halo orbit keep it far enough away?
So, a bunch of guys in St. Louis want to explore Europe, but realize that taking a riverboat across the Atlantic would be Really Damn Hard. They figure, hey, let’s set up a harbor on an island somewhere about halfway across the ocean. And then start arguing the merits of Bermuda vs. the Azores.
Meanwhile, they are planning to evacuate and demolish New Orleans in eight years or so because what they want is the glitter of Europe and all they get down in Louisiana is a cheap imitiation in a swamp.
Sorry, but I’m not going to work up any enthusiasm over L1 or L2, much less argue the (negligible) difference between the two, until there’s a serious LEO operations base in place. Reaching LEO at all is hard enough; doing so affordably is probably at the limit of our ability – some people credibly argue still beyond our ability – and that leg of the trip really has to be done in one giant leap.
So once you’ve reached that foothold, you stop. There, and not one step further, is where you consolidate and set up a base to support the next step. Which is something we should have done fifty years ago. Trying to go beyond LEO, without a base in LEO, that’s taking a riverboat out into the Atlantic because you really can’t wait for the glory of Boldly Going…, and can’t be bothered setting up the infrastructure to do it right.
We already have an ISS, what more do you want?
The ISS isn’t in an ecliptic orbit or even close to one, so it’s not that useful as a staging area. Perhaps when they get closer to de-orbiting it, a private space firm will offer to launch the fuel necessary for a major plane change instead.
The need for a plane change in LEO is a pernicious myth. You can transfer from the ISS to a Lagrange point and from there to the moon or any interplanetary destination you might want. The stop at a Lagrange point is crucial, but it’s a good idea anyway, for many reasons.
How about a LEO space station that is actually useful as a staging point for expeditions farther out?
ISS is a scientific laboratory, and a foreign-aid project, period. It is in a rather inconvenient orbit for any missions that don’t involve Russians, it has not provisions for assembling or even just fuelling spacecraft, it can barely support a crew large enough just to maintain itself, it has never staged a mission beyond LEO, and it is scheduled for decomissioning before anyone is seriously planning to do exploration beyond LEO.
And those limitations can’t be rescinded by simply launching a tanker with some fuel for a plane change. We learned a great deal building the ISS in the first place, and there may be a way to keep it running in some capacity past 2020. But it isn’t a LEO operations base, and it will be cheaper to build a new LEO operations base from scratch than to try and use ISS for that purpose.
The next humans on the Moon, the first ones on Mars, will almost certainly stop at a space station in LEO to change ships. That space station will not be ISS.
It could be ISS, its orbit is not at all impractical, but I’d love to see it replaced by a cheaper (yet possibly larger) commercially run station. I fully agree that such a LEO station is more important than a Lagrange gateway, useful though that would be. Note that this is the opposite of what I’m arguing for refueling (Lagrange first, LEO later and refueling first, habitat later) and that has good technical reasons.
John, you missed the point.
Building ISS was really hard. It was a management nightmare. Years behind schedule. Hundreds of percent over budget. NASA should be exploring, not building bases. It isn’t any good at that. So —
Building ISS 2 at L-2 will be even easier! Queue the heroic music! Call out the space cadets! Put Rick Tumlinson in front of a television camera!
We never learn. 🙂
Exploring what?
I dunno where you’ve been for the last 4 years, but the Moon has been locked up to human exploration by the simple equation that a lander will apparently cost so much and take so long.
Mars is still a bridge too far and this asteroid business is nothing but a placeholder for “somewhere else”.
I’m not quite sure I understand your point. I think it translates as, “NASA has too much money — this will solve the problem”? 🙂
They don’t have the money to go anywhere.. right now, they’re in denial about this fact. The Gateway plan is about the cheapest way to give the program a “destination”.
Give the program a “destination”.
LOL. “NASA needs a destination.” Sounds like you’re channelling Brother Zubrin. 🙂
NASA already has a destination, Trent. It’s called ISS.
What NASA needs is not a destination but a purpose.
cheapest way
Not by a long shot. If NASA needs a rest stop at L2, all they need to do is ring Excalibur Almaz. They already has a plan for establishing a station at L2 *and* the major hardware.
Building a EML-1/2 outpost that uses hardware originally designed for the ISS would certainly lower the cost for the effort. Using existing rockets would keep the costs down even more compared to the original ISS method of assembly using the Shuttle.
If we’re going to say we learned the lesson of the ISS, certainly one way to prove it is to RE-USE as much of it as possible, whether it’s building more of the same or peeling working parts of the ISS.
“there’s nothing else”was heard about Shuttle. Look how well that worked.
While I would much prefer to hear Congress say “gee, these NASA dorks are useless, let’s shut down the agency”, that’s not going to happen. So you have your choice: Gateway or …
It will cost $200m to purchase a BA330 and put it in orbit with life support for six. How is it too soon to put it at a Lagrange point? Once there it needs a bit of station keeping (even at L4 or L5 I’d imagine.) Other than that it can just sit there until needed for something, whatever that something is. Build it and they will come.
Last I heard, the plan was to engage Bigelow to provide a module via an SAA.
Presumably, you’re talking about the blister stuck on the end of the structure?
http://img.gawkerassets.com/img/1807ryfr2cco1jpg/original.jpg
That looks like an inflatable module of some sort, but it’s clearly not a BA330.
As for this being done under a Space Act Agreement, I’d like to know who told you that. NASA’s official position, under CCDEV, has been that Space Act Agreements cannot be used to procure operational hardware. It has to be done under the FARs. Unless your source is in a position to overrule that decision, I would discount his statement.
Also, since ISS Stepping Stone is intended to be another international space station, I would presume the international partners will have some say in who gets to build the modules. (Actually, I expect another huge food fight.)
Pardon me for sounding cynical, Trent, but I remember the SFF telling us we should support ISS so that Bigelow could provide a module under an SAA.
This is an old story. We’re asked to support a huge government program in return for a tiny commercial portion — which shrinks over time.
It turns out this entire discussion may be based on a bad assumption — that the press reports are accurate. NASA has responded with a statement saying this is only one of several options being considered.
http://www.spacepolicyonline.com/news/nasa-responds-to-orlando-sentinel-story-on-possible-outpost-at-earth-moon-l2
That does not surprise me. I had a hard time believing NASA would announce something like this before the election. NASA employees have told me that they’ve been told to hold off on much, *much* smaller projects until after the election.
Heh, I figured the title of this post had to be some sort of US cultural reference that I didn’t get and a little googling reveals it refers to the state song of Kansas. They sure have a spiffy state song!
Do you guys actually pronounce Lagrange so that it rhymes with range or is it a visual pun?