Category Archives: Space

Doubts About Depots

Josh Hopkins has a thoughtful article over at The Space Review on the issues that must be addressed by proponents of propellant depots. I may have a response a little later, but I would note that Boeing has done a lot of work on the concept, and may have answers to some of the questions. In any event, we could have resolved them with a tiny fraction of the money that we just pissed away on Ares over the past four years.

[Update early afternoon]

In comments over there, Jon Goff makes one of the points that I would have had I gotten around to it (we’re getting ready to move, and writing SBIRs among other things, around here). It’s worth repeating:

2-Regarding launch costs: I think most depot researchers, like myself, would agree that if the cost for propellant delivery were truly likely to be in the $30-60kg range, that depots weren’t likely to make sense. However, is using delivery of cargo to a manned space station, where the cargo carriers themselves have to function as pressurized space station modules, really that realistic of a starting point for estimating the cost of propellant delivery to a likely unmanned depot? I know that that was probably the easiest way to do the analysis, since those numbers are available…but aren’t we setting up a strawman here? First you pick the obviously most expensive route (having the tankers be fully-functional prox-ops vehicles), and then pick one of the most expensive possible cases of such vehicles–vehicles designed to interface with a manned space station.

This is a typical tactic of opponents of an idea — to pick a worst case, and sort of imply that it’s a best one. It is not a realistic assumption, and was one of the flaws that jumped out at me at the time.

Another one is the concern about departure windows. Yes, launching from earth gives you more flexibility, but so what? If there are multiple opportunities per month from orbit (and there are, depending on how much you want to pay in delta vee for wider windows), then it doesn’t help you much to be able to launch more often from earth when your HLV architecture won’t be able to afford to launch more than a few times a year, even using the cost estimates of its most ardent proponents.

[Tuesday morning update]

Clark Lindsey has further thoughts.

[Bumped]

Why Mars Is Hard

Jim Oberg has a good piece today. It’s just not as easy as the Barsoomophiles want to believe. That doesn’t mean that it shouldn’t be an ultimate goal, but we need to put first things first — reducing the costs of launch, developing critical technologies (particularly propellant handing and manufacturing from ISRU) and preliminary scouting to the moons before it will be practical to put people on the surface.

[Mid-afternoon update]

It’s official: NASA is a jobs program. Not that that’s news…

“…critical skills”, “industrial base”, and “workforce retention” have been frequently-mentioned items in the committee’s deliberations to date, so I suppose I should have seen this coming, but it’s still one of the starkest illustrations I’ve encountered why government programs and NASA in particular will never accomplish the goal of making humans a spacefaring species.

Fortunately, there are alternate paths.

In Defense Of Phobos

This WaPo piece by Joel Achenbach has something missing:

The panel will give the administration a menu of options that includes some that require a boost in funding for human spaceflight, which currently costs a little less than $10 billion a year, including the shuttle, the station and the Constellation program. Those options will include variations of a lunar program — the committee appears to prefer to see astronauts making sorties to various locations on the moon rather than concentrating on a single outpost at the moon’s pole, which is the current plan.

The committee is clearly most animated by what it calls the “Deep Space” option, a strategy that emphasizes getting astronauts far beyond low Earth orbit but not necessarily plunking them down on alien worlds. Instead, the Deep Space strategy would send them to near-Earth asteroids and to gravitationally significant points in space, known as Lagrange points, that are beyond the Earth’s protective magnetosphere.

Astronauts might even go all the way to Phobos, a tiny moon of Mars, where the spaceship wouldn’t land so much as rendezvous, in the same way a spacecraft docks at the International Space Station. That might seem a long way to go without touching down on the planet below. But the Deep Space option steers clear of “gravity wells,” which is to say the surface of any planet or large moon. The energy requirements of going up and down those steep gravity hills are so great that it would take many heavy-lift rocket ships to carry supplies and fuel on a mission to the Martian surface. A human landing on Mars is presently beyond NASA’s reach under any reasonable budgetary scenario, the committee has determined.

Note that there is absolutely no discussion of refueling, though that was a key feature of several of the Augustine options. The piece seems to be entirely focused (as the press tends to do, in its simplistic reporting) on destinations, and their various attributes, desirable or otherwise. This notion of a “long way to go without touching down on the planet below” seems to be an artifact of limited imagination.

First of all, once you’re at Phobos, if you send the right equipment, you might in fact be able manufacture the propellant needed to descend to the surface, manufacture propellant there, and come back up. The additional mass needed to do this would be trivial, compared to the IMLEO (initial mass in low earth orbit) required to do a Mars landing staged from earth. All it would take is a refuelable lander, and the equipment necessary to process the asteroid (which is what Phobos or Deimos are, other than their location).

But beyond that, what’s wrong with Phobos? I think that John Logsdon’s attitude is blinkered as well (not that that would be anything new):

Any strategy going forward must cope with the obvious problem that the United States has already visited the moon, and the solar system offers earthlings few other appealing places to go that are anywhere close at hand. Logsdon said he wasn’t sure that the Deep Space option, with its emphasis on “flybys” rather than landings, would be easy to sell to the public.

“I wonder myself if just flying around and not landing anywhere would be very attractive,” he said.

This from a guy who has never expressed any interest or desire to go himself, but thinks he knows what people want from a space program. First of all, you aren’t “not landing anywhere.” You are landing on frickin’ Phobos. The fact that it’s a lot easier than having to descend into a gravity well doesn’t make it less interesting. Yes, obviously, most people would rather walk on Mars, but (at least in NASA’s plans) most people aren’t going to be able to do any of these things. And on such a huge planet, even if someone lands on Mars, will it be the most interesting part of Mars? Not initially. Armstrong and Aldrin landed in the Sea of Tranquility not for any particular points of interest, but because it was the biggest flattest mare they knew of on the near side. It’s not like the first Mars explorers are going to climb Olympus Mons.

Seeing the earth from ISS, through glass and with their own eyes, unfiltered by electronics, is the most fascinating thing that astronauts there do. Why would we think that looking at Mars from Phobos would be of any less interest?

While I’m not that big on the voyeurism inherent in the NASA human spaceflight program as currently executed, I would think that having humans orbiting the Red Planet, and reporting back their experiences in their own words, would be pretty damned exciting (though I’d hope that given how picky they can be about astronaut selection, one of the criteria they would use was communications ability and articulateness, and even poetic ability — a lot of astronauts are good at this, but many aren’t, and when they are, it seems to be accidental, e.g., Mike Collins). There is no reason that you should have to descend into a deep gravity well to make deep space exploration exciting, and I tire of the notion that there is.

Thoughts From Augustine

He was on the Newshour last night. You can listen here. It’s nice to hear him making the airmail analogy for providing commercial space markets.

[Update a few minutes later]

I’m listening to the Jeff Hoffman interview, and he’s using the same analogy. It would be nice to get this meme into the main stream.

Ares I-X

isn’t getting much love in comments over at Space Transport News. At least not the kind that its supporters would like to see:

Perhaps NASA should keep the Ares I-X in storage until the 4th of July next year. I imagine the flaming propellant debris cloud would be pretty cool to watch.
Posted by Neil H. at 08/15/09 12:28:55

4th of July is too long to wait. I vote for New Years fireworks spectacular.
Posted by john hare at 08/15/09 13:02:52

How about Labor Day, send Summer out with a bang.
Posted by anonymous at 08/15/09 13:16:56

This “test,” which isn’t testing actual flight hardware, has cost (so far) a third of a billion dollars. That’s about the same as the estimate for the launch escape system for the Dragon. Sometimes it seems that people who advocate more money for NASA seem to have no concept of cost and value.

The President’s Space Policy Dilemma

A good wrap up over at the Orlando Sentinel:

For NASA allies on Capitol Hill, news that the agency does not have enough money to do what it wants is not so shocking. For years, members of congressional science committees have complained about underfunding.

But in a time of enormous budget deficits, a major boost is seen as unlikely.

“NASA is getting $18 billion a year. That’s more than all the other [space] agencies in the world combined. It’s very difficult to make the argument for more money,” said Vincent Sabathier, of the Center for Strategic and International Studies, a Washington think tank.

Sabathier said NASA’s best hope lies in giving a greater role to its international partners to develop key components of an exploration system, such as using a French rocket to launch a U.S. capsule.

One point that people don’t understand, though, is that it isn’t a budget problem per se. It is a budget problem in the context of the politics. As I said over at Space Politics:

It is disheartening — but not surprising — to read that the Augustine Commission doesn’t see any way the current NASA budget can get us back to the Moon or to any of the spectacular alternatives that have been contemplated in anything like a reasonable time frame.

Actually, it’s not that the NASA budget can’t do it — it’s that NASA can’t do it with that budget, given its political constraints. Certainly it could be done for that amount of money, or even a lot less.

A long as we have a political requirement to maintain thousands of jobs at KSC and Marshall and Houston, it’s going to be hard to reduce costs. That’s a point that needs to be made strongly in the panel’s report. If the politicians want to shut down human spaceflight, or dramatically increase the budget, we should at least be clear on why those are the two options — it’s not because it is as intrinsically expensive as NASA always makes it. By the time Dragon is flying with crew, Elon will have spent far less than a billion dollars, a tiny percentage of what NASA plans to spend on Orion and Ares I. And the difference in size doesn’t explain the difference in cost. What does explain it is that he’s spending his own money, and his primary focus is on developing space hardware that closes a business case, not “creating or saving” (to use the administration’s wonderfully nebulous criterion) “jobs.”

More Augustine Thoughts

…from Clark Lindsey. I have to say that Sally Ride has risen considerably in my esteem in the past couple months. And I’m a little disappointed, but not shocked that Bo Bejmuk (with whom I worked at Rockwell) doesn’t quite seem to get it. Operational costs are key. NASA simply can’t expect to just have money shoved at them.

[Update a few minutes later]

Lindsey versus Coppinger. It’s quite the beat down.

I was going to respond, but haven’t had the time. I read Rob’s stuff, and sometimes I just shake my head. He has an apparently massive capability to delude himself on both the politics and the economics. He’s been whistling past Ares I’s graveyard for months.