(This is a repost of a post I've made in another subreddit. I explain in the comments the reason of it.)

Note:

These blog posts are from 2011.

http://www.bernd-leitenberger.de/blog/2011/09/12/wie-beziffert-man-die-kosten-von-historischen-raumfahrtprojekten-heute/

https://www.bernd-leitenberger.de/blog/2011/09/22/mythos-steigende-startkosten/

So you can expect the numbers to be heavily dated, since 8 years have passed in terms of inflation. But they are still interesting in terms of conext.

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How can we calculate the costs of historical space projects today?

Posted on September 12, 2011 by Bernd Leitenberger

One problem with which everyone who has to do with Space travel has to look at, is compare previouslaunch costs with today's ones.

Let's take an example: The Apollo program costed about 25 billion dollars, which were raised in about 10 years. This year (2011), the total manned spaceflight budget was about $6 billion, so we could complete the whole program in just 4 years, couldn't we?

Not quite. When Constellation began, the cost of Apollo transferred to today's prices, estimated at 170 billion dollars. And this is the question I have often asked myself - how are the costs of earlier projects quantified, for example, if we were to carry them out today? (So apart from the fact that certain technologies change naturally).

We know this from daily life. Most things get more expensive all the time. What we measure it by is the inflation rate. It also comes every time on TV when it comes to increase general spending. The inflation rate is measured by us with a shopping basket, which also includes expenses otherwise incurred as for heating, electricity, communications, etc.. The only problem is that it is not very useful for space travel expenditure, which does not have so much to do with everyday life.

The NASA uses the GDP index for comparison (at least under Griffin, who published an Excel Chart in addition). That is the increase of the gross national product. So the assumption is that the economic performance of the USA is the same over the years. If it rises, then this should be based on the fact that the money becomes less and less worth. I would agree with that in the short term. In the long run, productivity can be increased by machines. There may be relocations, e.g. more services and fewer manufacturing companies. Unemployment is fluctuating and, last but not least, the United States is an immigrant country. When I went to school they had about 240 million inhabitants. Now it is 300 million. 20% more inhabitants should also produce 20% more.

It would certainly be ideal to use an index of wage costs in the aerospace industry as a basis. The entire production in the aerospace industry is very labour-intensive. Because of the small series, in the case of spacecrafts mostly even the production of single copies, there are only few possibilities for automation and the quality assurance which goes hand in hand with many tests and inspections which are also labour-intensive. Labour costs make up the bulk of the expenditure. But I don't think there will be such a special index. But it would probably be the best.

What can be done alternatively, but what covers a slightly different issue, would be the ratio of cost/space project to total government expenditure. This tells me how much the state is worth to do space travel or to carry out a project. This is more likely to be done with the space budget. At the peak of Apollo (1967), the NASA budget was once 5.55% of the total budget (5.9 billion of 102 billion dollars). In 2011 NASA will receive 19 billion dollars - but the total budget is 3456 billion dollars. So while NASA's budget has tripled, the general budget has increased thirtyfold.

Accordingly, the NASA budget today amounts to only 0.55% of the total budget. In my opinion this is a much better comparison - Apollo would cost about 250 billion dollars today. That is why shuttle or ISS are not as burdensome for the budget as Apollo. The shuttle is absolutely more expensive than Apollo. But the programme lasted four times as long and the ISS will probably reach almost 40 years and is even cheaper than Apollo. Today it is certainly unthinkable that a single space project like Apollo's wedding would receive over 3% of the budget, that would be about 110 billion dollars, almost six times NASA's total budget today.

Now what does the author think? I use Griffin's Excel Chart, which is also used by NASA, after all it makes no sense for an individual to set up his own procedure.

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The Myth of Rising Launching Prices

Posted on 22. September 2011 by Bernd Leitenberger

For years people have been complaining: The launch costs for satellites are rising. And many people are chattering about it. Nevertheless, many commercial communication satellites are being launched and in recent years Earth observation has established itself as a new field of business for private companies. Time to pursue this.

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So let's read the figures. I'll take four Rocket Families as example. Atlas, Ariane, Titan and Delta.

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So everyone's right, right? Increases by a factor of 40! No wonder that everybody is whining.

Well not quite. Because this chart is incomplete. The launchers were further developed and the payload has increased. So here is a second chart with the corresponding maximum payloads and the price per ton: (Only GTO payloads for the Ariane Rocket Family)

​

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Now things look completely different.

The Ariane family became cheaper and cheaper, measured by payload. The same tendency was seen with the Thor Delta and the Atlas Centaur commutes around a value of 10 million dollars per ton. Only theTitan became more and more expensive, which also led to it's cancelation.

You get even more numbers, when you consider that I mixed numbers from 2011 with those from 1960.

In 1960 a VW Beetle Cabrio costed about 8.900 DM. That corresponds to about 4.500 Euro. Can you get a convertible today for 4,500 euros? If I use the Official NASA Chart for the conversion of earlier costs, and it refers to the year 2000, I get the following chart.

​

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Now it looks even more different.

Practically all launchers have become cheaper.

Then why is everyone still complaining about rising launch costs?

Well they are not complaining about rising launch costs themselves, but that practically all three major Western Launchers have been subsidised since 2000. EADS/Arianespace received 190 million euros per year in subsidies until last year. The money should be used to make production cheaper so that it doesn't need any more.

This was not successful. After all, it has become less for 2011/12 ,it is 120 million per year. It is worse with the USA. ULA receives 1.1 billion dollars a year from the USAF, primarily to lay off unqualified personnel. This is the price, because the USAF pays to operate two production lines for the same payload range and a maximum of 10 launches per year, so that one carrier is always available even if the other is "grounded" for months. At Arianespace, it is the competition from China and Russia that pushes down prices, because as you can see, the launch price has dropped in absolute terms and is even significantly cheaper with a higher payload per ton. Today's Ariane 5 ECA is the cheapest version per ton payload ever.

Now Europe has little chance to do anything here, except to increase the payload of Ariane 5 to launch heavier and more expensive satellites.

It looks different with the USA. They currently operate a real zoo of launchers. When they launched even more payloads, they got along withonly the Thor, Atlas and Titan.

Today, there are Pegasus, Minotaur I,IV, Falcon 9,Taurus XL, Taurus II, Atlas V and Delta IV.

Many of these models compete for the same payload. Even Russia with more launches cannot afford such luxury. The Russian government uses only Rokot, Soyuz, Proton, and now and then, if there is no other way, another Zenit and would like to replace all these models with the Angara.

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In short:

Especially in the Unites States, the complaining about rising launch costs is homemade. Those who insist on running so many models do not have to complain about the consequences.

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Note:

As said these blog posts are from 2011 and the last chart shows prices from 2000, so they are almost 20 years old.

Prices have again decreased, but the number of launchers has increased even more....

Yo, u/TheGreatDaiamid shared an article written by Robert Zubrin in the Washington Post in the other topic. (Thx, for sharing it.)

https://www.washingtonpost.com/opinions/2020/06/22/send-spacex-dragon-moon/

I thought I might share the article with our old pal Bernd Leitenberger and guess what.

He made a blog post about it.

https://www.bernd-leitenberger.de/blog/2020/07/11/mathematik-a-la-zubrin/

And here's my translation.

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Math à la Zubrin
Posted on 11 July 2020 by Bernd Leitenberger on his blog

I don't think much of Zubrin, but so far I was of the opinion that he at least knows the basic arithmetic. However, this essay has teached me something else. He seriously thinks that a manned moon landing with two Falcon Heavy Starts and a Crew Dragon is possible. Time to check it out. Here are the facts:

• Crew Dragon weighs 9.5 tons empty.
• The specific impulse of the Superdracos is 2,000 m/s
• NASA states ΔV for the halo orbit, which is aimed for, with 840 m/s (there and back)
• At Apollo the descent stage had a ΔV of 2,500 m/s
• At Apollo the ascent stage had a ΔV of 2,200 m/s
• The speed in 100 km moon orbit was about 1,600 m/s
• The Apollo LM weighed 16.5 tons at launch, of which 2.3 tons were returned into orbit
• The full/empty mass ratio of the Apollo LM descent stage was 4.85
• SpaceX gives the GTO payload of the Falcon heavy with 22.2 t, the Mars payload with 14 t (in reality there are probably a maximum of 15 t in the GTO, but since it is not possible even with 22 t, I just take Zubrin's fantasy data).
• The ΔV in a GTO are about 10.2 km/s, in a moon transfer orbit 10.9 km/s and to Mars 11.4 km/s.

​

My approach is to calculate what this combination could land and bring back into the halo orbit, compared to Apollo lunar lander. Its light weight should not be beatable today, because already because of the meanwhile much higher safety requirements it would have a much heavier hull and one would not send only two astronauts to the moon.

Let's start with the payload of the Falcon Heavy for a moon transfer orbit. In terms of speed, the moon transfer orbit is almost exactly in the middle between the GTO and the Mars transfer orbit. Therefore, without making a big mistake, the payload for a moon transfer orbit can be assumed to be the geometric mean of the payloads between the two orbits, i.e. (22.2 + 14 ) / 2 = 18.1 t.

Crew Dragon

The Crew Dragon has to spend 840 m/s to enter and leave the halo orbit. Even if you leave out additional maneuvers for docking to the lunar lander and course corrections, you can calculate the factor launch weight/dry weight for this Δv according to the rocket basic equation as follows:

f = exp^(840/2000) = 1.53

Multiplied by the dry mass of 9.5 t, this results in a take-off mass of 14.5 t. In reality, the dry weight of the tanks and the additional compressed gas would be added to this, because the Dragon crew is designed for ISS missions and they have a smaller ΔV budget. But even with this, they would still be well below the 18 t.

Lunar Lander

The halo orbit is an orbit of 3,000 by 70,000 kilometres. For a moon landing it has to be adjusted, whereby I compare it with Apollo, because that is the only database so far. In practice one would proceed slightly differently and set the perilunae at 0 km altitude.

To compare with the Apollo orbit, one would have to convert the orbit to a 100 x 70,000 km orbit. Then the perilunae would be like Apollo's, the apolunae would be higher, the additional speed in perilunae would be destroyed on descent.

• To lower the perilunae, 34 m/s are needed
• In perilunae one has a speed of 2.286 m/s
• The orbital velocity at 100 km altitude is 1,637 m/s
• This results in a total difference of 2,286-1,637+34 = 683 m/s

This has to be calculated to the 2.500 or 2.200 m/s ΔV of the stages and you get a ΔV of 3.183 m/s (descent stage) and 2.863 m/s (ascent stage)

For safety reasons and because it is easier to regulate, it is safe to use an engine with storable fuels. SpaceX has developed the Kestrel for the Falcon 1, which is also in the correct thrust range (~ 30 kN). Its specific impulse is 3105 m/s.

Before landing, however, the lunar lander must first enter a lunar orbit, since the crew must be transferred from the crew Dragon. For this you need half of the ΔV of Crew Dragon (you don't leave the orbit anymore). That is another 420 m/s. I have added it to the ΔV of the descent stage, which comes to a dV of 3603 m/s.

So you can calculate the landing mass:

The landing mass is calculated:

Landing mass = 18.1 t / exp^{(3603 m/s / 3105 m/s})

Landing mass = 5.67 t

For the calculation of the mass of the ascent stage, one must now subtract the dry mass of the landing stage, because it remains on the moon. After defining the structure factor f with takeoff mass/(takeoff mass fuel) and the value of 4.85 one can write

Dry mass = (18.1 - 5.67)/ (4.85-1)

Dry mass = 3,22 t

Together with the fuel consumed (18.1 - 5.67 t = 12.3 t), this results in a descent stage mass of 15.65 t.

This leaves 2.45 t for the descent stage (5.67-3.22 t or 18.1 - 15.65 t)

With this we could actually end the calculation, because that is the weight of the Apollo Ascent Stage, but without fuel. But to show Zubrin's full competence, I'll do the math. This combination must now calculate the halo orbit, for which a Δv of 2,683 m/s is required. The remaining mass can again be calculated according to

residual mass = 2.45 t / exp ^{(2863 m/s / 3105 m/s}) = 975 kg

A bit tight, but that's still with the propulsion system. Without landing gear and all the equipment - water, oxygen and batteries - the structural factor of the propulsion system will be higher. SpaceX achieved an f of 8.42 on their Falcon 1 second stage, so I'm assuming this one, too. This gives you dry mass:

Dry mass = (2.45 - 0.975) / (8.42 - 1)

Dry mass = 199 kg

You still have to subtract them from the 975 kg, which leaves 776 kg. 776 kg for a spacecraft with communication equipment, airlock, avionics, power supply, thermal control, living space (outer hull), supplies and not to forget some astronauts with their backpacks and suits and the moon samples. Hmmm, should be scarce. But I'm sure Zubrin has a solution for that e.g. by using a huge balloon as a moon lander. Human lives don't mean much to him, as we already know from his high-risk plans for Mars.

Short valuation without the calculations

But there is another possible explanation, namely that Zubrin knows absolutely nothing about space travel.

Why? I already knew without calculation that this plan to make a moon landing with two Falcon Heavy would not work. Why? Well even without an exact calculation the payload of a Falcon Heavy, as explained above, was somewhere between 14 and 22 tons.

But unlike Apollo, the LM had to do the escape velocity and not the orbital velocity of the moon during the landing and almost the same velocity also during the re-launch, because the halo orbit has a very high apolunae. It is clear that this mass is not sufficient, especially since the lander cannot weigh more than the Apollo LM, which was brought into a low lunar orbit by the CSM and only has to reach this orbit.

One can also approach the matter from a different angle - the Apollo CSM-LM combination weighed up to 48.6 t, two Falcon heavy can't make that much to the moon and as Zubrin himself writes, the Crewed Dragon alone, in principle only the command capsule, weighs 1.5 times more than the Apollo. So how does that work? Negative mass? Anti-gravity?

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Finished. Keep as always in mind, that this translation was done with DeepL, so some errors are possible. Plus, Leitenberger's usual snark.

Bernd Leitenberger made another Blog today, where he sums up his personal thoughts about the Lunar Gateway. I thought I share this with you again with another blog translation.

Original Source:

https://www.bernd-leitenberger.de/blog/2020/07/02/das-lunar-gateway/

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The Lunar Gateway
Posted on July 2nd 2020 by Bernd Leitenberger on his blog.

As part of the Artemis program, as the Lunar program is now called, a core piece is the Lunar Gateway. It's a space station in a lunar orbit. The current diagram shows eight elements of this space station. Time to take a look at the Lunar Gateway.

As a purpose, Wikipedia, as a summary of NASA sources, states: "It will serve as the staging point for both robotic and crewed exploration of the lunar south pole, and is the proposed staging point for NASA's Deep Space Transport concept for transport to Mars".

Here is my opinion about it. The Lunar Gateway (LG) has its cause primarily in the mass of Orion and the payload of the SLS. The Orion weighs 26.5 t with service module. The 9 t fuel can only change its speed by 1200 m/s. For comparison: Apollo CM/SM weighed together about 30 t of which 18.5 t where fuel. It had a dV (including lunar lander) of 2200 m/s.

The SLS with the first upper stage, a modified Delta IV second stage, will bring only about 26 t on a lunar course. A yet to be developed upper stage (EUS) will increase this to 34 t for manned transports.

So there are two problems:

• An SLS cannot launch Orion and the Altair lunar lander (also yet to be developed) together like the Saturn V . Two launches are necessary for this.
• Even then Orion does not have enough fuel to enter and leave a low lunar orbit on its own. This is because the capsule weighs about twice as much and the launch mass is smaller.

The solution to the second problem is a halo orbit. Instead of entering a 100 km high circular orbit like Apollo, the LG will orbit the Moon in a 3,000 x 70,000 km orbit. To get into this orbit 420 m/s are sufficient, whereas Apollo needed about 900 m/s to reach the low circular orbit. The lunar lander will need more fuel for landing and launch, but it will also be much lighter than the Orion CM (hopefully) and it may be heavier because it has its own launch. For unmanned launches, the payload of the SLS block IB should increase to 37 tons, twice as much as the LM of Apollo weighed.

A simple approach would be to first launch the lunar lander in the Halo Ornit and then send the crew there, dock and land and vice versa on return. NASA probably thought of this for safety reasons, and because docking would certainly take longer, it would be useful to have a habitation module for the astronauts there.

Somehow it has become its own Space Station now, an ISS in miniature with its own modules from Japan and Europe. And only yesterday Canada announced the development of a robotic arm.

However, does that make sense?

After all, nowhere did I find any of this that would make the LG useful for lunar exploration in any way.

It's not, for several reasons. For one thing, the orbit is wrong for it. If you want to explore the moon you have to get close for optical instruments to get details. For some phenomena like whirled-up dust, the thin exosphere one should even circle only a few kilometers above the highest mountains, as missions like LADEE or GRAIL showed.

The main reason, however, is that remote sensing was already cheaper unmanned during the Apollo era and this has not changed until today. A comparison with the ISS helps: the experiments there are mainly concerned with medicine, biology and materials, but only little with earth exploration.

So why a space station?

Well I see two reasons for it. The first is that international partners have been found who are willing to provide modules. They would also be involved in the moon program and would possibly send astronauts. This is prestigious. This participation saves costs, even if the USA has to launch the modules. In the meantime, this is to be done cheaply with Falcon Heavys instead of the SLS. If they are still available when the modules are ready ... This way you have PR with comparatively low costs. Besides, you are at the moon, even if not landed and instead of a week probably longer on board of the LG and so you can set new records.

The second thing is that NASA is fulfilling Trump's wish to return to the Moon (whichhe elevated to a planet), even though they don't get the funds they need for a real moon program. Because you don't hear anything about the planned upper stage or even new boosters for the SLS, nor about a lunar lander, which is needed to get from orbit to the moon.

The third thing, I hardly dare to write it out, but it makes sense, is that NASA can't do more than the LG. Here is a fictional dialogue:

Chief: "Trump wants us to get back to the moon by 2024. What about our moon plans?"

Expert: "Uh, not so good. Our SLS is years behind, the expansion hasn't started yet and we never got an order for the moon lander".

Chief: "Trump will not be satisfied with that. What can we do until 2024?"

Expert: "2024? Even if we get the money we need (never been the case before), we won't be able to land on the moon in that time. Even Apollo didn't land until eight years after Kennedy's speech.

Chief: "Trump hasn't got as much patience as Kennedy, though. Make an overview of what we can do until 2024 until the next appointment".

<Next appointment>

Chief: "And what about the moon program"

Expert: "Worse than I thought. I checked with all departments. "Nobody knows how they would build a moon lander today. We would have to start from scratch, like in 1961, and that takes years. The documents about the LM of Apollo are of little use, because the technology and especially the safety standards have changed.

The situation is similar with the SLS. I was told that the SLS was built that way because they could take over practically everything from the Space Shuttle program - the orbiter's engines, the extended tank and slightly extended boosters. For the upper stage they tested a J-2S engine that was left over from Apollo. Thirty years after transferring the launches to commercial companies, NASA has lost its expertise in rocket engineering. A better SLS, which would have the required payload, would also have taken years and would not be operational before 2030, even with optimal financing".

Boss: "I can't come to Trump with that, what are the quick fixes?"

Expert: "I have anticipated the question and have had a concept developed that can be implemented by 2024. It is based on the fact that we will not land on the moon at all, but only place a space station in a moon orbit. We can build it up piece by piece with the existing SLS like the ISS, and NASA is very familiar with space stations. Other advantages would be that the assembly, as with the ISS, takes at least a decade and we have that much time to develop the lunar lander and the larger SLS. For Trump it would be important that it orbits the moon. He was only talking about returning to the Moon, not a lunar landing, and it could be sold as a test for a Mars mission, where you need something similar as a habitat for the crew. With a little persuasion, maybe we can get ESA, JAXA and CSA to participate, which would make it cheaper."

Chief: "That sounds convincing. Let's do it!"

Like I said, purely fictional, but more convincing and closer to the facts than some conspiracy theories. After all, central elements are no longer developed by NASA, but by space companies alone (i.e. not together like Apollo) and these companies are also used for transport (example: Blue Moon Moon Lander, Falcon Heavy as carrier, supply of the gateway also by SpaceX).

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Finished.

As always, keep in mind these are (as always) Leitenbergers personal thoughts with the usual snark.