Remembering ROMBUS and days of future passed

They were heady days, the 1960s. Back then nothing seemed too big to engineer on Earth. Or off it.

Launch of Apollo 11, atop a Saturn V booster. One of the readers of this blog's Dad was the pad safety officer for Apollo 11. How cool is THAT? Public domain, NASA.

Apollo 11 departs by Saturn V. Public domain, NASA.

When the moon race began in 1961, humanity had barely begun to step into space. But the job was done – twice. The Soviets had a serious programme, but started late, were under-funded, and work was divided between rival bureaux. Then Sergei Korolev died. With him died any chance of their N-1 moon booster working. The US equivalent, Wernher von Braun’s Saturn V, won the day.

Both derived from technologies von Braun pioneered in the 1930s. The Saturn V was a direct descendant of the V-2, with the same arrangement of  traditional rocket engines and massive fuel tanks.

Project Deimos departs Earth orbit with one of Bono's colossal ROMBUS boosters. Public domain, NASA.

ROMBUS leaving for Mars, 9 May 1986. Public domain, NASA.

What that added up to was weight. It’s why a conventional single-stage rocket can’t make orbit with useful payload; too much mass is taken up in structure. Von Braun’s Saturn V managed a mass-ratio of 22 because it had three stages. The problem was that each stage was discarded after one use. Costs were astronomical.

However, they weren’t the only way ahead. In 1964, Douglas Aircraft engineer Philip Bono proposed a ‘plug nozzle’ engine that did away with the combustion chamber and complex cooling systems. Fuel (liquid hydrogen) was stored in jettisonable external tanks, with the oxidiser (liquid oxygen) inside the booster.

ROMBUS in Mars orbit: Mars Excursion Module backs away ready for landing. Public domain, NASA.

ROMBUS in Mars orbit: Mars Excursion Module backs away for landing, late November 1986. Public domain, NASA.

Bono called it ROMBUS – Reusable Orbital Module-Booster & Utility Shuttle. The design he and his associates came up with was enormous, with a launch mass of just over 6,300 tonnes. That was nearly twice the mass of a Saturn V, but the mass-ratio available in ROMBUS was good enough to fly to orbit in one hit, dropping external tanks along the way. What’s more, it could re-enter using the plug as a heat shield, pumping residual fuel across it as a coolant. And fly again, up to five or six times per booster. It was a different approach from carpeting the bottom of the Atlantic with dead Saturn stages.

Bono calculated that ROMBUS could put 450 tonnes into low Earth orbit, nearly four times that of Saturn V. The Moon was within reach of the system – and then Bono came up with a plan for flying one of his colossal boosters to Mars and back.

Mars Excursion Module docking with the huge ROMBUS booster in Mars orbit. Public domain, NASA.

Mars Excursion Module docking with the gigantic ROMBUS booster in Mars orbit, September 1987. Public domain, NASA.

Bono estimated that ROMBUS could be flying by 1975 and drop launch costs to $12-per-pound to orbit, in 1964 terms. That compared wonderfully with the $150/pound of Saturn. Development costs were estimated at nearly $4.1 billion in 1964 dollars, this when the entire Apollo project was budgeted at $18 billion.

Technical issues relating to the plug nozzle would likely have taken some solving. Still, we can imagine the what-if scenarios. Project Selena looked towards a 1000-person lunar colony by 1984, and – providing ways could be found of stopping the cryo-fuels from boiling off during the 800-day mission – Project Deimos would have landed six astronauts on Mars by November 1986.

Bono’s huge rocket was a vision of its age – a vision of the 1960s, a vision of the era before humanity lost the dream, when anything seemed possible. But it never came to pass – and I can’t help thinking that today, that vision simply isn’t there.

What happened?

Copyright © Matthew Wright 2014

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4 comments on “Remembering ROMBUS and days of future passed

  1. That’s one I never heard of. Thanks for bringing it up!

    That question, that question…Why aren’t we on Mars? Why aren’t we looking even further out? NASA even thinks “warp drive” of some sort might be possible, and with it FTL travel. The possibilities arising from such explorations are uncountable.

    When I was six or seven, about the same time as Project Apollo got started, I really believed we’d be populating the inner solar system at least by now — the 21st Century, fer cryin’ out loud! OK, so maybe there were a few things we didn’t know like the long term effects of weightlessness and the radiation environment of space, but hey, if we’d had more incentive to solve those problems, maybe we could have done so by now.

    I have come to believe that there is a certain mentality that happens to coincide with that of most or all of the people who rise to the top of politics and finance which is more akin to the motivations and psychology of the pre-revolution French aristocracy and clergy — or the same bunch in pre-Soviet Russia. This mentality knows that change is not merely bad but may even consider it evil. (I don’t like to use the word “evil.” The supernatural connotations can be a little too weird. It’s the only word that fits, though.) Ray Bradbury wrote a story that epitomizes that point of view; something about a Chinese emperor who watched a man being carried aloft in a kite, and had the inventor put to death because the emperor saw that such man-carrying kites would carry soldiers over the Great Wall of China. Extend the logic of that theme out for a bit, and my point should be clear.

    Not all of those who “rise to the top” should be seen in that way; look at Bill Gates, or even better, Elon Musk. But those exceptions simply go to prove the point I’m trying to make.

    I would like to think that the current political climate here in the States — which I’ve heard described as a “Know-Nothing movement whose like hasn’t been seen in 160 years” (I think that was David Brin) — is the last gasp of this paradigm of political thought that has dominated the planet for nearly all of known history. But there’s no way to know that.

    • I suspect if it was politically advantageous to fund manned spaceflight to the extent it was in the 1960s, it would still be happening. I also wonder if the loss of the rocket dream isn’t a generational change. There was a popular mind set in the early-mid twentieth century that -looking back – we know to be flawed in many ways. And yet its do-anything aspect won WWII for the democracies and then took us to the Moon. The startling ‘generation gap’ that followed – when the ‘baby boomers’ rejected the rather staid world of their parents (shaped by two world war) seems to have caused a fairly significant ground-shift. It’s had a positive side. But it’s also had a down-side; and to my mind, we lost the space dream when that happened.

      That notion of the entitled few at the top of whatever structure or system they’ve got, not wanting to change it is, alas, so common through history I have to suppose it’s part of the human condition. I doubt we’ve seen the last of it…unfortunately. It’s not limited to the west – it’s a general human problem.

  2. It seems that most individuals with power, have no real vision beyond their own bank accounts. Tom named a few exceptions in his comments. However, they are few and far between. Once an economic benefit exists to move the world space programs forward, i have no doubt the technology will appear. That’s why current missions are so important.

    • Yes, they are – incredibly important. It worries me though. Space exploration for “no” economic reason – really – has benefits that we cannot imagine at the time. Serendipity can be a wonderful friend. Apollo? Sure, it got men to the moon. It also gave us memory foam mattresses, teflon frypans, and the microprocessor revolution. It’s good to see so much effort at the moment going into reviving the space effort – three manned spacecraft under development in the US and at least two new rockets. Plus possibly Skylon in the UK, though I think it’s more talk than reality just now. But it’s still got nothing like the impetus of Apollo. Sigh…

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